[ty] Always infer the submodule literal for submodule attribute-access, even when we emit a diagnostic

## Summary

Derived from #17371

Fixes astral-sh/ty#256
Fixes https://github.com/astral-sh/ty/issues/1415
Fixes https://github.com/astral-sh/ty/issues/1433
Fixes https://github.com/astral-sh/ty/issues/1524

Properly handles any kind of recursive inference and prevents panics.

---

Let me explain techniques for converging fixed-point iterations during
recursive type inference.
There are two types of type inference that naively don't converge
(causing salsa to panic): divergent type inference and oscillating type
inference.

### Divergent type inference

Divergent type inference occurs when eagerly expanding a recursive type.
A typical example is this:

```python
class C:
    def f(self, other: "C"):
        self.x = (other.x, 1)

reveal_type(C().x) # revealed: Unknown | tuple[Unknown | tuple[Unknown | tuple[..., Literal[1]], Literal[1]], Literal[1]]
```

To solve this problem, we have already introduced `Divergent` types
(https://github.com/astral-sh/ruff/pull/20312). `Divergent` types are
treated as a kind of dynamic type [^1].

```python
Unknown | tuple[Unknown | tuple[Unknown | tuple[..., Literal[1]], Literal[1]], Literal[1]]
=> Unknown | tuple[Divergent, Literal[1]]
```

When a query function that returns a type enters a cycle, it sets
`Divergent` as the cycle initial value (instead of `Never`). Then, in
the cycle recovery function, it reduces the nesting of types containing
`Divergent` to converge.

```python
0th: Divergent
1st: Unknown | tuple[Divergent, Literal[1]]
2nd: Unknown | tuple[Unknown | tuple[Divergent, Literal[1]], Literal[1]]
=> Unknown | tuple[Divergent, Literal[1]]
```

Each cycle recovery function for each query should operate only on the
`Divergent` type originating from that query.
For this reason, while `Divergent` appears the same as `Any` to the
user, it internally carries some information: the location where the
cycle occurred. Previously, we roughly identified this by having the
scope where the cycle occurred, but with the update to salsa, functions
that create cycle initial values ​​can now receive a `salsa::Id`
(https://github.com/salsa-rs/salsa/pull/1012). This is an opaque ID that
uniquely identifies the cycle head (the query that is the starting point
for the fixed-point iteration). `Divergent` now has this `salsa::Id`.

### Oscillating type inference

Now, another thing to consider is oscillating type inference.
Oscillating type inference arises from the fact that monotonicity is
broken. Monotonicity here means that for a query function, if it enters
a cycle, the calculation must start from a "bottom value" and progress
towards the final result with each cycle. Monotonicity breaks down in
type systems that have features like overloading and overriding.

```python
class Base:
    def flip(self) -> "Sub":
        return Sub()

class Sub(Base):
    def flip(self) -> "Base":
        return Base()

class C:
    def __init__(self, x: Sub):
        self.x = x

    def replace_with(self, other: "C"):
        self.x = other.x.flip()

reveal_type(C(Sub()).x)
```

Naive fixed-point iteration results in `Divergent -> Sub -> Base -> Sub
-> ...`, which oscillates forever without diverging or converging. To
address this, the salsa API has been modified so that the cycle recovery
function receives the value of the previous cycle
(https://github.com/salsa-rs/salsa/pull/1012).
The cycle recovery function returns the union type of the current cycle
and the previous cycle. In the above example, the result type for each
cycle is `Divergent -> Sub -> Base (= Sub | Base) -> Base`, which
converges.

The final result of oscillating type inference does not contain
`Divergent` because `Divergent` that appears in a union type can be
removed, as is clear from the expansion. This simplification is
performed at the same time as nesting reduction.

```
T | Divergent = T | (T | (T | ...)) = T
```

[^1]: In theory, it may be possible to strictly treat types containing
`Divergent` types as recursive types, but we probably shouldn't go that
deep yet. (AFAIK, there are no PEPs that specify how to handle
implicitly recursive types that aren't named by type aliases)

## Performance analysis

A happy side effect of this PR is that we've observed widespread
performance improvements!
This is likely due to the removal of the `ITERATIONS_BEFORE_FALLBACK`
and max-specialization depth trick
(https://github.com/astral-sh/ty/issues/1433,
https://github.com/astral-sh/ty/issues/1415), which means we reach a
fixed point much sooner.

## Ecosystem analysis

The changes look good overall.
You may notice changes in the converged values ​​for recursive types,
this is because the way recursive types are normalized has been changed.
Previously, types containing `Divergent` types were normalized by
replacing them with the `Divergent` type itself, but in this PR, types
with a nesting level of 2 or more that contain `Divergent` types are
normalized by replacing them with a type with a nesting level of 1. This
means that information about the non-divergent parts of recursive types
is no longer lost.

```python
# previous
tuple[tuple[Divergent, int], int] => Divergent
# now
tuple[tuple[Divergent, int], int] => tuple[Divergent, int]
```

The false positive error introduced in this PR occurs in class
definitions with self-referential base classes, such as the one below.

```python
from typing_extensions import Generic, TypeVar

T = TypeVar("T")
U = TypeVar("U")

class Base2(Generic[T, U]): ...

# TODO: no error
# error: [unsupported-base] "Unsupported class base with type `<class 'Base2[Sub2, U@Sub2]'> | <class 'Base2[Sub2[Unknown], U@Sub2]'>`"
class Sub2(Base2["Sub2", U]): ...
```

This is due to the lack of support for unions of MROs, or because cyclic
legacy generic types are not inferred as generic types early in the
query cycle.

## Test Plan

All samples listed in astral-sh/ty#256 are tested and passed without any
panic!

## Acknowledgments

Thanks to @MichaReiser for working on bug fixes and improvements to
salsa for this PR. @carljm also contributed early on to the discussion
of the query convergence mechanism proposed in this PR.

---------

Co-authored-by: Carl Meyer <carl@astral.sh>

.github/workflows/ci.yaml

@@ -261,15 +261,15 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@725a8794d15fc7563f59595bd9556495c0564878 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@537c30d2b45cc3aa3fb35e2bbcfb61ef93fd6f02 # v2.62.52
+        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
-        uses: taiki-e/install-action@537c30d2b45cc3aa3fb35e2bbcfb61ef93fd6f02 # v2.62.52
+        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
         with:
           tool: cargo-insta
       - name: "Install uv"
-        uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
           enable-cache: "true"
       - name: ty mdtests (GitHub annotations)
@@ -284,6 +284,10 @@ jobs:
         run: cargo insta test --all-features --unreferenced reject --test-runner nextest
       - name: Dogfood ty on py-fuzzer
         run: uv run --project=./python/py-fuzzer cargo run -p ty check --project=./python/py-fuzzer
+      - name: Dogfood ty on the scripts directory
+        run: uv run --project=./scripts cargo run -p ty check --project=./scripts
+      - name: Dogfood ty on ty_benchmark
+        run: uv run --project=./scripts/ty_benchmark cargo run -p ty check --project=./scripts/ty_benchmark
       # Check for broken links in the documentation.
       - run: cargo doc --all --no-deps
         env:
@@ -319,11 +323,11 @@ jobs:
       - name: "Install mold"
         uses: rui314/setup-mold@725a8794d15fc7563f59595bd9556495c0564878 # v1
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@537c30d2b45cc3aa3fb35e2bbcfb61ef93fd6f02 # v2.62.52
+        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
         with:
           tool: cargo-nextest
       - name: "Install uv"
-        uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
           enable-cache: "true"
       - name: "Run tests"
@@ -352,11 +356,11 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo nextest"
-        uses: taiki-e/install-action@537c30d2b45cc3aa3fb35e2bbcfb61ef93fd6f02 # v2.62.52
+        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
         with:
           tool: cargo-nextest
       - name: "Install uv"
-        uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
           enable-cache: "true"
       - name: "Run tests"
@@ -462,7 +466,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:
           shared-key: ruff-linux-debug
@@ -497,7 +501,7 @@ jobs:
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - name: "Install Rust toolchain"
         run: rustup component add rustfmt
       # Run all code generation scripts, and verify that the current output is
@@ -532,7 +536,7 @@ jobs:
           ref: ${{ github.event.pull_request.base.ref }}
           persist-credentials: false
 
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           activate-environment: true
@@ -638,7 +642,7 @@ jobs:
         with:
           fetch-depth: 0
           persist-credentials: false
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
@@ -697,7 +701,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
@@ -748,7 +752,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
@@ -792,7 +796,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: Install uv
-        uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
           python-version: 3.13
           activate-environment: true
@@ -947,13 +951,13 @@ jobs:
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
 
       - name: "Install Rust toolchain"
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@537c30d2b45cc3aa3fb35e2bbcfb61ef93fd6f02 # v2.62.52
+        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
         with:
           tool: cargo-codspeed
 
@@ -987,13 +991,13 @@ jobs:
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
 
       - name: "Install Rust toolchain"
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@537c30d2b45cc3aa3fb35e2bbcfb61ef93fd6f02 # v2.62.52
+        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
         with:
           tool: cargo-codspeed
 
@@ -1027,13 +1031,13 @@ jobs:
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:
           save-if: ${{ github.ref == 'refs/heads/main' }}
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
 
       - name: "Install Rust toolchain"
         run: rustup show
 
       - name: "Install codspeed"
-        uses: taiki-e/install-action@537c30d2b45cc3aa3fb35e2bbcfb61ef93fd6f02 # v2.62.52
+        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
         with:
           tool: cargo-codspeed
 

.github/workflows/daily_fuzz.yaml

@@ -34,7 +34,7 @@ jobs:
       - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
         with:
           persist-credentials: false
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"

.github/workflows/mypy_primer.yaml

@@ -43,7 +43,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
 
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:
@@ -81,7 +81,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
 
       - uses: Swatinem/rust-cache@f13886b937689c021905a6b90929199931d60db1 # v2.8.1
         with:

.github/workflows/publish-pypi.yml

@@ -22,7 +22,7 @@ jobs:
       id-token: write
     steps:
       - name: "Install uv"
-        uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - uses: actions/download-artifact@634f93cb2916e3fdff6788551b99b062d0335ce0 # v5.0.0
         with:
           pattern: wheels-*

.github/workflows/release.yml

@@ -60,7 +60,7 @@ jobs:
     env:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
         with:
           persist-credentials: false
           submodules: recursive
@@ -123,7 +123,7 @@ jobs:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
       BUILD_MANIFEST_NAME: target/distrib/global-dist-manifest.json
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
         with:
           persist-credentials: false
           submodules: recursive
@@ -174,7 +174,7 @@ jobs:
     outputs:
       val: ${{ steps.host.outputs.manifest }}
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
         with:
           persist-credentials: false
           submodules: recursive
@@ -250,7 +250,7 @@ jobs:
     env:
       GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
     steps:
-      - uses: actions/checkout@ff7abcd0c3c05ccf6adc123a8cd1fd4fb30fb493
+      - uses: actions/checkout@1af3b93b6815bc44a9784bd300feb67ff0d1eeb3
         with:
           persist-credentials: false
           submodules: recursive

.github/workflows/sync_typeshed.yaml

@@ -77,7 +77,7 @@ jobs:
         run: |
           git config --global user.name typeshedbot
           git config --global user.email '<>'
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - name: Sync typeshed stubs
         run: |
           rm -rf "ruff/${VENDORED_TYPESHED}"
@@ -131,7 +131,7 @@ jobs:
         with:
           persist-credentials: true
           ref: ${{ env.UPSTREAM_BRANCH}}
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - name: Setup git
         run: |
           git config --global user.name typeshedbot
@@ -170,7 +170,7 @@ jobs:
         with:
           persist-credentials: true
           ref: ${{ env.UPSTREAM_BRANCH}}
-      - uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+      - uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
       - name: Setup git
         run: |
           git config --global user.name typeshedbot
@@ -207,12 +207,12 @@ jobs:
         uses: rui314/setup-mold@725a8794d15fc7563f59595bd9556495c0564878 # v1
       - name: "Install cargo nextest"
         if: ${{ success() }}
-        uses: taiki-e/install-action@537c30d2b45cc3aa3fb35e2bbcfb61ef93fd6f02 # v2.62.52
+        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
         with:
           tool: cargo-nextest
       - name: "Install cargo insta"
         if: ${{ success() }}
-        uses: taiki-e/install-action@537c30d2b45cc3aa3fb35e2bbcfb61ef93fd6f02 # v2.62.52
+        uses: taiki-e/install-action@f79fe7514db78f0a7bdba3cb6dd9c1baa7d046d9 # v2.62.56
         with:
           tool: cargo-insta
       - name: Update snapshots

.github/workflows/ty-ecosystem-analyzer.yaml

@@ -33,7 +33,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
           enable-cache: true # zizmor: ignore[cache-poisoning] acceptable risk for CloudFlare pages artifact
 

.github/workflows/ty-ecosystem-report.yaml

@@ -29,7 +29,7 @@ jobs:
           persist-credentials: false
 
       - name: Install the latest version of uv
-        uses: astral-sh/setup-uv@5a7eac68fb9809dea845d802897dc5c723910fa3 # v7.1.3
+        uses: astral-sh/setup-uv@1e862dfacbd1d6d858c55d9b792c756523627244 # v7.1.4
         with:
           enable-cache: true # zizmor: ignore[cache-poisoning] acceptable risk for CloudFlare pages artifact
 

.vscode/settings.json

@@ -5,5 +5,6 @@
     "rust-analyzer.check.command": "clippy",
     "search.exclude": {
         "**/*.snap": true
-    }
+    },
+    "ty.diagnosticMode": "openFilesOnly"
 }

Cargo.lock

@@ -442,9 +442,9 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "4.5.51"
+version = "4.5.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4c26d721170e0295f191a69bd9a1f93efcdb0aff38684b61ab5750468972e5f5"
+checksum = "c9e340e012a1bf4935f5282ed1436d1489548e8f72308207ea5df0e23d2d03f8"
 dependencies = [
  "clap_builder",
  "clap_derive",
@@ -452,9 +452,9 @@ dependencies = [
 
 [[package]]
 name = "clap_builder"
-version = "4.5.51"
+version = "4.5.53"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "75835f0c7bf681bfd05abe44e965760fea999a5286c6eb2d59883634fd02011a"
+checksum = "d76b5d13eaa18c901fd2f7fca939fefe3a0727a953561fefdf3b2922b8569d00"
 dependencies = [
  "anstream",
  "anstyle",
@@ -1016,7 +1016,7 @@ dependencies = [
  "libc",
  "option-ext",
  "redox_users",
- "windows-sys 0.61.0",
+ "windows-sys 0.59.0",
 ]
 
 [[package]]
@@ -1108,7 +1108,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "39cab71617ae0d63f51a36d69f866391735b51691dbda63cf6f96d042b63efeb"
 dependencies = [
  "libc",
- "windows-sys 0.61.0",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -1255,7 +1255,7 @@ checksum = "ac7bb8710e1f09672102be7ddf39f764d8440ae74a9f4e30aaa4820dcdffa4af"
 dependencies = [
  "compact_str",
  "get-size-derive2",
- "hashbrown 0.16.0",
+ "hashbrown 0.16.1",
  "indexmap",
  "smallvec",
 ]
@@ -1353,9 +1353,9 @@ dependencies = [
 
 [[package]]
 name = "hashbrown"
-version = "0.16.0"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5419bdc4f6a9207fbeba6d11b604d481addf78ecd10c11ad51e76c2f6482748d"
+checksum = "841d1cc9bed7f9236f321df977030373f4a4163ae1a7dbfe1a51a2c1a51d9100"
 dependencies = [
  "equivalent",
 ]
@@ -1564,12 +1564,12 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.12.0"
+version = "2.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6717a8d2a5a929a1a2eb43a12812498ed141a0bcfb7e8f7844fbdbe4303bba9f"
+checksum = "0ad4bb2b565bca0645f4d68c5c9af97fba094e9791da685bf83cb5f3ce74acf2"
 dependencies = [
  "equivalent",
- "hashbrown 0.16.0",
+ "hashbrown 0.16.1",
  "serde",
  "serde_core",
 ]
@@ -1763,7 +1763,7 @@ dependencies = [
  "portable-atomic",
  "portable-atomic-util",
  "serde_core",
- "windows-sys 0.61.0",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -3127,7 +3127,7 @@ dependencies = [
  "fern",
  "glob",
  "globset",
- "hashbrown 0.16.0",
+ "hashbrown 0.16.1",
  "imperative",
  "insta",
  "is-macro",
@@ -3570,7 +3570,7 @@ dependencies = [
  "errno",
  "libc",
  "linux-raw-sys",
- "windows-sys 0.61.0",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -3935,9 +3935,9 @@ checksum = "804f44ed3c63152de6a9f90acbea1a110441de43006ea51bcce8f436196a288b"
 
 [[package]]
 name = "syn"
-version = "2.0.110"
+version = "2.0.111"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a99801b5bd34ede4cf3fc688c5919368fea4e4814a4664359503e6015b280aea"
+checksum = "390cc9a294ab71bdb1aa2e99d13be9c753cd2d7bd6560c77118597410c4d2e87"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3971,7 +3971,7 @@ dependencies = [
  "getrandom 0.3.4",
  "once_cell",
  "rustix",
- "windows-sys 0.61.0",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]
@@ -4462,7 +4462,7 @@ dependencies = [
  "drop_bomb",
  "get-size2",
  "glob",
- "hashbrown 0.16.0",
+ "hashbrown 0.16.1",
  "indexmap",
  "indoc",
  "insta",
@@ -4474,6 +4474,7 @@ dependencies = [
  "quickcheck_macros",
  "ruff_annotate_snippets",
  "ruff_db",
+ "ruff_diagnostics",
  "ruff_index",
  "ruff_macros",
  "ruff_memory_usage",
@@ -4519,6 +4520,7 @@ dependencies = [
  "lsp-types",
  "regex",
  "ruff_db",
+ "ruff_diagnostics",
  "ruff_macros",
  "ruff_notebook",
  "ruff_python_ast",
@@ -5020,7 +5022,7 @@ version = "0.1.11"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c2a7b1c03c876122aa43f3020e6c3c3ee5c05081c9a00739faf7503aeba10d22"
 dependencies = [
- "windows-sys 0.61.0",
+ "windows-sys 0.52.0",
 ]
 
 [[package]]

crates/ruff_benchmark/Cargo.toml

@@ -59,8 +59,6 @@ divan = { workspace = true, optional = true }
 anyhow = { workspace = true }
 codspeed-criterion-compat = { workspace = true, default-features = false, optional = true }
 criterion = { workspace = true, default-features = false, optional = true }
-rayon = { workspace = true }
-rustc-hash = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
 tracing = { workspace = true }
@@ -88,3 +86,7 @@ mimalloc = { workspace = true }
 
 [target.'cfg(all(not(target_os = "windows"), not(target_os = "openbsd"), any(target_arch = "x86_64", target_arch = "aarch64", target_arch = "powerpc64", target_arch = "riscv64")))'.dev-dependencies]
 tikv-jemallocator = { workspace = true }
+
+[dev-dependencies]
+rustc-hash = { workspace = true }
+rayon = { workspace = true }

crates/ruff_linter/resources/test/fixtures/flake8_bandit/S310.py

@@ -45,3 +45,22 @@ urllib.request.urlopen(urllib.request.Request(url))
 # https://github.com/astral-sh/ruff/issues/15522
 map(urllib.request.urlopen, [])
 foo = urllib.request.urlopen
+
+# https://github.com/astral-sh/ruff/issues/21462
+path = "https://example.com/data.csv"
+urllib.request.urlretrieve(path, "data.csv")
+url = "https://example.com/api"
+urllib.request.Request(url)
+
+# Test resolved f-strings and concatenated string literals
+fstring_url = f"https://example.com/data.csv"
+urllib.request.urlopen(fstring_url)
+urllib.request.Request(fstring_url)
+
+concatenated_url = "https://" + "example.com/data.csv"
+urllib.request.urlopen(concatenated_url)
+urllib.request.Request(concatenated_url)
+
+nested_concatenated = "http://" + "example.com" + "/data.csv"
+urllib.request.urlopen(nested_concatenated)
+urllib.request.Request(nested_concatenated)

crates/ruff_linter/resources/test/fixtures/ruff/RUF066.py

@@ -0,0 +1,70 @@
+import abc
+import typing
+
+
+class User:  # Test normal class properties
+    @property
+    def name(self):  # ERROR: No return
+        f"{self.first_name} {self.last_name}"
+
+    @property
+    def age(self):  # OK: Returning something
+        return 100
+
+    def method(self):  # OK: Not a property
+        x = 1
+
+    @property
+    def nested(self):  # ERROR: Property itself doesn't return
+        def inner():
+            return 0
+
+    @property
+    def stub(self): ...  # OK: A stub; doesn't return anything
+
+
+class UserMeta(metaclass=abc.ABCMeta):  # Test properies inside of an ABC class
+    @property
+    @abc.abstractmethod
+    def abstr_prop1(self): ...  # OK: Abstract methods doesn't need to return anything
+
+    @property
+    @abc.abstractmethod
+    def abstr_prop2(self):  # OK: Abstract methods doesn't need to return anything
+        """
+        A cool docstring
+        """
+
+    @property
+    def prop1(self):  # OK: Returning a value
+        return 1
+
+    @property
+    def prop2(self):  # ERROR: Not returning something (even when we are inside an ABC)
+        50
+
+    def method(self):  # OK: Not a property
+        x = 1
+
+
+def func():  # OK: Not a property
+    x = 1
+
+
+class Proto(typing.Protocol):  # Tests for a Protocol class
+    @property
+    def prop1(self) -> int: ...  # OK: A stub property
+
+
+class File:  # Extra tests for things like yield/yield from/raise
+    @property
+    def stream1(self):  # OK: Yields something
+        yield
+
+    @property
+    def stream2(self):  # OK: Yields from something
+        yield from self.stream1
+
+    @property
+    def children(self):  # OK: Raises
+        raise ValueError("File does not have children")

crates/ruff_linter/src/checkers/ast/analyze/statement.rs

@@ -347,6 +347,9 @@ pub(crate) fn statement(stmt: &Stmt, checker: &mut Checker) {
             if checker.is_rule_enabled(Rule::InvalidArgumentName) {
                 pep8_naming::rules::invalid_argument_name_function(checker, function_def);
             }
+            if checker.is_rule_enabled(Rule::PropertyWithoutReturn) {
+                ruff::rules::property_without_return(checker, function_def);
+            }
         }
         Stmt::Return(_) => {
             if checker.is_rule_enabled(Rule::ReturnInInit) {

crates/ruff_linter/src/codes.rs

@@ -1058,6 +1058,7 @@ pub fn code_to_rule(linter: Linter, code: &str) -> Option<(RuleGroup, Rule)> {
         (Ruff, "063") => rules::ruff::rules::AccessAnnotationsFromClassDict,
         (Ruff, "064") => rules::ruff::rules::NonOctalPermissions,
         (Ruff, "065") => rules::ruff::rules::LoggingEagerConversion,
+        (Ruff, "066") => rules::ruff::rules::PropertyWithoutReturn,
 
         (Ruff, "100") => rules::ruff::rules::UnusedNOQA,
         (Ruff, "101") => rules::ruff::rules::RedirectedNOQA,

crates/ruff_linter/src/preview.rs

@@ -279,3 +279,10 @@ pub(crate) const fn is_extended_snmp_api_path_detection_enabled(settings: &Linte
 pub(crate) const fn is_enumerate_for_loop_int_index_enabled(settings: &LinterSettings) -> bool {
     settings.preview.is_enabled()
 }
+
+// https://github.com/astral-sh/ruff/pull/21469
+pub(crate) const fn is_s310_resolve_string_literal_bindings_enabled(
+    settings: &LinterSettings,
+) -> bool {
+    settings.preview.is_enabled()
+}

crates/ruff_linter/src/rules/flake8_bandit/mod.rs

@@ -10,11 +10,11 @@ mod tests {
     use anyhow::Result;
     use test_case::test_case;
 
-    use crate::assert_diagnostics;
     use crate::registry::Rule;
     use crate::settings::LinterSettings;
     use crate::settings::types::PreviewMode;
     use crate::test::test_path;
+    use crate::{assert_diagnostics, assert_diagnostics_diff};
 
     #[test_case(Rule::Assert, Path::new("S101.py"))]
     #[test_case(Rule::BadFilePermissions, Path::new("S103.py"))]
@@ -112,14 +112,19 @@ mod tests {
             rule_code.noqa_code(),
             path.to_string_lossy()
         );
-        let diagnostics = test_path(
+
+        assert_diagnostics_diff!(
+            snapshot,
             Path::new("flake8_bandit").join(path).as_path(),
+            &LinterSettings {
+                preview: PreviewMode::Disabled,
+                ..LinterSettings::for_rule(rule_code)
+            },
             &LinterSettings {
                 preview: PreviewMode::Enabled,
                 ..LinterSettings::for_rule(rule_code)
-            },
-        )?;
-        assert_diagnostics!(snapshot, diagnostics);
+            }
+        );
         Ok(())
     }
 

crates/ruff_linter/src/rules/flake8_bandit/rules/suspicious_function_call.rs

@@ -4,11 +4,16 @@
 use itertools::Either;
 use ruff_macros::{ViolationMetadata, derive_message_formats};
 use ruff_python_ast::{self as ast, Arguments, Decorator, Expr, ExprCall, Operator};
+use ruff_python_semantic::SemanticModel;
+use ruff_python_semantic::analyze::typing::find_binding_value;
 use ruff_text_size::{Ranged, TextRange};
 
 use crate::Violation;
 use crate::checkers::ast::Checker;
-use crate::preview::is_suspicious_function_reference_enabled;
+use crate::preview::{
+    is_s310_resolve_string_literal_bindings_enabled, is_suspicious_function_reference_enabled,
+};
+use crate::settings::LinterSettings;
 
 /// ## What it does
 /// Checks for calls to `pickle` functions or modules that wrap them.
@@ -1016,6 +1021,25 @@ fn suspicious_function(
             || has_prefix(chars.skip_while(|c| c.is_whitespace()), "https://")
     }
 
+    /// Resolves `expr` to its binding and checks if the resolved expression starts with an HTTP or HTTPS prefix.
+    fn expression_starts_with_http_prefix(
+        expr: &Expr,
+        semantic: &SemanticModel,
+        settings: &LinterSettings,
+    ) -> bool {
+        let resolved_expression = if is_s310_resolve_string_literal_bindings_enabled(settings)
+            && let Some(name_expr) = expr.as_name_expr()
+            && let Some(binding_id) = semantic.only_binding(name_expr)
+            && let Some(value) = find_binding_value(semantic.binding(binding_id), semantic)
+        {
+            value
+        } else {
+            expr
+        };
+
+        leading_chars(resolved_expression).is_some_and(has_http_prefix)
+    }
+
     /// Return the leading characters for an expression, if it's a string literal, f-string, or
     /// string concatenation.
     fn leading_chars(expr: &Expr) -> Option<impl Iterator<Item = char> + Clone + '_> {
@@ -1139,17 +1163,19 @@ fn suspicious_function(
         // URLOpen (`Request`)
         ["urllib", "request", "Request"] | ["six", "moves", "urllib", "request", "Request"] => {
             if let Some(arguments) = arguments {
-                // If the `url` argument is a string literal or an f-string, allow `http` and `https` schemes.
+                // If the `url` argument is a string literal (including resolved bindings), allow `http` and `https` schemes.
                 if arguments.args.iter().all(|arg| !arg.is_starred_expr())
                     && arguments
                         .keywords
                         .iter()
                         .all(|keyword| keyword.arg.is_some())
                 {
-                    if arguments
-                        .find_argument_value("url", 0)
-                        .and_then(leading_chars)
-                        .is_some_and(has_http_prefix)
+                    if let Some(url_expr) = arguments.find_argument_value("url", 0)
+                        && expression_starts_with_http_prefix(
+                            url_expr,
+                            checker.semantic(),
+                            checker.settings(),
+                        )
                     {
                         return;
                     }
@@ -1186,19 +1212,25 @@ fn suspicious_function(
                                     name.segments() == ["urllib", "request", "Request"]
                                 })
                             {
-                                if arguments
-                                    .find_argument_value("url", 0)
-                                    .and_then(leading_chars)
-                                    .is_some_and(has_http_prefix)
+                                if let Some(url_expr) = arguments.find_argument_value("url", 0)
+                                    && expression_starts_with_http_prefix(
+                                        url_expr,
+                                        checker.semantic(),
+                                        checker.settings(),
+                                    )
                                 {
                                     return;
                                 }
                             }
                         }
 
-                        // If the `url` argument is a string literal, allow `http` and `https` schemes.
+                        // If the `url` argument is a string literal (including resolved bindings), allow `http` and `https` schemes.
                         Some(expr) => {
-                            if leading_chars(expr).is_some_and(has_http_prefix) {
+                            if expression_starts_with_http_prefix(
+                                expr,
+                                checker.semantic(),
+                                checker.settings(),
+                            ) {
                                 return;
                             }
                         }

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__S310_S310.py.snap

@@ -254,3 +254,84 @@ S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom sch
 42 | urllib.request.urlopen(urllib.request.Request(url))
    |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:51:1
+   |
+49 | # https://github.com/astral-sh/ruff/issues/21462
+50 | path = "https://example.com/data.csv"
+51 | urllib.request.urlretrieve(path, "data.csv")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+52 | url = "https://example.com/api"
+53 | urllib.request.Request(url)
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:53:1
+   |
+51 | urllib.request.urlretrieve(path, "data.csv")
+52 | url = "https://example.com/api"
+53 | urllib.request.Request(url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
+54 |
+55 | # Test resolved f-strings and concatenated string literals
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:57:1
+   |
+55 | # Test resolved f-strings and concatenated string literals
+56 | fstring_url = f"https://example.com/data.csv"
+57 | urllib.request.urlopen(fstring_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+58 | urllib.request.Request(fstring_url)
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:58:1
+   |
+56 | fstring_url = f"https://example.com/data.csv"
+57 | urllib.request.urlopen(fstring_url)
+58 | urllib.request.Request(fstring_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+59 |
+60 | concatenated_url = "https://" + "example.com/data.csv"
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:61:1
+   |
+60 | concatenated_url = "https://" + "example.com/data.csv"
+61 | urllib.request.urlopen(concatenated_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+62 | urllib.request.Request(concatenated_url)
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:62:1
+   |
+60 | concatenated_url = "https://" + "example.com/data.csv"
+61 | urllib.request.urlopen(concatenated_url)
+62 | urllib.request.Request(concatenated_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+63 |
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:65:1
+   |
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+65 | urllib.request.urlopen(nested_concatenated)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+66 | urllib.request.Request(nested_concatenated)
+   |
+
+S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
+  --> S310.py:66:1
+   |
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+65 | urllib.request.urlopen(nested_concatenated)
+66 | urllib.request.Request(nested_concatenated)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+   |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S301_S301.py.snap

@@ -1,15 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S301 `pickle` and modules that wrap it can be unsafe when used to deserialize untrusted data, possible security issue
- --> S301.py:3:1
-  |
-1 | import pickle
-2 |
-3 | pickle.loads()
-  | ^^^^^^^^^^^^^^
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
+--- Summary ---
+Removed: 0
+Added: 2
+
+--- Added ---
 S301 `pickle` and modules that wrap it can be unsafe when used to deserialize untrusted data, possible security issue
  --> S301.py:7:5
   |
@@ -19,6 +19,7 @@ S301 `pickle` and modules that wrap it can be unsafe when used to deserialize un
 8 | foo = pickle.load
   |
 
+
 S301 `pickle` and modules that wrap it can be unsafe when used to deserialize untrusted data, possible security issue
  --> S301.py:8:7
   |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S307_S307.py.snap

@@ -1,24 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S307 Use of possibly insecure function; consider using `ast.literal_eval`
- --> S307.py:3:7
-  |
-1 | import os
-2 |
-3 | print(eval("1+1"))  # S307
-  |       ^^^^^^^^^^^
-4 | print(eval("os.getcwd()"))  # S307
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S307 Use of possibly insecure function; consider using `ast.literal_eval`
- --> S307.py:4:7
-  |
-3 | print(eval("1+1"))  # S307
-4 | print(eval("os.getcwd()"))  # S307
-  |       ^^^^^^^^^^^^^^^^^^^
-  |
+--- Summary ---
+Removed: 0
+Added: 2
 
+--- Added ---
 S307 Use of possibly insecure function; consider using `ast.literal_eval`
   --> S307.py:16:5
    |
@@ -28,6 +19,7 @@ S307 Use of possibly insecure function; consider using `ast.literal_eval`
 17 | foo = eval
    |
 
+
 S307 Use of possibly insecure function; consider using `ast.literal_eval`
   --> S307.py:17:7
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S308_S308.py.snap

@@ -1,60 +1,37 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
- --> S308.py:6:5
-  |
-4 | def bad_func():
-5 |     inject = "harmful_input"
-6 |     mark_safe(inject)
-  |     ^^^^^^^^^^^^^^^^^
-7 |     mark_safe("I will add" + inject + "to my string")
-8 |     mark_safe("I will add %s to my string" % inject)
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
- --> S308.py:7:5
-  |
-5 |     inject = "harmful_input"
-6 |     mark_safe(inject)
-7 |     mark_safe("I will add" + inject + "to my string")
-  |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-8 |     mark_safe("I will add %s to my string" % inject)
-9 |     mark_safe("I will add {} to my string".format(inject))
-  |
+--- Summary ---
+Removed: 2
+Added: 4
 
+--- Removed ---
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:8:5
+  --> S308.py:16:1
    |
- 6 |     mark_safe(inject)
- 7 |     mark_safe("I will add" + inject + "to my string")
- 8 |     mark_safe("I will add %s to my string" % inject)
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
- 9 |     mark_safe("I will add {} to my string".format(inject))
-10 |     mark_safe(f"I will add {inject} to my string")
+16 | @mark_safe
+   | ^^^^^^^^^^
+17 | def some_func():
+18 |     return '<script>alert("evil!")</script>'
    |
 
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:9:5
-   |
- 7 |     mark_safe("I will add" + inject + "to my string")
- 8 |     mark_safe("I will add %s to my string" % inject)
- 9 |     mark_safe("I will add {} to my string".format(inject))
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-10 |     mark_safe(f"I will add {inject} to my string")
-   |
 
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:10:5
+  --> S308.py:36:1
    |
- 8 |     mark_safe("I will add %s to my string" % inject)
- 9 |     mark_safe("I will add {} to my string".format(inject))
-10 |     mark_safe(f"I will add {inject} to my string")
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-11 |
-12 | def good_func():
+36 | @mark_safe
+   | ^^^^^^^^^^
+37 | def some_func():
+38 |     return '<script>alert("evil!")</script>'
    |
 
+
+
+--- Added ---
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
   --> S308.py:16:2
    |
@@ -64,59 +41,6 @@ S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
 18 |     return '<script>alert("evil!")</script>'
    |
 
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:26:5
-   |
-24 | def bad_func():
-25 |     inject = "harmful_input"
-26 |     mark_safe(inject)
-   |     ^^^^^^^^^^^^^^^^^
-27 |     mark_safe("I will add" + inject + "to my string")
-28 |     mark_safe("I will add %s to my string" % inject)
-   |
-
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:27:5
-   |
-25 |     inject = "harmful_input"
-26 |     mark_safe(inject)
-27 |     mark_safe("I will add" + inject + "to my string")
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-28 |     mark_safe("I will add %s to my string" % inject)
-29 |     mark_safe("I will add {} to my string".format(inject))
-   |
-
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:28:5
-   |
-26 |     mark_safe(inject)
-27 |     mark_safe("I will add" + inject + "to my string")
-28 |     mark_safe("I will add %s to my string" % inject)
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-29 |     mark_safe("I will add {} to my string".format(inject))
-30 |     mark_safe(f"I will add {inject} to my string")
-   |
-
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:29:5
-   |
-27 |     mark_safe("I will add" + inject + "to my string")
-28 |     mark_safe("I will add %s to my string" % inject)
-29 |     mark_safe("I will add {} to my string".format(inject))
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-30 |     mark_safe(f"I will add {inject} to my string")
-   |
-
-S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
-  --> S308.py:30:5
-   |
-28 |     mark_safe("I will add %s to my string" % inject)
-29 |     mark_safe("I will add {} to my string".format(inject))
-30 |     mark_safe(f"I will add {inject} to my string")
-   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-31 |
-32 | def good_func():
-   |
 
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
   --> S308.py:36:2
@@ -127,6 +51,7 @@ S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
 38 |     return '<script>alert("evil!")</script>'
    |
 
+
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
   --> S308.py:42:5
    |
@@ -136,6 +61,7 @@ S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
 43 | foo = mark_safe
    |
 
+
 S308 Use of `mark_safe` may expose cross-site scripting vulnerabilities
   --> S308.py:43:7
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S310_S310.py.snap

@@ -1,260 +1,106 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
- --> S310.py:6:1
-  |
-4 | urllib.request.urlopen(url=f'http://www.google.com')
-5 | urllib.request.urlopen(url='http://' + 'www' + '.google.com')
-6 | urllib.request.urlopen(url='http://www.google.com', **kwargs)
-  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-7 | urllib.request.urlopen(url=f'http://www.google.com', **kwargs)
-8 | urllib.request.urlopen('http://www.google.com')
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
- --> S310.py:7:1
-  |
-5 | urllib.request.urlopen(url='http://' + 'www' + '.google.com')
-6 | urllib.request.urlopen(url='http://www.google.com', **kwargs)
-7 | urllib.request.urlopen(url=f'http://www.google.com', **kwargs)
-  | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-8 | urllib.request.urlopen('http://www.google.com')
-9 | urllib.request.urlopen(f'http://www.google.com')
-  |
+--- Summary ---
+Removed: 8
+Added: 2
 
