Disable CRL checks during Windows test CI

2025-02-05 15:24:44 -06:00
1090 changed files with 11598 additions and 28286 deletions
--- a/.github/renovate.json5
+++ b/.github/renovate.json5
@@ -58,12 +58,6 @@
      description: "Disable PRs updating GitHub runners (e.g. 'runs-on: macos-14')",
      enabled: false,
    },
-    {
-      // TODO: Remove this once the codebase is upgrade to v4 (https://github.com/astral-sh/ruff/pull/16069)
-      matchPackageNames: ["tailwindcss"],
-      matchManagers: ["npm"],
-      enabled: false,
-    },
    {
      // Disable updates of `zip-rs`; intentionally pinned for now due to ownership change
      // See: https://github.com/astral-sh/uv/issues/3642
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -217,6 +217,11 @@ jobs:
      - uses: Swatinem/rust-cache@v2
      - name: "Install Rust toolchain"
        run: rustup show
+      # There are spurious CRL server offline errors when downloading
+      # `cargo-bloat` with curl below, so we just disable them for now
+      - name: "Disable SChannel CRL checks"
+        run: |
+          reg add "HKLM\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL" /v EnableCRLCheck /t REG_DWORD /d 0 /f
      - name: "Install cargo nextest"
        uses: taiki-e/install-action@v2
        with:
@@ -712,7 +717,7 @@ jobs:
          just test

  benchmarks:
-    runs-on: ubuntu-24.04
+    runs-on: ubuntu-22.04
    needs: determine_changes
    if: ${{ github.repository == 'astral-sh/ruff' && !contains(github.event.pull_request.labels.*.name, 'no-test') && (needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main') }}
    timeout-minutes: 20
--- a/.github/workflows/publish-playground.yml
+++ b/.github/workflows/publish-playground.yml
@@ -35,8 +35,6 @@ jobs:
          cache: "npm"
          cache-dependency-path: playground/package-lock.json
      - uses: jetli/wasm-pack-action@v0.4.0
-        with:
-          version: v0.13.1
      - uses: jetli/wasm-bindgen-action@v0.2.0
      - name: "Run wasm-pack"
        run: wasm-pack build --target web --out-dir ../../playground/src/pkg crates/ruff_wasm
@@ -51,7 +49,7 @@ jobs:
        working-directory: playground
      - name: "Deploy to Cloudflare Pages"
        if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        uses: cloudflare/wrangler-action@v3.14.0
+        uses: cloudflare/wrangler-action@v3.13.1
        with:
          apiToken: ${{ secrets.CF_API_TOKEN }}
          accountId: ${{ secrets.CF_ACCOUNT_ID }}
--- a/.github/workflows/publish-wasm.yml
+++ b/.github/workflows/publish-wasm.yml
@@ -35,8 +35,6 @@ jobs:
      - name: "Install Rust toolchain"
        run: rustup target add wasm32-unknown-unknown
      - uses: jetli/wasm-pack-action@v0.4.0
-        with:
-          version: v0.13.1
      - uses: jetli/wasm-bindgen-action@v0.2.0
      - name: "Run wasm-pack build"
        run: wasm-pack build --target ${{ matrix.target }} crates/ruff_wasm
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -60,7 +60,7 @@ repos:
          - black==25.1.0

  - repo: https://github.com/crate-ci/typos
-    rev: v1.29.7
+    rev: v1.29.5
    hooks:
      - id: typos

@@ -74,7 +74,7 @@ repos:
        pass_filenames: false # This makes it a lot faster

  - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.9.6
+    rev: v0.9.4
    hooks:
      - id: ruff-format
      - id: ruff
@@ -84,7 +84,7 @@ repos:

  # Prettier
  - repo: https://github.com/rbubley/mirrors-prettier
-    rev: v3.5.1
+    rev: v3.4.2
    hooks:
      - id: prettier
        types: [yaml]
@@ -92,7 +92,7 @@ repos:
  # zizmor detects security vulnerabilities in GitHub Actions workflows.
  # Additional configuration for the tool is found in `.github/zizmor.yml`
  - repo: https://github.com/woodruffw/zizmor-pre-commit
-    rev: v1.3.1
+    rev: v1.3.0
    hooks:
      - id: zizmor

--- a/BREAKING_CHANGES.md
+++ b/BREAKING_CHANGES.md
@@ -209,8 +209,8 @@ This change only affects those using Ruff under its default rule set. Users that

 ### Remove support for emoji identifiers ([#7212](https://github.com/astral-sh/ruff/pull/7212))

-Previously, Ruff supported non-standards-compliant emoji identifiers such as `📦 = 1`.
-We decided to remove this non-standard language extension. Ruff now reports syntax errors for invalid emoji identifiers in your code, the same as CPython.
+Previously, Ruff supported the non-standard compliant emoji identifiers e.g. `📦 = 1`.
+We decided to remove this non-standard language extension, and Ruff now reports syntax errors for emoji identifiers in your code, the same as CPython.