+--- Removed ---
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:10:1
+  --> S310.py:51:1
    |
- 8 | urllib.request.urlopen('http://www.google.com')
- 9 | urllib.request.urlopen(f'http://www.google.com')
-10 | urllib.request.urlopen('file:///foo/bar/baz')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-11 | urllib.request.urlopen(url)
+49 | # https://github.com/astral-sh/ruff/issues/21462
+50 | path = "https://example.com/data.csv"
+51 | urllib.request.urlretrieve(path, "data.csv")
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+52 | url = "https://example.com/api"
+53 | urllib.request.Request(url)
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:11:1
+  --> S310.py:53:1
    |
- 9 | urllib.request.urlopen(f'http://www.google.com')
-10 | urllib.request.urlopen('file:///foo/bar/baz')
-11 | urllib.request.urlopen(url)
+51 | urllib.request.urlretrieve(path, "data.csv")
+52 | url = "https://example.com/api"
+53 | urllib.request.Request(url)
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-12 |
-13 | urllib.request.Request(url='http://www.google.com')
+54 |
+55 | # Test resolved f-strings and concatenated string literals
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:16:1
+  --> S310.py:57:1
    |
-14 | urllib.request.Request(url=f'http://www.google.com')
-15 | urllib.request.Request(url='http://' + 'www' + '.google.com')
-16 | urllib.request.Request(url='http://www.google.com', **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-17 | urllib.request.Request(url=f'http://www.google.com', **kwargs)
-18 | urllib.request.Request('http://www.google.com')
+55 | # Test resolved f-strings and concatenated string literals
+56 | fstring_url = f"https://example.com/data.csv"
+57 | urllib.request.urlopen(fstring_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+58 | urllib.request.Request(fstring_url)
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:17:1
+  --> S310.py:58:1
    |
-15 | urllib.request.Request(url='http://' + 'www' + '.google.com')
-16 | urllib.request.Request(url='http://www.google.com', **kwargs)
-17 | urllib.request.Request(url=f'http://www.google.com', **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-18 | urllib.request.Request('http://www.google.com')
-19 | urllib.request.Request(f'http://www.google.com')
+56 | fstring_url = f"https://example.com/data.csv"
+57 | urllib.request.urlopen(fstring_url)
+58 | urllib.request.Request(fstring_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+59 |
+60 | concatenated_url = "https://" + "example.com/data.csv"
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:20:1
+  --> S310.py:61:1
    |
-18 | urllib.request.Request('http://www.google.com')
-19 | urllib.request.Request(f'http://www.google.com')
-20 | urllib.request.Request('file:///foo/bar/baz')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-21 | urllib.request.Request(url)
+60 | concatenated_url = "https://" + "example.com/data.csv"
+61 | urllib.request.urlopen(concatenated_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+62 | urllib.request.Request(concatenated_url)
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:21:1
+  --> S310.py:62:1
    |
-19 | urllib.request.Request(f'http://www.google.com')
-20 | urllib.request.Request('file:///foo/bar/baz')
-21 | urllib.request.Request(url)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-22 |
-23 | urllib.request.URLopener().open(fullurl='http://www.google.com')
+60 | concatenated_url = "https://" + "example.com/data.csv"
+61 | urllib.request.urlopen(concatenated_url)
+62 | urllib.request.Request(concatenated_url)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+63 |
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:23:1
+  --> S310.py:65:1
    |
-21 | urllib.request.Request(url)
-22 |
-23 | urllib.request.URLopener().open(fullurl='http://www.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-24 | urllib.request.URLopener().open(fullurl=f'http://www.google.com')
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+65 | urllib.request.urlopen(nested_concatenated)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+66 | urllib.request.Request(nested_concatenated)
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:24:1
+  --> S310.py:66:1
    |
-23 | urllib.request.URLopener().open(fullurl='http://www.google.com')
-24 | urllib.request.URLopener().open(fullurl=f'http://www.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
+64 | nested_concatenated = "http://" + "example.com" + "/data.csv"
+65 | urllib.request.urlopen(nested_concatenated)
+66 | urllib.request.Request(nested_concatenated)
+   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
    |
 
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:25:1
-   |
-23 | urllib.request.URLopener().open(fullurl='http://www.google.com')
-24 | urllib.request.URLopener().open(fullurl=f'http://www.google.com')
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-   |
 
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:26:1
-   |
-24 | urllib.request.URLopener().open(fullurl=f'http://www.google.com')
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-28 | urllib.request.URLopener().open('http://www.google.com')
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:27:1
-   |
-25 | urllib.request.URLopener().open(fullurl='http://' + 'www' + '.google.com')
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-28 | urllib.request.URLopener().open('http://www.google.com')
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:28:1
-   |
-26 | urllib.request.URLopener().open(fullurl='http://www.google.com', **kwargs)
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-28 | urllib.request.URLopener().open('http://www.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:29:1
-   |
-27 | urllib.request.URLopener().open(fullurl=f'http://www.google.com', **kwargs)
-28 | urllib.request.URLopener().open('http://www.google.com')
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-31 | urllib.request.URLopener().open('file:///foo/bar/baz')
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:30:1
-   |
-28 | urllib.request.URLopener().open('http://www.google.com')
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-31 | urllib.request.URLopener().open('file:///foo/bar/baz')
-32 | urllib.request.URLopener().open(url)
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:31:1
-   |
-29 | urllib.request.URLopener().open(f'http://www.google.com')
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-31 | urllib.request.URLopener().open('file:///foo/bar/baz')
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-32 | urllib.request.URLopener().open(url)
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:32:1
-   |
-30 | urllib.request.URLopener().open('http://' + 'www' + '.google.com')
-31 | urllib.request.URLopener().open('file:///foo/bar/baz')
-32 | urllib.request.URLopener().open(url)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
-33 |
-34 | urllib.request.urlopen(url=urllib.request.Request('http://www.google.com'))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:37:1
-   |
-35 | urllib.request.urlopen(url=urllib.request.Request(f'http://www.google.com'))
-36 | urllib.request.urlopen(url=urllib.request.Request('http://' + 'www' + '.google.com'))
-37 | urllib.request.urlopen(url=urllib.request.Request('http://www.google.com'), **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-38 | urllib.request.urlopen(url=urllib.request.Request(f'http://www.google.com'), **kwargs)
-39 | urllib.request.urlopen(urllib.request.Request('http://www.google.com'))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:38:1
-   |
-36 | urllib.request.urlopen(url=urllib.request.Request('http://' + 'www' + '.google.com'))
-37 | urllib.request.urlopen(url=urllib.request.Request('http://www.google.com'), **kwargs)
-38 | urllib.request.urlopen(url=urllib.request.Request(f'http://www.google.com'), **kwargs)
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-39 | urllib.request.urlopen(urllib.request.Request('http://www.google.com'))
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:41:1
-   |
-39 | urllib.request.urlopen(urllib.request.Request('http://www.google.com'))
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-41 | urllib.request.urlopen(urllib.request.Request('file:///foo/bar/baz'))
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-42 | urllib.request.urlopen(urllib.request.Request(url))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:41:24
-   |
-39 | urllib.request.urlopen(urllib.request.Request('http://www.google.com'))
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-41 | urllib.request.urlopen(urllib.request.Request('file:///foo/bar/baz'))
-   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-42 | urllib.request.urlopen(urllib.request.Request(url))
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:42:1
-   |
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-41 | urllib.request.urlopen(urllib.request.Request('file:///foo/bar/baz'))
-42 | urllib.request.urlopen(urllib.request.Request(url))
-   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
-
-S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
-  --> S310.py:42:24
-   |
-40 | urllib.request.urlopen(urllib.request.Request(f'http://www.google.com'))
-41 | urllib.request.urlopen(urllib.request.Request('file:///foo/bar/baz'))
-42 | urllib.request.urlopen(urllib.request.Request(url))
-   |                        ^^^^^^^^^^^^^^^^^^^^^^^^^^^
-   |
 
+--- Added ---
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
   --> S310.py:46:5
    |
@@ -264,6 +110,7 @@ S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom sch
 47 | foo = urllib.request.urlopen
    |
 
+
 S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom schemes is often unexpected.
   --> S310.py:47:7
    |
@@ -271,4 +118,6 @@ S310 Audit URL open for permitted schemes. Allowing use of `file:` or custom sch
 46 | map(urllib.request.urlopen, [])
 47 | foo = urllib.request.urlopen
    |       ^^^^^^^^^^^^^^^^^^^^^^
+48 |
+49 | # https://github.com/astral-sh/ruff/issues/21462
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S311_S311.py.snap

@@ -1,103 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:10:1
-   |
- 9 | # Errors
-10 | random.Random()
-   | ^^^^^^^^^^^^^^^
-11 | random.random()
-12 | random.randrange()
-   |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:11:1
-   |
- 9 | # Errors
-10 | random.Random()
-11 | random.random()
-   | ^^^^^^^^^^^^^^^
-12 | random.randrange()
-13 | random.randint()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:12:1
-   |
-10 | random.Random()
-11 | random.random()
-12 | random.randrange()
-   | ^^^^^^^^^^^^^^^^^^
-13 | random.randint()
-14 | random.choice()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:13:1
-   |
-11 | random.random()
-12 | random.randrange()
-13 | random.randint()
-   | ^^^^^^^^^^^^^^^^
-14 | random.choice()
-15 | random.choices()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:14:1
-   |
-12 | random.randrange()
-13 | random.randint()
-14 | random.choice()
-   | ^^^^^^^^^^^^^^^
-15 | random.choices()
-16 | random.uniform()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:15:1
-   |
-13 | random.randint()
-14 | random.choice()
-15 | random.choices()
-   | ^^^^^^^^^^^^^^^^
-16 | random.uniform()
-17 | random.triangular()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:16:1
-   |
-14 | random.choice()
-15 | random.choices()
-16 | random.uniform()
-   | ^^^^^^^^^^^^^^^^
-17 | random.triangular()
-18 | random.randbytes()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:17:1
-   |
-15 | random.choices()
-16 | random.uniform()
-17 | random.triangular()
-   | ^^^^^^^^^^^^^^^^^^^
-18 | random.randbytes()
-   |
-
-S311 Standard pseudo-random generators are not suitable for cryptographic purposes
-  --> S311.py:18:1
-   |
-16 | random.uniform()
-17 | random.triangular()
-18 | random.randbytes()
-   | ^^^^^^^^^^^^^^^^^^
-19 |
-20 | # Unrelated
-   |
+--- Summary ---
+Removed: 0
+Added: 2
 
+--- Added ---
 S311 Standard pseudo-random generators are not suitable for cryptographic purposes
   --> S311.py:26:5
    |
@@ -107,6 +19,7 @@ S311 Standard pseudo-random generators are not suitable for cryptographic purpos
 27 | foo = random.randrange
    |
 
+
 S311 Standard pseudo-random generators are not suitable for cryptographic purposes
   --> S311.py:27:7
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S312_S312.py.snap

@@ -1,15 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
- --> S312.py:3:1
-  |
-1 | from telnetlib import Telnet
-2 |
-3 | Telnet("localhost", 23)
-  | ^^^^^^^^^^^^^^^^^^^^^^^
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
+--- Summary ---
+Removed: 0
+Added: 3
+
+--- Added ---
 S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
  --> S312.py:7:5
   |
@@ -19,6 +19,7 @@ S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
 8 | foo = Telnet
   |
 
+
 S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
   --> S312.py:8:7
    |
@@ -30,6 +31,7 @@ S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
 10 | import telnetlib
    |
 
+
 S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
   --> S312.py:11:5
    |
@@ -39,13 +41,3 @@ S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
 12 |
 13 | from typing import Annotated
    |
-
-S312 Telnet is considered insecure. Use SSH or some other encrypted protocol.
-  --> S312.py:14:24
-   |
-13 | from typing import Annotated
-14 | foo: Annotated[Telnet, telnetlib.Telnet()]
-   |                        ^^^^^^^^^^^^^^^^^^
-15 |
-16 | def _() -> Telnet: ...
-   |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S508_S508.py.snap

@@ -1,26 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
- --> S508.py:3:25
-  |
-1 | from pysnmp.hlapi import CommunityData
-2 |
-3 | CommunityData("public", mpModel=0)  # S508
-  |                         ^^^^^^^^^
-4 | CommunityData("public", mpModel=1)  # S508
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
- --> S508.py:4:25
-  |
-3 | CommunityData("public", mpModel=0)  # S508
-4 | CommunityData("public", mpModel=1)  # S508
-  |                         ^^^^^^^^^
-5 |
-6 | CommunityData("public", mpModel=2)  # OK
-  |
+--- Summary ---
+Removed: 0
+Added: 8
 
+--- Added ---
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:18:46
    |
@@ -32,6 +21,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 20 | pysnmp.hlapi.v1arch.asyncio.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:19:58
    |
@@ -42,6 +32,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 21 | pysnmp.hlapi.v1arch.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:20:53
    |
@@ -53,6 +44,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 22 | pysnmp.hlapi.v3arch.asyncio.auth.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:21:45
    |
@@ -64,6 +56,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 23 | pysnmp.hlapi.v3arch.asyncio.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:22:58
    |
@@ -75,6 +68,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 24 | pysnmp.hlapi.v3arch.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:23:53
    |
@@ -86,6 +80,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 25 | pysnmp.hlapi.auth.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:24:45
    |
@@ -96,6 +91,7 @@ S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
 25 | pysnmp.hlapi.auth.CommunityData("public", mpModel=0)  # S508
    |
 
+
 S508 The use of SNMPv1 and SNMPv2 is insecure. Use SNMPv3 if able.
   --> S508.py:25:43
    |

crates/ruff_linter/src/rules/flake8_bandit/snapshots/ruff_linter__rules__flake8_bandit__tests__preview__S509_S509.py.snap

@@ -1,24 +1,15 @@
 ---
 source: crates/ruff_linter/src/rules/flake8_bandit/mod.rs
 ---
-S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
- --> S509.py:4:12
-  |
-4 | insecure = UsmUserData("securityName")  # S509
-  |            ^^^^^^^^^^^
-5 | auth_no_priv = UsmUserData("securityName", "authName")  # S509
-  |
+--- Linter settings ---
+-linter.preview = disabled
++linter.preview = enabled
 
-S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
- --> S509.py:5:16
-  |
-4 | insecure = UsmUserData("securityName")  # S509
-5 | auth_no_priv = UsmUserData("securityName", "authName")  # S509
-  |                ^^^^^^^^^^^
-6 |
-7 | less_insecure = UsmUserData("securityName", "authName", "privName")  # OK
-  |
+--- Summary ---
+Removed: 0
+Added: 4
 
+--- Added ---
 S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
   --> S509.py:15:1
    |
@@ -30,6 +21,7 @@ S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv`
 17 | pysnmp.hlapi.v3arch.asyncio.auth.UsmUserData("user")  # S509
    |
 
+
 S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
   --> S509.py:16:1
    |
@@ -40,6 +32,7 @@ S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv`
 18 | pysnmp.hlapi.auth.UsmUserData("user")  # S509
    |
 
+
 S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
   --> S509.py:17:1
    |
@@ -50,6 +43,7 @@ S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv`
 18 | pysnmp.hlapi.auth.UsmUserData("user")  # S509
    |
 
+
 S509 You should not use SNMPv3 without encryption. `noAuthNoPriv` & `authNoPriv` is insecure.
   --> S509.py:18:1
    |

crates/ruff_linter/src/rules/flake8_pie/rules/unnecessary_placeholder.rs

@@ -1,8 +1,6 @@
 use ruff_macros::{ViolationMetadata, derive_message_formats};
-use ruff_python_ast::helpers::map_subscript;
 use ruff_python_ast::whitespace::trailing_comment_start_offset;
 use ruff_python_ast::{Expr, ExprStringLiteral, Stmt, StmtExpr};
-use ruff_python_semantic::{ScopeKind, SemanticModel};
 use ruff_text_size::Ranged;
 
 use crate::checkers::ast::Checker;
@@ -101,7 +99,7 @@ pub(crate) fn unnecessary_placeholder(checker: &Checker, body: &[Stmt]) {
                 // Ellipses are significant in protocol methods and abstract methods.
                 // Specifically, Pyright uses the presence of an ellipsis to indicate that
                 // a method is a stub, rather than a default implementation.
-                if in_protocol_or_abstract_method(checker.semantic()) {
+                if checker.semantic().in_protocol_or_abstract_method() {
                     return;
                 }
                 Placeholder::Ellipsis
@@ -163,21 +161,3 @@ impl std::fmt::Display for Placeholder {
         }
     }
 }
-
-/// Return `true` if the [`SemanticModel`] is in a `typing.Protocol` subclass or an abstract
-/// method.
-fn in_protocol_or_abstract_method(semantic: &SemanticModel) -> bool {
-    semantic.current_scopes().any(|scope| match scope.kind {
-        ScopeKind::Class(class_def) => class_def
-            .bases()
-            .iter()
-            .any(|base| semantic.match_typing_expr(map_subscript(base), "Protocol")),
-        ScopeKind::Function(function_def) => {
-            ruff_python_semantic::analyze::visibility::is_abstract(
-                &function_def.decorator_list,
-                semantic,
-            )
-        }
-        _ => false,
-    })
-}

crates/ruff_linter/src/rules/ruff/mod.rs

@@ -115,6 +115,7 @@ mod tests {
     #[test_case(Rule::NonOctalPermissions, Path::new("RUF064.py"))]
     #[test_case(Rule::LoggingEagerConversion, Path::new("RUF065_0.py"))]
     #[test_case(Rule::LoggingEagerConversion, Path::new("RUF065_1.py"))]
+    #[test_case(Rule::PropertyWithoutReturn, Path::new("RUF066.py"))]
     #[test_case(Rule::RedirectedNOQA, Path::new("RUF101_0.py"))]
     #[test_case(Rule::RedirectedNOQA, Path::new("RUF101_1.py"))]
     #[test_case(Rule::InvalidRuleCode, Path::new("RUF102.py"))]

crates/ruff_linter/src/rules/ruff/rules/mod.rs

@@ -35,6 +35,7 @@ pub(crate) use non_octal_permissions::*;
 pub(crate) use none_not_at_end_of_union::*;
 pub(crate) use parenthesize_chained_operators::*;
 pub(crate) use post_init_default::*;
+pub(crate) use property_without_return::*;
 pub(crate) use pytest_raises_ambiguous_pattern::*;
 pub(crate) use quadratic_list_summation::*;
 pub(crate) use redirected_noqa::*;
@@ -99,6 +100,7 @@ mod non_octal_permissions;
 mod none_not_at_end_of_union;
 mod parenthesize_chained_operators;
 mod post_init_default;
+mod property_without_return;
 mod pytest_raises_ambiguous_pattern;
 mod quadratic_list_summation;
 mod redirected_noqa;

crates/ruff_linter/src/rules/ruff/rules/property_without_return.rs

@@ -0,0 +1,119 @@
+use ruff_macros::{ViolationMetadata, derive_message_formats};
+use ruff_python_ast::identifier::Identifier;
+use ruff_python_ast::visitor::{Visitor, walk_expr, walk_stmt};
+use ruff_python_ast::{Expr, Stmt, StmtFunctionDef};
+use ruff_python_semantic::analyze::{function_type, visibility};
+
+use crate::checkers::ast::Checker;
+use crate::{FixAvailability, Violation};
+
+/// ## What it does
+/// Detects class `@property` methods that does not have a `return` statement.
+///
+/// ## Why is this bad?
+/// Property methods are expected to return a computed value, a missing return in a property usually indicates an implementation mistake.
+///
+/// ## Example
+/// ```python
+/// class User:
+///     @property
+///     def full_name(self):
+///         f"{self.first_name} {self.last_name}"
+/// ```
+///
+/// Use instead:
+/// ```python
+/// class User:
+///     @property
+///     def full_name(self):
+///         return f"{self.first_name} {self.last_name}"
+/// ```
+///
+/// ## References
+/// - [Python documentation: The property class](https://docs.python.org/3/library/functions.html#property)
+#[derive(ViolationMetadata)]
+#[violation_metadata(preview_since = "0.14.7")]
+pub(crate) struct PropertyWithoutReturn {
+    name: String,
+}
+
+impl Violation for PropertyWithoutReturn {
+    const FIX_AVAILABILITY: FixAvailability = FixAvailability::None;
+
+    #[derive_message_formats]
+    fn message(&self) -> String {
+        let Self { name } = self;
+        format!("`{name}` is a property without a `return` statement")
+    }
+}
+
+/// RUF066
+pub(crate) fn property_without_return(checker: &Checker, function_def: &StmtFunctionDef) {
+    let semantic = checker.semantic();
+
+    if checker.source_type.is_stub() || semantic.in_protocol_or_abstract_method() {
+        return;
+    }
+
+    let StmtFunctionDef {
+        decorator_list,
+        body,
+        name,
+        ..
+    } = function_def;
+
+    if !visibility::is_property(decorator_list, [], semantic)
+        || visibility::is_overload(decorator_list, semantic)
+        || function_type::is_stub(function_def, semantic)
+    {
+        return;
+    }
+
+    let mut visitor = PropertyVisitor::default();
+    visitor.visit_body(body);
+    if visitor.found {
+        return;
+    }
+
+    checker.report_diagnostic(
+        PropertyWithoutReturn {
+            name: name.to_string(),
+        },
+        function_def.identifier(),
+    );
+}
+
+#[derive(Default)]
+struct PropertyVisitor {
+    found: bool,
+}
+
+// NOTE: We are actually searching for the presence of
+// `yield`/`yield from`/`raise`/`return` statement/expression,
+// as having one of those indicates that there's likely no implementation mistake
+impl Visitor<'_> for PropertyVisitor {
+    fn visit_expr(&mut self, expr: &Expr) {
+        if self.found {
+            return;
+        }
+
+        match expr {
+            Expr::Yield(_) | Expr::YieldFrom(_) => self.found = true,
+            _ => walk_expr(self, expr),
+        }
+    }
+
+    fn visit_stmt(&mut self, stmt: &Stmt) {
+        if self.found {
+            return;
+        }
+
+        match stmt {
+            Stmt::Return(_) | Stmt::Raise(_) => self.found = true,
+            Stmt::FunctionDef(_) => {
+                // Do not recurse into nested functions; they're evaluated separately.
+            }
+            _ => walk_stmt(self, stmt),
+        }
+    }
+}

crates/ruff_linter/src/rules/ruff/snapshots/ruff_linter__rules__ruff__tests__RUF066_RUF066.py.snap

@@ -0,0 +1,31 @@
+---
+source: crates/ruff_linter/src/rules/ruff/mod.rs
+---
+RUF066 `name` is a property without a `return` statement
+ --> RUF066.py:7:9
+  |
+5 | class User:  # Test normal class properties
+6 |     @property
+7 |     def name(self):  # ERROR: No return
+  |         ^^^^
+8 |         f"{self.first_name} {self.last_name}"
+  |
+
+RUF066 `nested` is a property without a `return` statement
+  --> RUF066.py:18:9
+   |
+17 |     @property
+18 |     def nested(self):  # ERROR: Property itself doesn't return
+   |         ^^^^^^
+19 |         def inner():
+20 |             return 0
+   |
+
+RUF066 `prop2` is a property without a `return` statement
+  --> RUF066.py:43:9
+   |
+42 |     @property
+43 |     def prop2(self):  # ERROR: Not returning something (even when we are inside an ABC)
+   |         ^^^^^
+44 |         50
+   |

crates/ruff_python_ast/src/nodes.rs

@@ -773,10 +773,14 @@ pub trait StringFlags: Copy {
     }
 
     /// The total length of the string's closer.
-    /// This is always equal to `self.quote_len()`,
-    /// but is provided here for symmetry with the `opener_len()` method.
+    /// This is always equal to `self.quote_len()`, except when the string is unclosed,
+    /// in which case the length is zero.
     fn closer_len(self) -> TextSize {
-        self.quote_len()
+        if self.is_unclosed() {
+            TextSize::default()
+        } else {
+            self.quote_len()
+        }
     }
 
     fn as_any_string_flags(self) -> AnyStringFlags {

crates/ruff_python_parser/resources/inline/err/ipython_help_escape_command_error_recovery_1.py

@@ -0,0 +1,3 @@
+# parse_options: {"mode": "ipython"}
+with (a, ?b)
+?

crates/ruff_python_parser/resources/inline/err/ipython_help_escape_command_error_recovery_2.py

@@ -0,0 +1,3 @@
+# parse_options: {"mode": "ipython"}
+with (a, ?b
+?

crates/ruff_python_parser/resources/inline/err/ipython_help_escape_command_error_recovery_3.py

@@ -0,0 +1,4 @@
+# parse_options: {"mode": "ipython"}
+with a, ?b
+?
+x = 1

crates/ruff_python_parser/src/parser/mod.rs

@@ -1115,7 +1115,27 @@ impl RecoveryContextKind {
                     TokenKind::Colon => Some(ListTerminatorKind::ErrorRecovery),
                     _ => None,
                 },
-                WithItemKind::Unparenthesized | WithItemKind::ParenthesizedExpression => p
+                // test_err ipython_help_escape_command_error_recovery_1
+                // # parse_options: {"mode": "ipython"}
+                // with (a, ?b)
+                // ?
+
+                // test_err ipython_help_escape_command_error_recovery_2
+                // # parse_options: {"mode": "ipython"}
+                // with (a, ?b
+                // ?
+
+                // test_err ipython_help_escape_command_error_recovery_3
+                // # parse_options: {"mode": "ipython"}
+                // with a, ?b
+                // ?
+                // x = 1
+                WithItemKind::Unparenthesized => matches!(
+                    p.current_token_kind(),
+                    TokenKind::Colon | TokenKind::Newline
+                )
+                .then_some(ListTerminatorKind::Regular),
+                WithItemKind::ParenthesizedExpression => p
                     .at(TokenKind::Colon)
                     .then_some(ListTerminatorKind::Regular),
             },

crates/ruff_python_parser/tests/snapshots/invalid_syntax@ipython_help_escape_command_error_recovery_1.py.snap

@@ -0,0 +1,84 @@
+---
+source: crates/ruff_python_parser/tests/fixtures.rs
+input_file: crates/ruff_python_parser/resources/inline/err/ipython_help_escape_command_error_recovery_1.py
+---
+## AST
+
+```
+Module(
+    ModModule {
+        node_index: NodeIndex(None),
+        range: 0..52,
+        body: [
+            With(
+                StmtWith {
+                    node_index: NodeIndex(None),
+                    range: 37..49,
+                    is_async: false,
+                    items: [
+                        WithItem {
+                            range: 43..44,
+                            node_index: NodeIndex(None),
+                            context_expr: Name(
+                                ExprName {
+                                    node_index: NodeIndex(None),
+                                    range: 43..44,
+                                    id: Name("a"),
+                                    ctx: Load,
+                                },
+                            ),
+                            optional_vars: None,
+                        },
+                        WithItem {
+                            range: 47..48,
+                            node_index: NodeIndex(None),
+                            context_expr: Name(
+                                ExprName {
+                                    node_index: NodeIndex(None),
+                                    range: 47..48,
+                                    id: Name("b"),
+                                    ctx: Load,
+                                },
+                            ),
+                            optional_vars: None,
+                        },
+                    ],
+                    body: [],
+                },
+            ),
+            IpyEscapeCommand(
+                StmtIpyEscapeCommand {
+                    node_index: NodeIndex(None),
+                    range: 50..51,
+                    kind: Help,
+                    value: "",
+                },
+            ),
+        ],
+    },
+)
+```
+## Errors
+
+  |
+1 | # parse_options: {"mode": "ipython"}
+2 | with (a, ?b)
+  |          ^ Syntax Error: Expected `,`, found `?`
+3 | ?
+  |
+
+
+  |
+1 | # parse_options: {"mode": "ipython"}
+2 | with (a, ?b)
+  |             ^ Syntax Error: Expected `:`, found newline
+3 | ?
+  |
+
+
+  |
+1 | # parse_options: {"mode": "ipython"}
+2 | with (a, ?b)
+3 | ?
+  | ^ Syntax Error: Expected an indented block after `with` statement
+  |

crates/ruff_python_parser/tests/snapshots/invalid_syntax@ipython_help_escape_command_error_recovery_2.py.snap

@@ -0,0 +1,80 @@
+---
+source: crates/ruff_python_parser/tests/fixtures.rs
+input_file: crates/ruff_python_parser/resources/inline/err/ipython_help_escape_command_error_recovery_2.py
+---
+## AST
+
+```
+Module(
+    ModModule {
+        node_index: NodeIndex(None),
+        range: 0..51,
+        body: [
+            With(
+                StmtWith {
+                    node_index: NodeIndex(None),
+                    range: 37..51,
+                    is_async: false,
+                    items: [
+                        WithItem {
+                            range: 42..51,
+                            node_index: NodeIndex(None),
+                            context_expr: Tuple(
+                                ExprTuple {
+                                    node_index: NodeIndex(None),
+                                    range: 42..51,
+                                    elts: [
+                                        Name(
+                                            ExprName {
+                                                node_index: NodeIndex(None),
+                                                range: 43..44,
+                                                id: Name("a"),
+                                                ctx: Load,
+                                            },
+                                        ),
+                                        Name(
+                                            ExprName {
+                                                node_index: NodeIndex(None),
+                                                range: 47..48,
+                                                id: Name("b"),
+                                                ctx: Load,
+                                            },
+                                        ),
+                                    ],
+                                    ctx: Load,
+                                    parenthesized: true,
+                                },
+                            ),
+                            optional_vars: None,
+                        },
+                    ],
+                    body: [],
+                },
+            ),
+        ],
+    },
+)
+```
+## Errors
+
+  |
+1 | # parse_options: {"mode": "ipython"}
+2 | with (a, ?b
+  |          ^ Syntax Error: Expected an expression or a ')'
+3 | ?
+  |
+
+
+  |
+1 | # parse_options: {"mode": "ipython"}
+2 | with (a, ?b
+3 | ?
+  | ^ Syntax Error: Expected `,`, found `?`
+  |
+
+
+  |
+2 | with (a, ?b
+3 | ?
+  |  ^ Syntax Error: unexpected EOF while parsing
+  |

crates/ruff_python_parser/tests/snapshots/invalid_syntax@ipython_help_escape_command_error_recovery_3.py.snap

@@ -0,0 +1,112 @@
+---
+source: crates/ruff_python_parser/tests/fixtures.rs
+input_file: crates/ruff_python_parser/resources/inline/err/ipython_help_escape_command_error_recovery_3.py
+---
+## AST
+
+```
+Module(
+    ModModule {
+        node_index: NodeIndex(None),
+        range: 0..56,
+        body: [
+            With(
+                StmtWith {
+                    node_index: NodeIndex(None),
+                    range: 37..47,
+                    is_async: false,
+                    items: [
+                        WithItem {
+                            range: 42..43,
+                            node_index: NodeIndex(None),
+                            context_expr: Name(
+                                ExprName {
+                                    node_index: NodeIndex(None),
+                                    range: 42..43,
+                                    id: Name("a"),
+                                    ctx: Load,
+                                },
+                            ),
+                            optional_vars: None,
+                        },
+                        WithItem {
+                            range: 46..47,
+                            node_index: NodeIndex(None),
+                            context_expr: Name(
+                                ExprName {
+                                    node_index: NodeIndex(None),
+                                    range: 46..47,
+                                    id: Name("b"),
+                                    ctx: Load,
+                                },
+                            ),
+                            optional_vars: None,
+                        },
+                    ],
+                    body: [],
+                },
+            ),
+            IpyEscapeCommand(
+                StmtIpyEscapeCommand {
+                    node_index: NodeIndex(None),
+                    range: 48..49,
+                    kind: Help,
+                    value: "",
+                },
+            ),
+            Assign(
+                StmtAssign {
+                    node_index: NodeIndex(None),
+                    range: 50..55,
+                    targets: [
+                        Name(
+                            ExprName {
+                                node_index: NodeIndex(None),
+                                range: 50..51,
+                                id: Name("x"),
+                                ctx: Store,
+                            },
+                        ),
+                    ],
+                    value: NumberLiteral(
+                        ExprNumberLiteral {
+                            node_index: NodeIndex(None),
+                            range: 54..55,
+                            value: Int(
+                                1,
+                            ),
+                        },
+                    ),
+                },
+            ),
+        ],
+    },
+)
+```
+## Errors
+
+  |
+1 | # parse_options: {"mode": "ipython"}
+2 | with a, ?b
+  |         ^ Syntax Error: Expected `,`, found `?`
+3 | ?
+4 | x = 1
+  |
+
+
+  |
+1 | # parse_options: {"mode": "ipython"}
+2 | with a, ?b
+  |           ^ Syntax Error: Expected `:`, found newline
+3 | ?
+4 | x = 1
+  |
+
+
+  |
+1 | # parse_options: {"mode": "ipython"}
+2 | with a, ?b
+3 | ?
+  | ^ Syntax Error: Expected an indented block after `with` statement
+4 | x = 1
+  |

crates/ruff_python_semantic/src/model.rs

@@ -3,12 +3,13 @@ use std::path::Path;
 use bitflags::bitflags;
 use rustc_hash::FxHashMap;
 
-use ruff_python_ast::helpers::from_relative_import;
+use ruff_python_ast::helpers::{from_relative_import, map_subscript};
 use ruff_python_ast::name::{QualifiedName, UnqualifiedName};
 use ruff_python_ast::{self as ast, Expr, ExprContext, PySourceType, Stmt};
 use ruff_text_size::{Ranged, TextRange, TextSize};
 
 use crate::Imported;
+use crate::analyze::visibility;
 use crate::binding::{
     Binding, BindingFlags, BindingId, BindingKind, Bindings, Exceptions, FromImport, Import,
     SubmoduleImport,
@@ -2153,6 +2154,21 @@ impl<'a> SemanticModel<'a> {
             function.range() == function_def.range()
         })
     }
+
+    /// Return `true` if the model is in a `typing.Protocol` subclass or an abstract
+    /// method.
+    pub fn in_protocol_or_abstract_method(&self) -> bool {
+        self.current_scopes().any(|scope| match scope.kind {
+            ScopeKind::Class(class_def) => class_def
+                .bases()
+                .iter()
+                .any(|base| self.match_typing_expr(map_subscript(base), "Protocol")),
+            ScopeKind::Function(function_def) => {
+                visibility::is_abstract(&function_def.decorator_list, self)
+            }
+            _ => false,
+        })
+    }
 }
 
 pub struct ShadowedBinding {

crates/ty/docs/rules.md

@@ -39,7 +39,7 @@ def test(): -> "int":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20call-non-callable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L121" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L131" target="_blank">View source</a>
 </small>
 
 
@@ -63,7 +63,7 @@ Calling a non-callable object will raise a `TypeError` at runtime.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-argument-forms" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L165" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L175" target="_blank">View source</a>
 </small>
 
 
@@ -95,7 +95,7 @@ f(int)  # error
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-declarations" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L191" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L201" target="_blank">View source</a>
 </small>
 
 
@@ -126,7 +126,7 @@ a = 1
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L216" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L226" target="_blank">View source</a>
 </small>
 
 
@@ -158,7 +158,7 @@ class C(A, B): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-class-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L242" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L252" target="_blank">View source</a>
 </small>
 
 
@@ -184,13 +184,41 @@ class B(A): ...
 
 [method resolution order]: https://docs.python.org/3/glossary.html#term-method-resolution-order
 
+## `cyclic-type-alias-definition`
+
+<small>
+Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
+Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
+<a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-type-alias-definition" target="_blank">Related issues</a> ·
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L278" target="_blank">View source</a>
+</small>
+
+
+**What it does**
+
+Checks for type alias definitions that (directly or mutually) refer to themselves.
+
+**Why is it bad?**
+
+Although it is permitted to define a recursive type alias, it is not meaningful
+to have a type alias whose expansion can only result in itself, and is therefore not allowed.
+
+**Examples**
+
+```python
+type Itself = Itself
+
+type A = B
+type B = A
+```
+
 ## `duplicate-base`
 
 <small>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L307" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L339" target="_blank">View source</a>
 </small>
 
 
@@ -217,7 +245,7 @@ class B(A, A): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-kw-only" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L328" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L360" target="_blank">View source</a>
 </small>
 
 
@@ -329,7 +357,7 @@ def test(): -> "Literal[5]":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20inconsistent-mro" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L532" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L564" target="_blank">View source</a>
 </small>
 
 
@@ -359,7 +387,7 @@ class C(A, B): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20index-out-of-bounds" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L556" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L588" target="_blank">View source</a>
 </small>
 
 
@@ -385,7 +413,7 @@ t[3]  # IndexError: tuple index out of range
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20instance-layout-conflict" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L360" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L392" target="_blank">View source</a>
 </small>
 
 
@@ -474,7 +502,7 @@ an atypical memory layout.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-argument-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L610" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L642" target="_blank">View source</a>
 </small>
 
 
@@ -501,7 +529,7 @@ func("foo")  # error: [invalid-argument-type]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-assignment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L650" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L682" target="_blank">View source</a>
 </small>
 
 
@@ -529,7 +557,7 @@ a: int = ''
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-attribute-access" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1809" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1877" target="_blank">View source</a>
 </small>
 
 
@@ -563,7 +591,7 @@ C.instance_var = 3  # error: Cannot assign to instance variable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.19">0.0.1-alpha.19</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-await" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L672" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L704" target="_blank">View source</a>
 </small>
 
 
@@ -599,7 +627,7 @@ asyncio.run(main())
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L702" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L734" target="_blank">View source</a>
 </small>
 
 
@@ -623,7 +651,7 @@ class A(42): ...  # error: [invalid-base]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-context-manager" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L753" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L785" target="_blank">View source</a>
 </small>
 
 
@@ -650,7 +678,7 @@ with 1:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-declaration" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L774" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L806" target="_blank">View source</a>
 </small>
 
 
@@ -679,7 +707,7 @@ a: str
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-exception-caught" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L797" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L829" target="_blank">View source</a>
 </small>
 
 
@@ -717,13 +745,55 @@ except ZeroDivisionError:
 
  This rule corresponds to Ruff's [`except-with-non-exception-classes` (`B030`)](https://docs.astral.sh/ruff/rules/except-with-non-exception-classes)
 
+## `invalid-explicit-override`
+
+<small>
+Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
+Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.28">0.0.1-alpha.28</a> ·
+<a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-explicit-override" target="_blank">Related issues</a> ·
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1574" target="_blank">View source</a>
+</small>
+
+
+**What it does**
+
+Checks for methods that are decorated with `@override` but do not override any method in a superclass.
+
+**Why is this bad?**
+
+Decorating a method with `@override` declares to the type checker that the intention is that it should
+override a method from a superclass.
+
+**Example**
+
+
+```python
+from typing import override
+
+class A:
+    @override
+    def foo(self): ...  # Error raised here
+
+class B(A):
+    @override
+    def ffooo(self): ...  # Error raised here
+
+class C:
+    @override
+    def __repr__(self): ...  # fine: overrides `object.__repr__`
+
+class D(A):
+    @override
+    def foo(self): ...  # fine: overrides `A.foo`
+```
+
 ## `invalid-generic-class`
 
 <small>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-generic-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L833" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L865" target="_blank">View source</a>
 </small>
 
 
@@ -756,7 +826,7 @@ class C[U](Generic[T]): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.17">0.0.1-alpha.17</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L577" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L609" target="_blank">View source</a>
 </small>
 
 
@@ -795,7 +865,7 @@ carol = Person(name="Carol", age=25)  # typo!
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-legacy-type-variable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L859" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L891" target="_blank">View source</a>
 </small>
 
 
@@ -830,7 +900,7 @@ def f(t: TypeVar("U")): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L956" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L988" target="_blank">View source</a>
 </small>
 
 
@@ -858,13 +928,99 @@ class B(metaclass=f): ...
 
 - [Python documentation: Metaclasses](https://docs.python.org/3/reference/datamodel.html#metaclasses)
 
+## `invalid-method-override`
+
+<small>
+Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
+Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
+<a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-method-override" target="_blank">Related issues</a> ·
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2005" target="_blank">View source</a>
+</small>
+
+
+**What it does**
+
+Detects method overrides that violate the [Liskov Substitution Principle] ("LSP").
+
+The LSP states that an instance of a subtype should be substitutable for an instance of its supertype.
+Applied to Python, this means:
+1. All argument combinations a superclass method accepts
+   must also be accepted by an overriding subclass method.
+2. The return type of an overriding subclass method must be a subtype
+   of the return type of the superclass method.
+
+**Why is this bad?**
+
+Violating the Liskov Substitution Principle will lead to many of ty's assumptions and
+inferences being incorrect, which will mean that it will fail to catch many possible
+type errors in your code.
+
+**Example**
+
+```python
+class Super:
+    def method(self, x) -> int:
+        return 42
+
+class Sub(Super):
+    # Liskov violation: `str` is not a subtype of `int`,
+    # but the supertype method promises to return an `int`.
+    def method(self, x) -> str:  # error: [invalid-override]
+        return "foo"
+
+def accepts_super(s: Super) -> int:
+    return s.method(x=42)
+
+accepts_super(Sub())  # The result of this call is a string, but ty will infer
+                      # it to be an `int` due to the violation of the Liskov Substitution Principle.
+
+class Sub2(Super):
+    # Liskov violation: the superclass method can be called with a `x=`
+    # keyword argument, but the subclass method does not accept it.
+    def method(self, y) -> int:  # error: [invalid-override]
+       return 42
+
+accepts_super(Sub2())  # TypeError at runtime: method() got an unexpected keyword argument 'x'
+                       # ty cannot catch this error due to the violation of the Liskov Substitution Principle.
+```
+
+**Common issues**
+
+
+**Why does ty complain about my `__eq__` method?**
+
+
+`__eq__` and `__ne__` methods in Python are generally expected to accept arbitrary
+objects as their second argument, for example:
+
+```python
+class A:
+    x: int
+
+    def __eq__(self, other: object) -> bool:
+        # gracefully handle an object of an unexpected type
+        # without raising an exception
+        if not isinstance(other, A):
+            return False
+        return self.x == other.x
+```
+
+If `A.__eq__` here were annotated as only accepting `A` instances for its second argument,
+it would imply that you wouldn't be able to use `==` between instances of `A` and
+instances of unrelated classes without an exception possibly being raised. While some
+classes in Python do indeed behave this way, the strongly held convention is that it should
+be avoided wherever possible. As part of this check, therefore, ty enforces that `__eq__`
+and `__ne__` methods accept `object` as their second argument.
+
+[Liskov Substitution Principle]: https://en.wikipedia.org/wiki/Liskov_substitution_principle
+
 ## `invalid-named-tuple`
 
 <small>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.19">0.0.1-alpha.19</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-named-tuple" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L506" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L538" target="_blank">View source</a>
 </small>
 
 
@@ -896,7 +1052,7 @@ TypeError: can only inherit from a NamedTuple type and Generic
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-newtype" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L932" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L964" target="_blank">View source</a>
 </small>
 
 
@@ -926,7 +1082,7 @@ Baz = NewType("Baz", int | str)  # error: invalid base for `typing.NewType`
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L983" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1015" target="_blank">View source</a>
 </small>
 
 
@@ -976,7 +1132,7 @@ def foo(x: int) -> int: ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-parameter-default" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1082" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1114" target="_blank">View source</a>
 </small>
 
 
@@ -1002,7 +1158,7 @@ def f(a: int = ''): ...
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-paramspec" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L887" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L919" target="_blank">View source</a>
 </small>
 
 
@@ -1033,7 +1189,7 @@ P2 = ParamSpec("S2")  # error: ParamSpec name must match the variable it's assig
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-protocol" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L442" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L474" target="_blank">View source</a>
 </small>
 
 
@@ -1067,7 +1223,7 @@ TypeError: Protocols can only inherit from other protocols, got <class 'int'>
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-raise" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1102" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1134" target="_blank">View source</a>
 </small>
 
 
@@ -1116,7 +1272,7 @@ def g():
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-return-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L631" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L663" target="_blank">View source</a>
 </small>
 
 
@@ -1141,7 +1297,7 @@ def func() -> int:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-super-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1145" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1177" target="_blank">View source</a>
 </small>
 
 
@@ -1199,7 +1355,7 @@ TODO #14889
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.6">0.0.1-alpha.6</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-alias-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L911" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L943" target="_blank">View source</a>
 </small>
 
 
@@ -1226,7 +1382,7 @@ NewAlias = TypeAliasType(get_name(), int)        # error: TypeAliasType name mus
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-checking-constant" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1184" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1216" target="_blank">View source</a>
 </small>
 
 
@@ -1256,7 +1412,7 @@ TYPE_CHECKING = ''
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-form" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1208" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1240" target="_blank">View source</a>
 </small>
 
 
@@ -1286,7 +1442,7 @@ b: Annotated[int]  # `Annotated` expects at least two arguments
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1260" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1292" target="_blank">View source</a>
 </small>
 
 
@@ -1320,7 +1476,7 @@ f(10)  # Error
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1232" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1264" target="_blank">View source</a>
 </small>
 
 
@@ -1354,7 +1510,7 @@ class C:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-variable-constraints" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1288" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1320" target="_blank">View source</a>
 </small>
 
 
@@ -1389,7 +1545,7 @@ T = TypeVar('T', bound=str)  # valid bound TypeVar
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1317" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1349" target="_blank">View source</a>
 </small>
 
 
@@ -1414,7 +1570,7 @@ func()  # TypeError: func() missing 1 required positional argument: 'x'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-typed-dict-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1910" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1978" target="_blank">View source</a>
 </small>
 
 
@@ -1447,7 +1603,7 @@ alice["age"]  # KeyError
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20no-matching-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1336" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1368" target="_blank">View source</a>
 </small>
 
 
@@ -1476,7 +1632,7 @@ func("string")  # error: [no-matching-overload]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20non-subscriptable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1359" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1391" target="_blank">View source</a>
 </small>
 
 
@@ -1500,7 +1656,7 @@ Subscripting an object that does not support it will raise a `TypeError` at runt
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20not-iterable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1377" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1409" target="_blank">View source</a>
 </small>
 
 
@@ -1526,7 +1682,7 @@ for i in 34:  # TypeError: 'int' object is not iterable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20parameter-already-assigned" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1428" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1460" target="_blank">View source</a>
 </small>
 
 
@@ -1553,7 +1709,7 @@ f(1, x=2)  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20positional-only-parameter-as-kwarg" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1663" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1731" target="_blank">View source</a>
 </small>
 
 
@@ -1611,7 +1767,7 @@ def test(): -> "int":
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20static-assert-error" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1785" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1853" target="_blank">View source</a>
 </small>
 
 
@@ -1641,7 +1797,7 @@ static_assert(int(2.0 * 3.0) == 6)  # error: does not have a statically known tr
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20subclass-of-final-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1519" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1551" target="_blank">View source</a>
 </small>
 
 
@@ -1670,7 +1826,7 @@ class B(A): ...  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20too-many-positional-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1564" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1632" target="_blank">View source</a>
 </small>
 
 
@@ -1697,7 +1853,7 @@ f("foo")  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20type-assertion-failure" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1542" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1610" target="_blank">View source</a>
 </small>
 
 
@@ -1725,7 +1881,7 @@ def _(x: int):
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unavailable-implicit-super-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1585" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1653" target="_blank">View source</a>
 </small>
 
 
@@ -1771,7 +1927,7 @@ class A:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unknown-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1642" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1710" target="_blank">View source</a>
 </small>
 
 
@@ -1798,7 +1954,7 @@ f(x=1, y=2)  # Error raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1684" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1752" target="_blank">View source</a>
 </small>
 
 
@@ -1826,7 +1982,7 @@ A().foo  # AttributeError: 'A' object has no attribute 'foo'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1706" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1774" target="_blank">View source</a>
 </small>
 
 
@@ -1851,7 +2007,7 @@ import foo  # ModuleNotFoundError: No module named 'foo'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1725" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1793" target="_blank">View source</a>
 </small>
 
 
@@ -1876,7 +2032,7 @@ print(x)  # NameError: name 'x' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-bool-conversion" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1397" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1429" target="_blank">View source</a>
 </small>
 
 
@@ -1913,7 +2069,7 @@ b1 < b2 < b1  # exception raised here
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-operator" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1744" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1812" target="_blank">View source</a>
 </small>
 
 
@@ -1941,7 +2097,7 @@ A() + A()  # TypeError: unsupported operand type(s) for +: 'A' and 'A'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20zero-stepsize-in-slice" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1766" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1834" target="_blank">View source</a>
 </small>
 
 
@@ -1966,7 +2122,7 @@ l[1:10:0]  # ValueError: slice step cannot be zero
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20ambiguous-protocol-member" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L471" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L503" target="_blank">View source</a>
 </small>
 
 
@@ -2007,7 +2163,7 @@ class SubProto(BaseProto, Protocol):
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.16">0.0.1-alpha.16</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20deprecated" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L286" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L318" target="_blank">View source</a>
 </small>
 
 
@@ -2034,7 +2190,7 @@ old_func()  # emits [deprecated] diagnostic
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20ignore-comment-unknown-rule" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L40" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L47" target="_blank">View source</a>
 </small>
 
 
@@ -2065,7 +2221,7 @@ a = 20 / 0  # ty: ignore[division-by-zero]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-ignore-comment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L65" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L72" target="_blank">View source</a>
 </small>
 
 
@@ -2095,7 +2251,7 @@ a = 20 / 0  # type: ignore
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1449" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1481" target="_blank">View source</a>
 </small>
 
 
@@ -2123,7 +2279,7 @@ A.c  # AttributeError: type object 'A' has no attribute 'c'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-implicit-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L139" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L149" target="_blank">View source</a>
 </small>
 
 
@@ -2155,7 +2311,7 @@ A()[0]  # TypeError: 'A' object is not subscriptable
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1471" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1503" target="_blank">View source</a>
 </small>
 
 
@@ -2187,7 +2343,7 @@ from module import a  # ImportError: cannot import name 'a' from 'module'
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20redundant-cast" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1837" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1905" target="_blank">View source</a>
 </small>
 
 
@@ -2214,7 +2370,7 @@ cast(int, f())  # Redundant
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20undefined-reveal" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1624" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1692" target="_blank">View source</a>
 </small>
 
 
@@ -2238,7 +2394,7 @@ reveal_type(1)  # NameError: name 'reveal_type' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.15">0.0.1-alpha.15</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-global" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1858" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1926" target="_blank">View source</a>
 </small>
 
 
@@ -2296,7 +2452,7 @@ def g():
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.7">0.0.1-alpha.7</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L720" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L752" target="_blank">View source</a>
 </small>
 
 
@@ -2335,7 +2491,7 @@ class D(C): ...  # error: [unsupported-base]
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20useless-overload-body" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1026" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1058" target="_blank">View source</a>
 </small>
 
 
@@ -2398,7 +2554,7 @@ def foo(x: int | str) -> int | str:
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20division-by-zero" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L268" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L300" target="_blank">View source</a>
 </small>
 
 
@@ -2422,7 +2578,7 @@ Dividing by zero raises a `ZeroDivisionError` at runtime.
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1497" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1529" target="_blank">View source</a>
 </small>
 
 
@@ -2450,7 +2606,7 @@ print(x)  # NameError: name 'x' is not defined
 Default level: <a href="../rules.md#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unused-ignore-comment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L15" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L22" target="_blank">View source</a>
 </small>
 
 

crates/ty/src/lib.rs

@@ -313,7 +313,8 @@ impl MainLoop {
                     let terminal_settings = db.project().settings(db).terminal();
                     let display_config = DisplayDiagnosticConfig::default()
                         .format(terminal_settings.output_format.into())
-                        .color(colored::control::SHOULD_COLORIZE.should_colorize());
+                        .color(colored::control::SHOULD_COLORIZE.should_colorize())
+                        .show_fix_diff(true);
 
                     if check_revision == revision {
                         if db.project().files(db).is_empty() {

crates/ty/tests/cli/python_environment.rs

@@ -37,7 +37,8 @@ fn config_override_python_version() -> anyhow::Result<()> {
     5 | print(sys.last_exc)
       |       ^^^^^^^^^^^^
       |
-    info: Python 3.11 was assumed when accessing `last_exc`
+    info: The member may be available on other Python versions or platforms
+    info: Python 3.11 was assumed when resolving the `last_exc` attribute
      --> pyproject.toml:3:18
       |
     2 | [tool.ty.environment]
@@ -1179,6 +1180,8 @@ fn defaults_to_a_new_python_version() -> anyhow::Result<()> {
             import os
 
             os.grantpt(1) # only available on unix, Python 3.13 or newer
+
+            from typing import LiteralString  # added in Python 3.11
             "#,
         ),
     ])?;
@@ -1194,8 +1197,11 @@ fn defaults_to_a_new_python_version() -> anyhow::Result<()> {
     3 |
     4 | os.grantpt(1) # only available on unix, Python 3.13 or newer
       | ^^^^^^^^^^
+    5 |
+    6 | from typing import LiteralString  # added in Python 3.11
       |
-    info: Python 3.10 was assumed when accessing `grantpt`
+    info: The member may be available on other Python versions or platforms
+    info: Python 3.10 was assumed when resolving the `grantpt` attribute
      --> ty.toml:3:18
       |
     2 | [environment]
@@ -1205,7 +1211,26 @@ fn defaults_to_a_new_python_version() -> anyhow::Result<()> {
       |
     info: rule `unresolved-attribute` is enabled by default
 
-    Found 1 diagnostic
+    error[unresolved-import]: Module `typing` has no member `LiteralString`
+     --> main.py:6:20
+      |
+    4 | os.grantpt(1) # only available on unix, Python 3.13 or newer
+    5 |
+    6 | from typing import LiteralString  # added in Python 3.11
+      |                    ^^^^^^^^^^^^^
+      |
+    info: The member may be available on other Python versions or platforms
+    info: Python 3.10 was assumed when resolving imports
+     --> ty.toml:3:18
+      |
+    2 | [environment]
+    3 | python-version = "3.10"
+      |                  ^^^^^^ Python 3.10 assumed due to this configuration setting
+    4 | python-platform = "linux"
+      |
+    info: rule `unresolved-import` is enabled by default
+
+    Found 2 diagnostics
 
     ----- stderr -----
     "#);
@@ -1225,6 +1250,8 @@ fn defaults_to_a_new_python_version() -> anyhow::Result<()> {
             import os
 
             os.grantpt(1) # only available on unix, Python 3.13 or newer
+
+            from typing import LiteralString  # added in Python 3.11
             "#,
         ),
     ])?;

crates/ty_completion_eval/completion-evaluation-tasks.csv

@@ -18,11 +18,11 @@ numpy-array,main.py,1,1
 object-attr-instance-methods,main.py,0,1
 object-attr-instance-methods,main.py,1,1
 pass-keyword-completion,main.py,0,1
-raise-uses-base-exception,main.py,0,2
+raise-uses-base-exception,main.py,0,1
 scope-existing-over-new-import,main.py,0,1
 scope-prioritize-closer,main.py,0,2
 scope-simple-long-identifier,main.py,0,1
 tstring-completions,main.py,0,1
 ty-extensions-lower-stdlib,main.py,0,8
 type-var-typing-over-ast,main.py,0,3
-type-var-typing-over-ast,main.py,1,279
+type-var-typing-over-ast,main.py,1,278

crates/ty_ide/src/completion.rs

@@ -9,9 +9,10 @@ use ruff_python_ast::name::Name;
 use ruff_python_codegen::Stylist;
 use ruff_python_parser::{Token, TokenAt, TokenKind, Tokens};
 use ruff_text_size::{Ranged, TextLen, TextRange, TextSize};
+use ty_python_semantic::types::UnionType;
 use ty_python_semantic::{
-    Completion as SemanticCompletion, ModuleName, NameKind, SemanticModel,
-    types::{CycleDetector, Type},
+    Completion as SemanticCompletion, KnownModule, ModuleName, NameKind, SemanticModel,
+    types::{CycleDetector, KnownClass, Type},
 };
 
 use crate::docstring::Docstring;
@@ -82,6 +83,31 @@ impl<'db> Completions<'db> {
     fn force_add(&mut self, completion: Completion<'db>) {
         self.items.push(completion);
     }
+
+    /// Tags completions with whether they are known to be usable in
+    /// a `raise` context.
+    ///
+    /// It's possible that some completions are usable in a `raise`
+    /// but aren't marked by this method. That is, false negatives are
+    /// possible but false positives are not.
+    fn tag_raisable(&mut self) {
+        let raisable_type = UnionType::from_elements(
+            self.db,
+            [
+                KnownClass::BaseException.to_subclass_of(self.db),
+                KnownClass::BaseException.to_instance(self.db),
+            ],
+        );
+        for item in &mut self.items {
+            let Some(ty) = item.ty else { continue };
+            item.is_definitively_raisable = ty.is_assignable_to(self.db, raisable_type);
+        }
+    }
+
+    /// Removes any completion that doesn't satisfy the given predicate.
+    fn retain(&mut self, predicate: impl FnMut(&Completion<'_>) -> bool) {
+        self.items.retain(predicate);
+    }
 }
 
 impl<'db> Extend<SemanticCompletion<'db>> for Completions<'db> {
@@ -153,6 +179,13 @@ pub struct Completion<'db> {
     /// Whether this item only exists for type checking purposes and
     /// will be missing at runtime
     pub is_type_check_only: bool,
+    /// Whether this item can definitively be used in a `raise` context.
+    ///
+    /// Note that this may not always be computed. (i.e., Only computed
+    /// when we are in a `raise` context.) And also note that if this
+    /// is `true`, then it's definitively usable in `raise`, but if
+    /// it's `false`, it _may_ still be usable in `raise`.
+    pub is_definitively_raisable: bool,
     /// The documentation associated with this item, if
     /// available.
     pub documentation: Option<Docstring>,
@@ -177,6 +210,7 @@ impl<'db> Completion<'db> {
             import: None,
             builtin: semantic.builtin,
             is_type_check_only,
+            is_definitively_raisable: false,
             documentation,
         }
     }
@@ -257,6 +291,7 @@ impl<'db> Completion<'db> {
             import: None,
             builtin: false,
             is_type_check_only: false,
+            is_definitively_raisable: false,
             documentation: None,
         }
     }
@@ -271,6 +306,7 @@ impl<'db> Completion<'db> {
             import: None,
             builtin: true,
             is_type_check_only: false,
+            is_definitively_raisable: false,
             documentation: None,
         }
     }
@@ -364,6 +400,20 @@ pub fn completion<'db>(
         }
     }
 
+    if is_raising_exception(tokens) {
+        completions.tag_raisable();
+
+        // As a special case, and because it's a common footgun, we
+        // specifically disallow `NotImplemented` in this context.
+        // `NotImplementedError` should be used instead. So if we can
+        // definitively detect `NotImplemented`, then we can safely
+        // omit it from suggestions.
+        completions.retain(|item| {
+            let Some(ty) = item.ty else { return true };
+            !ty.is_notimplemented(db)
+        });
+    }
+
     completions.into_completions()
 }
 
@@ -427,7 +477,8 @@ fn add_unimported_completions<'db>(
     let members = importer.members_in_scope_at(scoped.node, scoped.node.start());
 
     for symbol in all_symbols(db, &completions.query) {
-        if symbol.module.file(db) == Some(file) {
+        if symbol.module.file(db) == Some(file) || symbol.module.is_known(db, KnownModule::Builtins)
+        {
             continue;
         }
 
@@ -450,6 +501,7 @@ fn add_unimported_completions<'db>(
             builtin: false,
             // TODO: `is_type_check_only` requires inferring the type of the symbol
             is_type_check_only: false,
+            is_definitively_raisable: false,
             documentation: None,
         });
     }
@@ -1263,7 +1315,8 @@ fn find_typed_text(
     if last.end() < offset || last.range().is_empty() {
         return None;
     }
-    Some(source[last.range()].to_string())
+    let range = TextRange::new(last.start(), offset);
+    Some(source[range].to_string())
 }
 
 /// Whether the last token is in a place where we should not provide completions.
@@ -1354,10 +1407,52 @@ fn is_in_variable_binding(parsed: &ParsedModuleRef, offset: TextSize, typed: Opt
             type_param.name.range.contains_range(range)
         }
         ast::AnyNodeRef::StmtFor(stmt_for) => stmt_for.target.range().contains_range(range),
+        // The AST does not produce `ast::AnyNodeRef::Parameter` nodes for keywords
+        // or otherwise invalid syntax. Rather they are captured in a
+        // `ast::AnyNodeRef::Parameters` node as "empty space". To ensure
+        // we still suppress suggestions even when the syntax is technically
+        // invalid we extract the token under the cursor and check if it makes
+        // up that "empty space" inside the Parameters Node. If it does, we know
+        // that we are still binding variables, just that the current state is
+        // syntatically invalid. Hence we suppress autocomplete suggestons
+        // also in those cases.
+        ast::AnyNodeRef::Parameters(params) => {
+            if !params.range.contains_range(range) {
+                return false;
+            }
+            params
+                .iter()
+                .map(|param| param.range())
+                .all(|r| !r.contains_range(range))
+        }
         _ => false,
     })
 }
 
+/// Returns true when the cursor is after a `raise` keyword.
+fn is_raising_exception(tokens: &[Token]) -> bool {
+    /// The maximum number of tokens we're willing to
+    /// look-behind to find a `raise` keyword.
+    const LIMIT: usize = 10;
+
+    // This only looks for things like `raise foo.bar.baz.qu<CURSOR>`.
+    // Technically, any kind of expression is allowed after `raise`.
+    // But we may not always want to treat it specially. So we're
+    // rather conservative about what we consider "raising an
+    // exception" to be for the purposes of completions. The failure
+    // mode here is that we may wind up suggesting things that
+    // shouldn't be raised. The benefit is that when this heuristic
+    // does work, we won't suggest things that shouldn't be raised.
+    for token in tokens.iter().rev().take(LIMIT) {
+        match token.kind() {
+            TokenKind::Name | TokenKind::Dot => continue,
+            TokenKind::Raise => return true,
+            _ => return false,
+        }
+    }
+    false
+}
+
 /// Order completions according to the following rules:
 ///
 /// 1) Names with no underscore prefix
@@ -1370,8 +1465,16 @@ fn is_in_variable_binding(parsed: &ParsedModuleRef, offset: TextSize, typed: Opt
 /// This has the effect of putting all dunder attributes after "normal"
 /// attributes, and all single-underscore attributes after dunder attributes.
 fn compare_suggestions(c1: &Completion, c2: &Completion) -> Ordering {
-    fn key<'a>(completion: &'a Completion) -> (bool, bool, bool, NameKind, bool, &'a Name) {
+    fn key<'a>(completion: &'a Completion) -> (bool, bool, bool, bool, NameKind, bool, &'a Name) {
         (
+            // This is only true when we are both in a `raise` context
+            // *and* we know this suggestion is definitively usable
+            // in a `raise` context. So we should sort these before
+            // anything else.
+            !completion.is_definitively_raisable,
+            // When `None`, a completion is for something in the
+            // current module, which we should generally prefer over
+            // something from outside the module.
             completion.module_name.is_some(),
             // At time of writing (2025-11-11), keyword completions
             // are classified as builtins, which makes them sort after
@@ -1549,6 +1652,21 @@ mod tests {
         );
     }
 
+    #[test]
+    fn inside_token() {
+        let test = completion_test_builder(
+            "\
+foo_bar_baz = 1
+x = foo<CURSOR>bad
+",
+        );
+
+        assert_snapshot!(
+            test.skip_builtins().build().snapshot(),
+            @"foo_bar_baz",
+        );
+    }
+
     #[test]
     fn type_keyword_dedup() {
         let test = completion_test_builder(
@@ -5263,6 +5381,45 @@ def foo(p<CURSOR>
         );
     }
 
+    #[test]
+    fn no_completions_in_function_param_keyword() {
+        let builder = completion_test_builder(
+            "\
+def foo(in<CURSOR>
+",
+        );
+        assert_snapshot!(
+            builder.build().snapshot(),
+            @"<No completions found>",
+        );
+    }
+
+    #[test]
+    fn no_completions_in_function_param_multi_keyword() {
+        let builder = completion_test_builder(
+            "\
+def foo(param, in<CURSOR>
+",
+        );
+        assert_snapshot!(
+            builder.build().snapshot(),
+            @"<No completions found>",
+        );
+    }
+
+    #[test]
+    fn no_completions_in_function_param_multi_keyword_middle() {
+        let builder = completion_test_builder(
+            "\
+def foo(param, in<CURSOR>, param_two
+",
+        );
+        assert_snapshot!(
+            builder.build().snapshot(),
+            @"<No completions found>",
+        );
+    }
+
     #[test]
     fn no_completions_in_function_type_param() {
         let builder = completion_test_builder(

crates/ty_ide/src/doc_highlights.rs

@@ -3,6 +3,7 @@ use crate::references::{ReferencesMode, references};
 use crate::{Db, ReferenceTarget};
 use ruff_db::files::File;
 use ruff_text_size::TextSize;
+use ty_python_semantic::SemanticModel;
 
 /// Find all document highlights for a symbol at the given position.
 /// Document highlights are limited to the current file only.
@@ -13,9 +14,10 @@ pub fn document_highlights(
 ) -> Option<Vec<ReferenceTarget>> {
     let parsed = ruff_db::parsed::parsed_module(db, file);
     let module = parsed.load(db);
+    let model = SemanticModel::new(db, file);
 
     // Get the definitions for the symbol at the cursor position
-    let goto_target = find_goto_target(&module, offset)?;
+    let goto_target = find_goto_target(&model, &module, offset)?;
 
     // Use DocumentHighlights mode which limits search to current file only
     references(db, file, &goto_target, ReferencesMode::DocumentHighlights)

crates/ty_ide/src/goto.rs

@@ -61,6 +61,7 @@ pub(crate) enum GotoTarget<'a> {
     /// ```
     ImportModuleComponent {
         module_name: String,
+        level: u32,
         component_index: usize,
         component_range: TextRange,
     },
@@ -189,6 +190,24 @@ pub(crate) enum GotoTarget<'a> {
         /// The call of the callable
         call: &'a ast::ExprCall,
     },
+
+    /// Go to on a sub-expression of a string annotation's sub-AST
+    ///
+    /// ```py
+    /// x: "int | None"
+    ///           ^^^^
+    /// ```
+    ///
+    /// This is equivalent to `GotoTarget::Expression` but the expression
+    /// isn't actually in the AST.
+    StringAnnotationSubexpr {
+        /// The string literal that is a string annotation.
+        string_expr: &'a ast::ExprStringLiteral,
+        /// The range to query in the sub-AST for the sub-expression.
+        subrange: TextRange,
+        /// If the expression is a Name of some kind this is the name (just a cached result).
+        name: Option<String>,
+    },
 }
 
 /// The resolved definitions for a `GotoTarget`
@@ -226,7 +245,7 @@ impl<'db> DefinitionsOrTargets<'db> {
     /// In this case it basically returns exactly what was found.
     pub(crate) fn declaration_targets(
         self,
-        db: &'db dyn crate::Db,
+        db: &'db dyn ty_python_semantic::Db,
     ) -> Option<crate::NavigationTargets> {
         match self {
             DefinitionsOrTargets::Definitions(definitions) => {
@@ -242,7 +261,7 @@ impl<'db> DefinitionsOrTargets<'db> {
     /// if the definition we have is found in a stub file.
     pub(crate) fn definition_targets(
         self,
-        db: &'db dyn crate::Db,
+        db: &'db dyn ty_python_semantic::Db,
     ) -> Option<crate::NavigationTargets> {
         match self {
             DefinitionsOrTargets::Definitions(definitions) => {
@@ -302,26 +321,51 @@ impl GotoTarget<'_> {
             // (i.e. the type of `MyClass` in `MyClass()` is `<class MyClass>` and not `() -> MyClass`)
             GotoTarget::Call { callable, .. } => callable.inferred_type(model),
             GotoTarget::TypeParamTypeVarName(typevar) => typevar.inferred_type(model),
+            GotoTarget::ImportModuleComponent {
+                module_name,
+                component_index,
+                level,
+                ..
+            } => {
+                // We don't currently support hovering the bare `.` so there is always a name
+                let module = import_name(module_name, *component_index);
+                model.resolve_module_type(Some(module), *level)?
+            }
+            GotoTarget::StringAnnotationSubexpr {
+                string_expr,
+                subrange,
+                ..
+            } => {
+                let (subast, _submodel) = model.enter_string_annotation(string_expr)?;
+                let submod = subast.syntax();
+                let subnode = covering_node(submod.into(), *subrange).node();
+
+                // The type checker knows the type of the full annotation but nothing else
+                if AnyNodeRef::from(&*submod.body) == subnode {
+                    string_expr.inferred_type(model)
+                } else {
+                    // TODO: force the typechecker to tell us its secrets
+                    // (it computes but then immediately discards these types)
+                    return None;
+                }
+            }
+            GotoTarget::BinOp { expression, .. } => {
+                let (_, ty) = ty_python_semantic::definitions_for_bin_op(model, expression)?;
+                ty
+            }
+            GotoTarget::UnaryOp { expression, .. } => {
+                let (_, ty) = ty_python_semantic::definitions_for_unary_op(model, expression)?;
+                ty
+            }
             // TODO: Support identifier targets
             GotoTarget::PatternMatchRest(_)
             | GotoTarget::PatternKeywordArgument(_)
             | GotoTarget::PatternMatchStarName(_)
             | GotoTarget::PatternMatchAsName(_)
-            | GotoTarget::ImportModuleComponent { .. }
             | GotoTarget::TypeParamParamSpecName(_)
             | GotoTarget::TypeParamTypeVarTupleName(_)
             | GotoTarget::NonLocal { .. }
             | GotoTarget::Globals { .. } => return None,
-            GotoTarget::BinOp { expression, .. } => {
-                let (_, ty) =
-                    ty_python_semantic::definitions_for_bin_op(model.db(), model, expression)?;
-                ty
-            }
-            GotoTarget::UnaryOp { expression, .. } => {
-                let (_, ty) =
-                    ty_python_semantic::definitions_for_unary_op(model.db(), model, expression)?;
-                ty
-            }
         };
 
         Some(ty)
@@ -333,7 +377,7 @@ impl GotoTarget<'_> {
         model: &SemanticModel,
     ) -> Option<String> {
         if let GotoTarget::Call { call, .. } = self {
-            call_type_simplified_by_overloads(model.db(), model, call)
+            call_type_simplified_by_overloads(model, call)
         } else {
             None
         }
@@ -353,37 +397,25 @@ impl GotoTarget<'_> {
     /// as just returning a raw `NavigationTarget`.
     pub(crate) fn get_definition_targets<'db>(
         &self,
-        file: ruff_db::files::File,
-        db: &'db dyn crate::Db,
+        model: &SemanticModel<'db>,
         alias_resolution: ImportAliasResolution,
     ) -> Option<DefinitionsOrTargets<'db>> {
         use crate::NavigationTarget;
-
         match self {
-            GotoTarget::Expression(expression) => definitions_for_expression(db, file, expression)
+            GotoTarget::Expression(expression) => definitions_for_expression(model, *expression)
                 .map(DefinitionsOrTargets::Definitions),
-
             // For already-defined symbols, they are their own definitions
-            GotoTarget::FunctionDef(function) => {
-                let model = SemanticModel::new(db, file);
-                Some(DefinitionsOrTargets::Definitions(vec![
-                    ResolvedDefinition::Definition(function.definition(&model)),
-                ]))
-            }
+            GotoTarget::FunctionDef(function) => Some(DefinitionsOrTargets::Definitions(vec![
+                ResolvedDefinition::Definition(function.definition(model)),
+            ])),
 
-            GotoTarget::ClassDef(class) => {
-                let model = SemanticModel::new(db, file);
-                Some(DefinitionsOrTargets::Definitions(vec![
-                    ResolvedDefinition::Definition(class.definition(&model)),
-                ]))
-            }
+            GotoTarget::ClassDef(class) => Some(DefinitionsOrTargets::Definitions(vec![
+                ResolvedDefinition::Definition(class.definition(model)),
+            ])),
 
-            GotoTarget::Parameter(parameter) => {
-                let model = SemanticModel::new(db, file);
-                Some(DefinitionsOrTargets::Definitions(vec![
-                    ResolvedDefinition::Definition(parameter.definition(&model)),
-                ]))
-            }
+            GotoTarget::Parameter(parameter) => Some(DefinitionsOrTargets::Definitions(vec![
+                ResolvedDefinition::Definition(parameter.definition(model)),
+            ])),
 
             // For import aliases (offset within 'y' or 'z' in "from x import y as z")
             GotoTarget::ImportSymbolAlias {
@@ -392,8 +424,7 @@ impl GotoTarget<'_> {
                 let symbol_name = alias.name.as_str();
                 Some(DefinitionsOrTargets::Definitions(
                     definitions_for_imported_symbol(
-                        db,
-                        file,
+                        model,
                         import_from,
                         symbol_name,
                         alias_resolution,
@@ -404,29 +435,23 @@ impl GotoTarget<'_> {
             GotoTarget::ImportModuleComponent {
                 module_name,
                 component_index,
+                level,
                 ..
             } => {
-                // Handle both `import foo.bar` and `from foo.bar import baz` where offset is within module component
-                let components: Vec<&str> = module_name.split('.').collect();
-
-                // Build the module name up to and including the component containing the offset
-                let target_module_name = components[..=*component_index].join(".");
-
-                // Try to resolve the module
-                definitions_for_module(db, &target_module_name)
+                // We don't currently support hovering the bare `.` so there is always a name
+                let module = import_name(module_name, *component_index);
+                definitions_for_module(model, Some(module), *level)
             }
 
             // Handle import aliases (offset within 'z' in "import x.y as z")
             GotoTarget::ImportModuleAlias { alias } => {
                 if alias_resolution == ImportAliasResolution::ResolveAliases {
-                    let full_module_name = alias.name.as_str();
-                    // Try to resolve the module
-                    definitions_for_module(db, full_module_name)
+                    definitions_for_module(model, Some(alias.name.as_str()), 0)
                 } else {
                     let alias_range = alias.asname.as_ref().unwrap().range;
                     Some(DefinitionsOrTargets::Targets(
                         crate::NavigationTargets::single(NavigationTarget {
-                            file,
+                            file: model.file(),
                             focus_range: alias_range,
                             full_range: alias.range(),
                         }),
@@ -439,14 +464,13 @@ impl GotoTarget<'_> {
                 keyword,
                 call_expression,
             } => Some(DefinitionsOrTargets::Definitions(
-                definitions_for_keyword_argument(db, file, keyword, call_expression),
+                definitions_for_keyword_argument(model, keyword, call_expression),
             )),
 
             // For exception variables, they are their own definitions (like parameters)
             GotoTarget::ExceptVariable(except_handler) => {
-                let model = SemanticModel::new(db, file);
                 Some(DefinitionsOrTargets::Definitions(vec![
-                    ResolvedDefinition::Definition(except_handler.definition(&model)),
+                    ResolvedDefinition::Definition(except_handler.definition(model)),
                 ]))
             }
 