 ### Improved GitLab fingerprints ([#7203](https://github.com/astral-sh/ruff/pull/7203))

--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,153 +1,5 @@
 # Changelog

-## 0.9.7
-
-### Preview features
-
- Consider `__new__` methods as special function type for enforcing class method or static method rules ([#13305](https://github.com/astral-sh/ruff/pull/13305))
- \[`airflow`\] Improve the internal logic to differentiate deprecated symbols (`AIR303`) ([#16013](https://github.com/astral-sh/ruff/pull/16013))
- \[`refurb`\] Manual timezone monkeypatching (`FURB162`) ([#16113](https://github.com/astral-sh/ruff/pull/16113))
- \[`ruff`\] Implicit class variable in dataclass (`RUF045`) ([#14349](https://github.com/astral-sh/ruff/pull/14349))
- \[`ruff`\] Skip singleton starred expressions for `incorrectly-parenthesized-tuple-in-subscript` (`RUF031`) ([#16083](https://github.com/astral-sh/ruff/pull/16083))
- \[`refurb`\] Check for subclasses includes subscript expressions (`FURB189`) ([#16155](https://github.com/astral-sh/ruff/pull/16155))
-
-### Rule changes
-
- \[`flake8-comprehensions`\]: Handle trailing comma in `C403` fix ([#16110](https://github.com/astral-sh/ruff/pull/16110))
- \[`flake8-debugger`\] Also flag `sys.breakpointhook` and `sys.__breakpointhook__` (`T100`) ([#16191](https://github.com/astral-sh/ruff/pull/16191))
- \[`pydocstyle`\] Handle arguments with the same names as sections (`D417`) ([#16011](https://github.com/astral-sh/ruff/pull/16011))
- \[`pylint`\] Correct ordering of arguments in fix for `if-stmt-min-max` (`PLR1730`) ([#16080](https://github.com/astral-sh/ruff/pull/16080))
- \[`pylint`\] Do not offer fix for raw strings (`PLE251`) ([#16132](https://github.com/astral-sh/ruff/pull/16132))
- \[`pyupgrade`\] Do not upgrade functional `TypedDicts` with private field names to the class-based syntax (`UP013`) ([#16219](https://github.com/astral-sh/ruff/pull/16219))
- \[`pyupgrade`\] Handle micro version numbers correctly (`UP036`) ([#16091](https://github.com/astral-sh/ruff/pull/16091))
- \[`pyupgrade`\] Unwrap unary expressions correctly (`UP018`) ([#15919](https://github.com/astral-sh/ruff/pull/15919))
- \[`ruff`\] Skip `RUF001` diagnostics when visiting string type definitions ([#16122](https://github.com/astral-sh/ruff/pull/16122))
- \[`flake8-pyi`\] Avoid flagging `custom-typevar-for-self` on metaclass methods (`PYI019`) ([#16141](https://github.com/astral-sh/ruff/pull/16141))
- \[`pycodestyle`\] Exempt `site.addsitedir(...)` calls (`E402`) ([#16251](https://github.com/astral-sh/ruff/pull/16251))
-
-### Formatter
-
- Fix unstable formatting of trailing end-of-line comments of parenthesized attribute values ([#16187](https://github.com/astral-sh/ruff/pull/16187))
-
-### Server
-
- Fix handling of requests received after shutdown message ([#16262](https://github.com/astral-sh/ruff/pull/16262))
- Ignore `source.organizeImports.ruff` and `source.fixAll.ruff` code actions for a notebook cell ([#16154](https://github.com/astral-sh/ruff/pull/16154))
- Include document specific debug info for `ruff.printDebugInformation` ([#16215](https://github.com/astral-sh/ruff/pull/16215))
- Update server to return the debug info as string with `ruff.printDebugInformation` ([#16214](https://github.com/astral-sh/ruff/pull/16214))
-
-### CLI
-
- Warn on invalid `noqa` even when there are no diagnostics ([#16178](https://github.com/astral-sh/ruff/pull/16178))
- Better error messages while loading configuration `extend`s ([#15658](https://github.com/astral-sh/ruff/pull/15658))
-
-### Bug fixes
-
- \[`refurb`\] Correctly handle lengths of literal strings in `slice-to-remove-prefix-or-suffix` (`FURB188`) ([#16237](https://github.com/astral-sh/ruff/pull/16237))
-
-### Documentation
-
- Add FAQ entry for `source.*` code actions in Notebook ([#16212](https://github.com/astral-sh/ruff/pull/16212))
- Add `SECURITY.md` ([#16224](https://github.com/astral-sh/ruff/pull/16224))
-
-## 0.9.6
-
-### Preview features
-
- \[`airflow`\] Add `external_task.{ExternalTaskMarker, ExternalTaskSensor}` for `AIR302` ([#16014](https://github.com/astral-sh/ruff/pull/16014))
- \[`flake8-builtins`\] Make strict module name comparison optional (`A005`) ([#15951](https://github.com/astral-sh/ruff/pull/15951))
- \[`flake8-pyi`\] Extend fix to Python \<= 3.9 for `redundant-none-literal` (`PYI061`) ([#16044](https://github.com/astral-sh/ruff/pull/16044))
- \[`pylint`\] Also report when the object isn't a literal (`PLE1310`) ([#15985](https://github.com/astral-sh/ruff/pull/15985))
- \[`ruff`\] Implement `indented-form-feed` (`RUF054`) ([#16049](https://github.com/astral-sh/ruff/pull/16049))
- \[`ruff`\] Skip type definitions for `missing-f-string-syntax` (`RUF027`) ([#16054](https://github.com/astral-sh/ruff/pull/16054))
-
-### Rule changes
-
- \[`flake8-annotations`\] Correct syntax for `typing.Union` in suggested return type fixes for `ANN20x` rules ([#16025](https://github.com/astral-sh/ruff/pull/16025))
- \[`flake8-builtins`\] Match upstream module name comparison (`A005`) ([#16006](https://github.com/astral-sh/ruff/pull/16006))
- \[`flake8-comprehensions`\] Detect overshadowed `list`/`set`/`dict`, ignore variadics and named expressions (`C417`) ([#15955](https://github.com/astral-sh/ruff/pull/15955))
- \[`flake8-pie`\] Remove following comma correctly when the unpacked dictionary is empty (`PIE800`) ([#16008](https://github.com/astral-sh/ruff/pull/16008))
- \[`flake8-simplify`\] Only trigger `SIM401` on known dictionaries ([#15995](https://github.com/astral-sh/ruff/pull/15995))
- \[`pylint`\] Do not report calls when object type and argument type mismatch, remove custom escape handling logic (`PLE1310`) ([#15984](https://github.com/astral-sh/ruff/pull/15984))
- \[`pyupgrade`\] Comments within parenthesized value ranges should not affect applicability (`UP040`) ([#16027](https://github.com/astral-sh/ruff/pull/16027))
- \[`pyupgrade`\] Don't introduce invalid syntax when upgrading old-style type aliases with parenthesized multiline values (`UP040`) ([#16026](https://github.com/astral-sh/ruff/pull/16026))
- \[`pyupgrade`\] Ensure we do not rename two type parameters to the same name (`UP049`) ([#16038](https://github.com/astral-sh/ruff/pull/16038))
- \[`pyupgrade`\] \[`ruff`\] Don't apply renamings if the new name is shadowed in a scope of one of the references to the binding (`UP049`, `RUF052`) ([#16032](https://github.com/astral-sh/ruff/pull/16032))
- \[`ruff`\] Update `RUF009` to behave similar to `B008` and ignore attributes with immutable types ([#16048](https://github.com/astral-sh/ruff/pull/16048))
-