@@ -455,7 +479,10 @@ impl GotoTarget<'_> {
                 if let Some(rest_name) = &pattern_mapping.rest {
                     let range = rest_name.range;
                     Some(DefinitionsOrTargets::Targets(
-                        crate::NavigationTargets::single(NavigationTarget::new(file, range)),
+                        crate::NavigationTargets::single(NavigationTarget::new(
+                            model.file(),
+                            range,
+                        )),
                     ))
                 } else {
                     None
@@ -467,7 +494,10 @@ impl GotoTarget<'_> {
                 if let Some(name) = &pattern_as.name {
                     let range = name.range;
                     Some(DefinitionsOrTargets::Targets(
-                        crate::NavigationTargets::single(NavigationTarget::new(file, range)),
+                        crate::NavigationTargets::single(NavigationTarget::new(
+                            model.file(),
+                            range,
+                        )),
                     ))
                 } else {
                     None
@@ -478,9 +508,9 @@ impl GotoTarget<'_> {
             //
             // Prefer the function impl over the callable so that its docstrings win if defined.
             GotoTarget::Call { callable, call } => {
-                let mut definitions = definitions_for_callable(db, file, call);
+                let mut definitions = definitions_for_callable(model, call);
                 let expr_definitions =
-                    definitions_for_expression(db, file, callable).unwrap_or_default();
+                    definitions_for_expression(model, *callable).unwrap_or_default();
                 definitions.extend(expr_definitions);
 
                 if definitions.is_empty() {
@@ -491,23 +521,46 @@ impl GotoTarget<'_> {
             }
 
             GotoTarget::BinOp { expression, .. } => {
-                let model = SemanticModel::new(db, file);
-
                 let (definitions, _) =
-                    ty_python_semantic::definitions_for_bin_op(db, &model, expression)?;
+                    ty_python_semantic::definitions_for_bin_op(model, expression)?;
 
                 Some(DefinitionsOrTargets::Definitions(definitions))
             }
 
             GotoTarget::UnaryOp { expression, .. } => {
-                let model = SemanticModel::new(db, file);
                 let (definitions, _) =
-                    ty_python_semantic::definitions_for_unary_op(db, &model, expression)?;
+                    ty_python_semantic::definitions_for_unary_op(model, expression)?;
 
                 Some(DefinitionsOrTargets::Definitions(definitions))
             }
 
-            _ => None,
+            // String annotations sub-expressions require us to recurse into the sub-AST
+            GotoTarget::StringAnnotationSubexpr {
+                string_expr,
+                subrange,
+                ..
+            } => {
+                let (subast, submodel) = model.enter_string_annotation(string_expr)?;
+                let subexpr = covering_node(subast.syntax().into(), *subrange)
+                    .node()
+                    .as_expr_ref()?;
+                definitions_for_expression(&submodel, subexpr)
+                    .map(DefinitionsOrTargets::Definitions)
+            }
+            GotoTarget::NonLocal { identifier } | GotoTarget::Globals { identifier } => {
+                Some(DefinitionsOrTargets::Definitions(definitions_for_name(
+                    model,
+                    identifier.as_str(),
+                    AnyNodeRef::Identifier(identifier),
+                )))
+            }
+
+            // TODO: implement these
+            GotoTarget::PatternKeywordArgument(..)
+            | GotoTarget::PatternMatchStarName(..)
+            | GotoTarget::TypeParamTypeVarName(..)
+            | GotoTarget::TypeParamParamSpecName(..)
+            | GotoTarget::TypeParamTypeVarTupleName(..) => None,
         }
     }
 
@@ -526,6 +579,7 @@ impl GotoTarget<'_> {
                 ast::ExprRef::Attribute(attr) => Some(Cow::Borrowed(attr.attr.as_str())),
                 _ => None,
             },
+            GotoTarget::StringAnnotationSubexpr { name, .. } => name.as_deref().map(Cow::Borrowed),
             GotoTarget::FunctionDef(function) => Some(Cow::Borrowed(function.name.as_str())),
             GotoTarget::ClassDef(class) => Some(Cow::Borrowed(class.name.as_str())),
             GotoTarget::Parameter(parameter) => Some(Cow::Borrowed(parameter.name.as_str())),
@@ -586,6 +640,7 @@ impl GotoTarget<'_> {
 
     /// Creates a `GotoTarget` from a `CoveringNode` and an offset within the node
     pub(crate) fn from_covering_node<'a>(
+        model: &SemanticModel,
         covering_node: &crate::find_node::CoveringNode<'a>,
         offset: TextSize,
         tokens: &Tokens,
@@ -632,6 +687,7 @@ impl GotoTarget<'_> {
                                 {
                                     return Some(GotoTarget::ImportModuleComponent {
                                         module_name: full_name.to_string(),
+                                        level: 0,
                                         component_index,
                                         component_range,
                                     });
@@ -672,14 +728,12 @@ impl GotoTarget<'_> {
                     // Handle offset within module name in from import statements
                     if let Some(module_expr) = &from.module {
                         let full_module_name = module_expr.to_string();
-
-                        if let Some((component_index, component_range)) = find_module_component(
-                            &full_module_name,
-                            module_expr.range.start(),
-                            offset,
-                        ) {
+                        if let Some((component_index, component_range)) =
+                            find_module_component(&full_module_name, module_expr.start(), offset)
+                        {
                             return Some(GotoTarget::ImportModuleComponent {
                                 module_name: full_module_name,
+                                level: from.level,
                                 component_index,
                                 component_range,
                             });
@@ -786,6 +840,31 @@ impl GotoTarget<'_> {
                 Some(GotoTarget::Expression(unary.into()))
             }
 
+            node @ AnyNodeRef::ExprStringLiteral(string_expr) => {
+                // Check if we've clicked on a sub-GotoTarget inside a string annotation's sub-AST
+                if let Some((subast, submodel)) = model.enter_string_annotation(string_expr)
+                    && let Some(GotoTarget::Expression(subexpr)) = find_goto_target_impl(
+                        &submodel,
+                        subast.tokens(),
+                        subast.syntax().into(),
+                        offset,
+                    )
+                {
+                    let name = match subexpr {
+                        ast::ExprRef::Name(name) => Some(name.id.to_string()),
+                        ast::ExprRef::Attribute(attr) => Some(attr.attr.to_string()),
+                        _ => None,
+                    };
+                    Some(GotoTarget::StringAnnotationSubexpr {
+                        string_expr,
+                        subrange: subexpr.range(),
+                        name,
+                    })
+                } else {
+                    node.as_expr_ref().map(GotoTarget::Expression)
+                }
+            }
+
             node => {
                 // Check if this is seemingly a callable being invoked (the `x` in `x(...)`)
                 let parent = covering_node.parent();
@@ -821,6 +900,7 @@ impl Ranged for GotoTarget<'_> {
             GotoTarget::ImportModuleComponent {
                 component_range, ..
             } => *component_range,
+            GotoTarget::StringAnnotationSubexpr { subrange, .. } => *subrange,
             GotoTarget::ImportModuleAlias { alias } => alias.asname.as_ref().unwrap().range,
             GotoTarget::ExceptVariable(except) => except.name.as_ref().unwrap().range,
             GotoTarget::KeywordArgument { keyword, .. } => keyword.arg.as_ref().unwrap().range,
@@ -840,9 +920,9 @@ impl Ranged for GotoTarget<'_> {
 }
 
 /// Converts a collection of `ResolvedDefinition` items into `NavigationTarget` items.
-fn convert_resolved_definitions_to_targets(
-    db: &dyn crate::Db,
-    definitions: Vec<ty_python_semantic::ResolvedDefinition<'_>>,
+fn convert_resolved_definitions_to_targets<'db>(
+    db: &'db dyn ty_python_semantic::Db,
+    definitions: Vec<ty_python_semantic::ResolvedDefinition<'db>>,
 ) -> Vec<crate::NavigationTarget> {
     definitions
         .into_iter()
@@ -876,27 +956,28 @@ fn convert_resolved_definitions_to_targets(
 
 /// Shared helper to get definitions for an expr (that is presumably a name/attr)
 fn definitions_for_expression<'db>(
-    db: &'db dyn crate::Db,
-    file: ruff_db::files::File,
-    expression: &ruff_python_ast::ExprRef<'_>,
+    model: &SemanticModel<'db>,
+    expression: ruff_python_ast::ExprRef<'_>,
 ) -> Option<Vec<ResolvedDefinition<'db>>> {
     match expression {
-        ast::ExprRef::Name(name) => Some(definitions_for_name(db, file, name)),
+        ast::ExprRef::Name(name) => Some(definitions_for_name(
+            model,
+            name.id.as_str(),
+            expression.into(),
+        )),
         ast::ExprRef::Attribute(attribute) => Some(ty_python_semantic::definitions_for_attribute(
-            db, file, attribute,
+            model, attribute,
         )),
         _ => None,
     }
 }
 
 fn definitions_for_callable<'db>(
-    db: &'db dyn crate::Db,
-    file: ruff_db::files::File,
+    model: &SemanticModel<'db>,
     call: &ast::ExprCall,
 ) -> Vec<ResolvedDefinition<'db>> {
-    let model = SemanticModel::new(db, file);
     // Attempt to refine to a specific call
-    let signature_info = call_signature_details(db, &model, call);
+    let signature_info = call_signature_details(model, call);
     signature_info
         .into_iter()
         .filter_map(|signature| signature.definition.map(ResolvedDefinition::Definition))
@@ -905,7 +986,7 @@ fn definitions_for_callable<'db>(
 
 /// Shared helper to map and convert resolved definitions into navigation targets.
 fn definitions_to_navigation_targets<'db>(
-    db: &dyn crate::Db,
+    db: &dyn ty_python_semantic::Db,
     stub_mapper: Option<&StubMapper<'db>>,
     mut definitions: Vec<ty_python_semantic::ResolvedDefinition<'db>>,
 ) -> Option<crate::NavigationTargets> {
@@ -920,12 +1001,21 @@ fn definitions_to_navigation_targets<'db>(
     }
 }
 
-pub(crate) fn find_goto_target(
-    parsed: &ParsedModuleRef,
+pub(crate) fn find_goto_target<'a>(
+    model: &'a SemanticModel,
+    parsed: &'a ParsedModuleRef,
     offset: TextSize,
-) -> Option<GotoTarget<'_>> {
-    let token = parsed
-        .tokens()
+) -> Option<GotoTarget<'a>> {
+    find_goto_target_impl(model, parsed.tokens(), parsed.syntax().into(), offset)
+}
+
+pub(crate) fn find_goto_target_impl<'a>(
+    model: &'a SemanticModel,
+    tokens: &'a Tokens,
+    syntax: AnyNodeRef<'a>,
+    offset: TextSize,
+) -> Option<GotoTarget<'a>> {
+    let token = tokens
         .at_offset(offset)
         .max_by_key(|token| match token.kind() {
             TokenKind::Name
@@ -946,30 +1036,26 @@ pub(crate) fn find_goto_target(
         return None;
     }
 
-    let covering_node = covering_node(parsed.syntax().into(), token.range())
-        .find_first(|node| node.is_identifier() || node.is_expression())
+    let covering_node = covering_node(syntax, token.range())
+        .find_first(|node| {
+            node.is_identifier() || node.is_expression() || node.is_stmt_import_from()
+        })
         .ok()?;
 
-    GotoTarget::from_covering_node(&covering_node, offset, parsed.tokens())
+    GotoTarget::from_covering_node(model, &covering_node, offset, tokens)
 }
 
 /// Helper function to resolve a module name and create a navigation target.
 fn definitions_for_module<'db>(
-    db: &'db dyn crate::Db,
-    module_name_str: &str,
+    model: &SemanticModel<'db>,
+    module: Option<&str>,
+    level: u32,
 ) -> Option<DefinitionsOrTargets<'db>> {
-    use ty_python_semantic::{ModuleName, resolve_module};
-
-    if let Some(module_name) = ModuleName::new(module_name_str) {
-        if let Some(resolved_module) = resolve_module(db, &module_name) {
-            if let Some(module_file) = resolved_module.file(db) {
-                return Some(DefinitionsOrTargets::Definitions(vec![
-                    ResolvedDefinition::Module(module_file),
-                ]));
-            }
-        }
-    }
-    None
+    let module = model.resolve_module(module, level)?;
+    let file = module.file(model.db())?;
+    Some(DefinitionsOrTargets::Definitions(vec![
+        ResolvedDefinition::Module(file),
+    ]))
 }
 
 /// Helper function to extract module component information from a dotted module name
@@ -983,9 +1069,7 @@ fn find_module_component(
 
     // Split the module name into components and find which one contains the offset
     let mut current_pos = 0;
-    let components: Vec<&str> = full_module_name.split('.').collect();
-
-    for (i, component) in components.iter().enumerate() {
+    for (i, component) in full_module_name.split('.').enumerate() {
         let component_start = current_pos;
         let component_end = current_pos + component.len();
 
@@ -1004,3 +1088,16 @@ fn find_module_component(
 
     None
 }
+
+/// Helper to get the module name up to the given component index
+fn import_name(module_name: &str, component_index: usize) -> &str {
+    // We want everything to the left of the nth `.`
+    // If there's no nth `.` then we want the whole thing.
+    let idx = module_name
+        .match_indices('.')
+        .nth(component_index)
+        .map(|(idx, _)| idx)
+        .unwrap_or(module_name.len());
+
+    &module_name[..idx]
+}

crates/ty_ide/src/goto_declaration.rs

@@ -3,7 +3,7 @@ use crate::{Db, NavigationTargets, RangedValue};
 use ruff_db::files::{File, FileRange};
 use ruff_db::parsed::parsed_module;
 use ruff_text_size::{Ranged, TextSize};
-use ty_python_semantic::ImportAliasResolution;
+use ty_python_semantic::{ImportAliasResolution, SemanticModel};
 
 /// Navigate to the declaration of a symbol.
 ///
@@ -16,10 +16,11 @@ pub fn goto_declaration(
     offset: TextSize,
 ) -> Option<RangedValue<NavigationTargets>> {
     let module = parsed_module(db, file).load(db);
-    let goto_target = find_goto_target(&module, offset)?;
+    let model = SemanticModel::new(db, file);
+    let goto_target = find_goto_target(&model, &module, offset)?;
 
     let declaration_targets = goto_target
-        .get_definition_targets(file, db, ImportAliasResolution::ResolveAliases)?
+        .get_definition_targets(&model, ImportAliasResolution::ResolveAliases)?
         .declaration_targets(db)?;
 
     Some(RangedValue {
@@ -888,6 +889,190 @@ def another_helper(path):
         ");
     }
 
+    #[test]
+    fn goto_declaration_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:4:7
+          |
+        2 | a: "MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:4:7
+          |
+        2 | a: "MyClass | No" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:5
+          |
+        2 | a: "MyClass | No" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_declaration_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_declaration(), @"No goto target found");
+    }
+
     #[test]
     fn goto_declaration_nested_instance_attribute() {
         let test = cursor_test(
@@ -1069,6 +1254,45 @@ def outer():
         "#);
     }
 
+    #[test]
+    fn goto_declaration_nonlocal_stmt() {
+        let test = cursor_test(
+            r#"
+def outer():
+    xy = "outer_value"
+    
+    def inner():
+        nonlocal x<CURSOR>y
+        xy = "modified"
+        return x  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:3:5
+          |
+        2 | def outer():
+        3 |     xy = "outer_value"
+          |     ^^
+        4 |
+        5 |     def inner():
+          |
+        info: Source
+         --> main.py:6:18
+          |
+        5 |     def inner():
+        6 |         nonlocal xy
+          |                  ^^
+        7 |         xy = "modified"
+        8 |         return x  # Should find the nonlocal x declaration in outer scope
+          |
+        "#);
+    }
+
     #[test]
     fn goto_declaration_global_binding() {
         let test = cursor_test(
@@ -1103,6 +1327,41 @@ def function():
         "#);
     }
 
+    #[test]
+    fn goto_declaration_global_stmt() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_<CURSOR>var
+    global_var = "modified"
+    return global_var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.goto_declaration(), @r#"
+        info[goto-declaration]: Declaration
+         --> main.py:2:1
+          |
+        2 | global_var = "global_value"
+          | ^^^^^^^^^^
+        3 |
+        4 | def function():
+          |
+        info: Source
+         --> main.py:5:12
+          |
+        4 | def function():
+        5 |     global global_var
+          |            ^^^^^^^^^^
+        6 |     global_var = "modified"
+        7 |     return global_var  # Should find the global variable declaration
+          |
+        "#);
+    }
+
     #[test]
     fn goto_declaration_inherited_attribute() {
         let test = cursor_test(

crates/ty_ide/src/goto_definition.rs

@@ -3,7 +3,7 @@ use crate::{Db, NavigationTargets, RangedValue};
 use ruff_db::files::{File, FileRange};
 use ruff_db::parsed::parsed_module;
 use ruff_text_size::{Ranged, TextSize};
-use ty_python_semantic::ImportAliasResolution;
+use ty_python_semantic::{ImportAliasResolution, SemanticModel};
 
 /// Navigate to the definition of a symbol.
 ///
@@ -17,10 +17,10 @@ pub fn goto_definition(
     offset: TextSize,
 ) -> Option<RangedValue<NavigationTargets>> {
     let module = parsed_module(db, file).load(db);
-    let goto_target = find_goto_target(&module, offset)?;
-
+    let model = SemanticModel::new(db, file);
+    let goto_target = find_goto_target(&model, &module, offset)?;
     let definition_targets = goto_target
-        .get_definition_targets(file, db, ImportAliasResolution::ResolveAliases)?
+        .get_definition_targets(&model, ImportAliasResolution::ResolveAliases)?
         .definition_targets(db)?;
 
     Some(RangedValue {

crates/ty_ide/src/goto_references.rs

@@ -3,6 +3,7 @@ use crate::references::{ReferencesMode, references};
 use crate::{Db, ReferenceTarget};
 use ruff_db::files::File;
 use ruff_text_size::TextSize;
+use ty_python_semantic::SemanticModel;
 
 /// Find all references to a symbol at the given position.
 /// Search for references across all files in the project.
@@ -14,9 +15,10 @@ pub fn goto_references(
 ) -> Option<Vec<ReferenceTarget>> {
     let parsed = ruff_db::parsed::parsed_module(db, file);
     let module = parsed.load(db);
+    let model = SemanticModel::new(db, file);
 
     // Get the definitions for the symbol at the cursor position
-    let goto_target = find_goto_target(&module, offset)?;
+    let goto_target = find_goto_target(&model, &module, offset)?;
 
     let mode = if include_declaration {
         ReferencesMode::References
@@ -147,7 +149,6 @@ result = calculate_sum(value=42)
     }
 
     #[test]
-    #[ignore] // TODO: Enable when nonlocal support is fully implemented in goto.rs
     fn test_nonlocal_variable_references() {
         let test = cursor_test(
             "
@@ -181,7 +182,7 @@ def outer_function():
         2 | def outer_function():
         3 |     counter = 0
           |     ^^^^^^^
-        4 |     
+        4 |
         5 |     def increment():
           |
 
@@ -212,7 +213,7 @@ def outer_function():
          7 |         counter += 1
          8 |         return counter
            |                ^^^^^^^
-         9 |     
+         9 |
         10 |     def decrement():
            |
 
@@ -243,7 +244,7 @@ def outer_function():
         12 |         counter -= 1
         13 |         return counter
            |                ^^^^^^^
-        14 |     
+        14 |
         15 |     # Use counter in outer scope
            |
 
@@ -264,14 +265,13 @@ def outer_function():
         18 |     decrement()
         19 |     final = counter
            |             ^^^^^^^
-        20 |     
+        20 |
         21 |     return increment, decrement
            |
         ");
     }
 
     #[test]
-    #[ignore] // TODO: Enable when global support is fully implemented in goto.rs
     fn test_global_variable_references() {
         let test = cursor_test(
             "
@@ -710,6 +710,194 @@ cls = MyClass
         ");
     }
 
+    #[test]
+    fn references_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @r#"
+        info[references]: Reference 1
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[references]: Reference 2
+         --> main.py:4:7
+          |
+        2 | a: "MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn references_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @r#"
+        info[references]: Reference 1
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[references]: Reference 2
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn references_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @"No references found");
+    }
+
+    #[test]
+    fn references_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @r#"
+        info[references]: Reference 1
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[references]: Reference 2
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn references_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @"No references found");
+    }
+
+    #[test]
+    fn references_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @"No references found");
+    }
+
+    #[test]
+    fn references_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @r#"
+        info[references]: Reference 1
+         --> main.py:2:5
+          |
+        2 | a: "MyClass | No" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[references]: Reference 2
+         --> main.py:4:7
+          |
+        2 | a: "MyClass | No" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn references_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.references(), @"No references found");
+    }
+
     #[test]
     fn test_multi_file_function_references() {
         let test = CursorTest::builder()

crates/ty_ide/src/goto_type_definition.rs

@@ -11,9 +11,9 @@ pub fn goto_type_definition(
     offset: TextSize,
 ) -> Option<RangedValue<NavigationTargets>> {
     let module = parsed_module(db, file).load(db);
-    let goto_target = find_goto_target(&module, offset)?;
-
     let model = SemanticModel::new(db, file);
+    let goto_target = find_goto_target(&model, &module, offset)?;
+
     let ty = goto_target.inferred_type(&model)?;
 
     tracing::debug!("Inferred type of covering node is {}", ty.display(db));
@@ -285,6 +285,300 @@ mod tests {
         ");
     }
 
+    #[test]
+    fn goto_type_of_import_module() {
+        let mut test = cursor_test(
+            r#"
+            import l<CURSOR>ib
+            "#,
+        );
+
+        test.write_file("lib.py", "a = 10").unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+         --> lib.py:1:1
+          |
+        1 | a = 10
+          | ^^^^^^
+          |
+        info: Source
+         --> main.py:2:8
+          |
+        2 | import lib
+          |        ^^^
+          |
+        ");
+    }
+
+    #[test]
+    fn goto_type_of_import_module_multi1() {
+        let mut test = cursor_test(
+            r#"
+            import li<CURSOR>b.submod
+            "#,
+        );
+
+        test.write_file("lib/__init__.py", "b = 7").unwrap();
+        test.write_file("lib/submod.py", "a = 10").unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+         --> lib/__init__.py:1:1
+          |
+        1 | b = 7
+          | ^^^^^
+          |
+        info: Source
+         --> main.py:2:8
+          |
+        2 | import lib.submod
+          |        ^^^
+          |
+        ");
+    }
+
+    #[test]
+    fn goto_type_of_import_module_multi2() {
+        let mut test = cursor_test(
+            r#"
+            import lib.subm<CURSOR>od
+            "#,
+        );
+
+        test.write_file("lib/__init__.py", "b = 7").unwrap();
+        test.write_file("lib/submod.py", "a = 10").unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+         --> lib/submod.py:1:1
+          |
+        1 | a = 10
+          | ^^^^^^
+          |
+        info: Source
+         --> main.py:2:12
+          |
+        2 | import lib.submod
+          |            ^^^^^^
+          |
+        ");
+    }
+
+    #[test]
+    fn goto_type_of_from_import_module() {
+        let mut test = cursor_test(
+            r#"
+            from l<CURSOR>ib import a
+            "#,
+        );
+
+        test.write_file("lib.py", "a = 10").unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+         --> lib.py:1:1
+          |
+        1 | a = 10
+          | ^^^^^^
+          |
+        info: Source
+         --> main.py:2:6
+          |
+        2 | from lib import a
+          |      ^^^
+          |
+        ");
+    }
+
+    #[test]
+    fn goto_type_of_from_import_module_multi1() {
+        let mut test = cursor_test(
+            r#"
+            from li<CURSOR>b.submod import a
+            "#,
+        );
+
+        test.write_file("lib/__init__.py", "b = 7").unwrap();
+        test.write_file("lib/submod.py", "a = 10").unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+         --> lib/__init__.py:1:1
+          |
+        1 | b = 7
+          | ^^^^^
+          |
+        info: Source
+         --> main.py:2:6
+          |
+        2 | from lib.submod import a
+          |      ^^^
+          |
+        ");
+    }
+
+    #[test]
+    fn goto_type_of_from_import_module_multi2() {
+        let mut test = cursor_test(
+            r#"
+            from lib.subm<CURSOR>od import a
+            "#,
+        );
+
+        test.write_file("lib/__init__.py", "b = 7").unwrap();
+        test.write_file("lib/submod.py", "a = 10").unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+         --> lib/submod.py:1:1
+          |
+        1 | a = 10
+          | ^^^^^^
+          |
+        info: Source
+         --> main.py:2:10
+          |
+        2 | from lib.submod import a
+          |          ^^^^^^
+          |
+        ");
+    }
+
+    #[test]
+    fn goto_type_of_from_import_rel1() {
+        let mut test = CursorTest::builder()
+            .source(
+                "lib/sub/__init__.py",
+                r#"
+            from .bot.bot<CURSOR>mod import *
+            sub = 2
+            "#,
+            )
+            .build();
+
+        test.write_file("lib/__init__.py", "lib = 1").unwrap();
+        // test.write_file("lib/sub/__init__.py", "sub = 2").unwrap();
+        test.write_file("lib/sub/bot/__init__.py", "bot = 3")
+            .unwrap();
+        test.write_file("lib/sub/submod.py", "submod = 21").unwrap();
+        test.write_file("lib/sub/bot/botmod.py", "botmod = 31")
+            .unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+         --> lib/sub/bot/botmod.py:1:1
+          |
+        1 | botmod = 31
+          | ^^^^^^^^^^^
+          |
+        info: Source
+         --> lib/sub/__init__.py:2:11
+          |
+        2 | from .bot.botmod import *
+          |           ^^^^^^
+        3 | sub = 2
+          |
+        ");
+    }
+
+    #[test]
+    fn goto_type_of_from_import_rel2() {
+        let mut test = CursorTest::builder()
+            .source(
+                "lib/sub/__init__.py",
+                r#"
+            from .bo<CURSOR>t.botmod import *
+            sub = 2
+            "#,
+            )
+            .build();
+
+        test.write_file("lib/__init__.py", "lib = 1").unwrap();
+        // test.write_file("lib/sub/__init__.py", "sub = 2").unwrap();
+        test.write_file("lib/sub/bot/__init__.py", "bot = 3")
+            .unwrap();
+        test.write_file("lib/sub/submod.py", "submod = 21").unwrap();
+        test.write_file("lib/sub/bot/botmod.py", "botmod = 31")
+            .unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+         --> lib/sub/bot/__init__.py:1:1
+          |
+        1 | bot = 3
+          | ^^^^^^^
+          |
+        info: Source
+         --> lib/sub/__init__.py:2:7
+          |
+        2 | from .bot.botmod import *
+          |       ^^^
+        3 | sub = 2
+          |
+        ");
+    }
+
+    #[test]
+    fn goto_type_of_from_import_rel3() {
+        let mut test = CursorTest::builder()
+            .source(
+                "lib/sub/__init__.py",
+                r#"
+            from .<CURSOR>bot.botmod import *
+            sub = 2
+            "#,
+            )
+            .build();
+
+        test.write_file("lib/__init__.py", "lib = 1").unwrap();
+        // test.write_file("lib/sub/__init__.py", "sub = 2").unwrap();
+        test.write_file("lib/sub/bot/__init__.py", "bot = 3")
+            .unwrap();
+        test.write_file("lib/sub/submod.py", "submod = 21").unwrap();
+        test.write_file("lib/sub/bot/botmod.py", "botmod = 31")
+            .unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @r"
+        info[goto-type-definition]: Type definition
+         --> lib/sub/bot/__init__.py:1:1
+          |
+        1 | bot = 3
+          | ^^^^^^^
+          |
+        info: Source
+         --> lib/sub/__init__.py:2:7
+          |
+        2 | from .bot.botmod import *
+          |       ^^^
+        3 | sub = 2
+          |
+        ");
+    }
+
+    #[test]
+    fn goto_type_of_from_import_rel4() {
+        let mut test = CursorTest::builder()
+            .source(
+                "lib/sub/__init__.py",
+                r#"
+            from .<CURSOR> import submod
+            sub = 2
+            "#,
+            )
+            .build();
+
+        test.write_file("lib/__init__.py", "lib = 1").unwrap();
+        // test.write_file("lib/sub/__init__.py", "sub = 2").unwrap();
+        test.write_file("lib/sub/bot/__init__.py", "bot = 3")
+            .unwrap();
+        test.write_file("lib/sub/submod.py", "submod = 21").unwrap();
+        test.write_file("lib/sub/bot/botmod.py", "botmod = 31")
+            .unwrap();
+
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
     #[test]
     fn goto_type_of_expression_with_module() {
         let mut test = cursor_test(
@@ -450,6 +744,226 @@ mod tests {
         assert_snapshot!(test.goto_type_definition(), @"No type definitions found");
     }
 
+    #[test]
+    fn goto_type_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+         --> main.py:4:7
+          |
+        2 | a: "MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_type_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "None | MyClass" = 1
+          |    ^^^^^^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[goto-type-definition]: Type definition
+           --> stdlib/types.pyi:950:11
+            |
+        948 | if sys.version_info >= (3, 10):
+        949 |     @final
+        950 |     class NoneType:
+            |           ^^^^^^^^
+        951 |         """The type of the None singleton."""
+            |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "None | MyClass" = 1
+          |    ^^^^^^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_type_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+         --> main.py:4:7
+          |
+        2 | a: "None | MyClass" = 1
+        3 |
+        4 | class MyClass:
+          |       ^^^^^^^
+        5 |     """some docs"""
+          |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "None | MyClass" = 1
+          |    ^^^^^^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+
+        info[goto-type-definition]: Type definition
+           --> stdlib/types.pyi:950:11
+            |
+        948 | if sys.version_info >= (3, 10):
+        949 |     @final
+        950 |     class NoneType:
+            |           ^^^^^^^^
+        951 |         """The type of the None singleton."""
+            |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "None | MyClass" = 1
+          |    ^^^^^^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+         --> main.py:2:4
+          |
+        2 | a: "MyClass |" = 1
+          |    ^^^^^^^^^^^
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_type_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
     #[test]
     fn goto_type_on_keyword_argument() {
         let test = cursor_test(
@@ -548,6 +1062,118 @@ f(**kwargs<CURSOR>)
         "#);
     }
 
+    #[test]
+    fn goto_type_nonlocal_binding() {
+        let test = cursor_test(
+            r#"
+def outer():
+    x = "outer_value"
+    
+    def inner():
+        nonlocal x
+        x = "modified"
+        return x<CURSOR>  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+           --> stdlib/builtins.pyi:915:7
+            |
+        914 | @disjoint_base
+        915 | class str(Sequence[str]):
+            |       ^^^
+        916 |     """str(object='') -> str
+        917 |     str(bytes_or_buffer[, encoding[, errors]]) -> str
+            |
+        info: Source
+          --> main.py:8:16
+           |
+         6 |         nonlocal x
+         7 |         x = "modified"
+         8 |         return x  # Should find the nonlocal x declaration in outer scope
+           |                ^
+         9 |
+        10 |     return inner
+           |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_nonlocal_stmt() {
+        let test = cursor_test(
+            r#"
+def outer():
+    xy = "outer_value"
+    
+    def inner():
+        nonlocal x<CURSOR>y
+        xy = "modified"
+        return x  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
+    #[test]
+    fn goto_type_global_binding() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_var
+    global_var = "modified"
+    return global_<CURSOR>var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.goto_type_definition(), @r#"
+        info[goto-type-definition]: Type definition
+           --> stdlib/builtins.pyi:915:7
+            |
+        914 | @disjoint_base
+        915 | class str(Sequence[str]):
+            |       ^^^
+        916 |     """str(object='') -> str
+        917 |     str(bytes_or_buffer[, encoding[, errors]]) -> str
+            |
+        info: Source
+         --> main.py:7:12
+          |
+        5 |     global global_var
+        6 |     global_var = "modified"
+        7 |     return global_var  # Should find the global variable declaration
+          |            ^^^^^^^^^^
+          |
+        "#);
+    }
+
+    #[test]
+    fn goto_type_global_stmt() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_<CURSOR>var
+    global_var = "modified"
+    return global_var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.goto_type_definition(), @"No goto target found");
+    }
+
     #[test]
     fn goto_type_of_expression_with_builtin() {
         let test = cursor_test(

crates/ty_ide/src/hover.rs

@@ -11,7 +11,8 @@ use ty_python_semantic::{DisplaySettings, SemanticModel};
 
 pub fn hover(db: &dyn Db, file: File, offset: TextSize) -> Option<RangedValue<Hover<'_>>> {
     let parsed = parsed_module(db, file).load(db);
-    let goto_target = find_goto_target(&parsed, offset)?;
+    let model = SemanticModel::new(db, file);
+    let goto_target = find_goto_target(&model, &parsed, offset)?;
 
     if let GotoTarget::Expression(expr) = goto_target {
         if expr.is_literal_expr() {
@@ -19,11 +20,9 @@ pub fn hover(db: &dyn Db, file: File, offset: TextSize) -> Option<RangedValue<Ho
         }
     }
 
-    let model = SemanticModel::new(db, file);
     let docs = goto_target
         .get_definition_targets(
-            file,
-            db,
+            &model,
             ty_python_semantic::ImportAliasResolution::ResolveAliases,
         )
         .and_then(|definitions| definitions.docstring(db))
@@ -905,6 +904,191 @@ mod tests {
         ");
     }
 
+    #[test]
+    fn hover_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @r#"
+        MyClass
+        ---------------------------------------------
+        some docs
+
+        ---------------------------------------------
+        ```python
+        MyClass
+        ```
+        ---
+        some docs
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^-^
+          |     |    |
+          |     |    Cursor offset
+          |     source
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @r#"
+        some docs
+
+        ---------------------------------------------
+        some docs
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^-^^
+          |            |   |
+          |            |   Cursor offset
+          |            source
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
+    #[test]
+    fn hover_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @r#"
+        some docs
+
+        ---------------------------------------------
+        some docs
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^- Cursor offset
+          |            |
+          |            source
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
+    #[test]
+    fn hover_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
+    #[test]
+    fn hover_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @r#"
+        some docs
+
+        ---------------------------------------------
+        some docs
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:2:5
+          |
+        2 | a: "MyClass | No" = 1
+          |     ^^^^-^^
+          |     |   |
+          |     |   Cursor offset
+          |     source
+        3 |
+        4 | class MyClass:
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
     #[test]
     fn hover_overload_type_disambiguated1() {
         let test = CursorTest::builder()
@@ -1464,6 +1648,117 @@ def ab(a: int, *, c: int):
         ");
     }
 
+    #[test]
+    fn hover_nonlocal_binding() {
+        let test = cursor_test(
+            r#"
+def outer():
+    x = "outer_value"
+    
+    def inner():
+        nonlocal x
+        x = "modified"
+        return x<CURSOR>  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.hover(), @r#"
+        Literal["modified"]
+        ---------------------------------------------
+        ```python
+        Literal["modified"]
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+          --> main.py:8:16
+           |
+         6 |         nonlocal x
+         7 |         x = "modified"
+         8 |         return x  # Should find the nonlocal x declaration in outer scope
+           |                ^- Cursor offset
+           |                |
+           |                source
+         9 |
+        10 |     return inner
+           |
+        "#);
+    }
+
+    #[test]
+    fn hover_nonlocal_stmt() {
+        let test = cursor_test(
+            r#"
+def outer():
+    xy = "outer_value"
+    
+    def inner():
+        nonlocal x<CURSOR>y
+        xy = "modified"
+        return x  # Should find the nonlocal x declaration in outer scope
+    
+    return inner
+"#,
+        );
+
+        // Should find the variable declaration in the outer scope, not the nonlocal statement
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
+    #[test]
+    fn hover_global_binding() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_var
+    global_var = "modified"
+    return global_<CURSOR>var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.hover(), @r#"
+        Literal["modified"]
+        ---------------------------------------------
+        ```python
+        Literal["modified"]
+        ```
+        ---------------------------------------------
+        info[hover]: Hovered content is
+         --> main.py:7:12
+          |
+        5 |     global global_var
+        6 |     global_var = "modified"
+        7 |     return global_var  # Should find the global variable declaration
+          |            ^^^^^^^-^^
+          |            |      |
+          |            |      Cursor offset
+          |            source
+          |
+        "#);
+    }
+
+    #[test]
+    fn hover_global_stmt() {
+        let test = cursor_test(
+            r#"
+global_var = "global_value"
+
+def function():
+    global global_<CURSOR>var
+    global_var = "modified"
+    return global_var  # Should find the global variable declaration
+"#,
+        );
+
+        // Should find the global variable declaration, not the global statement
+        assert_snapshot!(test.hover(), @"Hover provided no content");
+    }
+
     #[test]
     fn hover_module_import() {
         let mut test = cursor_test(
@@ -1488,11 +1783,17 @@ def ab(a: int, *, c: int):
         .unwrap();
 
         assert_snapshot!(test.hover(), @r"
+        <module 'lib'>
+        ---------------------------------------------
         The cool lib_py module!
 
         Wow this module rocks.
 
         ---------------------------------------------
+        ```python
+        <module 'lib'>
+        ```
+        ---
         The cool lib/_py module!  
           
         Wow this module rocks.

crates/ty_ide/src/inlay_hints.rs

@@ -6,8 +6,8 @@ use ruff_db::parsed::parsed_module;
 use ruff_python_ast::visitor::source_order::{self, SourceOrderVisitor, TraversalSignal};
 use ruff_python_ast::{AnyNodeRef, ArgOrKeyword, Expr, ExprUnaryOp, Stmt, UnaryOp};
 use ruff_text_size::{Ranged, TextRange, TextSize};
-use ty_python_semantic::types::Type;
 use ty_python_semantic::types::ide_support::inlay_hint_call_argument_details;
+use ty_python_semantic::types::{Type, TypeDetail};
 use ty_python_semantic::{HasType, SemanticModel};
 
 #[derive(Debug, Clone)]
@@ -15,10 +15,12 @@ pub struct InlayHint {
     pub position: TextSize,
     pub kind: InlayHintKind,
     pub label: InlayHintLabel,
+    pub text_edits: Vec<InlayHintTextEdit>,
 }
 
 impl InlayHint {
-    fn variable_type(position: TextSize, ty: Type, db: &dyn Db) -> Self {
+    fn variable_type(expr: &Expr, ty: Type, db: &dyn Db, allow_edits: bool) -> Self {
+        let position = expr.range().end();
         // Render the type to a string, and get subspans for all the types that make it up
         let details = ty.display(db).to_string_parts();
 
@@ -34,7 +36,7 @@ impl InlayHint {
         let mut label_parts = vec![": ".into()];
         for (target, detail) in details.targets.iter().zip(&details.details) {
             match detail {
-                ty_python_semantic::types::TypeDetail::Type(ty) => {
+                TypeDetail::Type(ty) => {
                     let start = target.start().to_usize();
                     let end = target.end().to_usize();
                     // If we skipped over some bytes, push them with no target
@@ -50,9 +52,9 @@ impl InlayHint {
                         offset = end;
                     }
                 }
-                ty_python_semantic::types::TypeDetail::SignatureStart
-                | ty_python_semantic::types::TypeDetail::SignatureEnd
-                | ty_python_semantic::types::TypeDetail::Parameter(_) => {
+                TypeDetail::SignatureStart
+                | TypeDetail::SignatureEnd
+                | TypeDetail::Parameter(_) => {
                     // Don't care about these
                 }
             }
@@ -62,10 +64,20 @@ impl InlayHint {
             label_parts.push(details.label[offset..details.label.len()].into());
         }
 
+        let text_edits = if details.is_valid_syntax && allow_edits {
+            vec![InlayHintTextEdit {
+                range: TextRange::new(position, position),
+                new_text: format!(": {}", details.label),
+            }]
+        } else {
+            vec![]
+        };
+
         Self {
             position,
             kind: InlayHintKind::Type,
             label: InlayHintLabel { parts: label_parts },
+            text_edits,
         }
     }
 
@@ -83,6 +95,7 @@ impl InlayHint {
             position,
             kind: InlayHintKind::CallArgumentName,
             label: InlayHintLabel { parts: label_parts },
+            text_edits: vec![],
         }
     }
 
@@ -175,6 +188,12 @@ impl From<&str> for InlayHintLabelPart {
     }
 }
 
+#[derive(Debug, Clone)]
+pub struct InlayHintTextEdit {
+    pub range: TextRange,
+    pub new_text: String,
+}
+
 pub fn inlay_hints(
     db: &dyn Db,
     file: File,
@@ -234,6 +253,7 @@ struct InlayHintVisitor<'a, 'db> {
     in_assignment: bool,
     range: TextRange,
     settings: &'a InlayHintSettings,
+    in_no_edits_allowed: bool,
 }
 
 impl<'a, 'db> InlayHintVisitor<'a, 'db> {
@@ -245,15 +265,16 @@ impl<'a, 'db> InlayHintVisitor<'a, 'db> {
             in_assignment: false,
             range,
             settings,
+            in_no_edits_allowed: false,
         }
     }
 
-    fn add_type_hint(&mut self, position: TextSize, ty: Type<'db>) {
+    fn add_type_hint(&mut self, expr: &Expr, ty: Type<'db>, allow_edits: bool) {
         if !self.settings.variable_types {
             return;
         }
 
-        let inlay_hint = InlayHint::variable_type(position, ty, self.db);
+        let inlay_hint = InlayHint::variable_type(expr, ty, self.db, allow_edits);
 
         self.hints.push(inlay_hint);
     }
@@ -297,9 +318,13 @@ impl SourceOrderVisitor<'_> for InlayHintVisitor<'_, '_> {
         match stmt {
             Stmt::Assign(assign) => {
                 self.in_assignment = !type_hint_is_excessive_for_expr(&assign.value);
+                if !annotations_are_valid_syntax(assign) {
+                    self.in_no_edits_allowed = true;
+                }
                 for target in &assign.targets {
                     self.visit_expr(target);
                 }
+                self.in_no_edits_allowed = false;
                 self.in_assignment = false;
 
                 self.visit_expr(&assign.value);
@@ -325,7 +350,7 @@ impl SourceOrderVisitor<'_> for InlayHintVisitor<'_, '_> {
                 if self.in_assignment {
                     if name.ctx.is_store() {
                         let ty = expr.inferred_type(&self.model);
-                        self.add_type_hint(expr.range().end(), ty);
+                        self.add_type_hint(expr, ty, !self.in_no_edits_allowed);
                     }
                 }
                 source_order::walk_expr(self, expr);
@@ -334,7 +359,7 @@ impl SourceOrderVisitor<'_> for InlayHintVisitor<'_, '_> {
                 if self.in_assignment {
                     if attribute.ctx.is_store() {
                         let ty = expr.inferred_type(&self.model);
-                        self.add_type_hint(expr.range().end(), ty);
+                        self.add_type_hint(expr, ty, !self.in_no_edits_allowed);
                     }
                 }
                 source_order::walk_expr(self, expr);
@@ -420,6 +445,22 @@ fn type_hint_is_excessive_for_expr(expr: &Expr) -> bool {
     }
 }
 
+fn annotations_are_valid_syntax(stmt_assign: &ruff_python_ast::StmtAssign) -> bool {
+    if stmt_assign.targets.len() > 1 {
+        return false;
+    }
+
+    if stmt_assign
+        .targets
+        .iter()
+        .any(|target| matches!(target, Expr::Tuple(_)))
+    {
+        return false;
+    }
+
+    true
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -427,6 +468,7 @@ mod tests {
     use crate::NavigationTarget;
     use crate::tests::IntoDiagnostic;
     use insta::{assert_snapshot, internals::SettingsBindDropGuard};
+    use itertools::Itertools;
     use ruff_db::{
         diagnostic::{
             Annotation, Diagnostic, DiagnosticFormat, DiagnosticId, DisplayDiagnosticConfig,
@@ -517,12 +559,15 @@ mod tests {
         fn inlay_hints_with_settings(&mut self, settings: &InlayHintSettings) -> String {
             let hints = inlay_hints(&self.db, self.file, self.range, settings);
 
-            let mut buf = source_text(&self.db, self.file).as_str().to_string();
+            let mut inlay_hint_buf = source_text(&self.db, self.file).as_str().to_string();
+            let mut text_edit_buf = inlay_hint_buf.clone();
 
             let mut tbd_diagnostics = Vec::new();
 
             let mut offset = 0;
 
+            let mut edit_offset = 0;
+
             for hint in hints {
                 let end_position = hint.position.to_usize() + offset;
                 let mut hint_str = "[".to_string();
@@ -538,36 +583,65 @@ mod tests {
                     hint_str.push_str(part.text());
                 }
 
+                for edit in hint.text_edits {
+                    let start = edit.range.start().to_usize() + edit_offset;
+                    let end = edit.range.end().to_usize() + edit_offset;
+
+                    text_edit_buf.replace_range(start..end, &edit.new_text);
+
+                    if start == end {
+                        edit_offset += edit.new_text.len();
+                    } else {
+                        edit_offset += edit.new_text.len() - edit.range.len().to_usize();
+                    }
+                }
+
                 hint_str.push(']');
                 offset += hint_str.len();
 
-                buf.insert_str(end_position, &hint_str);
+                inlay_hint_buf.insert_str(end_position, &hint_str);
             }
 
-            self.db.write_file("main2.py", &buf).unwrap();
+            self.db.write_file("main2.py", &inlay_hint_buf).unwrap();
             let inlayed_file =
                 system_path_to_file(&self.db, "main2.py").expect("newly written file to existing");
 
-            let diagnostics = tbd_diagnostics.into_iter().map(|(label_range, target)| {
+            let location_diagnostics = tbd_diagnostics.into_iter().map(|(label_range, target)| {
                 InlayHintLocationDiagnostic::new(FileRange::new(inlayed_file, label_range), &target)
             });
 
-            let mut rendered_diagnostics = self.render_diagnostics(diagnostics);
+            let mut rendered_diagnostics = location_diagnostics
+                .map(|diagnostic| self.render_diagnostic(diagnostic))
+                .join("");
 
             if !rendered_diagnostics.is_empty() {
                 rendered_diagnostics = format!(
                     "{}{}",
                     crate::MarkupKind::PlainText.horizontal_line(),
                     rendered_diagnostics
+                        .strip_suffix("\n")
+                        .unwrap_or(&rendered_diagnostics)
                 );
             }
 
-            format!("{buf}{rendered_diagnostics}",)
+            let rendered_edit_diagnostic = if edit_offset != 0 {
+                let edit_diagnostic = InlayHintEditDiagnostic::new(text_edit_buf);
+                let text_edit_buf = self.render_diagnostic(edit_diagnostic);
+
+                format!(
+                    "{}{}",
+                    crate::MarkupKind::PlainText.horizontal_line(),
+                    text_edit_buf
+                )
+            } else {
+                String::new()
+            };
+
+            format!("{inlay_hint_buf}{rendered_diagnostics}{rendered_edit_diagnostic}",)
         }
 
-        fn render_diagnostics<I, D>(&self, diagnostics: I) -> String
+        fn render_diagnostic<D>(&self, diagnostic: D) -> String
         where
-            I: IntoIterator<Item = D>,
             D: IntoDiagnostic,
         {
             use std::fmt::Write;
@@ -578,10 +652,8 @@ mod tests {
                 .color(false)
                 .format(DiagnosticFormat::Full);
 
-            for diagnostic in diagnostics {
-                let diag = diagnostic.into_diagnostic();
-                write!(buf, "{}", diag.display(&self.db, &config)).unwrap();
-            }
+            let diag = diagnostic.into_diagnostic();
+            write!(buf, "{}", diag.display(&self.db, &config)).unwrap();
 
             buf
         }
@@ -728,6 +800,20 @@ mod tests {
         10 | bb[: Literal[b"foo"]] = aa
            |              ^^^^^^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def i(x: int, /) -> int:
+            return x
+
+        x = 1
+        y: Literal[1] = x
+        z: int = i(1)
+        w: int = z
+        aa = b'foo'
+        bb: Literal[b"foo"] = aa
         "#);
     }
 
@@ -1321,6 +1407,20 @@ mod tests {
         10 | w[: tuple[int, str]] = z
            |                ^^^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def i(x: int, /) -> int:
+            return x
+        def s(x: str, /) -> str:
+            return x
+
+        x = (1, 'abc')
+        y: tuple[Literal[1], Literal["abc"]] = x
+        z: tuple[int, str] = (i(1), s('abc'))
+        w: tuple[int, str] = z
         "#);
     }
 
@@ -1654,6 +1754,18 @@ mod tests {
         8 | w[: int] = z
           |     ^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def i(x: int, /) -> int:
+            return x
+
+        x: int = 1
+        y: Literal[1] = x
+        z: int = i(1)
+        w: int = z
         "#);
     }
 
@@ -1691,6 +1803,15 @@ mod tests {
           |     ^^^
         5 | z = x
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def i(x: int, /) -> int:
+            return x
+        x: int = i(1)
+        z = x
         "#);
     }
 
@@ -1810,6 +1931,18 @@ mod tests {
         8 | a.y[: int] = int(3)
           |       ^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class A:
+            def __init__(self, y):
+                self.x: int = int(1)
+                self.y: Unknown = y
+
+        a: A = A(2)
+        a.y: int = int(3)
         "#);
     }
 
@@ -2640,6 +2773,22 @@ mod tests {
         12 | k[: list[Unknown | int | float]] = [-1, -2.0]
            |                          ^^^^^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        a: list[Unknown | int] = [1, 2]
+        b: list[Unknown | float] = [1.0, 2.0]
+        c: list[Unknown | bool] = [True, False]
+        d: list[Unknown | None] = [None, None]
+        e: list[Unknown | str] = ["hel", "lo"]
+        f: list[Unknown | str] = ['the', 're']
+        g: list[Unknown | str] = [f"{ft}", f"{ft}"]
+        h: list[Unknown | Template] = [t"wow %d", t"wow %d"]
+        i: list[Unknown | bytes] = [b'/x01', b'/x02']
+        j: list[Unknown | int | float] = [+1, +2.0]
+        k: list[Unknown | int | float] = [-1, -2.0]
         "#);
     }
 
@@ -2811,6 +2960,19 @@ mod tests {
         9 | c[: MyClass], d[: MyClass] = (MyClass(), MyClass())
           |                   ^^^^^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class MyClass:
+            def __init__(self):
+                self.x: int = 1
+
+        x: MyClass = MyClass()
+        y: tuple[MyClass, MyClass] = (MyClass(), MyClass())
+        a, b = MyClass(), MyClass()
+        c, d = (MyClass(), MyClass())
         "#);
     }
 
@@ -3681,6 +3843,20 @@ mod tests {
         10 | c[: MyClass[Unknown | int, str]], d[: MyClass[Unknown | int, str]] = (MyClass([x=][42], [y=]("a", "b")), MyClass([x=][42], [y=]("a", "…
            |                                                                                                                             ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class MyClass[T, U]:
+            def __init__(self, x: list[T], y: tuple[U, U]):
+                self.x = x
+                self.y = y
+
+        x: MyClass[Unknown | int, str] = MyClass([42], ("a", "b"))
+        y: tuple[MyClass[Unknown | int, str], MyClass[Unknown | int, str]] = (MyClass([42], ("a", "b")), MyClass([42], ("a", "b")))
+        a, b = MyClass([42], ("a", "b")), MyClass([42], ("a", "b"))
+        c, d = (MyClass([42], ("a", "b")), MyClass([42], ("a", "b")))
         "#);
     }
 
@@ -3836,6 +4012,20 @@ mod tests {
         10 | foo([x=]val.y)
            |      ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def foo(x: int): pass
+        class MyClass:
+            def __init__(self):
+                self.x: int = 1
+                self.y: int = 2
+        val: MyClass = MyClass()
+
+        foo(val.x)
+        foo(val.y)
         ");
     }
 
@@ -3901,6 +4091,20 @@ mod tests {
         10 | foo([x=]x.y)
            |      ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def foo(x: int): pass
+        class MyClass:
+            def __init__(self):
+                self.x: int = 1
+                self.y: int = 2
+        x: MyClass = MyClass()
+
+        foo(x.x)
+        foo(x.y)
         ");
     }
 
@@ -3969,6 +4173,22 @@ mod tests {
         12 | foo([x=]val.y())
            |      ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def foo(x: int): pass
+        class MyClass:
+            def __init__(self):
+            def x() -> int:
+                return 1
+            def y() -> int:
+                return 2
+        val: MyClass = MyClass()
+
+        foo(val.x())
+        foo(val.y())
         ");
     }
 
@@ -4043,6 +4263,24 @@ mod tests {
         14 | foo([x=]val.y()[1])
            |      ^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        from typing import List
+
+        def foo(x: int): pass
+        class MyClass:
+            def __init__(self):
+            def x() -> List[int]:
+                return 1
+            def y() -> List[int]:
+                return 2
+        val: MyClass = MyClass()
+
+        foo(val.x()[0])
+        foo(val.y()[1])
         ");
     }
 
@@ -4193,6 +4431,17 @@ mod tests {
         7 | foo([x=]y[0])
           |      ^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def foo(x: int): pass
+        x: list[Unknown | int] = [1]
+        y: list[Unknown | int] = [2]
+
+        foo(x[0])
+        foo(y[0])
         "#);
     }
 
@@ -4378,6 +4627,15 @@ mod tests {
         5 | f[: Foo] = Foo([x=]1)
           |                 ^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class Foo:
+            def __init__(self, x: int): pass
+        Foo(1)
+        f: Foo = Foo(1)
         ");
     }
 
@@ -4450,6 +4708,15 @@ mod tests {
         5 | f[: Foo] = Foo([x=]1)
           |                 ^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class Foo:
+            def __new__(cls, x: int): pass
+        Foo(1)
+        f: Foo = Foo(1)
         ");
     }
 
@@ -5197,6 +5464,15 @@ mod tests {
           |         ^^^^^^^^^^^^^
         5 | my_func(x="hello")
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        from typing import LiteralString
+        def my_func(x: LiteralString):
+            y: LiteralString = x
+        my_func(x="hello")
         "#);
     }
 
@@ -5339,6 +5615,23 @@ mod tests {
         13 |     y[: Literal[1, 2, 3, "hello"] | None] = x
            |                                     ^^^^
            |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def branch(cond: int):
+            if cond < 10:
+                x = 1
+            elif cond < 20:
+                x = 2
+            elif cond < 30:
+                x = 3
+            elif cond < 40:
+                x = "hello"
+            else:
+                x = None
+            y: Literal[1, 2, 3, "hello"] | None = x
         "#);
     }
 
@@ -5454,6 +5747,13 @@ mod tests {
         3 |     y[: type[list[str]]] = type(x)
           |                   ^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        def f(x: list[str]):
+            y: type[list[str]] = type(x)
         "#);
     }
 
@@ -5493,6 +5793,16 @@ mod tests {
         6 | ab[: property] = F.whatever
           |      ^^^^^^^^
           |
+
+        ---------------------------------------------
+        info[inlay-hint-edit]: File after edits
+        info: Source
+
+        class F:
+            @property
+            def whatever(self): ...
+
+        ab: property = F.whatever
         ");
     }
 
@@ -5810,6 +6120,196 @@ mod tests {
         ");
     }
 
+    #[test]
+    fn test_function_signature_inlay_hint() {
+        let mut test = inlay_hint_test(
+            "
+                  def foo(x: int, *y: bool, z: str | int | list[str]): ...
+
+                  a = foo",
+        );
+
+        assert_snapshot!(test.inlay_hints(), @r#"
+        def foo(x: int, *y: bool, z: str | int | list[str]): ...
+
+        a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+        ---------------------------------------------
+        info[inlay-hint-location]: Inlay Hint Target
+           --> stdlib/builtins.pyi:348:7
+            |
+        347 | @disjoint_base
+        348 | class int:
+            |       ^^^
+        349 |     """int([x]) -> integer
+        350 |     int(x, base=10) -> integer
+            |
+        info: Source
+         --> main2.py:4:16
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                ^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+            --> stdlib/builtins.pyi:2591:7
+             |
+        2590 | @final
+        2591 | class bool(int):
+             |       ^^^^
+        2592 |     """Returns True when the argument is true, False otherwise.
+        2593 |     The builtins True and False are the only two instances of the class bool.
+             |
+        info: Source
+         --> main2.py:4:25
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                         ^^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+           --> stdlib/builtins.pyi:915:7
+            |
+        914 | @disjoint_base
+        915 | class str(Sequence[str]):
+            |       ^^^
+        916 |     """str(object='') -> str
+        917 |     str(bytes_or_buffer[, encoding[, errors]]) -> str
+            |
+        info: Source
+         --> main2.py:4:37
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                     ^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+           --> stdlib/builtins.pyi:348:7
+            |
+        347 | @disjoint_base
+        348 | class int:
+            |       ^^^
+        349 |     """int([x]) -> integer
+        350 |     int(x, base=10) -> integer
+            |
+        info: Source
+         --> main2.py:4:43
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                           ^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+            --> stdlib/builtins.pyi:2802:7
+             |
+        2801 | @disjoint_base
+        2802 | class list(MutableSequence[_T]):
+             |       ^^^^
+        2803 |     """Built-in mutable sequence.
+             |
+        info: Source
+         --> main2.py:4:49
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                                 ^^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+           --> stdlib/builtins.pyi:915:7
+            |
+        914 | @disjoint_base
+        915 | class str(Sequence[str]):
+            |       ^^^
+        916 |     """str(object='') -> str
+        917 |     str(bytes_or_buffer[, encoding[, errors]]) -> str
+            |
+        info: Source
+         --> main2.py:4:54
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                                      ^^^
+          |
+
+        info[inlay-hint-location]: Inlay Hint Target
+          --> stdlib/ty_extensions.pyi:20:1
+           |
+        19 | # Types
+        20 | Unknown = object()
+           | ^^^^^^^
+        21 | AlwaysTruthy = object()
+        22 | AlwaysFalsy = object()
+           |
+        info: Source
+         --> main2.py:4:63
+          |
+        2 | def foo(x: int, *y: bool, z: str | int | list[str]): ...
+        3 |
+        4 | a[: def foo(x: int, *y: bool, *, z: str | int | list[str]) -> Unknown] = foo
+          |                                                               ^^^^^^^
+          |
+        "#);
+    }
+
+    #[test]
+    fn test_module_inlay_hint() {
+        let mut test = inlay_hint_test(
+            "
+                      import foo
+
+                      a = foo",
+        );
+
+        test.with_extra_file("foo.py", "'''Foo module'''");
+
+        assert_snapshot!(test.inlay_hints(), @r"
+        import foo
+
+        a[: <module 'foo'>] = foo
+        ---------------------------------------------
+        info[inlay-hint-location]: Inlay Hint Target
+         --> foo.py:1:1
+          |
+        1 | '''Foo module'''
+          | ^^^^^^^^^^^^^^^^
+          |
+        info: Source
+         --> main2.py:4:5
+          |
+        2 | import foo
+        3 |
+        4 | a[: <module 'foo'>] = foo
+          |     ^^^^^^^^^^^^^^
+          |
+        ");
+    }
+
+    #[test]
+    fn test_literal_type_alias_inlay_hint() {
+        let mut test = inlay_hint_test(
+            "
+                        from typing import Literal
+
+                        a = Literal['a', 'b', 'c']",
+        );
+
+        assert_snapshot!(test.inlay_hints(), @r"
+        from typing import Literal
+
+        a[: <typing.Literal special form>] = Literal['a', 'b', 'c']
+        ");
+    }
+
     struct InlayHintLocationDiagnostic {
         source: FileRange,
         target: FileRange,
@@ -5847,4 +6347,31 @@ mod tests {
             main
         }
     }
+
+    struct InlayHintEditDiagnostic {
+        file_content: String,
+    }
+
+    impl InlayHintEditDiagnostic {
+        fn new(file_content: String) -> Self {
+            Self { file_content }
+        }
+    }
+
+    impl IntoDiagnostic for InlayHintEditDiagnostic {
+        fn into_diagnostic(self) -> Diagnostic {
+            let mut main = Diagnostic::new(
+                DiagnosticId::Lint(LintName::of("inlay-hint-edit")),
+                Severity::Info,
+                "File after edits".to_string(),
+            );
+
+            main.sub(SubDiagnostic::new(
+                SubDiagnosticSeverity::Info,
+                format!("{}\n{}", "Source", self.file_content),
+            ));
+
+            main
+        }
+    }
 }

crates/ty_ide/src/lib.rs

@@ -33,7 +33,9 @@ pub use document_symbols::document_symbols;
 pub use goto::{goto_declaration, goto_definition, goto_type_definition};
 pub use goto_references::goto_references;
 pub use hover::hover;
-pub use inlay_hints::{InlayHintKind, InlayHintLabel, InlayHintSettings, inlay_hints};
+pub use inlay_hints::{
+    InlayHintKind, InlayHintLabel, InlayHintSettings, InlayHintTextEdit, inlay_hints,
+};
 pub use markup::MarkupKind;
 pub use references::ReferencesMode;
 pub use rename::{can_rename, rename};

crates/ty_ide/src/references.rs

@@ -20,7 +20,7 @@ use ruff_python_ast::{
 };
 use ruff_python_parser::Tokens;
 use ruff_text_size::{Ranged, TextRange};
-use ty_python_semantic::ImportAliasResolution;
+use ty_python_semantic::{ImportAliasResolution, SemanticModel};
 
 /// Mode for references search behavior
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
@@ -48,8 +48,9 @@ pub(crate) fn references(
     // Get the definitions for the symbol at the cursor position
 
     // When finding references, do not resolve any local aliases.
+    let model = SemanticModel::new(db, file);
     let target_definitions_nav = goto_target
-        .get_definition_targets(file, db, ImportAliasResolution::PreserveAliases)?
+        .get_definition_targets(&model, ImportAliasResolution::PreserveAliases)?
         .definition_targets(db)?;
     let target_definitions: Vec<NavigationTarget> = target_definitions_nav.into_iter().collect();
 
@@ -121,10 +122,10 @@ fn references_for_file(
 ) {
     let parsed = ruff_db::parsed::parsed_module(db, file);
     let module = parsed.load(db);
+    let model = SemanticModel::new(db, file);
 
     let mut finder = LocalReferencesFinder {
-        db,
-        file,
+        model: &model,
         target_definitions,
         references,
         mode,
@@ -156,8 +157,7 @@ fn is_symbol_externally_visible(goto_target: &GotoTarget<'_>) -> bool {
 
 /// AST visitor to find all references to a specific symbol by comparing semantic definitions
 struct LocalReferencesFinder<'a> {
-    db: &'a dyn Db,
-    file: File,
+    model: &'a SemanticModel<'a>,
     tokens: &'a Tokens,
     target_definitions: &'a [NavigationTarget],
     references: &'a mut Vec<ReferenceTarget>,
@@ -226,6 +226,22 @@ impl<'a> SourceOrderVisitor<'a> for LocalReferencesFinder<'a> {
                     self.check_identifier_reference(rest_name);
                 }
             }
+            AnyNodeRef::ExprStringLiteral(string_expr) if self.should_include_declaration() => {
+                // Highlight the sub-AST of a string annotation
+                if let Some((sub_ast, sub_model)) = self.model.enter_string_annotation(string_expr)
+                {
+                    let mut sub_finder = LocalReferencesFinder {
+                        model: &sub_model,
+                        target_definitions: self.target_definitions,
+                        references: self.references,
+                        mode: self.mode,
+                        tokens: sub_ast.tokens(),
+                        target_text: self.target_text,
+                        ancestors: Vec::new(),
+                    };
+                    sub_finder.visit_expr(sub_ast.expr());
+                }
+            }
             AnyNodeRef::Alias(alias) if self.should_include_declaration() => {
                 // Handle import alias declarations
                 if let Some(asname) = &alias.asname {
@@ -284,14 +300,13 @@ impl LocalReferencesFinder<'_> {
         // the node is fine here. Offsets matter only for import statements
         // where the identifier might be a multi-part module name.
         let offset = covering_node.node().start();
-
         if let Some(goto_target) =
-            GotoTarget::from_covering_node(covering_node, offset, self.tokens)
+            GotoTarget::from_covering_node(self.model, covering_node, offset, self.tokens)
         {
             // Get the definitions for this goto target
             if let Some(current_definitions_nav) = goto_target
-                .get_definition_targets(self.file, self.db, ImportAliasResolution::PreserveAliases)
-                .and_then(|definitions| definitions.declaration_targets(self.db))
+                .get_definition_targets(self.model, ImportAliasResolution::PreserveAliases)
+                .and_then(|definitions| definitions.declaration_targets(self.model.db()))
             {
                 let current_definitions: Vec<NavigationTarget> =
                     current_definitions_nav.into_iter().collect();
@@ -300,7 +315,7 @@ impl LocalReferencesFinder<'_> {
                     // Determine if this is a read or write reference
                     let kind = self.determine_reference_kind(covering_node);
                     let target =
-                        ReferenceTarget::new(self.file, covering_node.node().range(), kind);
+                        ReferenceTarget::new(self.model.file(), covering_node.node().range(), kind);
                     self.references.push(target);
                 }
             }

crates/ty_ide/src/rename.rs

@@ -3,15 +3,16 @@ use crate::references::{ReferencesMode, references};
 use crate::{Db, ReferenceTarget};
 use ruff_db::files::File;
 use ruff_text_size::{Ranged, TextSize};
-use ty_python_semantic::ImportAliasResolution;
+use ty_python_semantic::{ImportAliasResolution, SemanticModel};
 
 /// Returns the range of the symbol if it can be renamed, None if not.
 pub fn can_rename(db: &dyn Db, file: File, offset: TextSize) -> Option<ruff_text_size::TextRange> {
     let parsed = ruff_db::parsed::parsed_module(db, file);
     let module = parsed.load(db);
+    let model = SemanticModel::new(db, file);
 
     // Get the definitions for the symbol at the offset
-    let goto_target = find_goto_target(&module, offset)?;
+    let goto_target = find_goto_target(&model, &module, offset)?;
 
     // Don't allow renaming of import module components
     if matches!(
@@ -24,7 +25,7 @@ pub fn can_rename(db: &dyn Db, file: File, offset: TextSize) -> Option<ruff_text
     let current_file_in_project = is_file_in_project(db, file);
 
     if let Some(definition_targets) = goto_target
-        .get_definition_targets(file, db, ImportAliasResolution::PreserveAliases)
+        .get_definition_targets(&model, ImportAliasResolution::PreserveAliases)
         .and_then(|definitions| definitions.declaration_targets(db))
     {
         for target in &definition_targets {
@@ -58,9 +59,10 @@ pub fn rename(
 ) -> Option<Vec<ReferenceTarget>> {
     let parsed = ruff_db::parsed::parsed_module(db, file);
     let module = parsed.load(db);
+    let model = SemanticModel::new(db, file);
 
     // Get the definitions for the symbol at the offset
-    let goto_target = find_goto_target(&module, offset)?;
+    let goto_target = find_goto_target(&model, &module, offset)?;
 
     // Clients shouldn't call us with an empty new name, but just in case...
     if new_name.is_empty() {
@@ -337,6 +339,162 @@ class DataProcessor:
         ");
     }
 
+    #[test]
+    fn rename_string_annotation1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCla<CURSOR>ss" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @r#"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:2:5
+          |
+        2 | a: "MyClass" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |       -------
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn rename_string_annotation2() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyCl<CURSOR>ass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @r#"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |       -------
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn rename_string_annotation3() {
+        let test = cursor_test(
+            r#"
+        a: "None |<CURSOR> MyClass" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @"Cannot rename");
+    }
+
+    #[test]
+    fn rename_string_annotation4() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass<CURSOR>" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @r#"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:2:12
+          |
+        2 | a: "None | MyClass" = 1
+          |            ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |       -------
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn rename_string_annotation5() {
+        let test = cursor_test(
+            r#"
+        a: "None | MyClass"<CURSOR> = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @"Cannot rename");
+    }
+
+    #[test]
+    fn rename_string_annotation_dangling1() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass |" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @"Cannot rename");
+    }
+
+    #[test]
+    fn rename_string_annotation_dangling2() {
+        let test = cursor_test(
+            r#"
+        a: "MyCl<CURSOR>ass | No" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @r#"
+        info[rename]: Rename symbol (found 2 locations)
+         --> main.py:2:5
+          |
+        2 | a: "MyClass | No" = 1
+          |     ^^^^^^^
+        3 |
+        4 | class MyClass:
+          |       -------
+        5 |     """some docs"""
+          |
+        "#);
+    }
+
+    #[test]
+    fn rename_string_annotation_dangling3() {
+        let test = cursor_test(
+            r#"
+        a: "MyClass | N<CURSOR>o" = 1
+
+        class MyClass:
+            """some docs"""
+        "#,
+        );
+
+        assert_snapshot!(test.rename("MyNewClass"), @"Cannot rename");
+    }
+
     #[test]
     fn test_cannot_rename_import_module_component() {
         // Test that we cannot rename parts of module names in import statements

crates/ty_ide/src/semantic_tokens.rs

@@ -187,9 +187,9 @@ impl Deref for SemanticTokens {
 /// Pass None to get tokens for the entire file.
 pub fn semantic_tokens(db: &dyn Db, file: File, range: Option<TextRange>) -> SemanticTokens {
     let parsed = parsed_module(db, file).load(db);
-    let semantic_model = SemanticModel::new(db, file);
+    let model = SemanticModel::new(db, file);
 
-    let mut visitor = SemanticTokenVisitor::new(&semantic_model, file, range);
+    let mut visitor = SemanticTokenVisitor::new(&model, range);
     visitor.visit_body(parsed.suite());
 
     SemanticTokens::new(visitor.tokens)
@@ -197,8 +197,7 @@ pub fn semantic_tokens(db: &dyn Db, file: File, range: Option<TextRange>) -> Sem
 
 /// AST visitor that collects semantic tokens.
 struct SemanticTokenVisitor<'db> {
-    semantic_model: &'db SemanticModel<'db>,
-    file: File,
+    model: &'db SemanticModel<'db>,
     tokens: Vec<SemanticToken>,
     in_class_scope: bool,
     in_type_annotation: bool,
@@ -207,14 +206,9 @@ struct SemanticTokenVisitor<'db> {
 }
 
 impl<'db> SemanticTokenVisitor<'db> {
-    fn new(
-        semantic_model: &'db SemanticModel<'db>,
-        file: File,
-        range_filter: Option<TextRange>,
-    ) -> Self {
+    fn new(model: &'db SemanticModel<'db>, range_filter: Option<TextRange>) -> Self {
         Self {
-            semantic_model,
-            file,
+            model,
             tokens: Vec::new(),
             in_class_scope: false,
             in_target_creating_definition: false,
@@ -265,7 +259,7 @@ impl<'db> SemanticTokenVisitor<'db> {
 
     fn classify_name(&self, name: &ast::ExprName) -> (SemanticTokenType, SemanticTokenModifier) {
         // First try to classify the token based on its definition kind.
-        let definition = definition_for_name(self.semantic_model.db(), self.file, name);
+        let definition = definition_for_name(self.model, name);
 
         if let Some(definition) = definition {
             let name_str = name.id.as_str();
@@ -275,7 +269,7 @@ impl<'db> SemanticTokenVisitor<'db> {
         }
 
         // Fall back to type-based classification.
-        let ty = name.inferred_type(self.semantic_model);
+        let ty = name.inferred_type(self.model);
         let name_str = name.id.as_str();
         self.classify_from_type_and_name_str(ty, name_str)
     }
@@ -286,7 +280,7 @@ impl<'db> SemanticTokenVisitor<'db> {
         name_str: &str,
     ) -> Option<(SemanticTokenType, SemanticTokenModifier)> {
         let mut modifiers = SemanticTokenModifier::empty();
-        let db = self.semantic_model.db();
+        let db = self.model.db();
         let model = SemanticModel::new(db, definition.file(db));
 
         match definition.kind(db) {
@@ -712,12 +706,12 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
                 for alias in &import.names {
                     if let Some(asname) = &alias.asname {
                         // For aliased imports (from X import Y as Z), classify Z based on what Y is
-                        let ty = alias.inferred_type(self.semantic_model);
+                        let ty = alias.inferred_type(self.model);
                         let (token_type, modifiers) = self.classify_from_alias_type(ty, asname);
                         self.add_token(asname, token_type, modifiers);
                     } else {
                         // For direct imports (from X import Y), use semantic classification
-                        let ty = alias.inferred_type(self.semantic_model);
+                        let ty = alias.inferred_type(self.model);
                         let (token_type, modifiers) =
                             self.classify_from_alias_type(ty, &alias.name);
                         self.add_token(&alias.name, token_type, modifiers);
@@ -837,7 +831,7 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
                 self.visit_expr(&attr.value);
 
                 // Then add token for the attribute name (e.g., 'path' in 'os.path')
-                let ty = expr.inferred_type(self.semantic_model);
+                let ty = expr.inferred_type(self.model);
                 let (token_type, modifiers) =
                     Self::classify_from_type_for_attribute(ty, &attr.attr);
                 self.add_token(&attr.attr, token_type, modifiers);
@@ -881,6 +875,17 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
 
                 self.visit_expr(&named.value);
             }
+            ast::Expr::StringLiteral(string_expr) => {
+                // Highlight the sub-AST of a string annotation
+                if let Some((sub_ast, sub_model)) = self.model.enter_string_annotation(string_expr)
+                {
+                    let mut sub_visitor = SemanticTokenVisitor::new(&sub_model, None);
+                    sub_visitor.visit_expr(sub_ast.expr());
+                    self.tokens.extend(sub_visitor.tokens);
+                } else {
+                    walk_expr(self, expr);
+                }
+            }
             _ => {
                 // For all other expression types, let the default visitor handle them
                 walk_expr(self, expr);
@@ -1061,6 +1066,17 @@ impl SourceOrderVisitor<'_> for SemanticTokenVisitor<'_> {
             }
         }
     }
+
+    fn visit_comprehension(&mut self, comp: &ast::Comprehension) {
+        self.in_target_creating_definition = true;
+        self.visit_expr(&comp.target);
+        self.in_target_creating_definition = false;
+
+        self.visit_expr(&comp.iter);
+        for if_clause in &comp.ifs {
+            self.visit_expr(if_clause);
+        }
+    }
 }
 
 #[cfg(test)]
@@ -1564,6 +1580,50 @@ from mymodule import CONSTANT, my_function, MyClass
         "#);
     }
 
+    #[test]
+    fn test_str_annotation() {
+        let test = SemanticTokenTest::new(
+            r#"
+x: int = 1
+y: "int" = 1
+z = "int"
+w1: "int | str" = "hello"
+w2: "int | sr" = "hello"
+w3: "int | " = "hello"
+w4: "float"
+w5: "float
+"#,
+        );
+
+        let tokens = test.highlight_file();
+
+        assert_snapshot!(test.to_snapshot(&tokens), @r#"
+        "x" @ 1..2: Variable [definition]
+        "int" @ 4..7: Class
+        "1" @ 10..11: Number
+        "y" @ 12..13: Variable [definition]
+        "int" @ 16..19: Class
+        "1" @ 23..24: Number
+        "z" @ 25..26: Variable [definition]
+        "\"int\"" @ 29..34: String
+        "w1" @ 35..37: Variable [definition]
+        "int" @ 40..43: Class
+        "str" @ 46..49: Class
+        "\"hello\"" @ 53..60: String
+        "w2" @ 61..63: Variable [definition]
+        "int" @ 66..69: Class
+        "sr" @ 72..74: Variable
+        "\"hello\"" @ 78..85: String
+        "w3" @ 86..88: Variable [definition]
+        "\"int | \"" @ 90..98: String
+        "\"hello\"" @ 101..108: String
+        "w4" @ 109..111: Variable [definition]
+        "float" @ 114..119: Class
+        "w5" @ 121..123: Variable [definition]
+        "float" @ 126..131: Class
+        "#);
+    }
+
     #[test]
     fn test_attribute_classification() {
         let test = SemanticTokenTest::new(
@@ -2595,6 +2655,50 @@ with open("file.txt") as f:
         "#);
     }
 
+    #[test]
+    fn test_comprehensions() {
+        let test = SemanticTokenTest::new(
+            r#"
+list_comp = [x for x in range(10) if x % 2 == 0]
+set_comp = {x for x in range(10)}
+dict_comp = {k: v for k, v in zip(["a", "b"], [1, 2])}
+generator = (x for x in range(10))
+"#,
+        );
+
+        let tokens = test.highlight_file();
+        assert_snapshot!(test.to_snapshot(&tokens), @r#"
+        "list_comp" @ 1..10: Variable [definition]
+        "x" @ 14..15: Variable
+        "x" @ 20..21: Variable [definition]
+        "range" @ 25..30: Class
+        "10" @ 31..33: Number
+        "x" @ 38..39: Variable
+        "2" @ 42..43: Number
+        "0" @ 47..48: Number
+        "set_comp" @ 50..58: Variable [definition]
+        "x" @ 62..63: Variable
+        "x" @ 68..69: Variable [definition]
+        "range" @ 73..78: Class
+        "10" @ 79..81: Number
+        "dict_comp" @ 84..93: Variable [definition]
+        "k" @ 97..98: Variable
+        "v" @ 100..101: Variable
+        "k" @ 106..107: Variable [definition]
+        "v" @ 109..110: Variable [definition]
+        "zip" @ 114..117: Class
+        "\"a\"" @ 119..122: String
+        "\"b\"" @ 124..127: String
+        "1" @ 131..132: Number
+        "2" @ 134..135: Number
+        "generator" @ 139..148: Variable [definition]
+        "x" @ 152..153: Variable
+        "x" @ 158..159: Variable [definition]
+        "range" @ 163..168: Class
+        "10" @ 169..171: Number
+        "#);
+    }
+
     /// Regression test for <https://github.com/astral-sh/ty/issues/1406>
     #[test]
     fn test_invalid_kwargs() {

crates/ty_ide/src/signature_help.rs

@@ -74,7 +74,7 @@ pub fn signature_help(db: &dyn Db, file: File, offset: TextSize) -> Option<Signa
 
     // Get signature details from the semantic analyzer.
     let signature_details: Vec<CallSignatureDetails<'_>> =
-        call_signature_details(db, &model, call_expr);
+        call_signature_details(&model, call_expr);
 
     if signature_details.is_empty() {
         return None;

crates/ty_ide/src/stub_mapping.rs

@@ -11,12 +11,12 @@ use crate::cached_vendored_root;
 /// other language server providers (like hover, completion, and signature help) to find
 /// docstrings for functions that resolve to stubs.
 pub(crate) struct StubMapper<'db> {
-    db: &'db dyn crate::Db,
+    db: &'db dyn ty_python_semantic::Db,
     cached_vendored_root: Option<SystemPathBuf>,
 }
 
 impl<'db> StubMapper<'db> {
-    pub(crate) fn new(db: &'db dyn crate::Db) -> Self {
+    pub(crate) fn new(db: &'db dyn ty_python_semantic::Db) -> Self {
         let cached_vendored_root = cached_vendored_root(db);
         Self {
             db,

crates/ty_python_semantic/Cargo.toml

@@ -13,6 +13,7 @@ license = { workspace = true }
 [dependencies]
 ruff_db = { workspace = true }
 ruff_annotate_snippets = { workspace = true }
+ruff_diagnostics = { workspace = true }
 ruff_index = { workspace = true, features = ["salsa"] }
 ruff_macros = { workspace = true }
 ruff_memory_usage = { workspace = true }

crates/ty_python_semantic/resources/corpus/classliteral_decorators_cycle.py

@@ -0,0 +1,26 @@
+try:
+    type name_4 = name_1
+finally:
+    from .. import name_3
+
+try:
+    pass
+except* 0:
+    pass
+else:
+    def name_1() -> name_4:
+        pass
+
+    @name_1
+    def name_3():
+        pass
+finally:
+    try:
+        pass
+    except* 0:
+        assert name_3
+    finally:
+
+        @name_3
+        class name_1:
+            pass

crates/ty_python_semantic/resources/corpus/cyclic_reassignment.py

@@ -0,0 +1,5 @@
+class foo[_: foo](object): ...
+
+[_] = (foo,) = foo
+
+def foo(): ...

crates/ty_python_semantic/resources/corpus/cyclic_type_alias.py

@@ -0,0 +1,20 @@
+name_3: Foo = 0
+name_4 = 0
+
+if _0:
+    type name_3 = name_5
+    type name_4 = name_3
+
+_1: name_3
+
+def name_1(_2: name_4):
+    pass
+
+match 0:
+    case name_1._3:
+        pass
+    case 1:
+        type name_5 = name_4
+    case name_5:
+        pass
+name_3 = name_5

crates/ty_python_semantic/resources/mdtest/annotations/literal_string.md

@@ -35,6 +35,8 @@ bad_nesting: Literal[LiteralString]  # error: [invalid-type-form]
 
 `LiteralString` cannot be parameterized.
 
+<!-- snapshot-diagnostics -->
+
 ```py
 from typing_extensions import LiteralString
 