-### Server
-
- Root exclusions in the server to project root ([#16043](https://github.com/astral-sh/ruff/pull/16043))
-
-### Bug fixes
-
- \[`flake8-datetime`\] Ignore `.replace()` calls while looking for `.astimezone` ([#16050](https://github.com/astral-sh/ruff/pull/16050))
- \[`flake8-type-checking`\] Avoid `TC004` false positive where the runtime definition is provided by `__getattr__` ([#16052](https://github.com/astral-sh/ruff/pull/16052))
-
-### Documentation
-
- Improve `ruff-lsp` migration document ([#16072](https://github.com/astral-sh/ruff/pull/16072))
- Undeprecate `ruff.nativeServer` ([#16039](https://github.com/astral-sh/ruff/pull/16039))
-
-## 0.9.5
-
-### Preview features
-
- Recognize all symbols named `TYPE_CHECKING` for `in_type_checking_block` ([#15719](https://github.com/astral-sh/ruff/pull/15719))
- \[`flake8-comprehensions`\] Handle builtins at top of file correctly for `unnecessary-dict-comprehension-for-iterable` (`C420`) ([#15837](https://github.com/astral-sh/ruff/pull/15837))
- \[`flake8-logging`\] `.exception()` and `exc_info=` outside exception handlers (`LOG004`, `LOG014`) ([#15799](https://github.com/astral-sh/ruff/pull/15799))
- \[`flake8-pyi`\] Fix incorrect behaviour of `custom-typevar-return-type` preview-mode autofix if `typing` was already imported (`PYI019`) ([#15853](https://github.com/astral-sh/ruff/pull/15853))
- \[`flake8-pyi`\] Fix more complex cases (`PYI019`) ([#15821](https://github.com/astral-sh/ruff/pull/15821))
- \[`flake8-pyi`\] Make `PYI019` autofixable for `.py` files in preview mode as well as stubs ([#15889](https://github.com/astral-sh/ruff/pull/15889))
- \[`flake8-pyi`\] Remove type parameter correctly when it is the last (`PYI019`) ([#15854](https://github.com/astral-sh/ruff/pull/15854))
- \[`pylint`\] Fix missing parens in unsafe fix for `unnecessary-dunder-call` (`PLC2801`) ([#15762](https://github.com/astral-sh/ruff/pull/15762))
- \[`pyupgrade`\] Better messages and diagnostic range (`UP015`) ([#15872](https://github.com/astral-sh/ruff/pull/15872))
- \[`pyupgrade`\] Rename private type parameters in PEP 695 generics (`UP049`) ([#15862](https://github.com/astral-sh/ruff/pull/15862))
- \[`refurb`\] Also report non-name expressions (`FURB169`) ([#15905](https://github.com/astral-sh/ruff/pull/15905))
- \[`refurb`\] Mark fix as unsafe if there are comments (`FURB171`) ([#15832](https://github.com/astral-sh/ruff/pull/15832))
- \[`ruff`\] Classes with mixed type variable style (`RUF053`) ([#15841](https://github.com/astral-sh/ruff/pull/15841))
- \[`airflow`\] `BashOperator` has been moved to `airflow.providers.standard.operators.bash.BashOperator` (`AIR302`) ([#15922](https://github.com/astral-sh/ruff/pull/15922))
- \[`flake8-pyi`\] Add autofix for unused-private-type-var (`PYI018`) ([#15999](https://github.com/astral-sh/ruff/pull/15999))
- \[`flake8-pyi`\] Significantly improve accuracy of `PYI019` if preview mode is enabled ([#15888](https://github.com/astral-sh/ruff/pull/15888))
-
-### Rule changes
-
- Preserve triple quotes and prefixes for strings ([#15818](https://github.com/astral-sh/ruff/pull/15818))
- \[`flake8-comprehensions`\] Skip when `TypeError` present from too many (kw)args for `C410`,`C411`, and `C418` ([#15838](https://github.com/astral-sh/ruff/pull/15838))
- \[`flake8-pyi`\] Rename `PYI019` and improve its diagnostic message ([#15885](https://github.com/astral-sh/ruff/pull/15885))
- \[`pep8-naming`\] Ignore `@override` methods (`N803`) ([#15954](https://github.com/astral-sh/ruff/pull/15954))
- \[`pyupgrade`\] Reuse replacement logic from `UP046` and `UP047` to preserve more comments (`UP040`) ([#15840](https://github.com/astral-sh/ruff/pull/15840))
- \[`ruff`\] Analyze deferred annotations before enforcing `mutable-(data)class-default` and `function-call-in-dataclass-default-argument` (`RUF008`,`RUF009`,`RUF012`) ([#15921](https://github.com/astral-sh/ruff/pull/15921))
- \[`pycodestyle`\] Exempt `sys.path += ...` calls (`E402`) ([#15980](https://github.com/astral-sh/ruff/pull/15980))
-
-### Configuration
-
- Config error only when `flake8-import-conventions` alias conflicts with `isort.required-imports` bound name ([#15918](https://github.com/astral-sh/ruff/pull/15918))
- Workaround Even Better TOML crash related to `allOf` ([#15992](https://github.com/astral-sh/ruff/pull/15992))
-
-### Bug fixes
-
- \[`flake8-comprehensions`\] Unnecessary `list` comprehension (rewrite as a `set` comprehension) (`C403`) - Handle extraneous parentheses around list comprehension ([#15877](https://github.com/astral-sh/ruff/pull/15877))
- \[`flake8-comprehensions`\] Handle trailing comma in fixes for `unnecessary-generator-list/set` (`C400`,`C401`) ([#15929](https://github.com/astral-sh/ruff/pull/15929))
- \[`flake8-pyi`\] Fix several correctness issues with `custom-type-var-return-type` (`PYI019`) ([#15851](https://github.com/astral-sh/ruff/pull/15851))
- \[`pep8-naming`\] Consider any number of leading underscore for `N801` ([#15988](https://github.com/astral-sh/ruff/pull/15988))
- \[`pyflakes`\] Visit forward annotations in `TypeAliasType` as types (`F401`) ([#15829](https://github.com/astral-sh/ruff/pull/15829))
- \[`pylint`\] Correct min/max auto-fix and suggestion for (`PL1730`) ([#15930](https://github.com/astral-sh/ruff/pull/15930))
- \[`refurb`\] Handle unparenthesized tuples correctly (`FURB122`, `FURB142`) ([#15953](https://github.com/astral-sh/ruff/pull/15953))
- \[`refurb`\] Avoid `None | None` as well as better detection and fix (`FURB168`) ([#15779](https://github.com/astral-sh/ruff/pull/15779))
-
-### Documentation
-
- Add deprecation warning for `ruff-lsp` related settings ([#15850](https://github.com/astral-sh/ruff/pull/15850))
- Docs (`linter.md`): clarify that Python files are always searched for in subdirectories ([#15882](https://github.com/astral-sh/ruff/pull/15882))
- Fix a typo in `non_pep695_generic_class.rs` ([#15946](https://github.com/astral-sh/ruff/pull/15946))
- Improve Docs: Pylint subcategories' codes ([#15909](https://github.com/astral-sh/ruff/pull/15909))
- Remove non-existing `lint.extendIgnore` editor setting ([#15844](https://github.com/astral-sh/ruff/pull/15844))
- Update black deviations ([#15928](https://github.com/astral-sh/ruff/pull/15928))
- Mention `UP049` in `UP046` and `UP047`, add `See also` section to `UP040` ([#15956](https://github.com/astral-sh/ruff/pull/15956))
- Add instance variable examples to `RUF012` ([#15982](https://github.com/astral-sh/ruff/pull/15982))
- Explain precedence for `ignore` and `select` config ([#15883](https://github.com/astral-sh/ruff/pull/15883))
-
 ## 0.9.4