@@ -42,7 +44,6 @@ from typing_extensions import LiteralString
 a: LiteralString[str]
 
 # error: [invalid-type-form]
-# error: [unresolved-reference] "Name `foo` used when not defined"
 b: LiteralString["foo"]
 ```
 

crates/ty_python_semantic/resources/mdtest/assignment/annotations.md

@@ -222,10 +222,10 @@ reveal_type(r)  # revealed: dict[int | str, int | str]
 ## Incorrect collection literal assignments are complained about
 
 ```py
-# error: [invalid-assignment] "Object of type `list[Unknown | int]` is not assignable to `list[str]`"
+# error: [invalid-assignment] "Object of type `list[str | int]` is not assignable to `list[str]`"
 a: list[str] = [1, 2, 3]
 
-# error: [invalid-assignment] "Object of type `set[Unknown | int | str]` is not assignable to `set[int]`"
+# error: [invalid-assignment] "Object of type `set[int | str]` is not assignable to `set[int]`"
 b: set[int] = {1, 2, "3"}
 ```
 
@@ -422,7 +422,7 @@ reveal_type(d)  # revealed: list[int | tuple[int, int]]
 e: list[int] = f(True)
 reveal_type(e)  # revealed: list[int]
 
-# error: [invalid-assignment] "Object of type `list[str]` is not assignable to `list[int]`"
+# error: [invalid-assignment] "Object of type `list[int | str]` is not assignable to `list[int]`"
 g: list[int] = f("a")
 
 # error: [invalid-assignment] "Object of type `list[str]` is not assignable to `tuple[int]`"
@@ -459,12 +459,12 @@ reveal_type(b)  # revealed: TD
 
 # error: [missing-typed-dict-key] "Missing required key 'x' in TypedDict `TD` constructor"
 # error: [invalid-key] "Unknown key "y" for TypedDict `TD`"
-# error: [invalid-assignment] "Object of type `Unknown | dict[Unknown | str, Unknown | int]` is not assignable to `TD`"
+# error: [invalid-assignment] "Object of type `TD | dict[Unknown | str, Unknown | int]` is not assignable to `TD`"
 c: TD = f([{"y": 0}, {"x": 1}])
 
 # error: [missing-typed-dict-key] "Missing required key 'x' in TypedDict `TD` constructor"
 # error: [invalid-key] "Unknown key "y" for TypedDict `TD`"
-# error: [invalid-assignment] "Object of type `Unknown | dict[Unknown | str, Unknown | int]` is not assignable to `TD | None`"
+# error: [invalid-assignment] "Object of type `TD | None | dict[Unknown | str, Unknown | int]` is not assignable to `TD | None`"
 c: TD | None = f([{"y": 0}, {"x": 1}])
 ```
 
@@ -715,3 +715,17 @@ def _(a: int, b: str, c: int | str):
     x9: int | str | None = f(lst(c))
     reveal_type(x9)  # revealed: int | str | None
 ```
+
+## Forward annotation with unclosed string literal
+
+Regression test for [#1611](https://github.com/astral-sh/ty/issues/1611).
+
+<!-- blacken-docs:off -->
+
+```py
+# error: [invalid-syntax]
+# error: [invalid-syntax-in-forward-annotation]
+a:'
+```
+
+<!-- blacken-docs:on -->

crates/ty_python_semantic/resources/mdtest/attributes.md

@@ -1904,6 +1904,7 @@ we only consider the attribute assignment to be valid if the assigned attribute
 from typing import Literal
 
 class Date:
+    # error: [invalid-method-override]
     def __setattr__(self, name: Literal["day", "month", "year"], value: int) -> None:
         pass
 
@@ -2382,6 +2383,34 @@ class B:
 
 reveal_type(B().x)  # revealed: Unknown | Literal[1]
 reveal_type(A().x)  # revealed: Unknown | Literal[1]
+
+class Base:
+    def flip(self) -> "Sub":
+        return Sub()
+
+class Sub(Base):
+    # error: [invalid-method-override]
+    def flip(self) -> "Base":
+        return Base()
+
+class C2:
+    def __init__(self, x: Sub):
+        self.x = x
+
+    def replace_with(self, other: "C2"):
+        self.x = other.x.flip()
+
+reveal_type(C2(Sub()).x)  # revealed: Unknown | Base
+
+class C3:
+    def __init__(self, x: Sub):
+        self.x = [x]
+
+    def replace_with(self, other: "C3"):
+        self.x = [self.x[0].flip()]
+
+# TODO: should be `Unknown | list[Unknown | Sub] | list[Unknown | Base]`
+reveal_type(C3(Sub()).x)  # revealed: Unknown | list[Unknown | Sub] | list[Divergent]
 ```
 
 And cycles between many attributes:
@@ -2431,6 +2460,30 @@ class ManyCycles:
         reveal_type(self.x5)  # revealed: Unknown | int
         reveal_type(self.x6)  # revealed: Unknown | int
         reveal_type(self.x7)  # revealed: Unknown | int
+
+class ManyCycles2:
+    def __init__(self: "ManyCycles2"):
+        self.x1 = [0]
+        self.x2 = [1]
+        self.x3 = [1]
+
+    def f1(self: "ManyCycles2"):
+        # TODO: should be Unknown | list[Unknown | int] | list[Divergent]
+        reveal_type(self.x3)  # revealed: Unknown | list[Unknown | int] | list[Divergent] | list[Divergent]
+
+        self.x1 = [self.x2] + [self.x3]
+        self.x2 = [self.x1] + [self.x3]
+        self.x3 = [self.x1] + [self.x2]
+
+    def f2(self: "ManyCycles2"):
+        self.x1 = self.x2 + self.x3
+        self.x2 = self.x1 + self.x3
+        self.x3 = self.x1 + self.x2
+
+    def f3(self: "ManyCycles2"):
+        self.x1 = self.x2 + self.x3
+        self.x2 = self.x1 + self.x3
+        self.x3 = self.x1 + self.x2
 ```
 
 This case additionally tests our union/intersection simplification logic:
@@ -2610,12 +2663,18 @@ reveal_type(Answer.__members__)  # revealed: MappingProxyType[str, Unknown]
 
 ## Divergent inferred implicit instance attribute types
 
+If an implicit attribute is defined recursively and type inference diverges, the divergent part is
+filled in with the dynamic type `Divergent`. Types containing `Divergent` can be seen as "cheap"
+recursive types: they are not true recursive types based on recursive type theory, so no unfolding
+is performed when you use them.
+
 ```py
 class C:
     def f(self, other: "C"):
         self.x = (other.x, 1)
 
 reveal_type(C().x)  # revealed: Unknown | tuple[Divergent, Literal[1]]
+reveal_type(C().x[0])  # revealed: Unknown | Divergent
 ```
 
 This also works if the tuple is not constructed directly:
@@ -2654,11 +2713,11 @@ And it also works for homogeneous tuples:
 def make_homogeneous_tuple(x: T) -> tuple[T, ...]:
     return (x, x)
 
-class E:
-    def f(self, other: "E"):
+class F:
+    def f(self, other: "F"):
         self.x = make_homogeneous_tuple(other.x)
 
-reveal_type(E().x)  # revealed: Unknown | tuple[Divergent, ...]
+reveal_type(F().x)  # revealed: Unknown | tuple[Divergent, ...]
 ```
 
 ## Attributes of standard library modules that aren't yet defined
@@ -2710,10 +2769,10 @@ We give special diagnostics for this common case too:
 import foo
 import baz
 
-# error: [unresolved-attribute]
-reveal_type(foo.bar)  # revealed: Unknown
-# error: [unresolved-attribute]
-reveal_type(baz.bar)  # revealed: Unknown
+# error: [possibly-missing-attribute]
+reveal_type(foo.bar)  # revealed: <module 'foo.bar'>
+# error: [possibly-missing-attribute]
+reveal_type(baz.bar)  # revealed: <module 'baz.bar'>
 ```
 
 ## References

crates/ty_python_semantic/resources/mdtest/bidirectional.md

@@ -268,8 +268,8 @@ class A:
 
 A(f(1))
 
-# error: [invalid-argument-type] "Argument to function `__new__` is incorrect: Expected `list[int | str]`, found `list[list[Unknown]]`"
-# error: [invalid-argument-type] "Argument to bound method `__init__` is incorrect: Expected `list[int | None]`, found `list[list[Unknown]]`"
+# error: [invalid-argument-type] "Argument to function `__new__` is incorrect: Expected `list[int | str]`, found `list[int | None | list[Unknown]] & list[int | str | list[Unknown]] & list[list[Unknown]]`"
+# error: [invalid-argument-type] "Argument to bound method `__init__` is incorrect: Expected `list[int | None]`, found `list[int | None | list[Unknown]] & list[int | str | list[Unknown]] & list[list[Unknown]]`"
 A(f([]))
 ```
 

crates/ty_python_semantic/resources/mdtest/call/builtins.md

@@ -57,7 +57,7 @@ type("Foo", Base, {})
 # error: [invalid-argument-type] "Argument to class `type` is incorrect: Expected `tuple[type, ...]`, found `tuple[Literal[1], Literal[2]]`"
 type("Foo", (1, 2), {})
 
-# error: [invalid-argument-type] "Argument to class `type` is incorrect: Expected `dict[str, Any]`, found `dict[Unknown | bytes, Unknown | int]`"
+# error: [invalid-argument-type] "Argument to class `type` is incorrect: Expected `dict[str, Any]`, found `dict[str | bytes, Any]`"
 type("Foo", (Base,), {b"attr": 1})
 ```
 

crates/ty_python_semantic/resources/mdtest/call/callables_as_descriptors.md

@@ -237,4 +237,26 @@ class Matrix:
 Matrix() < Matrix()
 ```
 
+## `self`-binding behaviour of function-like `Callable`s
+
+Binding the `self` parameter of a function-like `Callable` creates a new `Callable` that is also
+function-like:
+
+`main.py`:
+
+```py
+from typing import Callable
+
+def my_lossy_decorator(fn: Callable[..., int]) -> Callable[..., int]:
+    return fn
+
+class MyClass:
+    @my_lossy_decorator
+    def method(self) -> int:
+        return 42
+
+reveal_type(MyClass().method)  # revealed: (...) -> int
+reveal_type(MyClass().method.__name__)  # revealed: str
+```
+
 [`tensorbase`]: https://github.com/pytorch/pytorch/blob/f3913ea641d871f04fa2b6588a77f63efeeb9f10/torch/_tensor.py#L1084-L1092

crates/ty_python_semantic/resources/mdtest/call/union.md

@@ -277,6 +277,6 @@ def _(flag: bool):
     x = f({"x": 1})
     reveal_type(x)  # revealed: int
 
-    # error: [invalid-argument-type] "Argument to function `f` is incorrect: Expected `T`, found `dict[Unknown | str, Unknown | int]`"
+    # error: [invalid-argument-type] "Argument to function `f` is incorrect: Expected `T`, found `dict[str, int] & dict[Unknown | str, Unknown | int]`"
     f({"y": 1})
 ```

crates/ty_python_semantic/resources/mdtest/class/super.md

@@ -501,8 +501,8 @@ class A[T]:
         return a
 
 class B[T](A[T]):
-    def f(self, b: T) -> T:
-        return super().f(b)
+    def f(self, a: T) -> T:
+        return super().f(a)
 ```
 
 ## Invalid Usages

crates/ty_python_semantic/resources/mdtest/comparison/instances/rich_comparison.md

@@ -24,10 +24,10 @@ class GtReturnType: ...
 class GeReturnType: ...
 
 class A:
-    def __eq__(self, other: A) -> EqReturnType:
+    def __eq__(self, other: A) -> EqReturnType:  # error: [invalid-method-override]
         return EqReturnType()
 
-    def __ne__(self, other: A) -> NeReturnType:
+    def __ne__(self, other: A) -> NeReturnType:  # error: [invalid-method-override]
         return NeReturnType()
 
     def __lt__(self, other: A) -> LtReturnType:
@@ -66,10 +66,10 @@ class GtReturnType: ...
 class GeReturnType: ...
 
 class A:
-    def __eq__(self, other: B) -> EqReturnType:
+    def __eq__(self, other: B) -> EqReturnType:  # error: [invalid-method-override]
         return EqReturnType()
 
-    def __ne__(self, other: B) -> NeReturnType:
+    def __ne__(self, other: B) -> NeReturnType:  # error: [invalid-method-override]
         return NeReturnType()
 
     def __lt__(self, other: B) -> LtReturnType:
@@ -111,10 +111,10 @@ class GtReturnType: ...
 class GeReturnType: ...
 
 class A:
-    def __eq__(self, other: B) -> EqReturnType:
+    def __eq__(self, other: B) -> EqReturnType:  # error: [invalid-method-override]
         return EqReturnType()
 
-    def __ne__(self, other: B) -> NeReturnType:
+    def __ne__(self, other: B) -> NeReturnType:  # error: [invalid-method-override]
         return NeReturnType()
 
     def __lt__(self, other: B) -> LtReturnType:
@@ -132,12 +132,10 @@ class A:
 class Unrelated: ...
 
 class B:
-    # To override builtins.object.__eq__ and builtins.object.__ne__
-    # TODO these should emit an invalid override diagnostic
-    def __eq__(self, other: Unrelated) -> B:
+    def __eq__(self, other: Unrelated) -> B:  # error: [invalid-method-override]
         return B()
 
-    def __ne__(self, other: Unrelated) -> B:
+    def __ne__(self, other: Unrelated) -> B:  # error: [invalid-method-override]
         return B()
 
 # Because `object.__eq__` and `object.__ne__` accept `object` in typeshed,
@@ -180,10 +178,10 @@ class GtReturnType: ...
 class GeReturnType: ...
 
 class A:
-    def __eq__(self, other: A) -> A:
+    def __eq__(self, other: A) -> A:  # error: [invalid-method-override]
         return A()
 
-    def __ne__(self, other: A) -> A:
+    def __ne__(self, other: A) -> A:  # error: [invalid-method-override]
         return A()
 
     def __lt__(self, other: A) -> A:
@@ -199,22 +197,22 @@ class A:
         return A()
 
 class B(A):
-    def __eq__(self, other: A) -> EqReturnType:
+    def __eq__(self, other: A) -> EqReturnType:  # error: [invalid-method-override]
         return EqReturnType()
 
-    def __ne__(self, other: A) -> NeReturnType:
+    def __ne__(self, other: A) -> NeReturnType:  # error: [invalid-method-override]
         return NeReturnType()
 
-    def __lt__(self, other: A) -> LtReturnType:
+    def __lt__(self, other: A) -> LtReturnType:  # error: [invalid-method-override]
         return LtReturnType()
 
-    def __le__(self, other: A) -> LeReturnType:
+    def __le__(self, other: A) -> LeReturnType:  # error: [invalid-method-override]
         return LeReturnType()
 
-    def __gt__(self, other: A) -> GtReturnType:
+    def __gt__(self, other: A) -> GtReturnType:  # error: [invalid-method-override]
         return GtReturnType()
 
-    def __ge__(self, other: A) -> GeReturnType:
+    def __ge__(self, other: A) -> GeReturnType:  # error: [invalid-method-override]
         return GeReturnType()
 
 reveal_type(A() == B())  # revealed: EqReturnType
@@ -243,10 +241,10 @@ class A:
         return A()
 
 class B(A):
-    def __lt__(self, other: int) -> B:
+    def __lt__(self, other: int) -> B:  # error: [invalid-method-override]
         return B()
 
-    def __gt__(self, other: int) -> B:
+    def __gt__(self, other: int) -> B:  # error: [invalid-method-override]
         return B()
 
 reveal_type(A() < B())  # revealed: A
@@ -291,11 +289,10 @@ Please refer to the [docs](https://docs.python.org/3/reference/datamodel.html#ob
 from __future__ import annotations
 
 class A:
-    # TODO both these overrides should emit invalid-override diagnostic
-    def __eq__(self, other: int) -> A:
+    def __eq__(self, other: int) -> A:  # error: [invalid-method-override]
         return A()
 
-    def __ne__(self, other: int) -> A:
+    def __ne__(self, other: int) -> A:  # error: [invalid-method-override]
         return A()
 
 reveal_type(A() == A())  # revealed: bool

crates/ty_python_semantic/resources/mdtest/comparison/tuples.md

@@ -155,10 +155,10 @@ class GtReturnType: ...
 class GeReturnType: ...
 
 class A:
-    def __eq__(self, o: object) -> EqReturnType:
+    def __eq__(self, o: object) -> EqReturnType:  # error: [invalid-method-override]
         return EqReturnType()
 
-    def __ne__(self, o: object) -> NeReturnType:
+    def __ne__(self, o: object) -> NeReturnType:  # error: [invalid-method-override]
         return NeReturnType()
 
     def __lt__(self, o: A) -> LtReturnType:
@@ -386,6 +386,7 @@ class NotBoolable:
     __bool__: None = None
 
 class A:
+    # error: [invalid-method-override]
     def __eq__(self, other) -> NotBoolable:
         return NotBoolable()
 

crates/ty_python_semantic/resources/mdtest/cycle.md

@@ -32,6 +32,55 @@ reveal_type(p.x)  # revealed: Unknown | int
 reveal_type(p.y)  # revealed: Unknown | int
 ```
 
+## Self-referential bare type alias
+
+```toml
+[environment]
+python-version = "3.12"  # typing.TypeAliasType
+```
+
+```py
+from typing import Union, TypeAliasType, Sequence, Mapping
+
+A = list["A" | None]
+
+def f(x: A):
+    # TODO: should be `list[A | None]`?
+    reveal_type(x)  # revealed: list[Divergent]
+    # TODO: should be `A | None`?
+    reveal_type(x[0])  # revealed: Divergent
+
+JSONPrimitive = Union[str, int, float, bool, None]
+JSONValue = TypeAliasType("JSONValue", 'Union[JSONPrimitive, Sequence["JSONValue"], Mapping[str, "JSONValue"]]')
+```
+
+## Self-referential legacy type variables
+
+```py
+from typing import Generic, TypeVar
+
+B = TypeVar("B", bound="Base")
+
+class Base(Generic[B]):
+    pass
+
+T = TypeVar("T", bound="Foo[int]")
+
+class Foo(Generic[T]): ...
+```
+
+## Self-referential PEP-695 type variables
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+class Node[T: "Node[int]"]:
+    pass
+```
+
 ## Parameter default values
 
 This is a regression test for <https://github.com/astral-sh/ty/issues/1402>. When a parameter has a

crates/ty_python_semantic/resources/mdtest/diagnostics/same_names.md

@@ -171,7 +171,7 @@ class Config:
 import generic_a
 import generic_b
 
-# TODO should be error: [invalid-assignment] "Object of type `<class 'generic_b.Container[int]'>` is not assignable to `type[generic_a.Container[int]]`"
+# error: [invalid-assignment] "Object of type `<class 'generic_b.Container[int]'>` is not assignable to `type[generic_a.Container[int]]`"
 container: type[generic_a.Container[int]] = generic_b.Container[int]
 ```
 

crates/ty_python_semantic/resources/mdtest/expression/len.md

@@ -103,8 +103,7 @@ class UnknownLengthSubclassWithDunderLenOverridden(tuple[int, ...]):
 reveal_type(len(UnknownLengthSubclassWithDunderLenOverridden()))  # revealed: Literal[42]
 
 class FixedLengthSubclassWithDunderLenOverridden(tuple[int]):
-    # TODO: we should complain about this as a Liskov violation (incompatible override)
-    def __len__(self) -> Literal[42]:
+    def __len__(self) -> Literal[42]:  # error: [invalid-method-override]
         return 42
 
 reveal_type(len(FixedLengthSubclassWithDunderLenOverridden((1,))))  # revealed: Literal[42]

crates/ty_python_semantic/resources/mdtest/generics/legacy/classes.md

@@ -273,7 +273,7 @@ class C(Generic[T]):
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -289,7 +289,7 @@ class C(Generic[T]):
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -308,7 +308,7 @@ class C(Generic[T]):
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -327,7 +327,7 @@ class C(Generic[T]):
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 
 class D(Generic[T]):
@@ -338,7 +338,7 @@ class D(Generic[T]):
 
 reveal_type(D(1))  # revealed: D[int]
 
-# error: [invalid-assignment] "Object of type `D[str]` is not assignable to `D[int]`"
+# error: [invalid-assignment] "Object of type `D[int | str]` is not assignable to `D[int]`"
 wrong_innards: D[int] = D("five")
 ```
 
@@ -454,7 +454,7 @@ reveal_type(C(1, 1))  # revealed: C[int]
 reveal_type(C(1, "string"))  # revealed: C[int]
 reveal_type(C(1, True))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five", 1)
 ```
 
@@ -732,6 +732,14 @@ class Base(Generic[T]): ...
 class Sub(Base["Sub"]): ...
 
 reveal_type(Sub)  # revealed: <class 'Sub'>
+
+U = TypeVar("U")
+
+class Base2(Generic[T, U]): ...
+
+# TODO: no error
+# error: [unsupported-base] "Unsupported class base with type `<class 'Base2[Sub2, U@Sub2]'> | <class 'Base2[Sub2[Unknown], U@Sub2]'>`"
+class Sub2(Base2["Sub2", U]): ...
 ```
 
 #### Without string forward references
@@ -756,6 +764,8 @@ from typing_extensions import Generic, TypeVar
 
 T = TypeVar("T")
 
+# TODO: no error "Unsupported class base with type `<class 'list[Derived[T@Derived]]'> | <class 'list[@Todo]'>`"
+# error: [unsupported-base]
 class Derived(list[Derived[T]], Generic[T]): ...
 ```
 

crates/ty_python_semantic/resources/mdtest/generics/pep695/classes.md

@@ -249,7 +249,7 @@ class C[T]:
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -263,7 +263,7 @@ class C[T]:
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -280,7 +280,7 @@ class C[T]:
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 ```
 
@@ -297,7 +297,7 @@ class C[T]:
 
 reveal_type(C(1))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five")
 
 class D[T]:
@@ -310,7 +310,7 @@ class D[T]:
 
 reveal_type(D(1))  # revealed: D[int]
 
-# error: [invalid-assignment] "Object of type `D[str]` is not assignable to `D[int]`"
+# error: [invalid-assignment] "Object of type `D[int | str]` is not assignable to `D[int]`"
 wrong_innards: D[int] = D("five")
 ```
 
@@ -395,7 +395,7 @@ reveal_type(C(1, 1))  # revealed: C[int]
 reveal_type(C(1, "string"))  # revealed: C[int]
 reveal_type(C(1, True))  # revealed: C[int]
 
-# error: [invalid-assignment] "Object of type `C[str]` is not assignable to `C[int]`"
+# error: [invalid-assignment] "Object of type `C[int | str]` is not assignable to `C[int]`"
 wrong_innards: C[int] = C("five", 1)
 ```
 

crates/ty_python_semantic/resources/mdtest/generics/specialize_constrained.md

@@ -22,8 +22,10 @@ from ty_extensions import ConstraintSet, generic_context
 # fmt: off
 
 def unbounded[T]():
-    # revealed: ty_extensions.Specialization[T@unbounded = object]
+    # revealed: ty_extensions.Specialization[T@unbounded = Unknown]
     reveal_type(generic_context(unbounded).specialize_constrained(ConstraintSet.always()))
+    # revealed: ty_extensions.Specialization[T@unbounded = object]
+    reveal_type(generic_context(unbounded).specialize_constrained(ConstraintSet.range(Never, T, object)))
     # revealed: None
     reveal_type(generic_context(unbounded).specialize_constrained(ConstraintSet.never()))
 
@@ -88,6 +90,7 @@ that makes the test succeed.
 from typing import Any
 
 def bounded_by_gradual[T: Any]():
+    # TODO: revealed: ty_extensions.Specialization[T@bounded_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@bounded_by_gradual = object]
     reveal_type(generic_context(bounded_by_gradual).specialize_constrained(ConstraintSet.always()))
     # revealed: None
@@ -168,12 +171,16 @@ from typing import Any
 # fmt: off
 
 def constrained_by_gradual[T: (Base, Any)]():
+    # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Unknown]
+    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Base]
+    reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.always()))
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@constrained_by_gradual = object]
-    reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.always()))
+    reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Never, T, object)))
     # revealed: None
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.never()))
 
+    # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Base]
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Never, T, Base)))
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
@@ -181,14 +188,14 @@ def constrained_by_gradual[T: (Base, Any)]():
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Never, T, Unrelated)))
 
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
-    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Super]
+    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Base]
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Never, T, Super)))
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Super]
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Super, T, Super)))
 
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
-    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = object]
+    # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Base]
     reveal_type(generic_context(constrained_by_gradual).specialize_constrained(ConstraintSet.range(Sub, T, object)))
     # TODO: revealed: ty_extensions.Specialization[T@constrained_by_gradual = Any]
     # revealed: ty_extensions.Specialization[T@constrained_by_gradual = Sub]
@@ -288,7 +295,7 @@ class Unrelated: ...
 # fmt: off
 
 def mutually_bound[T: Base, U]():
-    # revealed: ty_extensions.Specialization[T@mutually_bound = Base, U@mutually_bound = object]
+    # revealed: ty_extensions.Specialization[T@mutually_bound = Base, U@mutually_bound = Unknown]
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.always()))
     # revealed: None
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.never()))
@@ -296,7 +303,7 @@ def mutually_bound[T: Base, U]():
     # revealed: ty_extensions.Specialization[T@mutually_bound = Base, U@mutually_bound = Base]
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.range(Never, U, T)))
 
-    # revealed: ty_extensions.Specialization[T@mutually_bound = Sub, U@mutually_bound = object]
+    # revealed: ty_extensions.Specialization[T@mutually_bound = Sub, U@mutually_bound = Unknown]
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.range(Never, T, Sub)))
     # revealed: ty_extensions.Specialization[T@mutually_bound = Sub, U@mutually_bound = Sub]
     reveal_type(generic_context(mutually_bound).specialize_constrained(ConstraintSet.range(Never, T, Sub) & ConstraintSet.range(Never, U, T)))

crates/ty_python_semantic/resources/mdtest/import/cyclic.md

@@ -38,7 +38,7 @@ See: <https://github.com/astral-sh/ty/issues/113>
 from pkg.sub import A
 
 # TODO: This should be `<class 'A'>`
-reveal_type(A)  # revealed: Never
+reveal_type(A)  # revealed: Divergent
 ```
 
 `pkg/outer.py`:

crates/ty_python_semantic/resources/mdtest/import/nonstandard_conventions.md

@@ -60,8 +60,8 @@ Y: int = 47
 import mypackage
 
 reveal_type(mypackage.imported.X)  # revealed: int
-# error: [unresolved-attribute] "Submodule `fails` may not be available"
-reveal_type(mypackage.fails.Y)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `fails` may not be available"
+reveal_type(mypackage.fails.Y)  # revealed: int
 ```
 
 ### In Non-Stub
@@ -90,8 +90,8 @@ Y: int = 47
 import mypackage
 
 reveal_type(mypackage.imported.X)  # revealed: int
-# error: [unresolved-attribute] "Submodule `fails` may not be available"
-reveal_type(mypackage.fails.Y)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `fails` may not be available"
+reveal_type(mypackage.fails.Y)  # revealed: int
 ```
 
 ## Absolute `from` Import of Direct Submodule in `__init__`
@@ -125,8 +125,8 @@ Y: int = 47
 import mypackage
 
 reveal_type(mypackage.imported.X)  # revealed: int
-# error: [unresolved-attribute] "Submodule `fails` may not be available"
-reveal_type(mypackage.fails.Y)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `fails` may not be available"
+reveal_type(mypackage.fails.Y)  # revealed: int
 ```
 
 ### In Non-Stub
@@ -155,8 +155,8 @@ Y: int = 47
 import mypackage
 
 reveal_type(mypackage.imported.X)  # revealed: int
-# error: [unresolved-attribute] "Submodule `fails` may not be available"
-reveal_type(mypackage.fails.Y)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `fails` may not be available"
+reveal_type(mypackage.fails.Y)  # revealed: int
 ```
 
 ## Import of Direct Submodule in `__init__`
@@ -184,8 +184,8 @@ X: int = 42
 import mypackage
 
 # TODO: this could work and would be nice to have?
-# error: [unresolved-attribute] "Submodule `imported` may not be available"
-reveal_type(mypackage.imported.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `imported` may not be available"
+reveal_type(mypackage.imported.X)  # revealed: int
 ```
 
 ### In Non-Stub
@@ -208,8 +208,8 @@ X: int = 42
 import mypackage
 
 # TODO: this could work and would be nice to have
-# error: [unresolved-attribute] "Submodule `imported` may not be available"
-reveal_type(mypackage.imported.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `imported` may not be available"
+reveal_type(mypackage.imported.X)  # revealed: int
 ```
 
 ## Relative `from` Import of Nested Submodule in `__init__`
@@ -242,10 +242,10 @@ X: int = 42
 import mypackage
 
 reveal_type(mypackage.submodule)  # revealed: <module 'mypackage.submodule'>
-# error: [unresolved-attribute] "Submodule `nested` may not be available"
-reveal_type(mypackage.submodule.nested)  # revealed: Unknown
-# error: [unresolved-attribute] "Submodule `nested` may not be available"
-reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested)  # revealed: <module 'mypackage.submodule.nested'>
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested.X)  # revealed: int
 # error: [unresolved-attribute] "has no member `nested`"
 reveal_type(mypackage.nested)  # revealed: Unknown
 # error: [unresolved-attribute] "has no member `nested`"
@@ -280,10 +280,10 @@ import mypackage
 
 reveal_type(mypackage.submodule)  # revealed: <module 'mypackage.submodule'>
 # TODO: this would be nice to support
-# error: [unresolved-attribute] "Submodule `nested` may not be available"
-reveal_type(mypackage.submodule.nested)  # revealed: Unknown
-# error: [unresolved-attribute] "Submodule `nested` may not be available"
-reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested)  # revealed: <module 'mypackage.submodule.nested'>
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested.X)  # revealed: int
 reveal_type(mypackage.nested)  # revealed: <module 'mypackage.submodule.nested'>
 reveal_type(mypackage.nested.X)  # revealed: int
 ```
@@ -318,10 +318,10 @@ X: int = 42
 import mypackage
 
 reveal_type(mypackage.submodule)  # revealed: <module 'mypackage.submodule'>
-# error: [unresolved-attribute] "Submodule `nested` may not be available"
-reveal_type(mypackage.submodule.nested)  # revealed: Unknown
-# error: [unresolved-attribute] "Submodule `nested` may not be available"
-reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested)  # revealed: <module 'mypackage.submodule.nested'>
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested.X)  # revealed: int
 # error: [unresolved-attribute] "has no member `nested`"
 reveal_type(mypackage.nested)  # revealed: Unknown
 # error: [unresolved-attribute] "has no member `nested`"
@@ -356,10 +356,10 @@ import mypackage
 
 reveal_type(mypackage.submodule)  # revealed: <module 'mypackage.submodule'>
 # TODO: this would be nice to support
-# error: [unresolved-attribute] "Submodule `nested` may not be available"
-reveal_type(mypackage.submodule.nested)  # revealed: Unknown
-# error: [unresolved-attribute] "Submodule `nested` may not be available"
-reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested)  # revealed: <module 'mypackage.submodule.nested'>
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested.X)  # revealed: int
 reveal_type(mypackage.nested)  # revealed: <module 'mypackage.submodule.nested'>
 reveal_type(mypackage.nested.X)  # revealed: int
 ```
@@ -393,12 +393,14 @@ X: int = 42
 ```py
 import mypackage
 