 ### Preview features
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -526,7 +526,7 @@ cargo benchmark
 #### Benchmark-driven Development

 Ruff uses [Criterion.rs](https://bheisler.github.io/criterion.rs/book/) for benchmarks. You can use
-`--save-baseline=<name>` to store an initial baseline benchmark (e.g., on `main`) and then use
+`--save-baseline=<name>` to store an initial baseline benchmark (e.g. on `main`) and then use
 `--benchmark=<name>` to compare against that benchmark. Criterion will print a message telling you
 if the benchmark improved/regressed compared to that baseline.

@@ -678,9 +678,9 @@ utils with it:
 23 Newline 24
 ```

- `cargo dev print-cst <file>`: Print the CST of a Python file using
+- `cargo dev print-cst <file>`: Print the CST of a python file using
    [LibCST](https://github.com/Instagram/LibCST), which is used in addition to the RustPython parser
-    in Ruff. For example, for `if True: pass # comment`, everything, including the whitespace, is represented:
+    in Ruff. E.g. for `if True: pass # comment` everything including the whitespace is represented:

 ```text
 Module {
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -29,12 +29,6 @@ dependencies = [
 "memchr",
 ]

-[[package]]
-name = "allocator-api2"
-version = "0.2.21"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "683d7910e743518b0e34f1186f92494becacb047c7b6bf616c96772180fef923"
-
 [[package]]
 name = "android-tzdata"
 version = "0.1.1"
@@ -360,9 +354,9 @@ dependencies = [

 [[package]]
 name = "clap"
-version = "4.5.29"
+version = "4.5.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8acebd8ad879283633b343856142139f2da2317c96b05b4dd6181c61e2480184"
+checksum = "769b0145982b4b48713e01ec42d61614425f27b7058bda7180a3a41f30104796"
 dependencies = [
 "clap_builder",
 "clap_derive",
@@ -370,9 +364,9 @@ dependencies = [

 [[package]]
 name = "clap_builder"
-version = "4.5.29"
+version = "4.5.27"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f6ba32cbda51c7e1dfd49acc1457ba1a7dec5b64fe360e828acb13ca8dc9c2f9"
+checksum = "1b26884eb4b57140e4d2d93652abfa49498b938b3c9179f9fc487b0acc3edad7"
 dependencies = [
 "anstream",
 "anstyle",
@@ -413,9 +407,9 @@ dependencies = [

 [[package]]
 name = "clap_derive"
-version = "4.5.28"
+version = "4.5.24"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "bf4ced95c6f4a675af3da73304b9ac4ed991640c36374e4b46795c49e17cf1ed"
+checksum = "54b755194d6389280185988721fffba69495eed5ee9feeee9a599b53db80318c"
 dependencies = [
 "heck",
 "proc-macro2",
@@ -444,22 +438,20 @@ dependencies = [

 [[package]]
 name = "codspeed"
-version = "2.8.0"
+version = "2.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "25d2f5a6570db487f5258e0bded6352fa2034c2aeb46bb5cc3ff060a0fcfba2f"
+checksum = "450a0e9df9df1c154156f4344f99d8f6f6e69d0fc4de96ef6e2e68b2ec3bce97"
 dependencies = [
 "colored 2.2.0",
 "libc",
- "serde",
 "serde_json",
- "uuid",
 ]

 [[package]]
 name = "codspeed-criterion-compat"
-version = "2.8.0"
+version = "2.7.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f53a55558dedec742b14aae3c5fec389361b8b5ca28c1aadf09dd91faf710074"
+checksum = "8eb1a6cb9c20e177fde58cdef97c1c7c9264eb1424fe45c4fccedc2fb078a569"
 dependencies = [
 "codspeed",
 "colored 2.2.0",
@@ -905,7 +897,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "33d852cb9b869c2a9b3df2f71a3074817f01e1844f839a144f5fcef059a4eb5d"
 dependencies = [
 "libc",
- "windows-sys 0.59.0",
+ "windows-sys 0.52.0",
 ]

 [[package]]
@@ -1039,8 +1031,10 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "c4567c8db10ae91089c99af84c68c38da3ec2f087c3f82960bcdbf3656b6f4d7"
 dependencies = [
 "cfg-if",
+ "js-sys",
 "libc",
 "wasi 0.11.0+wasi-snapshot-preview1",
+ "wasm-bindgen",
 ]

 [[package]]
@@ -1104,7 +1098,6 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "e5274423e17b7c9fc20b6e7e208532f9b19825d82dfd615708b70edd83df41f1"
 dependencies = [
 "ahash",
- "allocator-api2",
 ]

 [[package]]
@@ -1482,7 +1475,7 @@ checksum = "e19b23d53f35ce9f56aebc7d1bb4e6ac1e9c0db7ac85c8d1760c04379edced37"
 dependencies = [
 "hermit-abi 0.4.0",
 "libc",
- "windows-sys 0.59.0",
+ "windows-sys 0.52.0",
 ]

 [[package]]
@@ -2056,7 +2049,7 @@ dependencies = [
 "once_cell",
 "pep440_rs",
 "regex",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "serde",
 "smallvec",
 "thiserror 1.0.69",
@@ -2416,7 +2409,6 @@ dependencies = [
 "red_knot_server",
 "regex",
 "ruff_db",
- "ruff_python_ast",
 "ruff_python_trivia",
 "salsa",
 "tempfile",
@@ -2445,9 +2437,8 @@ dependencies = [
 "ruff_macros",
 "ruff_python_ast",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "salsa",
- "schemars",
 "serde",
 "thiserror 2.0.11",
 "toml",
@@ -2485,9 +2476,8 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "salsa",
- "schemars",
 "serde",
 "smallvec",
 "static_assertions",
@@ -2513,7 +2503,7 @@ dependencies = [
 "ruff_python_ast",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "serde",
 "serde_json",
 "shellexpand",
@@ -2535,11 +2525,10 @@ dependencies = [
 "regex",
 "ruff_db",
 "ruff_index",
- "ruff_python_ast",
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "salsa",
 "serde",
 "smallvec",
@@ -2566,9 +2555,9 @@ dependencies = [
 "js-sys",
 "log",
 "red_knot_project",
+ "red_knot_python_semantic",
 "ruff_db",
 "ruff_notebook",
- "ruff_python_ast",
 "wasm-bindgen",
 "wasm-bindgen-test",
 ]
@@ -2650,7 +2639,7 @@ dependencies = [

 [[package]]
 name = "ruff"
-version = "0.9.7"
+version = "0.9.4"
 dependencies = [
 "anyhow",
 "argfile",
@@ -2690,7 +2679,7 @@ dependencies = [
 "ruff_source_file",
 "ruff_text_size",
 "ruff_workspace",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "serde",
 "serde_json",
 "shellexpand",
@@ -2729,13 +2718,14 @@ dependencies = [
 "mimalloc",
 "rayon",
 "red_knot_project",
+ "red_knot_python_semantic",
 "ruff_db",
 "ruff_linter",
 "ruff_python_ast",
 "ruff_python_formatter",
 "ruff_python_parser",
 "ruff_python_trivia",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "tikv-jemallocator",
 ]

@@ -2757,10 +2747,10 @@ name = "ruff_db"
 version = "0.0.0"
 dependencies = [
 "camino",
+ "colored 3.0.0",
 "countme",
 "dashmap 6.1.0",
 "dunce",
- "etcetera",
 "filetime",
 "glob",
 "ignore",
@@ -2775,9 +2765,8 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "salsa",
- "schemars",
 "serde",
 "tempfile",
 "thiserror 2.0.11",
@@ -2802,7 +2791,6 @@ dependencies = [
 "libcst",
 "pretty_assertions",
 "rayon",
- "red_knot_project",
 "regex",
 "ruff",
 "ruff_diagnostics",
@@ -2846,7 +2834,7 @@ dependencies = [
 "ruff_cache",
 "ruff_macros",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "schemars",
 "serde",
 "static_assertions",
@@ -2878,13 +2866,12 @@ name = "ruff_index"
 version = "0.0.0"
 dependencies = [
 "ruff_macros",
- "salsa",
 "static_assertions",
 ]

 [[package]]
 name = "ruff_linter"
-version = "0.9.7"
+version = "0.9.4"
 dependencies = [
 "aho-corasick",
 "anyhow",
@@ -2926,7 +2913,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "schemars",
 "serde",
 "serde_json",
@@ -2988,8 +2975,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash 2.1.1",
- "salsa",
+ "rustc-hash 2.1.0",
 "schemars",
 "serde",
 ]
@@ -3036,7 +3022,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "schemars",
 "serde",
 "serde_json",
@@ -3083,7 +3069,7 @@ dependencies = [
 "ruff_python_trivia",
 "ruff_source_file",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "static_assertions",
 "unicode-ident",
 "unicode-normalization",
@@ -3114,7 +3100,7 @@ dependencies = [
 "ruff_python_parser",
 "ruff_python_stdlib",
 "ruff_text_size",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "schemars",
 "serde",
 "smallvec",
@@ -3173,7 +3159,7 @@ dependencies = [
 "ruff_source_file",
 "ruff_text_size",
 "ruff_workspace",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "serde",
 "serde_json",
 "shellexpand",
@@ -3203,7 +3189,7 @@ dependencies = [