-# error: [unresolved-attribute] "Submodule `submodule` may not be available"
-reveal_type(mypackage.submodule)  # revealed: Unknown
-# error: [unresolved-attribute] "Submodule `submodule` may not be available"
-reveal_type(mypackage.submodule.nested)  # revealed: Unknown
-# error: [unresolved-attribute] "Submodule `submodule` may not be available"
-reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `submodule` may not be available"
+reveal_type(mypackage.submodule)  # revealed: <module 'mypackage.submodule'>
+# error: [possibly-missing-attribute] "Submodule `submodule` may not be available"
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested)  # revealed: <module 'mypackage.submodule.nested'>
+# error: [possibly-missing-attribute] "Submodule `submodule` may not be available"
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested.X)  # revealed: int
 ```
 
 ### In Non-Stub
@@ -429,12 +431,14 @@ X: int = 42
 import mypackage
 
 # TODO: this would be nice to support
-# error: [unresolved-attribute] "Submodule `submodule` may not be available"
-reveal_type(mypackage.submodule)  # revealed: Unknown
-# error: [unresolved-attribute] "Submodule `submodule` may not be available"
-reveal_type(mypackage.submodule.nested)  # revealed: Unknown
-# error: [unresolved-attribute] "Submodule `submodule` may not be available"
-reveal_type(mypackage.submodule.nested.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `submodule` may not be available"
+reveal_type(mypackage.submodule)  # revealed: <module 'mypackage.submodule'>
+# error: [possibly-missing-attribute] "Submodule `submodule` may not be available"
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested)  # revealed: <module 'mypackage.submodule.nested'>
+# error: [possibly-missing-attribute] "Submodule `submodule` may not be available"
+# error: [possibly-missing-attribute] "Submodule `nested` may not be available"
+reveal_type(mypackage.submodule.nested.X)  # revealed: int
 ```
 
 ## Relative `from` Import of Direct Submodule in `__init__`, Mismatched Alias
@@ -460,8 +464,8 @@ X: int = 42
 ```py
 import mypackage
 
-# error: [unresolved-attribute] "Submodule `imported` may not be available"
-reveal_type(mypackage.imported.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `imported` may not be available"
+reveal_type(mypackage.imported.X)  # revealed: int
 # error: [unresolved-attribute] "has no member `imported_m`"
 reveal_type(mypackage.imported_m.X)  # revealed: Unknown
 ```
@@ -486,8 +490,8 @@ X: int = 42
 import mypackage
 
 # TODO: this would be nice to support, as it works at runtime
-# error: [unresolved-attribute] "Submodule `imported` may not be available"
-reveal_type(mypackage.imported.X)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `imported` may not be available"
+reveal_type(mypackage.imported.X)  # revealed: int
 reveal_type(mypackage.imported_m.X)  # revealed: int
 ```
 
@@ -647,8 +651,8 @@ reveal_type(mypackage.imported.X)  # revealed: int
 
 ## `from` Import of Other Package's Submodule
 
-`from mypackage import submodule` from outside the package is not modeled as a side-effect on
-`mypackage`, even in the importing file (this could be changed!).
+`from mypackage import submodule` and `from mypackage.submodule import not_a_submodule` from outside
+the package are both modeled as a side-effects on `mypackage`.
 
 ### In Stub
 
@@ -663,18 +667,28 @@ reveal_type(mypackage.imported.X)  # revealed: int
 X: int = 42
 ```
 
+`package2/__init__.pyi`:
+
+```pyi
+```
+
+`package2/submodule.pyi`:
+
+```pyi
+not_a_submodule: int
+```
+
 `main.py`:
 
 ```py
 import mypackage
+import package2
 from mypackage import imported
+from package2.submodule import not_a_submodule
 
 reveal_type(imported.X)  # revealed: int
-
-# TODO: this would be nice to support, but it's dangerous with available_submodule_attributes
-# for details, see: https://github.com/astral-sh/ty/issues/1488
-# error: [unresolved-attribute] "Submodule `imported` may not be available"
-reveal_type(mypackage.imported.X)  # revealed: Unknown
+reveal_type(mypackage.imported.X)  # revealed: int
+reveal_type(package2.submodule.not_a_submodule)  # revealed: int
 ```
 
 ### In Non-Stub
@@ -690,17 +704,28 @@ reveal_type(mypackage.imported.X)  # revealed: Unknown
 X: int = 42
 ```
 
+`package2/__init__.py`:
+
+```py
+```
+
+`package2/submodule.py`:
+
+```py
+not_a_submodule: int
+```
+
 `main.py`:
 
 ```py
 import mypackage
+import package2
 from mypackage import imported
+from package2.submodule import not_a_submodule
 
 reveal_type(imported.X)  # revealed: int
-
-# TODO: this would be nice to support, as it works at runtime
-# error: [unresolved-attribute] "Submodule `imported` may not be available"
-reveal_type(mypackage.imported.X)  # revealed: Unknown
+reveal_type(mypackage.imported.X)  # revealed: int
+reveal_type(package2.submodule.not_a_submodule)  # revealed: int
 ```
 
 ## `from` Import of Sibling Module
@@ -737,8 +762,8 @@ from mypackage import imported
 reveal_type(imported.X)  # revealed: int
 # error: [unresolved-attribute] "has no member `fails`"
 reveal_type(imported.fails.Y)  # revealed: Unknown
-# error: [unresolved-attribute] "Submodule `fails` may not be available"
-reveal_type(mypackage.fails.Y)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `fails` may not be available"
+reveal_type(mypackage.fails.Y)  # revealed: int
 ```
 
 ### In Non-Stub
@@ -770,8 +795,8 @@ from mypackage import imported
 
 reveal_type(imported.X)  # revealed: int
 reveal_type(imported.fails.Y)  # revealed: int
-# error: [unresolved-attribute] "Submodule `fails`"
-reveal_type(mypackage.fails.Y)  # revealed: Unknown
+# error: [possibly-missing-attribute] "Submodule `fails`"
+reveal_type(mypackage.fails.Y)  # revealed: int
 ```
 
 ## Fractal Re-export Nameclash Problems
@@ -859,6 +884,48 @@ from mypackage import funcmod
 x = funcmod(1)
 ```
 
+## A Tale of Two Modules
+
+`from typing import TYPE_CHECKING` has side-effects???
+
+### In Stub
+
+`mypackage/__init__.py`:
+
+```py
+from .conflicted.b import x
+```
+
+`mypackage/conflicted/__init__.py`:
+
+`mypackage/conflicted/other1/__init__.py`:
+
+```py
+x: int = 1
+```
+
+`mypackage/conflicted/b/__init__.py`:
+
+```py
+x: int = 1
+```
+
+`mypackage/conflicted/b/c/__init__.py`:
+
+```py
+y: int = 2
+```
+
+`main.py`:
+
+```py
+from typing import TYPE_CHECKING
+from mypackage.conflicted.other1 import x as x1
+import mypackage.conflicted.b.c
+
+reveal_type(mypackage.conflicted.b.c.y)  # revealed: int
+```
+
 ## Re-export Nameclash Problems In Functions
 
 `from` imports in an `__init__.py` at file scope should be visible to functions defined in the file:

crates/ty_python_semantic/resources/mdtest/import/relative.md

@@ -247,8 +247,8 @@ X: int = 42
 from . import foo
 import package
 
-# error: [unresolved-attribute]
-reveal_type(package.foo.X)  # revealed: Unknown
+# error: [possibly-missing-attribute]
+reveal_type(package.foo.X)  # revealed: int
 ```
 
 ## Relative imports at the top of a search path

crates/ty_python_semantic/resources/mdtest/import/tracking.md

@@ -116,3 +116,43 @@ b = 1
 
 ```py
 ```
+
+## Submodule is loaded in a non-global scope
+
+We recognise submodules as being available as attributes even if they are loaded in a function
+scope. The function might never be executed, which means that the submodule might never be loaded;
+however, we prefer to prioritise avoiding false positives over catching all possible errors here.
+
+`a/b.py`:
+
+```py
+```
+
+`a/c.py`:
+
+```py
+d = 42
+```
+
+`a/e/f.py`:
+
+```py
+```
+
+`main.py`:
+
+```py
+import a
+
+def f():
+    import a.b
+    from a.c import d
+    from a.e import f
+
+f()
+
+reveal_type(a.b)  # revealed: <module 'a.b'>
+reveal_type(a.c)  # revealed: <module 'a.c'>
+reveal_type(a.e)  # revealed: <module 'a.e'>
+reveal_type(a.e.f)  # revealed: <module 'a.e.f'>
+```

crates/ty_python_semantic/resources/mdtest/liskov.md

@@ -0,0 +1,585 @@
+# The Liskov Substitution Principle
+
+The Liskov Substitution Principle provides the basis for many of the assumptions a type checker
+generally makes about types in Python:
+
+> Subtype Requirement: Let ⁠`ϕ(x)`⁠ be a property provable about objects ⁠`x`⁠ of type `T`. Then
+> ⁠`ϕ(y)`⁠ should be true for objects ⁠`y` of type `S` where `S` is a subtype of `T`.
+
+In order for a type checker's assumptions to be sound, it is crucial for the type checker to enforce
+the Liskov Substitution Principle on code that it checks. In practice, this usually manifests as
+several checks for a type checker to perform when it checks a subclass `B` of a class `A`:
+
+1. Read-only attributes should only ever be overridden covariantly: if a property `A.p` resolves to
+    `int` when accessed, accessing `B.p` should either resolve to `int` or a subtype of `int`.
+1. Method return types should only ever be overridden covariantly: if a method `A.f` returns `int`
+    when called, calling `B.f` should also resolve to `int or a subtype of`int\`.
+1. Method parameters should only ever be overridden contravariantly: if a method `A.f` can be called
+    with an argument of type `bool`, then the method `B.f` must also be callable with type `bool`
+    (though it is permitted for the override to also accept other types)
+1. Mutable attributes should only ever be overridden invariantly: if a mutable attribute `A.attr`
+    resolves to type `str`, it can only be overridden on a subclass with exactly the same type.
+
+## Method return types
+
+<!-- snapshot-diagnostics -->
+
+```pyi
+class Super:
+    def method(self) -> int: ...
+
+class Sub1(Super):
+    def method(self) -> int: ...  # fine
+
+class Sub2(Super):
+    def method(self) -> bool: ...  # fine: `bool` is a subtype of `int`
+
+class Sub3(Super):
+    def method(self) -> object: ...  # error: [invalid-method-override]
+
+class Sub4(Super):
+    def method(self) -> str: ...  # error: [invalid-method-override]
+```
+
+## Method parameters
+
+<!-- snapshot-diagnostics -->
+
+```pyi
+class Super:
+    def method(self, x: int, /): ...
+
+class Sub1(Super):
+    def method(self, x: int, /): ...  # fine
+
+class Sub2(Super):
+    def method(self, x: object, /): ...  # fine: `method` still accepts any argument of type `int`
+
+class Sub4(Super):
+    def method(self, x: int | str, /): ...  # fine
+
+class Sub5(Super):
+    def method(self, x: int): ...  # fine: `x` can still be passed positionally
+
+class Sub6(Super):
+    # fine: `method()` can still be called with just a single argument
+    def method(self, x: int, *args): ...
+
+class Sub7(Super):
+    def method(self, x: int, **kwargs): ...  # fine
+
+class Sub8(Super):
+    def method(self, x: int, *args, **kwargs): ...  # fine
+
+class Sub9(Super):
+    def method(self, x: int, extra_positional_arg=42, /): ... # fine
+
+class Sub10(Super):
+    def method(self, x: int, extra_pos_or_kw_arg=42): ...  # fine
+
+class Sub11(Super):
+    def method(self, x: int, *, extra_kw_only_arg=42): ...  # fine
+
+class Sub12(Super):
+    # Some calls permitted by the superclass are now no longer allowed
+    # (the method can no longer be passed any arguments!)
+    def method(self, /): ...  # error: [invalid-method-override]
+
+class Sub13(Super):
+    # Some calls permitted by the superclass are now no longer allowed
+    # (the method can no longer be passed exactly one argument!)
+    def method(self, x, y, /): ...  # error: [invalid-method-override]
+
+class Sub14(Super):
+    # Some calls permitted by the superclass are now no longer allowed
+    # (x can no longer be passed positionally!)
+    def method(self, /, *, x): ...  # error: [invalid-method-override]
+
+class Sub15(Super):
+    # Some calls permitted by the superclass are now no longer allowed
+    # (x can no longer be passed any integer -- it now requires a bool!)
+    def method(self, x: bool, /): ...  # error: [invalid-method-override]
+
+class Super2:
+    def method2(self, x): ...
+
+class Sub16(Super2):
+    def method2(self, x, /): ...  # error: [invalid-method-override]
+
+class Sub17(Super2):
+    def method2(self, *, x): ...  # error: [invalid-method-override]
+
+class Super3:
+    def method3(self, *, x): ...
+
+class Sub18(Super3):
+    def method3(self, x): ...  # fine: `x` can still be used as a keyword argument
+
+class Sub19(Super3):
+    def method3(self, x, /): ...  # error: [invalid-method-override]
+
+class Super4:
+    def method(self, *args: int, **kwargs: str): ...
+
+class Sub20(Super4):
+    def method(self, *args: object, **kwargs: object): ...  # fine
+
+class Sub21(Super4):
+    def method(self, *args): ...  # error: [invalid-method-override]
+
+class Sub22(Super4):
+    def method(self, **kwargs): ...  # error: [invalid-method-override]
+
+class Sub23(Super4):
+    def method(self, x, *args, y, **kwargs): ...  # error: [invalid-method-override]
+```
+
+## The entire class hierarchy is checked
+
+If a child class's method definition is Liskov-compatible with the method definition on its parent
+class, Liskov compatibility must also nonetheless be checked with respect to the method definition
+on its grandparent class. This is because type checkers will treat the child class as a subtype of
+the grandparent class just as much as they treat it as a subtype of the parent class, so
+substitutability with respect to the grandparent class is just as important:
+
+<!-- snapshot-diagnostics -->
+
+`stub.pyi`:
+
+```pyi
+from typing import Any
+
+class Grandparent:
+    def method(self, x: int) -> None: ...
+
+class Parent(Grandparent):
+    def method(self, x: str) -> None: ...  # error: [invalid-method-override]
+
+class Child(Parent):
+    # compatible with the signature of `Parent.method`, but not with `Grandparent.method`:
+    def method(self, x: str) -> None: ...  # error: [invalid-method-override]
+
+class OtherChild(Parent):
+    # compatible with the signature of `Grandparent.method`, but not with `Parent.method`:
+    def method(self, x: int) -> None: ...  # error: [invalid-method-override]
+
+class GradualParent(Grandparent):
+    def method(self, x: Any) -> None: ...
+
+class ThirdChild(GradualParent):
+    # `GradualParent.method` is compatible with the signature of `Grandparent.method`,
+    # and `ThirdChild.method` is compatible with the signature of `GradualParent.method`,
+    # but `ThirdChild.method` is not compatible with the signature of `Grandparent.method`
+    def method(self, x: str) -> None: ...  # error: [invalid-method-override]
+```
+
+`other_stub.pyi`:
+
+```pyi
+class A:
+    def get(self, default): ...
+
+class B(A):
+    def get(self, default, /): ...  # error: [invalid-method-override]
+
+get = 56
+
+class C(B):
+    # `get` appears in the symbol table of `C`,
+    # but that doesn't confuse our diagnostic...
+    foo = get
+
+class D(C):
+    # compatible with `C.get` and `B.get`, but not with `A.get`
+    def get(self, my_default): ...  # error: [invalid-method-override]
+```
+
+## Non-generic methods on generic classes work as expected
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```pyi
+class A[T]:
+    def method(self, x: T) -> None: ...
+
+class B[T](A[T]):
+    def method(self, x: T) -> None: ...  # fine
+
+class C(A[int]):
+    def method(self, x: int) -> None: ...  # fine
+
+class D[T](A[T]):
+    def method(self, x: object) -> None: ...  # fine
+
+class E(A[int]):
+    def method(self, x: object) -> None: ...  # fine
+
+class F[T](A[T]):
+    # TODO: we should emit `invalid-method-override` on this:
+    # `str` is not necessarily a supertype of `T`!
+    def method(self, x: str) -> None: ...
+
+class G(A[int]):
+    def method(self, x: bool) -> None: ...  # error: [invalid-method-override]
+```
+
+## Generic methods on non-generic classes work as expected
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```pyi
+from typing import Never, Self
+
+class A:
+    def method[T](self, x: T) -> T: ...
+
+class B(A):
+    def method[T](self, x: T) -> T: ...  # fine
+
+class C(A):
+    def method(self, x: object) -> Never: ...  # fine
+
+class D(A):
+    # TODO: we should emit [invalid-method-override] here:
+    # `A.method` accepts an argument of any type,
+    # but `D.method` only accepts `int`s
+    def method(self, x: int) -> int: ...
+
+class A2:
+    def method(self, x: int) -> int: ...
+
+class B2(A2):
+    # fine: although `B2.method()` will not always return an `int`,
+    # an instance of `B2` can be substituted wherever an instance of `A2` is expected,
+    # and it *will* always return an `int` if it is passed an `int`
+    # (which is all that will be allowed if an instance of `A2` is expected)
+    def method[T](self, x: T) -> T: ...
+
+class C2(A2):
+    def method[T: int](self, x: T) -> T: ...
+
+class D2(A2):
+    # The type variable is bound to a type disjoint from `int`,
+    # so the method will not accept integers, and therefore this is an invalid override
+    def method[T: str](self, x: T) -> T: ...  # error: [invalid-method-override]
+
+class A3:
+    def method(self) -> Self: ...
+
+class B3(A3):
+    def method(self) -> Self: ...  # fine
+
+class C3(A3):
+    # TODO: should this be allowed?
+    # Mypy/pyright/pyrefly all allow it,
+    # but conceptually it seems similar to `B4.method` below,
+    # which mypy/pyrefly agree is a Liskov violation
+    # (pyright disagrees as of 20/11/2025: https://github.com/microsoft/pyright/issues/11128)
+    # when called on a subclass, `C3.method()` will not return an
+    # instance of that subclass
+    def method(self) -> C3: ...
+
+class D3(A3):
+    def method(self: Self) -> Self: ...  # fine
+
+class E3(A3):
+    def method(self: E3) -> Self: ...  # fine
+
+class F3(A3):
+    def method(self: A3) -> Self: ...  # fine
+
+class G3(A3):
+    def method(self: object) -> Self: ...  # fine
+
+class H3(A3):
+    # TODO: we should emit `invalid-method-override` here
+    # (`A3.method()` can be called on any instance of `A3`,
+    # but `H3.method()` can only be called on objects that are
+    # instances of `str`)
+    def method(self: str) -> Self: ...
+
+class I3(A3):
+    # TODO: we should emit `invalid-method-override` here
+    # (`I3.method()` cannot be called with any inhabited type!)
+    def method(self: Never) -> Self: ...
+
+class A4:
+    def method[T: int](self, x: T) -> T: ...
+
+class B4(A4):
+    # TODO: we should emit `invalid-method-override` here.
+    # `A4.method` promises that if it is passed a `bool`, it will return a `bool`,
+    # but this is not necessarily true for `B4.method`: if passed a `bool`,
+    # it could return a non-`bool` `int`!
+    def method(self, x: int) -> int: ...
+```
+
+## Generic methods on generic classes work as expected
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```pyi
+from typing import Never
+
+class A[T]:
+    def method[S](self, x: T, y: S) -> S: ...
+
+class B[T](A[T]):
+    def method[S](self, x: T, y: S) -> S: ...  # fine
+
+class C(A[int]):
+    def method[S](self, x: int, y: S) -> S: ...  # fine
+
+class D[T](A[T]):
+    def method[S](self, x: object, y: S) -> S: ...  # fine
+
+class E(A[int]):
+    def method[S](self, x: object, y: S) -> S: ...  # fine
+
+class F(A[int]):
+    def method(self, x: object, y: object) -> Never: ...  # fine
+
+class A2[T]:
+    def method(self, x: T, y: int) -> int: ...
+
+class B2[T](A2[T]):
+    def method[S](self, x: T, y: S) -> S: ...  # fine
+```
+
+## Fully qualified names are used in diagnostics where appropriate
+
+<!-- snapshot-diagnostics -->
+
+`a.pyi`:
+
+```pyi
+class A:
+    def foo(self, x): ...
+```
+
+`b.pyi`:
+
+```pyi
+import a
+
+class A(a.A):
+    def foo(self, y): ...  # error: [invalid-method-override]
+```
+
+## Excluded methods
+
+Certain special constructor methods are excluded from Liskov checks. None of the following classes
+cause us to emit any errors, therefore:
+
+```toml
+# This is so that the dataclasses machinery will generate `__replace__` methods for us
+# (the synthesized `__replace__` methods should not be reported as invalid overrides!)
+[environment]
+python-version = "3.13"
+```
+
+```pyi
+from dataclasses import dataclass
+from typing_extensions import Self
+
+class Grandparent: ...
+class Parent(Grandparent):
+    def __new__(cls, x: int) -> Self: ...
+    def __init__(self, x: int) -> None: ...
+
+class Child(Parent):
+    def __new__(cls, x: str, y: str) -> Self: ...
+    def __init__(self, x: str, y: str) -> Self: ...
+
+@dataclass(init=False)
+class DataSuper:
+    x: int
+
+    def __post_init__(self, x: int) -> None:
+        self.x = x
+
+@dataclass(init=False)
+class DataSub(DataSuper):
+    y: str
+
+    def __post_init__(self, x: int, y: str) -> None:
+        self.y = y
+        super().__post_init__(x)
+```
+
+## Edge case: function defined in another module and then assigned in a class body
+
+<!-- snapshot-diagnostics -->
+
+`foo.pyi`:
+
+```pyi
+def x(self, y: str): ...
+```
+
+`bar.pyi`:
+
+```pyi
+import foo
+
+class A:
+    def x(self, y: int): ...
+
+class B(A):
+    x = foo.x  # error: [invalid-method-override]
+
+class C:
+    x = foo.x
+
+class D(C):
+    def x(self, y: int): ...  # error: [invalid-method-override]
+```
+
+## Bad override of `__eq__`
+
+<!-- snapshot-diagnostics -->
+
+```py
+class Bad:
+    x: int
+    def __eq__(self, other: "Bad") -> bool:  # error: [invalid-method-override]
+        return self.x == other.x
+```
+
+## Synthesized methods
+
+`NamedTuple` classes and dataclasses both have methods generated at runtime that do not have
+source-code definitions. There are several scenarios to consider here:
+
+1. A synthesized method on a superclass is overridden by a "normal" (not synthesized) method on a
+    subclass
+1. A "normal" method on a superclass is overridden by a synthesized method on a subclass
+1. A synthesized method on a superclass is overridden by a synthesized method on a subclass
+
+<!-- snapshot-diagnostics -->
+
+```pyi
+from dataclasses import dataclass
+from typing import NamedTuple
+
+@dataclass(order=True)
+class Foo:
+    x: int
+
+class Bar(Foo):
+    def __lt__(self, other: Bar) -> bool: ...  # error: [invalid-method-override]
+
+# TODO: specifying `order=True` on the subclass means that a `__lt__` method is
+# generated that is incompatible with the generated `__lt__` method on the superclass.
+# We could consider detecting this and emitting a diagnostic, though maybe it shouldn't
+# be `invalid-method-override` since we'd emit it on the class definition rather than
+# on any method definition. Note also that no other type checker complains about this
+# as of 2025-11-21.
+@dataclass(order=True)
+class Bar2(Foo):
+    y: str
+
+# TODO: Although this class does not override any methods of `Foo`, the design of the
+# `order=True` stdlib dataclasses feature itself arguably violates the Liskov Substitution
+# Principle! Instances of `Bar3` cannot be substituted wherever an instance of `Foo` is
+# expected, because the generated `__lt__` method on `Foo` raises an error unless the r.h.s.
+# and `l.h.s.` have exactly the same `__class__` (it does not permit instances of `Foo` to
+# be compared with instances of subclasses of `Foo`).
+#
+# Many users would probably like their type checkers to alert them to cases where instances
+# of subclasses cannot be substituted for instances of superclasses, as this violates many
+# assumptions a type checker will make and makes it likely that a type checker will fail to
+# catch type errors elsewhere in the user's code. We could therefore consider treating all
+# `order=True` dataclasses as implicitly `@final` in order to enforce soundness. However,
+# this probably shouldn't be reported with the same error code as Liskov violations, since
+# the error does not stem from any method signatures written by the user. The example is
+# only included here for completeness.
+#
+# Note that no other type checker catches this error as of 2025-11-21.
+class Bar3(Foo): ...
+
+class Eggs:
+    def __lt__(self, other: Eggs) -> bool: ...
+
+# TODO: the generated `Ham.__lt__` method here incompatibly overrides `Eggs.__lt__`.
+# We could consider emitting a diagnostic here. As of 2025-11-21, mypy reports a
+# diagnostic here but pyright and pyrefly do not.
+@dataclass(order=True)
+class Ham(Eggs):
+    x: int
+
+class Baz(NamedTuple):
+    x: int
+
+class Spam(Baz):
+    def _asdict(self) -> tuple[int, ...]: ...  # error: [invalid-method-override]
+```
+
+## Staticmethods and classmethods
+
+Methods decorated with `@staticmethod` or `@classmethod` are checked in much the same way as other
+methods.
+
+<!-- snapshot-diagnostics -->
+
+```pyi
+class Parent:
+    def instance_method(self, x: int) -> int: ...
+    @classmethod
+    def class_method(cls, x: int) -> int: ...
+    @staticmethod
+    def static_method(x: int) -> int: ...
+
+class BadChild1(Parent):
+    @staticmethod
+    def instance_method(self, x: int) -> int: ...  # error: [invalid-method-override]
+    # TODO: we should emit `invalid-method-override` here.
+    # Although the method has the same signature as `Parent.class_method`
+    # when accessed on instances, it does not have the same signature as
+    # `Parent.class_method` when accessed on the class object itself
+    def class_method(cls, x: int) -> int: ...
+    def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+
+class BadChild2(Parent):
+    # TODO: we should emit `invalid-method-override` here.
+    # Although the method has the same signature as `Parent.class_method`
+    # when accessed on instances, it does not have the same signature as
+    # `Parent.class_method` when accessed on the class object itself.
+    #
+    # Note that whereas `BadChild1.class_method` is reported as a Liskov violation by
+    # mypy, pyright and pyrefly, pyright is the only one of those three to report a
+    # Liskov violation on this method as of 2025-11-23.
+    @classmethod
+    def instance_method(self, x: int) -> int: ...
+    @staticmethod
+    def class_method(cls, x: int) -> int: ...  # error: [invalid-method-override]
+    @classmethod
+    def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+
+class BadChild3(Parent):
+    @classmethod
+    def class_method(cls, x: bool) -> object: ...  # error: [invalid-method-override]
+    @staticmethod
+    def static_method(x: bool) -> object: ...  # error: [invalid-method-override]
+
+class GoodChild1(Parent):
+    @classmethod
+    def class_method(cls, x: int) -> int: ...
+    @staticmethod
+    def static_method(x: int) -> int: ...
+
+class GoodChild2(Parent):
+    @classmethod
+    def class_method(cls, x: object) -> bool: ...
+    @staticmethod
+    def static_method(x: object) -> bool: ...
+```

crates/ty_python_semantic/resources/mdtest/override.md

@@ -0,0 +1,314 @@
+# `typing.override`
+
+## Basics
+
+Decorating a method with `typing.override` decorator is an explicit indication to a type checker
+that the method is intended to override a method on a superclass. If the decorated method does not
+in fact override anything, a type checker should report a diagnostic on that method.
+
+<!-- snapshot-diagnostics -->
+
+```pyi
+from typing_extensions import override, Callable, TypeVar
+
+def lossy_decorator(fn: Callable) -> Callable: ...
+
+class A:
+    @override
+    def __repr__(self): ...  # fine: overrides `object.__repr__`
+
+class Parent:
+    def foo(self): ...
+    @property
+    def my_property1(self) -> int: ...
+    @property
+    def my_property2(self) -> int: ...
+    baz = None
+    @classmethod
+    def class_method1(cls) -> int: ...
+    @staticmethod
+    def static_method1() -> int: ...
+    @classmethod
+    def class_method2(cls) -> int: ...
+    @staticmethod
+    def static_method2() -> int: ...
+    @lossy_decorator
+    def decorated_1(self): ...
+    @lossy_decorator
+    def decorated_2(self): ...
+    @lossy_decorator
+    def decorated_3(self): ...
+
+class Child(Parent):
+    @override
+    def foo(self): ...  # fine: overrides `Parent.foo`
+    @property
+    @override
+    def my_property1(self) -> int: ...  # fine: overrides `Parent.my_property1`
+    @override
+    @property
+    def my_property2(self) -> int: ...  # fine: overrides `Parent.my_property2`
+    @override
+    def baz(self): ...  # fine: overrides `Parent.baz`
+    @classmethod
+    @override
+    def class_method1(cls) -> int: ...  # fine: overrides `Parent.class_method1`
+    @staticmethod
+    @override
+    def static_method1() -> int: ...  # fine: overrides `Parent.static_method1`
+    @override
+    @classmethod
+    def class_method2(cls) -> int: ...  # fine: overrides `Parent.class_method2`
+    @override
+    @staticmethod
+    def static_method2() -> int: ...  # fine: overrides `Parent.static_method2`
+    @override
+    def decorated_1(self): ...  # fine: overrides `Parent.decorated_1`
+    @override
+    @lossy_decorator
+    def decorated_2(self): ...  # fine: overrides `Parent.decorated_2`
+    @lossy_decorator
+    @override
+    def decorated_3(self): ...  # fine: overrides `Parent.decorated_3`
+
+class OtherChild(Parent): ...
+
+class Grandchild(OtherChild):
+    @override
+    def foo(self): ...  # fine: overrides `Parent.foo`
+    @override
+    @property
+    def bar(self) -> int: ...  # fine: overrides `Parent.bar`
+    @override
+    def baz(self): ...  # fine: overrides `Parent.baz`
+    @classmethod
+    @override
+    def class_method1(cls) -> int: ...  # fine: overrides `Parent.class_method1`
+    @staticmethod
+    @override
+    def static_method1() -> int: ...  # fine: overrides `Parent.static_method1`
+    @override
+    @classmethod
+    def class_method2(cls) -> int: ...  # fine: overrides `Parent.class_method2`
+    @override
+    @staticmethod
+    def static_method2() -> int: ...  # fine: overrides `Parent.static_method2`
+    @override
+    def decorated_1(self): ...  # fine: overrides `Parent.decorated_1`
+    @override
+    @lossy_decorator
+    def decorated_2(self): ...  # fine: overrides `Parent.decorated_2`
+    @lossy_decorator
+    @override
+    def decorated_3(self): ...  # fine: overrides `Parent.decorated_3`
+
+class Invalid:
+    @override
+    def ___reprrr__(self): ...  # error: [invalid-explicit-override]
+    @override
+    @classmethod
+    def foo(self): ...  # error: [invalid-explicit-override]
+    @classmethod
+    @override
+    def bar(self): ...  # error: [invalid-explicit-override]
+    @staticmethod
+    @override
+    def baz(): ...  # error: [invalid-explicit-override]
+    @override
+    @staticmethod
+    def eggs(): ...  # error: [invalid-explicit-override]
+    @property
+    @override
+    def bad_property1(self) -> int: ...  # TODO: should emit `invalid-explicit-override` here
+    @override
+    @property
+    def bad_property2(self) -> int: ...  # TODO: should emit `invalid-explicit-override` here
+    @lossy_decorator
+    @override
+    def lossy(self): ...  # TODO: should emit `invalid-explicit-override` here
+    @override
+    @lossy_decorator
+    def lossy2(self): ...  # TODO: should emit `invalid-explicit-override` here
+
+# TODO: all overrides in this class should cause us to emit *Liskov* violations,
+# but not `@override` violations
+class LiskovViolatingButNotOverrideViolating(Parent):
+    @override
+    @property
+    def foo(self) -> int: ...
+    @override
+    def my_property1(self) -> int: ...
+    @staticmethod
+    @override
+    def class_method1() -> int: ...
+    @classmethod
+    @override
+    def static_method1(cls) -> int: ...
+
+# Diagnostic edge case: `override` is very far away from the method definition in the source code:
+
+T = TypeVar("T")
+
+def identity(x: T) -> T: ...
+
+class Foo:
+    @override
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    @identity
+    def bar(self): ...  # error: [invalid-explicit-override]
+```
+
+## Overloads
+
+The typing spec states that for an overloaded method, `@override` should only be applied to the
+implementation function. However, we nonetheless respect the decorator in this situation, even
+though we also emit `invalid-overload` on these methods.
+
+```py
+from typing_extensions import override, overload
+
+class Spam:
+    @overload
+    def foo(self, x: str) -> str: ...
+    @overload
+    def foo(self, x: int) -> int: ...
+    @override
+    def foo(self, x: str | int) -> str | int:  # error: [invalid-explicit-override]
+        return x
+
+    @overload
+    @override
+    def bar(self, x: str) -> str: ...
+    @overload
+    @override
+    def bar(self, x: int) -> int: ...
+    @override
+    # error: [invalid-overload] "`@override` decorator should be applied only to the overload implementation"
+    # error: [invalid-overload] "`@override` decorator should be applied only to the overload implementation"
+    # error: [invalid-explicit-override]
+    def bar(self, x: str | int) -> str | int:
+        return x
+
+    @overload
+    @override
+    def baz(self, x: str) -> str: ...
+    @overload
+    def baz(self, x: int) -> int: ...
+    # error: [invalid-overload] "`@override` decorator should be applied only to the overload implementation"
+    # error: [invalid-explicit-override]
+    def baz(self, x: str | int) -> str | int:
+        return x
+```
+
+In a stub file, `@override` should always be applied to the first overload. Even if it isn't, we
+always emit `invalid-explicit-override` diagnostics on the first overload.
+
+`module.pyi`:
+
+```pyi
+from typing_extensions import override, overload
+
+class Spam:
+    @overload
+    def foo(self, x: str) -> str: ...  # error: [invalid-explicit-override]
+    @overload
+    @override
+    # error: [invalid-overload]  "`@override` decorator should be applied only to the first overload"
+    def foo(self, x: int) -> int: ...
+
+    @overload
+    @override
+    def bar(self, x: str) -> str: ...  # error: [invalid-explicit-override]
+    @overload
+    @override
+    # error: [invalid-overload]  "`@override` decorator should be applied only to the first overload"
+    def bar(self, x: int) -> int: ...
+
+    @overload
+    @override
+    def baz(self, x: str) -> str: ...  # error: [invalid-explicit-override]
+    @overload
+    def baz(self, x: int) -> int: ...
+```
+
+## Classes inheriting from `Any`
+
+```py
+from typing_extensions import Any, override
+from does_not_exist import SomethingUnknown  # error: [unresolved-import]
+
+class Parent1(Any): ...
+class Parent2(SomethingUnknown): ...
+
+class Child1(Parent1):
+    @override
+    def bar(self): ...  # fine
+
+class Child2(Parent2):
+    @override
+    def bar(self): ...  # fine
+```
+
+## Override of a synthesized method
+
+```pyi
+from typing_extensions import NamedTuple, TypedDict, override, Any, Self
+from dataclasses import dataclass
+
+@dataclass(order=True)
+class ParentDataclass:
+    x: int
+
+class Child(ParentDataclass):
+    @override
+    def __lt__(self, other: ParentDataclass) -> bool: ...  # fine
+
+class MyNamedTuple(NamedTuple):
+    x: int
+
+    @override
+    # TODO: this raises an exception at runtime (which we should emit a diagnostic for).
+    # It shouldn't be an `invalid-explicit-override` diagnostic, however.
+    def _asdict(self, /) -> dict[str, Any]: ...
+
+class MyNamedTupleParent(NamedTuple):
+    x: int
+
+class MyNamedTupleChild(MyNamedTupleParent):
+    @override
+    def _asdict(self, /) -> dict[str, Any]: ...  # fine
+
+class MyTypedDict(TypedDict):
+    x: int
+
+    @override
+    # TODO: it's invalid to define a method on a `TypedDict` class,
+    # so we should emit a diagnostic here.
+    # It shouldn't be an `invalid-explicit-override` diagnostic, however.
+    def copy(self) -> Self: ...
+
+class Grandparent(Any): ...
+
+class Parent(Grandparent, NamedTuple):  # error: [invalid-named-tuple]
+    x: int
+
+class Child(Parent):
+    @override
+    def foo(self): ...  # fine because `Any` is in the MRO
+```

crates/ty_python_semantic/resources/mdtest/pep613_type_aliases.md

@@ -144,17 +144,46 @@ def _(x: IntOrStr):
 ## Cyclic
 
 ```py
-from typing import TypeAlias
+from typing import TypeAlias, TypeVar, Union
+from types import UnionType
 
 RecursiveTuple: TypeAlias = tuple[int | "RecursiveTuple", str]
 
 def _(rec: RecursiveTuple):
+    # TODO should be `tuple[int | RecursiveTuple, str]`
     reveal_type(rec)  # revealed: tuple[Divergent, str]
 
 RecursiveHomogeneousTuple: TypeAlias = tuple[int | "RecursiveHomogeneousTuple", ...]
 