 [[package]]
 name = "ruff_wasm"
-version = "0.9.7"
+version = "0.9.4"
 dependencies = [
 "console_error_panic_hook",
 "console_log",
@@ -3237,7 +3223,6 @@ dependencies = [
 "glob",
 "globset",
 "ignore",
- "indexmap",
 "is-macro",
 "itertools 0.14.0",
 "log",
@@ -3256,7 +3241,7 @@ dependencies = [
 "ruff_python_semantic",
 "ruff_python_stdlib",
 "ruff_source_file",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "schemars",
 "serde",
 "shellexpand",
@@ -3283,9 +3268,9 @@ checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"

 [[package]]
 name = "rustc-hash"
-version = "2.1.1"
+version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "357703d41365b4b27c590e3ed91eabb1b663f07c4c084095e60cbed4362dff0d"
+checksum = "c7fb8039b3032c191086b10f11f319a6e99e1e82889c5cc6046f515c9db1d497"

 [[package]]
 name = "rustix"
@@ -3297,7 +3282,7 @@ dependencies = [
 "errno",
 "libc",
 "linux-raw-sys",
- "windows-sys 0.59.0",
+ "windows-sys 0.52.0",
 ]

 [[package]]
@@ -3315,19 +3300,17 @@ checksum = "6ea1a2d0a644769cc99faa24c3ad26b379b786fe7c36fd3c546254801650e6dd"
 [[package]]
 name = "salsa"
 version = "0.18.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=351d9cf0037be949d17800d0c7b4838e533c2ed6#351d9cf0037be949d17800d0c7b4838e533c2ed6"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=88a1d7774d78f048fbd77d40abca9ebd729fd1f0#88a1d7774d78f048fbd77d40abca9ebd729fd1f0"
 dependencies = [
 "append-only-vec",
 "arc-swap",
- "compact_str",
 "crossbeam",
 "dashmap 6.1.0",
- "hashbrown 0.14.5",
 "hashlink",
 "indexmap",
 "parking_lot",
 "rayon",
- "rustc-hash 2.1.1",
+ "rustc-hash 2.1.0",
 "salsa-macro-rules",
 "salsa-macros",
 "smallvec",
@@ -3337,12 +3320,12 @@ dependencies = [
 [[package]]
 name = "salsa-macro-rules"
 version = "0.1.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=351d9cf0037be949d17800d0c7b4838e533c2ed6#351d9cf0037be949d17800d0c7b4838e533c2ed6"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=88a1d7774d78f048fbd77d40abca9ebd729fd1f0#88a1d7774d78f048fbd77d40abca9ebd729fd1f0"

 [[package]]
 name = "salsa-macros"
 version = "0.18.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=351d9cf0037be949d17800d0c7b4838e533c2ed6#351d9cf0037be949d17800d0c7b4838e533c2ed6"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=88a1d7774d78f048fbd77d40abca9ebd729fd1f0#88a1d7774d78f048fbd77d40abca9ebd729fd1f0"
 dependencies = [
 "heck",
 "proc-macro2",
@@ -3551,9 +3534,9 @@ checksum = "56199f7ddabf13fe5074ce809e7d3f42b42ae711800501b5b16ea82ad029c39d"

 [[package]]
 name = "smallvec"
-version = "1.14.0"
+version = "1.13.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7fcf8323ef1faaee30a44a340193b1ac6814fd9b7b4e88e9d4519a3e4abe1cfd"
+checksum = "3c5e1a9a646d36c3599cd173a41282daf47c44583ad367b8e6837255952e5c67"

 [[package]]
 name = "snapbox"
@@ -3613,18 +3596,18 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"

 [[package]]
 name = "strum"
-version = "0.27.1"
+version = "0.26.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f64def088c51c9510a8579e3c5d67c65349dcf755e5479ad3d010aa6454e2c32"
+checksum = "8fec0f0aef304996cf250b31b5a10dee7980c85da9d759361292b8bca5a18f06"
 dependencies = [
 "strum_macros",
 ]

 [[package]]
 name = "strum_macros"
-version = "0.27.1"
+version = "0.26.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c77a8c5abcaf0f9ce05d62342b7d298c346515365c36b673df4ebe3ced01fde8"
+checksum = "4c6bee85a5a24955dc440386795aa378cd9cf82acd5f764469152d2270e581be"
 dependencies = [
 "heck",
 "proc-macro2",
@@ -3668,16 +3651,16 @@ dependencies = [

 [[package]]
 name = "tempfile"
-version = "3.17.0"
+version = "3.16.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "a40f762a77d2afa88c2d919489e390a12bdd261ed568e60cfa7e48d4e20f0d33"
+checksum = "38c246215d7d24f48ae091a2902398798e05d978b24315d6efbc00ede9a8bb91"
 dependencies = [
 "cfg-if",
 "fastrand",
 "getrandom 0.3.1",
 "once_cell",
 "rustix",
- "windows-sys 0.59.0",
+ "windows-sys 0.52.0",
 ]

 [[package]]
@@ -3866,9 +3849,9 @@ checksum = "1f3ccbac311fea05f86f61904b462b55fb3df8837a366dfc601a0161d0532f20"

 [[package]]
 name = "toml"
-version = "0.8.20"
+version = "0.8.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cd87a5cdd6ffab733b2f74bc4fd7ee5fff6634124999ac278c35fc78c6120148"
+checksum = "a1ed1f98e3fdc28d6d910e6737ae6ab1a93bf1985935a1193e68f93eeb68d24e"
 dependencies = [
 "serde",
 "serde_spanned",
@@ -4165,22 +4148,21 @@ checksum = "06abde3611657adf66d383f00b093d7faecc7fa57071cce2578660c9f1010821"

 [[package]]
 name = "uuid"
-version = "1.13.1"
+version = "1.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ced87ca4be083373936a67f8de945faa23b6b42384bd5b64434850802c6dccd0"
+checksum = "b3758f5e68192bb96cc8f9b7e2c2cfdabb435499a28499a42f8f984092adad4b"
 dependencies = [
- "getrandom 0.3.1",
- "js-sys",
- "rand 0.9.0",
+ "getrandom 0.2.15",
+ "rand 0.8.5",
 "uuid-macro-internal",
 "wasm-bindgen",
 ]

 [[package]]
 name = "uuid-macro-internal"
-version = "1.13.1"
+version = "1.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d28dd23acb5f2fa7bd2155ab70b960e770596b3bb6395119b40476c3655dfba4"
+checksum = "f8a86d88347b61a0e17b9908a67efcc594130830bf1045653784358dd023e294"
 dependencies = [
 "proc-macro2",
 "quote",
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -123,7 +123,7 @@ rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
 rustc-hash = { version = "2.0.0" }
 # When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "351d9cf0037be949d17800d0c7b4838e533c2ed6" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "88a1d7774d78f048fbd77d40abca9ebd729fd1f0" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }
@@ -143,8 +143,8 @@ snapbox = { version = "0.6.0", features = [
    "examples",
 ] }
 static_assertions = "1.1.0"
-strum = { version = "0.27.0", features = ["strum_macros"] }
-strum_macros = { version = "0.27.0" }
+strum = { version = "0.26.0", features = ["strum_macros"] }
+strum_macros = { version = "0.26.0" }
 syn = { version = "2.0.55" }
 tempfile = { version = "3.9.0" }
 test-case = { version = "3.3.1" }
--- a/README.md
+++ b/README.md
@@ -149,8 +149,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"

 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.9.7/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.9.7/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.9.4/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.9.4/install.ps1 | iex"
 ```

 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -183,7 +183,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
  # Ruff version.
-  rev: v0.9.7
+  rev: v0.9.4
  hooks:
    # Run the linter.
    - id: ruff
@@ -452,7 +452,6 @@ Ruff is used by a number of major open-source projects and companies, including:
 - ING Bank ([popmon](https://github.com/ing-bank/popmon), [probatus](https://github.com/ing-bank/probatus))
 - [Ibis](https://github.com/ibis-project/ibis)
 - [ivy](https://github.com/unifyai/ivy)
- [JAX](https://github.com/jax-ml/jax)
 - [Jupyter](https://github.com/jupyter-server/jupyter_server)
 - [Kraken Tech](https://kraken.tech/)
 - [LangChain](https://github.com/hwchase17/langchain)
--- a/SECURITY.md
+++ b/SECURITY.md
@@ -1,15 +0,0 @@
-# Security policy
-
-## Reporting a vulnerability
-
-If you have found a possible vulnerability, please email `security at astral dot sh`.
-
-## Bug bounties
-
-While we sincerely appreciate and encourage reports of suspected security problems, please note that
-Astral does not currently run any bug bounty programs.
-
-## Vulnerability disclosures
-
-Critical vulnerabilities will be disclosed via GitHub's
-[security advisory](https://github.com/astral-sh/ruff/security) system.
--- a/crates/red_knot/Cargo.toml
+++ b/crates/red_knot/Cargo.toml
@@ -16,7 +16,6 @@ red_knot_python_semantic = { workspace = true }
 red_knot_project = { workspace = true, features = ["zstd"] }
 red_knot_server = { workspace = true }
 ruff_db = { workspace = true, features = ["os", "cache"] }
-ruff_python_ast = { workspace = true }

 anyhow = { workspace = true }
 chrono = { workspace = true }
--- a/crates/red_knot/README.md
+++ b/crates/red_knot/README.md
@@ -1,25 +0,0 @@
-# Red Knot
-
-Red Knot is an extremely fast type checker.
-Currently, it is a work-in-progress and not ready for user testing.
-
-Red Knot is designed to prioritize good type inference, even in unannotated code,
-and aims to avoid false positives.
-
-While Red Knot will produce similar results to mypy and pyright on many codebases,
-100% compatibility with these tools is a non-goal.
-On some codebases, Red Knot's design decisions lead to different outcomes
-than you would get from running one of these more established tools.
-
-## Contributing
-
-Core type checking tests are written as Markdown code blocks.
-They can be found in [`red_knot_python_semantic/resources/mdtest`][resources-mdtest].
-See [`red_knot_test/README.md`][mdtest-readme] for more information
-on the test framework itself.
-
-The list of open issues can be found [here][open-issues].
-
-[mdtest-readme]: ../red_knot_test/README.md
-[open-issues]: https://github.com/astral-sh/ruff/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20label%3Ared-knot
-[resources-mdtest]: ../red_knot_python_semantic/resources/mdtest
--- a/crates/red_knot/src/args.rs
+++ b/crates/red_knot/src/args.rs
@@ -1,7 +1,7 @@
 use crate::logging::Verbosity;
 use crate::python_version::PythonVersion;
 use clap::{ArgAction, ArgMatches, Error, Parser};
-use red_knot_project::metadata::options::{EnvironmentOptions, Options, TerminalOptions};
+use red_knot_project::metadata::options::{EnvironmentOptions, Options};
 use red_knot_project::metadata::value::{RangedValue, RelativePathBuf};
 use red_knot_python_semantic::lint;
 use ruff_db::system::SystemPathBuf;
@@ -67,8 +67,8 @@ pub(crate) struct CheckCommand {
    pub(crate) rules: RulesArg,

    /// Use exit code 1 if there are any warning-level diagnostics.
-    #[arg(long, conflicts_with = "exit_zero", default_missing_value = "true", num_args=0..1)]
-    pub(crate) error_on_warning: Option<bool>,
+    #[arg(long, conflicts_with = "exit_zero")]
+    pub(crate) error_on_warning: bool,

    /// Always use exit code 0, even when there are error-level diagnostics.
    #[arg(long)]
@@ -107,9 +107,6 @@ impl CheckCommand {
                }),
                ..EnvironmentOptions::default()
            }),
-            terminal: Some(TerminalOptions {
-                error_on_warning: self.error_on_warning,
-            }),
            rules,
            ..Default::default()
        }
--- a/crates/red_knot/src/main.rs
+++ b/crates/red_knot/src/main.rs
@@ -11,17 +11,18 @@ use clap::Parser;
 use colored::Colorize;
 use crossbeam::channel as crossbeam_channel;
 use red_knot_project::metadata::options::Options;
+use red_knot_project::watch;
 use red_knot_project::watch::ProjectWatcher;
-use red_knot_project::{watch, Db};
 use red_knot_project::{ProjectDatabase, ProjectMetadata};
 use red_knot_server::run_server;
-use ruff_db::diagnostic::{Diagnostic, DisplayDiagnosticConfig, Severity};
+use ruff_db::diagnostic::{Diagnostic, Severity};
 use ruff_db::system::{OsSystem, System, SystemPath, SystemPathBuf};
 use salsa::plumbing::ZalsaDatabase;

 mod args;
 mod logging;
 mod python_version;
+mod verbosity;
 mod version;

 #[allow(clippy::print_stdout, clippy::unnecessary_wraps, clippy::print_stderr)]
@@ -96,15 +97,19 @@ fn run_check(args: CheckCommand) -> anyhow::Result<ExitStatus> {
    let system = OsSystem::new(cwd);
    let watch = args.watch;
    let exit_zero = args.exit_zero;
+    let min_error_severity = if args.error_on_warning {
+        Severity::Warning
+    } else {
+        Severity::Error
+    };

    let cli_options = args.into_options();
-    let mut project_metadata = ProjectMetadata::discover(system.current_directory(), &system)?;
-    project_metadata.apply_cli_options(cli_options.clone());
-    project_metadata.apply_configuration_files(&system)?;
+    let mut workspace_metadata = ProjectMetadata::discover(system.current_directory(), &system)?;
+    workspace_metadata.apply_cli_options(cli_options.clone());

-    let mut db = ProjectDatabase::new(project_metadata, system)?;
+    let mut db = ProjectDatabase::new(workspace_metadata, system)?;

-    let (main_loop, main_loop_cancellation_token) = MainLoop::new(cli_options);
+    let (main_loop, main_loop_cancellation_token) = MainLoop::new(cli_options, min_error_severity);

    // Listen to Ctrl+C and abort the watch mode.
    let main_loop_cancellation_token = Mutex::new(Some(main_loop_cancellation_token));
@@ -162,10 +167,18 @@ struct MainLoop {
    watcher: Option<ProjectWatcher>,

    cli_options: Options,
+
+    /// The minimum severity to consider an error when deciding the exit status.
+    ///
+    /// TODO(micha): Get from the terminal settings.
+    min_error_severity: Severity,
 }

 impl MainLoop {
-    fn new(cli_options: Options) -> (Self, MainLoopCancellationToken) {
+    fn new(
+        cli_options: Options,
+        min_error_severity: Severity,
+    ) -> (Self, MainLoopCancellationToken) {
        let (sender, receiver) = crossbeam_channel::bounded(10);

        (
@@ -174,6 +187,7 @@ impl MainLoop {
                receiver,
                watcher: None,
                cli_options,
+                min_error_severity,
            },
            MainLoopCancellationToken { sender },
        )
@@ -231,24 +245,14 @@ impl MainLoop {
                    result,
                    revision: check_revision,
                } => {
-                    let display_config = DisplayDiagnosticConfig::default()
-                        .color(colored::control::SHOULD_COLORIZE.should_colorize());
-
-                    let min_error_severity =
-                        if db.project().settings(db).terminal().error_on_warning {
-                            Severity::Warning
-                        } else {
-                            Severity::Error
-                        };
-
                    let failed = result
                        .iter()
-                        .any(|diagnostic| diagnostic.severity() >= min_error_severity);
+                        .any(|diagnostic| diagnostic.severity() >= self.min_error_severity);

                    if check_revision == revision {
                        #[allow(clippy::print_stdout)]
                        for diagnostic in result {
-                            println!("{}", diagnostic.display(db, &display_config));
+                            println!("{}", diagnostic.display(db));
                        }
                    } else {
                        tracing::debug!(
--- a/crates/red_knot/src/python_version.rs
+++ b/crates/red_knot/src/python_version.rs
@@ -40,7 +40,7 @@ impl std::fmt::Display for PythonVersion {
    }
 }

-impl From<PythonVersion> for ruff_python_ast::PythonVersion {
+impl From<PythonVersion> for red_knot_python_semantic::PythonVersion {
    fn from(value: PythonVersion) -> Self {
        match value {
            PythonVersion::Py37 => Self::PY37,
@@ -61,8 +61,8 @@ mod tests {
    #[test]
    fn same_default_as_python_version() {
        assert_eq!(
-            ruff_python_ast::PythonVersion::from(PythonVersion::default()),
-            ruff_python_ast::PythonVersion::default()
+            red_knot_python_semantic::PythonVersion::from(PythonVersion::default()),
+            red_knot_python_semantic::PythonVersion::default()
        );
    }
 }
--- a/crates/red_knot/src/verbosity.rs
+++ b/crates/red_knot/src/verbosity.rs
@@ -0,0 +1 @@
+
--- a/crates/red_knot/tests/cli.rs
+++ b/crates/red_knot/tests/cli.rs
@@ -98,7 +98,7 @@ fn cli_arguments_are_relative_to_the_current_directory() -> anyhow::Result<()> {
    ])?;

    // Make sure that the CLI fails when the `libs` directory is not in the search path.
-    assert_cmd_snapshot!(case.command().current_dir(case.root().join("child")), @r###"
+    assert_cmd_snapshot!(case.command().current_dir(case.project_dir().join("child")), @r###"
    success: false
    exit_code: 1
    ----- stdout -----
@@ -115,7 +115,7 @@ fn cli_arguments_are_relative_to_the_current_directory() -> anyhow::Result<()> {
    ----- stderr -----
    "###);

-    assert_cmd_snapshot!(case.command().current_dir(case.root().join("child")).arg("--extra-search-path").arg("../libs"), @r"
+    assert_cmd_snapshot!(case.command().current_dir(case.project_dir().join("child")).arg("--extra-search-path").arg("../libs"), @r"
        success: true
        exit_code: 0
        ----- stdout -----
@@ -167,7 +167,7 @@ fn paths_in_configuration_files_are_relative_to_the_project_root() -> anyhow::Re
        ),
    ])?;

-    assert_cmd_snapshot!(case.command().current_dir(case.root().join("child")), @r"
+    assert_cmd_snapshot!(case.command().current_dir(case.project_dir().join("child")), @r"