 def _(rec: RecursiveHomogeneousTuple):
+    # TODO should be `tuple[int | RecursiveHomogeneousTuple, ...]`
     reveal_type(rec)  # revealed: tuple[Divergent, ...]
+
+ClassInfo: TypeAlias = type | UnionType | tuple["ClassInfo", ...]
+reveal_type(ClassInfo)  # revealed: types.UnionType
+
+def my_isinstance(obj: object, classinfo: ClassInfo) -> bool:
+    # TODO should be `type | UnionType | tuple[ClassInfo, ...]`
+    reveal_type(classinfo)  # revealed: type | UnionType | tuple[Divergent, ...]
+    return isinstance(obj, classinfo)
+
+K = TypeVar("K")
+V = TypeVar("V")
+NestedDict: TypeAlias = dict[K, Union[V, "NestedDict[K, V]"]]
+
+def _(nested: NestedDict[str, int]):
+    # TODO should be `dict[str, int | NestedDict[str, int]]`
+    reveal_type(nested)  # revealed: @Todo(specialized generic alias in type expression)
+
+my_isinstance(1, int)
+my_isinstance(1, int | str)
+my_isinstance(1, (int, str))
+my_isinstance(1, (int, (str, float)))
+my_isinstance(1, (int, (str | float)))
+# error: [invalid-argument-type]
+my_isinstance(1, 1)
+# TODO should be an invalid-argument-type error
+my_isinstance(1, (int, (str, 1)))
 ```
 
 ## Conditionally imported on Python < 3.10

crates/ty_python_semantic/resources/mdtest/pep695_type_aliases.md

@@ -106,6 +106,29 @@ def _(flag: bool):
 ```py
 type ListOrSet[T] = list[T] | set[T]
 reveal_type(ListOrSet.__type_params__)  # revealed: tuple[TypeVar | ParamSpec | TypeVarTuple, ...]
+type Tuple1[T] = tuple[T]
+
+def _(cond: bool):
+    Generic = ListOrSet if cond else Tuple1
+
+    def _(x: Generic[int]):
+        reveal_type(x)  # revealed: list[int] | set[int] | tuple[int]
+
+try:
+    class Foo[T]:
+        x: T
+        def foo(self) -> T:
+            return self.x
+
+    ...
+except Exception:
+    class Foo[T]:
+        x: T
+        def foo(self) -> T:
+            return self.x
+
+def f(x: Foo[int]):
+    reveal_type(x.foo())  # revealed: int
 ```
 
 ## In unions and intersections
@@ -244,6 +267,47 @@ def f(x: IntOr, y: OrInt):
         reveal_type(x)  # revealed: Never
     if not isinstance(y, int):
         reveal_type(y)  # revealed: Never
+
+# error: [cyclic-type-alias-definition] "Cyclic definition of `Itself`"
+type Itself = Itself
+
+def foo(
+    # this is a very strange thing to do, but this is a regression test to ensure it doesn't panic
+    Itself: Itself,
+):
+    x: Itself
+    reveal_type(Itself)  # revealed: Divergent
+
+# A type alias defined with invalid recursion behaves as a dynamic type.
+foo(42)
+foo("hello")
+
+# error: [cyclic-type-alias-definition] "Cyclic definition of `A`"
+type A = B
+# error: [cyclic-type-alias-definition] "Cyclic definition of `B`"
+type B = A
+
+def bar(B: B):
+    x: B
+    reveal_type(B)  # revealed: Divergent
+
+# error: [cyclic-type-alias-definition] "Cyclic definition of `G`"
+type G[T] = G[T]
+# error: [cyclic-type-alias-definition] "Cyclic definition of `H`"
+type H[T] = I[T]
+# error: [cyclic-type-alias-definition] "Cyclic definition of `I`"
+type I[T] = H[T]
+
+# It's not possible to create an element of this type, but it's not an error for now
+type DirectRecursiveList[T] = list[DirectRecursiveList[T]]
+
+# TODO: this should probably be a cyclic-type-alias-definition error
+type Foo[T] = list[T] | Bar[T]
+type Bar[T] = int | Foo[T]
+
+def _(x: Bar[int]):
+    # TODO: should be `int | list[int]`
+    reveal_type(x)  # revealed: int | list[int] | Any
 ```
 
 ### With legacy generic
@@ -327,7 +391,7 @@ class C(P[T]):
     pass
 
 reveal_type(C[int]())  # revealed: C[int]
-reveal_type(C())  # revealed: C[Divergent]
+reveal_type(C())  # revealed: C[C[Divergent]]
 ```
 
 ### Union inside generic

crates/ty_python_semantic/resources/mdtest/protocols.md

@@ -2003,6 +2003,7 @@ python-version = "3.12"
 ```
 
 ```py
+from typing import final
 from typing_extensions import TypeVar, Self, Protocol
 from ty_extensions import is_equivalent_to, static_assert, is_assignable_to, is_subtype_of
 
@@ -2094,6 +2095,13 @@ class NominalReturningSelfNotGeneric:
     def g(self) -> "NominalReturningSelfNotGeneric":
         return self
 
+@final
+class Other: ...
+
+class NominalReturningOtherClass:
+    def g(self) -> Other:
+        raise NotImplementedError
+
 # TODO: should pass
 static_assert(is_equivalent_to(LegacyFunctionScoped, NewStyleFunctionScoped))  # error: [static-assert-error]
 
@@ -2112,8 +2120,7 @@ static_assert(not is_assignable_to(NominalLegacy, UsesSelf))
 static_assert(not is_assignable_to(NominalWithSelf, NewStyleFunctionScoped))
 static_assert(not is_assignable_to(NominalWithSelf, LegacyFunctionScoped))
 static_assert(is_assignable_to(NominalWithSelf, UsesSelf))
-# TODO: should pass
-static_assert(is_subtype_of(NominalWithSelf, UsesSelf))  # error: [static-assert-error]
+static_assert(is_subtype_of(NominalWithSelf, UsesSelf))
 
 # TODO: these should pass
 static_assert(not is_assignable_to(NominalNotGeneric, NewStyleFunctionScoped))  # error: [static-assert-error]
@@ -2126,6 +2133,8 @@ static_assert(not is_assignable_to(NominalReturningSelfNotGeneric, LegacyFunctio
 # TODO: should pass
 static_assert(not is_assignable_to(NominalReturningSelfNotGeneric, UsesSelf))  # error: [static-assert-error]
 
+static_assert(not is_assignable_to(NominalReturningOtherClass, UsesSelf))
+
 # These test cases are taken from the typing conformance suite:
 class ShapeProtocolImplicitSelf(Protocol):
     def set_scale(self, scale: float) -> Self: ...
@@ -3069,18 +3078,15 @@ from typing import Protocol
 from ty_extensions import static_assert, is_subtype_of, is_equivalent_to, is_disjoint_from
 
 class HasRepr(Protocol):
-    # TODO: we should emit a diagnostic here complaining about a Liskov violation
-    # (it incompatibly overrides `__repr__` from `object`, a supertype of `HasRepr`)
+    # error: [invalid-method-override]
     def __repr__(self) -> object: ...
 
 class HasReprRecursive(Protocol):
-    # TODO: we should emit a diagnostic here complaining about a Liskov violation
-    # (it incompatibly overrides `__repr__` from `object`, a supertype of `HasReprRecursive`)
+    # error: [invalid-method-override]
     def __repr__(self) -> "HasReprRecursive": ...
 
 class HasReprRecursiveAndFoo(Protocol):
-    # TODO: we should emit a diagnostic here complaining about a Liskov violation
-    # (it incompatibly overrides `__repr__` from `object`, a supertype of `HasReprRecursiveAndFoo`)
+    # error: [invalid-method-override]
     def __repr__(self) -> "HasReprRecursiveAndFoo": ...
     foo: int
 
@@ -3180,6 +3186,33 @@ from ty_extensions import reveal_protocol_interface
 reveal_protocol_interface(Foo)
 ```
 
+## Known panics
+
+### Protocols generic over TypeVars bound to forward references
+
+This test currently panics because the `ClassLiteral::explicit_bases` query fails to converge. See
+issue <https://github.com/astral-sh/ty/issues/1587>.
+
+<!-- expect-panic: execute: too many cycle iterations -->
+
+```py
+from typing import Any, Protocol, TypeVar
+
+T1 = TypeVar("T1", bound="A2[Any]")
+T2 = TypeVar("T2", bound="A1[Any]")
+T3 = TypeVar("T3", bound="B2[Any]")
+T4 = TypeVar("T4", bound="B1[Any]")
+
+class A1(Protocol[T1]):
+    def get_x(self): ...
+
+class A2(Protocol[T2]):
+    def get_y(self): ...
+
+class B1(A1[T3], Protocol[T3]): ...
+class B2(A2[T4], Protocol[T4]): ...
+```
+
 ## TODO
 
 Add tests for:

crates/ty_python_semantic/resources/mdtest/regression/1377_iteration_count_mismatch.md

@@ -2,10 +2,7 @@
 
 Regression test for <https://github.com/astral-sh/ty/issues/1377>.
 
-The code is an excerpt from <https://github.com/Gobot1234/steam.py> that is minimal enough to
-trigger the iteration count mismatch bug in Salsa.
-
-<!-- expect-panic: execute: too many cycle iterations -->
+The code is an excerpt from <https://github.com/Gobot1234/steam.py>.
 
 ```toml
 [environment]

crates/ty_python_semantic/resources/mdtest/snapshots/attributes.md_-_Attributes_-_Attributes_of_standa…_(49ba2c9016d64653).snap

@@ -32,7 +32,8 @@ error[unresolved-attribute]: Module `datetime` has no member `UTC`
 5 | # error: [unresolved-attribute]
 6 | reveal_type(datetime.fakenotreal)  # revealed: Unknown
   |
-info: Python 3.10 was assumed when accessing `UTC` because it was specified on the command line
+info: The member may be available on other Python versions or platforms
+info: Python 3.10 was assumed when resolving the `UTC` attribute because it was specified on the command line
 info: rule `unresolved-attribute` is enabled by default
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/attributes.md_-_Attributes_-_Unimported_submodule…_(2b6da09ed380b2).snap

@@ -30,39 +30,39 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/attributes.md
 1 | import foo
 2 | import baz
 3 | 
-4 | # error: [unresolved-attribute]
-5 | reveal_type(foo.bar)  # revealed: Unknown
-6 | # error: [unresolved-attribute]
-7 | reveal_type(baz.bar)  # revealed: Unknown
+4 | # error: [possibly-missing-attribute]
+5 | reveal_type(foo.bar)  # revealed: <module 'foo.bar'>
+6 | # error: [possibly-missing-attribute]
+7 | reveal_type(baz.bar)  # revealed: <module 'baz.bar'>
 ```
 
 # Diagnostics
 
 ```
-error[unresolved-attribute]: Submodule `bar` may not be available as an attribute on module `foo`
+warning[possibly-missing-attribute]: Submodule `bar` may not be available as an attribute on module `foo`
  --> src/main.py:5:13
   |
-4 | # error: [unresolved-attribute]
-5 | reveal_type(foo.bar)  # revealed: Unknown
+4 | # error: [possibly-missing-attribute]
+5 | reveal_type(foo.bar)  # revealed: <module 'foo.bar'>
   |             ^^^^^^^
-6 | # error: [unresolved-attribute]
-7 | reveal_type(baz.bar)  # revealed: Unknown
+6 | # error: [possibly-missing-attribute]
+7 | reveal_type(baz.bar)  # revealed: <module 'baz.bar'>
   |
 help: Consider explicitly importing `foo.bar`
-info: rule `unresolved-attribute` is enabled by default
+info: rule `possibly-missing-attribute` is enabled by default
 
 ```
 
 ```
-error[unresolved-attribute]: Submodule `bar` may not be available as an attribute on module `baz`
+warning[possibly-missing-attribute]: Submodule `bar` may not be available as an attribute on module `baz`
  --> src/main.py:7:13
   |
-5 | reveal_type(foo.bar)  # revealed: Unknown
-6 | # error: [unresolved-attribute]
-7 | reveal_type(baz.bar)  # revealed: Unknown
+5 | reveal_type(foo.bar)  # revealed: <module 'foo.bar'>
+6 | # error: [possibly-missing-attribute]
+7 | reveal_type(baz.bar)  # revealed: <module 'baz.bar'>
   |             ^^^^^^^
   |
 help: Consider explicitly importing `baz.bar`
-info: rule `unresolved-attribute` is enabled by default
+info: rule `possibly-missing-attribute` is enabled by default
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/invalid.md_-_Tests_for_invalid_ty…_-_Diagnostics_for_comm…_-_Module-literal_used_…_(652fec4fd4a6c63a).snap

@@ -34,29 +34,27 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/annotations/invalid.md
 # Diagnostics
 
 ```
-error[invalid-type-form]: Variable of type `<module 'datetime'>` is not allowed in a type expression
+error[invalid-type-form]: Module `datetime` is not valid in a type expression
  --> src/foo.py:3:10
   |
 1 | import datetime
 2 |
 3 | def f(x: datetime): ...  # error: [invalid-type-form]
-  |          ^^^^^^^^
+  |          ^^^^^^^^ Did you mean to use the module's member `datetime.datetime`?
   |
-info: Did you mean to use the module's member `datetime.datetime` instead?
 info: rule `invalid-type-form` is enabled by default
 
 ```
 
 ```
-error[invalid-type-form]: Variable of type `<module 'PIL.Image'>` is not allowed in a type expression
+error[invalid-type-form]: Module `PIL.Image` is not valid in a type expression
  --> src/bar.py:3:10
   |
 1 | from PIL import Image
 2 |
 3 | def g(x: Image): ...  # error: [invalid-type-form]
-  |          ^^^^^
+  |          ^^^^^ Did you mean to use the module's member `Image.Image`?
   |
-info: Did you mean to use the module's member `Image.Image` instead?
 info: rule `invalid-type-form` is enabled by default
 
 ```

crates/ty_python_semantic/resources/mdtest/snapshots/invalid_assignment.m…_-_Invalid_assignment_d…_-_Multiple_targets_(e20ddfd7a91affb0).snap

@@ -23,13 +23,13 @@ mdtest path: crates/ty_python_semantic/resources/mdtest/diagnostics/invalid_assi
 # Diagnostics
 
 ```
-error[invalid-assignment]: Object of type `tuple[Literal["a"], Literal["b"]]` is not assignable to `int`
+error[invalid-assignment]: Object of type `Literal["a"]` is not assignable to `int`
  --> src/mdtest_snippet.py:4:1
   |
 2 | y: str
 3 |
 4 | x, y = ("a", "b")  # error: [invalid-assignment]
-  | -      ^^^^^^^^^^ Incompatible value of type `tuple[Literal["a"], Literal["b"]]`
+  | -      ^^^^^^^^^^ Incompatible value of type `Literal["a"]`
   | |
   | Declared type `int`
 5 |
@@ -40,13 +40,13 @@ info: rule `invalid-assignment` is enabled by default
 ```
 
 ```
-error[invalid-assignment]: Object of type `tuple[Literal[0], Literal[0]]` is not assignable to `str`
+error[invalid-assignment]: Object of type `Literal[0]` is not assignable to `str`
  --> src/mdtest_snippet.py:6:4
   |
 4 | x, y = ("a", "b")  # error: [invalid-assignment]
 5 |
 6 | x, y = (0, 0)  # error: [invalid-assignment]
-  |    -   ^^^^^^ Incompatible value of type `tuple[Literal[0], Literal[0]]`
+  |    -   ^^^^^^ Incompatible value of type `Literal[0]`
   |    |
   |    Declared type `str`
   |

crates/ty_python_semantic/resources/mdtest/snapshots/liskov.md_-_The_Liskov_Substitut…_-_Bad_override_of_`__e…_(4b336040d5332220).snap

@@ -0,0 +1,52 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: liskov.md - The Liskov Substitution Principle - Bad override of `__eq__`
+mdtest path: crates/ty_python_semantic/resources/mdtest/liskov.md
+---
+
+# Python source files
+
+## mdtest_snippet.py
+
+```
+1 | class Bad:
+2 |     x: int
+3 |     def __eq__(self, other: "Bad") -> bool:  # error: [invalid-method-override]
+4 |         return self.x == other.x
+```
+
+# Diagnostics
+
+```
+error[invalid-method-override]: Invalid override of method `__eq__`
+   --> src/mdtest_snippet.py:3:9
+    |
+  1 | class Bad:
+  2 |     x: int
+  3 |     def __eq__(self, other: "Bad") -> bool:  # error: [invalid-method-override]
+    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `object.__eq__`
+  4 |         return self.x == other.x
+    |
+   ::: stdlib/builtins.pyi:142:9
+    |
+140 |     def __setattr__(self, name: str, value: Any, /) -> None: ...
+141 |     def __delattr__(self, name: str, /) -> None: ...
+142 |     def __eq__(self, value: object, /) -> bool: ...
+    |         -------------------------------------- `object.__eq__` defined here
+143 |     def __ne__(self, value: object, /) -> bool: ...
+144 |     def __str__(self) -> str: ...  # noqa: Y029
+    |
+info: This violates the Liskov Substitution Principle
+help: It is recommended for `__eq__` to work with arbitrary objects, for example:
+help
+help:     def __eq__(self, other: object) -> bool:
+help:         if not isinstance(other, Bad):
+help:             return False
+help:         return <logic to compare two `Bad` instances>
+help
+info: rule `invalid-method-override` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/liskov.md_-_The_Liskov_Substitut…_-_Edge_case___function_…_(c8756a54d1cb8499).snap

@@ -0,0 +1,82 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: liskov.md - The Liskov Substitution Principle - Edge case: function defined in another module and then assigned in a class body
+mdtest path: crates/ty_python_semantic/resources/mdtest/liskov.md
+---
+
+# Python source files
+
+## foo.pyi
+
+```
+1 | def x(self, y: str): ...
+```
+
+## bar.pyi
+
+```
+ 1 | import foo
+ 2 | 
+ 3 | class A:
+ 4 |     def x(self, y: int): ...
+ 5 | 
+ 6 | class B(A):
+ 7 |     x = foo.x  # error: [invalid-method-override]
+ 8 | 
+ 9 | class C:
+10 |     x = foo.x
+11 | 
+12 | class D(C):
+13 |     def x(self, y: int): ...  # error: [invalid-method-override]
+```
+
+# Diagnostics
+
+```
+error[invalid-method-override]: Invalid override of method `x`
+ --> src/bar.pyi:4:9
+  |
+3 | class A:
+4 |     def x(self, y: int): ...
+  |         --------------- `A.x` defined here
+5 |
+6 | class B(A):
+7 |     x = foo.x  # error: [invalid-method-override]
+  |     ^^^^^^^^^ Definition is incompatible with `A.x`
+8 |
+9 | class C:
+  |
+ ::: src/foo.pyi:1:5
+  |
+1 | def x(self, y: str): ...
+  |     --------------- Signature of `B.x`
+  |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `x`
+  --> src/bar.pyi:10:5
+   |
+ 9 | class C:
+10 |     x = foo.x
+   |     --------- `C.x` defined here
+11 |
+12 | class D(C):
+13 |     def x(self, y: int): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^ Definition is incompatible with `C.x`
+   |
+  ::: src/foo.pyi:1:5
+   |
+ 1 | def x(self, y: str): ...
+   |     --------------- Signature of `C.x`
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/liskov.md_-_The_Liskov_Substitut…_-_Fully_qualified_name…_(8f6f7c5aace58329).snap

@@ -0,0 +1,47 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: liskov.md - The Liskov Substitution Principle - Fully qualified names are used in diagnostics where appropriate
+mdtest path: crates/ty_python_semantic/resources/mdtest/liskov.md
+---
+
+# Python source files
+
+## a.pyi
+
+```
+1 | class A:
+2 |     def foo(self, x): ...
+```
+
+## b.pyi
+
+```
+1 | import a
+2 | 
+3 | class A(a.A):
+4 |     def foo(self, y): ...  # error: [invalid-method-override]
+```
+
+# Diagnostics
+
+```
+error[invalid-method-override]: Invalid override of method `foo`
+ --> src/b.pyi:4:9
+  |
+3 | class A(a.A):
+4 |     def foo(self, y): ...  # error: [invalid-method-override]
+  |         ^^^^^^^^^^^^ Definition is incompatible with `a.A.foo`
+  |
+ ::: src/a.pyi:2:9
+  |
+1 | class A:
+2 |     def foo(self, x): ...
+  |         ------------ `a.A.foo` defined here
+  |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/liskov.md_-_The_Liskov_Substitut…_-_Method_parameters_(d98059266bcc1e13).snap

@@ -0,0 +1,331 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: liskov.md - The Liskov Substitution Principle - Method parameters
+mdtest path: crates/ty_python_semantic/resources/mdtest/liskov.md
+---
+
+# Python source files
+
+## mdtest_snippet.pyi
+
+```
+ 1 | class Super:
+ 2 |     def method(self, x: int, /): ...
+ 3 | 
+ 4 | class Sub1(Super):
+ 5 |     def method(self, x: int, /): ...  # fine
+ 6 | 
+ 7 | class Sub2(Super):
+ 8 |     def method(self, x: object, /): ...  # fine: `method` still accepts any argument of type `int`
+ 9 | 
+10 | class Sub4(Super):
+11 |     def method(self, x: int | str, /): ...  # fine
+12 | 
+13 | class Sub5(Super):
+14 |     def method(self, x: int): ...  # fine: `x` can still be passed positionally
+15 | 
+16 | class Sub6(Super):
+17 |     # fine: `method()` can still be called with just a single argument
+18 |     def method(self, x: int, *args): ...
+19 | 
+20 | class Sub7(Super):
+21 |     def method(self, x: int, **kwargs): ...  # fine
+22 | 
+23 | class Sub8(Super):
+24 |     def method(self, x: int, *args, **kwargs): ...  # fine
+25 | 
+26 | class Sub9(Super):
+27 |     def method(self, x: int, extra_positional_arg=42, /): ... # fine
+28 | 
+29 | class Sub10(Super):
+30 |     def method(self, x: int, extra_pos_or_kw_arg=42): ...  # fine
+31 | 
+32 | class Sub11(Super):
+33 |     def method(self, x: int, *, extra_kw_only_arg=42): ...  # fine
+34 | 
+35 | class Sub12(Super):
+36 |     # Some calls permitted by the superclass are now no longer allowed
+37 |     # (the method can no longer be passed any arguments!)
+38 |     def method(self, /): ...  # error: [invalid-method-override]
+39 | 
+40 | class Sub13(Super):
+41 |     # Some calls permitted by the superclass are now no longer allowed
+42 |     # (the method can no longer be passed exactly one argument!)
+43 |     def method(self, x, y, /): ...  # error: [invalid-method-override]
+44 | 
+45 | class Sub14(Super):
+46 |     # Some calls permitted by the superclass are now no longer allowed
+47 |     # (x can no longer be passed positionally!)
+48 |     def method(self, /, *, x): ...  # error: [invalid-method-override]
+49 | 
+50 | class Sub15(Super):
+51 |     # Some calls permitted by the superclass are now no longer allowed
+52 |     # (x can no longer be passed any integer -- it now requires a bool!)
+53 |     def method(self, x: bool, /): ...  # error: [invalid-method-override]
+54 | 
+55 | class Super2:
+56 |     def method2(self, x): ...
+57 | 
+58 | class Sub16(Super2):
+59 |     def method2(self, x, /): ...  # error: [invalid-method-override]
+60 | 
+61 | class Sub17(Super2):
+62 |     def method2(self, *, x): ...  # error: [invalid-method-override]
+63 | 
+64 | class Super3:
+65 |     def method3(self, *, x): ...
+66 | 
+67 | class Sub18(Super3):
+68 |     def method3(self, x): ...  # fine: `x` can still be used as a keyword argument
+69 | 
+70 | class Sub19(Super3):
+71 |     def method3(self, x, /): ...  # error: [invalid-method-override]
+72 | 
+73 | class Super4:
+74 |     def method(self, *args: int, **kwargs: str): ...
+75 | 
+76 | class Sub20(Super4):
+77 |     def method(self, *args: object, **kwargs: object): ...  # fine
+78 | 
+79 | class Sub21(Super4):
+80 |     def method(self, *args): ...  # error: [invalid-method-override]
+81 | 
+82 | class Sub22(Super4):
+83 |     def method(self, **kwargs): ...  # error: [invalid-method-override]
+84 | 
+85 | class Sub23(Super4):
+86 |     def method(self, x, *args, y, **kwargs): ...  # error: [invalid-method-override]
+```
+
+# Diagnostics
+
+```
+error[invalid-method-override]: Invalid override of method `method`
+  --> src/mdtest_snippet.pyi:38:9
+   |
+36 |     # Some calls permitted by the superclass are now no longer allowed
+37 |     # (the method can no longer be passed any arguments!)
+38 |     def method(self, /): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^ Definition is incompatible with `Super.method`
+39 |
+40 | class Sub13(Super):
+   |
+  ::: src/mdtest_snippet.pyi:2:9
+   |
+ 1 | class Super:
+ 2 |     def method(self, x: int, /): ...
+   |         ----------------------- `Super.method` defined here
+ 3 |
+ 4 | class Sub1(Super):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method`
+  --> src/mdtest_snippet.pyi:43:9
+   |
+41 |     # Some calls permitted by the superclass are now no longer allowed
+42 |     # (the method can no longer be passed exactly one argument!)
+43 |     def method(self, x, y, /): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super.method`
+44 |
+45 | class Sub14(Super):
+   |
+  ::: src/mdtest_snippet.pyi:2:9
+   |
+ 1 | class Super:
+ 2 |     def method(self, x: int, /): ...
+   |         ----------------------- `Super.method` defined here
+ 3 |
+ 4 | class Sub1(Super):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method`
+  --> src/mdtest_snippet.pyi:48:9
+   |
+46 |     # Some calls permitted by the superclass are now no longer allowed
+47 |     # (x can no longer be passed positionally!)
+48 |     def method(self, /, *, x): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super.method`
+49 |
+50 | class Sub15(Super):
+   |
+  ::: src/mdtest_snippet.pyi:2:9
+   |
+ 1 | class Super:
+ 2 |     def method(self, x: int, /): ...
+   |         ----------------------- `Super.method` defined here
+ 3 |
+ 4 | class Sub1(Super):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method`
+  --> src/mdtest_snippet.pyi:53:9
+   |
+51 |     # Some calls permitted by the superclass are now no longer allowed
+52 |     # (x can no longer be passed any integer -- it now requires a bool!)
+53 |     def method(self, x: bool, /): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super.method`
+54 |
+55 | class Super2:
+   |
+  ::: src/mdtest_snippet.pyi:2:9
+   |
+ 1 | class Super:
+ 2 |     def method(self, x: int, /): ...
+   |         ----------------------- `Super.method` defined here
+ 3 |
+ 4 | class Sub1(Super):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method2`
+  --> src/mdtest_snippet.pyi:56:9
+   |
+55 | class Super2:
+56 |     def method2(self, x): ...
+   |         ---------------- `Super2.method2` defined here
+57 |
+58 | class Sub16(Super2):
+59 |     def method2(self, x, /): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super2.method2`
+60 |
+61 | class Sub17(Super2):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method2`
+  --> src/mdtest_snippet.pyi:62:9
+   |
+61 | class Sub17(Super2):
+62 |     def method2(self, *, x): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super2.method2`
+63 |
+64 | class Super3:
+   |
+  ::: src/mdtest_snippet.pyi:56:9
+   |
+55 | class Super2:
+56 |     def method2(self, x): ...
+   |         ---------------- `Super2.method2` defined here
+57 |
+58 | class Sub16(Super2):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method3`
+  --> src/mdtest_snippet.pyi:71:9
+   |
+70 | class Sub19(Super3):
+71 |     def method3(self, x, /): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super3.method3`
+72 |
+73 | class Super4:
+   |
+  ::: src/mdtest_snippet.pyi:65:9
+   |
+64 | class Super3:
+65 |     def method3(self, *, x): ...
+   |         ------------------- `Super3.method3` defined here
+66 |
+67 | class Sub18(Super3):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method`
+  --> src/mdtest_snippet.pyi:80:9
+   |
+79 | class Sub21(Super4):
+80 |     def method(self, *args): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super4.method`
+81 |
+82 | class Sub22(Super4):
+   |
+  ::: src/mdtest_snippet.pyi:74:9
+   |
+73 | class Super4:
+74 |     def method(self, *args: int, **kwargs: str): ...
+   |         --------------------------------------- `Super4.method` defined here
+75 |
+76 | class Sub20(Super4):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method`
+  --> src/mdtest_snippet.pyi:83:9
+   |
+82 | class Sub22(Super4):
+83 |     def method(self, **kwargs): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super4.method`
+84 |
+85 | class Sub23(Super4):
+   |
+  ::: src/mdtest_snippet.pyi:74:9
+   |
+73 | class Super4:
+74 |     def method(self, *args: int, **kwargs: str): ...
+   |         --------------------------------------- `Super4.method` defined here
+75 |
+76 | class Sub20(Super4):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method`
+  --> src/mdtest_snippet.pyi:86:9
+   |
+85 | class Sub23(Super4):
+86 |     def method(self, x, *args, y, **kwargs): ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super4.method`
+   |
+  ::: src/mdtest_snippet.pyi:74:9
+   |
+73 | class Super4:
+74 |     def method(self, *args: int, **kwargs: str): ...
+   |         --------------------------------------- `Super4.method` defined here
+75 |
+76 | class Sub20(Super4):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/liskov.md_-_The_Liskov_Substitut…_-_Method_return_types_(3e0c19bed14cfacd).snap

@@ -0,0 +1,75 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: liskov.md - The Liskov Substitution Principle - Method return types
+mdtest path: crates/ty_python_semantic/resources/mdtest/liskov.md
+---
+
+# Python source files
+
+## mdtest_snippet.pyi
+
+```
+ 1 | class Super:
+ 2 |     def method(self) -> int: ...
+ 3 | 
+ 4 | class Sub1(Super):
+ 5 |     def method(self) -> int: ...  # fine
+ 6 | 
+ 7 | class Sub2(Super):
+ 8 |     def method(self) -> bool: ...  # fine: `bool` is a subtype of `int`
+ 9 | 
+10 | class Sub3(Super):
+11 |     def method(self) -> object: ...  # error: [invalid-method-override]
+12 | 
+13 | class Sub4(Super):
+14 |     def method(self) -> str: ...  # error: [invalid-method-override]
+```
+
+# Diagnostics
+
+```
+error[invalid-method-override]: Invalid override of method `method`
+  --> src/mdtest_snippet.pyi:11:9
+   |
+10 | class Sub3(Super):
+11 |     def method(self) -> object: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super.method`
+12 |
+13 | class Sub4(Super):
+   |
+  ::: src/mdtest_snippet.pyi:2:9
+   |
+ 1 | class Super:
+ 2 |     def method(self) -> int: ...
+   |         ------------------- `Super.method` defined here
+ 3 |
+ 4 | class Sub1(Super):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `method`
+  --> src/mdtest_snippet.pyi:14:9
+   |
+13 | class Sub4(Super):
+14 |     def method(self) -> str: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Super.method`
+   |
+  ::: src/mdtest_snippet.pyi:2:9
+   |
+ 1 | class Super:
+ 2 |     def method(self) -> int: ...
+   |         ------------------- `Super.method` defined here
+ 3 |
+ 4 | class Sub1(Super):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```

crates/ty_python_semantic/resources/mdtest/snapshots/liskov.md_-_The_Liskov_Substitut…_-_Staticmethods_and_cl…_(49e28aae6fdd1291).snap

@@ -0,0 +1,220 @@
+---
+source: crates/ty_test/src/lib.rs
+expression: snapshot
+---
+---
+mdtest name: liskov.md - The Liskov Substitution Principle - Staticmethods and classmethods
+mdtest path: crates/ty_python_semantic/resources/mdtest/liskov.md
+---
+
+# Python source files
+
+## mdtest_snippet.pyi
+
+```
+ 1 | class Parent:
+ 2 |     def instance_method(self, x: int) -> int: ...
+ 3 |     @classmethod
+ 4 |     def class_method(cls, x: int) -> int: ...
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+ 7 | 
+ 8 | class BadChild1(Parent):
+ 9 |     @staticmethod
+10 |     def instance_method(self, x: int) -> int: ...  # error: [invalid-method-override]
+11 |     # TODO: we should emit `invalid-method-override` here.
+12 |     # Although the method has the same signature as `Parent.class_method`
+13 |     # when accessed on instances, it does not have the same signature as
+14 |     # `Parent.class_method` when accessed on the class object itself
+15 |     def class_method(cls, x: int) -> int: ...
+16 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+17 | 
+18 | class BadChild2(Parent):
+19 |     # TODO: we should emit `invalid-method-override` here.
+20 |     # Although the method has the same signature as `Parent.class_method`
+21 |     # when accessed on instances, it does not have the same signature as
+22 |     # `Parent.class_method` when accessed on the class object itself.
+23 |     #
+24 |     # Note that whereas `BadChild1.class_method` is reported as a Liskov violation by
+25 |     # mypy, pyright and pyrefly, pyright is the only one of those three to report a
+26 |     # Liskov violation on this method as of 2025-11-23.
+27 |     @classmethod
+28 |     def instance_method(self, x: int) -> int: ...
+29 |     @staticmethod
+30 |     def class_method(cls, x: int) -> int: ...  # error: [invalid-method-override]
+31 |     @classmethod
+32 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+33 | 
+34 | class BadChild3(Parent):
+35 |     @classmethod
+36 |     def class_method(cls, x: bool) -> object: ...  # error: [invalid-method-override]
+37 |     @staticmethod
+38 |     def static_method(x: bool) -> object: ...  # error: [invalid-method-override]
+39 | 
+40 | class GoodChild1(Parent):
+41 |     @classmethod
+42 |     def class_method(cls, x: int) -> int: ...
+43 |     @staticmethod
+44 |     def static_method(x: int) -> int: ...
+45 | 
+46 | class GoodChild2(Parent):
+47 |     @classmethod
+48 |     def class_method(cls, x: object) -> bool: ...
+49 |     @staticmethod
+50 |     def static_method(x: object) -> bool: ...
+```
+
+# Diagnostics
+
+```
+error[invalid-method-override]: Invalid override of method `instance_method`
+  --> src/mdtest_snippet.pyi:10:9
+   |
+ 8 | class BadChild1(Parent):
+ 9 |     @staticmethod
+10 |     def instance_method(self, x: int) -> int: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.instance_method`
+11 |     # TODO: we should emit `invalid-method-override` here.
+12 |     # Although the method has the same signature as `Parent.class_method`
+   |
+  ::: src/mdtest_snippet.pyi:2:9
+   |
+ 1 | class Parent:
+ 2 |     def instance_method(self, x: int) -> int: ...
+   |         ------------------------------------ `Parent.instance_method` defined here
+ 3 |     @classmethod
+ 4 |     def class_method(cls, x: int) -> int: ...
+   |
+info: `BadChild1.instance_method` is a staticmethod but `Parent.instance_method` is an instance method
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `static_method`
+  --> src/mdtest_snippet.pyi:16:9
+   |
+14 |     # `Parent.class_method` when accessed on the class object itself
+15 |     def class_method(cls, x: int) -> int: ...
+16 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.static_method`
+17 |
+18 | class BadChild2(Parent):
+   |
+  ::: src/mdtest_snippet.pyi:6:9
+   |
+ 4 |     def class_method(cls, x: int) -> int: ...
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |         ---------------------------- `Parent.static_method` defined here
+ 7 |
+ 8 | class BadChild1(Parent):
+   |
+info: `BadChild1.static_method` is an instance method but `Parent.static_method` is a staticmethod
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `class_method`
+  --> src/mdtest_snippet.pyi:30:9
+   |
+28 |     def instance_method(self, x: int) -> int: ...
+29 |     @staticmethod
+30 |     def class_method(cls, x: int) -> int: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.class_method`
+31 |     @classmethod
+32 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+   |
+  ::: src/mdtest_snippet.pyi:4:9
+   |
+ 2 |     def instance_method(self, x: int) -> int: ...
+ 3 |     @classmethod
+ 4 |     def class_method(cls, x: int) -> int: ...
+   |         -------------------------------- `Parent.class_method` defined here
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |
+info: `BadChild2.class_method` is a staticmethod but `Parent.class_method` is a classmethod
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `static_method`
+  --> src/mdtest_snippet.pyi:32:9
+   |
+30 |     def class_method(cls, x: int) -> int: ...  # error: [invalid-method-override]
+31 |     @classmethod
+32 |     def static_method(x: int) -> int: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.static_method`
+33 |
+34 | class BadChild3(Parent):
+   |
+  ::: src/mdtest_snippet.pyi:6:9
+   |
+ 4 |     def class_method(cls, x: int) -> int: ...
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |         ---------------------------- `Parent.static_method` defined here
+ 7 |
+ 8 | class BadChild1(Parent):
+   |
+info: `BadChild2.static_method` is a classmethod but `Parent.static_method` is a staticmethod
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `class_method`
+  --> src/mdtest_snippet.pyi:36:9
+   |
+34 | class BadChild3(Parent):
+35 |     @classmethod
+36 |     def class_method(cls, x: bool) -> object: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.class_method`
+37 |     @staticmethod
+38 |     def static_method(x: bool) -> object: ...  # error: [invalid-method-override]
+   |
+  ::: src/mdtest_snippet.pyi:4:9
+   |
+ 2 |     def instance_method(self, x: int) -> int: ...
+ 3 |     @classmethod
+ 4 |     def class_method(cls, x: int) -> int: ...
+   |         -------------------------------- `Parent.class_method` defined here
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```
+
+```
+error[invalid-method-override]: Invalid override of method `static_method`
+  --> src/mdtest_snippet.pyi:38:9
+   |
+36 |     def class_method(cls, x: bool) -> object: ...  # error: [invalid-method-override]
+37 |     @staticmethod
+38 |     def static_method(x: bool) -> object: ...  # error: [invalid-method-override]
+   |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Definition is incompatible with `Parent.static_method`
+39 |
+40 | class GoodChild1(Parent):
+   |
+  ::: src/mdtest_snippet.pyi:6:9
+   |
+ 4 |     def class_method(cls, x: int) -> int: ...
+ 5 |     @staticmethod
+ 6 |     def static_method(x: int) -> int: ...
+   |         ---------------------------- `Parent.static_method` defined here
+ 7 |
+ 8 | class BadChild1(Parent):
+   |
+info: This violates the Liskov Substitution Principle
+info: rule `invalid-method-override` is enabled by default
+
+```