        success: true
        exit_code: 0
        ----- stdout -----
@@ -575,37 +575,6 @@ fn exit_code_no_errors_but_error_on_warning_is_true() -> anyhow::Result<()> {
    Ok(())
 }

-#[test]
-fn exit_code_no_errors_but_error_on_warning_is_enabled_in_configuration() -> anyhow::Result<()> {
-    let case = TestCase::with_files([
-        ("test.py", r"print(x)  # [unresolved-reference]"),
-        (
-            "knot.toml",
-            r#"
-            [terminal]
-            error-on-warning = true
-        "#,
-        ),
-    ])?;
-
-    assert_cmd_snapshot!(case.command(), @r###"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    warning: lint:unresolved-reference
-     --> <temp_dir>/test.py:1:7
-      |
-    1 | print(x)  # [unresolved-reference]
-      |       - Name `x` used when not defined
-      |
-
-
-    ----- stderr -----
-    "###);
-
-    Ok(())
-}
-
 #[test]
 fn exit_code_both_warnings_and_errors() -> anyhow::Result<()> {
    let case = TestCase::with_file(
@@ -717,109 +686,6 @@ fn exit_code_exit_zero_is_true() -> anyhow::Result<()> {
    Ok(())
 }

-#[test]
-fn user_configuration() -> anyhow::Result<()> {
-    let case = TestCase::with_files([
-        (
-            "project/knot.toml",
-            r#"
-            [rules]
-            division-by-zero = "warn"
-            "#,
-        ),
-        (
-            "project/main.py",
-            r#"
-            y = 4 / 0
-
-            for a in range(0, y):
-                x = a
-
-            print(x)
-            "#,
-        ),
-    ])?;
-
-    let config_directory = case.root().join("home/.config");
-    let config_env_var = if cfg!(windows) {
-        "APPDATA"
-    } else {
-        "XDG_CONFIG_HOME"
-    };
-
-    assert_cmd_snapshot!(
-        case.command().current_dir(case.root().join("project")).env(config_env_var, config_directory.as_os_str()),
-        @r###"
-    success: true
-    exit_code: 0
-    ----- stdout -----
-    warning: lint:division-by-zero
-     --> <temp_dir>/project/main.py:2:5
-      |
-    2 | y = 4 / 0
-      |     ----- Cannot divide object of type `Literal[4]` by zero
-    3 |
-    4 | for a in range(0, y):
-      |
-
-    warning: lint:possibly-unresolved-reference
-     --> <temp_dir>/project/main.py:7:7
-      |
-    5 |     x = a
-    6 |
-    7 | print(x)
-      |       - Name `x` used when possibly not defined
-      |
-
-
-    ----- stderr -----
-    "###
-    );
-
-    // The user-level configuration promotes `possibly-unresolved-reference` to an error.
-    // Changing the level for `division-by-zero` has no effect, because the project-level configuration
-    // has higher precedence.
-    case.write_file(
-        config_directory.join("knot/knot.toml"),
-        r#"
-        [rules]
-        division-by-zero = "error"
-        possibly-unresolved-reference = "error"
-        "#,
-    )?;
-
-    assert_cmd_snapshot!(
-        case.command().current_dir(case.root().join("project")).env(config_env_var, config_directory.as_os_str()),
-        @r###"
-    success: false
-    exit_code: 1
-    ----- stdout -----
-    warning: lint:division-by-zero
-     --> <temp_dir>/project/main.py:2:5
-      |
-    2 | y = 4 / 0
-      |     ----- Cannot divide object of type `Literal[4]` by zero
-    3 |
-    4 | for a in range(0, y):
-      |
-
-    error: lint:possibly-unresolved-reference
-     --> <temp_dir>/project/main.py:7:7
-      |
-    5 |     x = a
-    6 |
-    7 | print(x)
-      |       ^ Name `x` used when possibly not defined
-      |
-
-
-    ----- stderr -----
-    "###
-    );
-
-    Ok(())
-}
-
 struct TestCase {
    _temp_dir: TempDir,
    _settings_scope: SettingsBindDropGuard,
@@ -887,7 +753,7 @@ impl TestCase {
        Ok(())
    }

-    fn root(&self) -> &Path {
+    fn project_dir(&self) -> &Path {
        &self.project_dir
    }

--- a/crates/red_knot/tests/file_watching.rs
+++ b/crates/red_knot/tests/file_watching.rs
@@ -9,14 +9,11 @@ use red_knot_project::metadata::pyproject::{PyProject, Tool};
 use red_knot_project::metadata::value::{RangedValue, RelativePathBuf};
 use red_knot_project::watch::{directory_watcher, ChangeEvent, ProjectWatcher};
 use red_knot_project::{Db, ProjectDatabase, ProjectMetadata};
-use red_knot_python_semantic::{resolve_module, ModuleName, PythonPlatform};
+use red_knot_python_semantic::{resolve_module, ModuleName, PythonPlatform, PythonVersion};
 use ruff_db::files::{system_path_to_file, File, FileError};
 use ruff_db::source::source_text;
-use ruff_db::system::{
-    OsSystem, System, SystemPath, SystemPathBuf, UserConfigDirectoryOverrideGuard,
-};
+use ruff_db::system::{OsSystem, SystemPath, SystemPathBuf};
 use ruff_db::Upcast;
-use ruff_python_ast::PythonVersion;

 struct TestCase {
    db: ProjectDatabase,
@@ -223,44 +220,17 @@ where
 }

 trait SetupFiles {
-    fn setup(self, context: &SetupContext) -> anyhow::Result<()>;
-}
-
-struct SetupContext<'a> {
-    system: &'a OsSystem,
-    root_path: &'a SystemPath,
-}
-
-impl<'a> SetupContext<'a> {
-    fn system(&self) -> &'a OsSystem {
-        self.system
-    }
-
-    fn join_project_path(&self, relative: impl AsRef<SystemPath>) -> SystemPathBuf {
-        self.project_path().join(relative)
-    }
-
-    fn project_path(&self) -> &SystemPath {
-        self.system.current_directory()
-    }
-
-    fn root_path(&self) -> &'a SystemPath {
-        self.root_path
-    }
-
-    fn join_root_path(&self, relative: impl AsRef<SystemPath>) -> SystemPathBuf {
-        self.root_path().join(relative)
-    }
+    fn setup(self, root_path: &SystemPath, project_path: &SystemPath) -> anyhow::Result<()>;
 }

 impl<const N: usize, P> SetupFiles for [(P, &'static str); N]
 where
    P: AsRef<SystemPath>,
 {
-    fn setup(self, context: &SetupContext) -> anyhow::Result<()> {
+    fn setup(self, _root_path: &SystemPath, project_path: &SystemPath) -> anyhow::Result<()> {
        for (relative_path, content) in self {
            let relative_path = relative_path.as_ref();
-            let absolute_path = context.join_project_path(relative_path);
+            let absolute_path = project_path.join(relative_path);
            if let Some(parent) = absolute_path.parent() {
                std::fs::create_dir_all(parent).with_context(|| {
                    format!("Failed to create parent directory for file `{relative_path}`")
@@ -280,10 +250,10 @@ where

 impl<F> SetupFiles for F
 where
-    F: FnOnce(&SetupContext) -> anyhow::Result<()>,
+    F: FnOnce(&SystemPath, &SystemPath) -> anyhow::Result<()>,
 {
-    fn setup(self, context: &SetupContext) -> anyhow::Result<()> {
-        self(context)
+    fn setup(self, root_path: &SystemPath, project_path: &SystemPath) -> anyhow::Result<()> {
+        self(root_path, project_path)
    }
 }

@@ -291,12 +261,13 @@ fn setup<F>(setup_files: F) -> anyhow::Result<TestCase>
 where
    F: SetupFiles,
 {
-    setup_with_options(setup_files, |_context| None)
+    setup_with_options(setup_files, |_root, _project_path| None)
 }

+// TODO: Replace with configuration?
 fn setup_with_options<F>(
    setup_files: F,
-    create_options: impl FnOnce(&SetupContext) -> Option<Options>,
+    create_options: impl FnOnce(&SystemPath, &SystemPath) -> Option<Options>,
 ) -> anyhow::Result<TestCase>
 where
    F: SetupFiles,
@@ -324,17 +295,13 @@ where
    std::fs::create_dir_all(project_path.as_std_path())
        .with_context(|| format!("Failed to create project directory `{project_path}`"))?;

-    let system = OsSystem::new(&project_path);
-    let setup_context = SetupContext {
-        system: &system,
-        root_path: &root_path,
-    };
-
    setup_files
-        .setup(&setup_context)
+        .setup(&root_path, &project_path)
        .context("Failed to setup test files")?;

-    if let Some(options) = create_options(&setup_context) {
+    let system = OsSystem::new(&project_path);
+
+    if let Some(options) = create_options(&root_path, &project_path) {
        std::fs::write(
            project_path.join("pyproject.toml").as_std_path(),
            toml::to_string(&PyProject {
@@ -348,9 +315,7 @@ where
        .context("Failed to write configuration")?;
    }

-    let mut project = ProjectMetadata::discover(&project_path, &system)?;
-    project.apply_configuration_files(&system)?;
-
+    let project = ProjectMetadata::discover(&project_path, &system)?;
    let program_settings = project.to_program_settings(&system);

    for path in program_settings
@@ -824,12 +789,10 @@ fn directory_deleted() -> anyhow::Result<()> {

 #[test]
 fn search_path() -> anyhow::Result<()> {
-    let mut case = setup_with_options([("bar.py", "import sub.a")], |context| {
+    let mut case = setup_with_options([("bar.py", "import sub.a")], |root_path, _project_path| {
        Some(Options {
            environment: Some(EnvironmentOptions {
-                extra_paths: Some(vec![RelativePathBuf::cli(
-                    context.join_root_path("site_packages"),
-                )]),
+                extra_paths: Some(vec![RelativePathBuf::cli(root_path.join("site_packages"))]),
                ..EnvironmentOptions::default()
            }),
            ..Options::default()
@@ -890,12 +853,10 @@ fn add_search_path() -> anyhow::Result<()> {

 #[test]
 fn remove_search_path() -> anyhow::Result<()> {
-    let mut case = setup_with_options([("bar.py", "import sub.a")], |context| {
+    let mut case = setup_with_options([("bar.py", "import sub.a")], |root_path, _project_path| {
        Some(Options {
            environment: Some(EnvironmentOptions {
-                extra_paths: Some(vec![RelativePathBuf::cli(
-                    context.join_root_path("site_packages"),
-                )]),
+                extra_paths: Some(vec![RelativePathBuf::cli(root_path.join("site_packages"))]),
                ..EnvironmentOptions::default()
            }),
            ..Options::default()
@@ -933,7 +894,7 @@ import os
 print(sys.last_exc, os.getegid())
 "#,
        )],
-        |_context| {
+        |_root_path, _project_path| {
            Some(Options {
                environment: Some(EnvironmentOptions {
                    python_version: Some(RangedValue::cli(PythonVersion::PY311)),
@@ -981,31 +942,21 @@ print(sys.last_exc, os.getegid())
 #[test]
 fn changed_versions_file() -> anyhow::Result<()> {
    let mut case = setup_with_options(
-        |context: &SetupContext| {
+        |root_path: &SystemPath, project_path: &SystemPath| {
+            std::fs::write(project_path.join("bar.py").as_std_path(), "import sub.a")?;
+            std::fs::create_dir_all(root_path.join("typeshed/stdlib").as_std_path())?;
+            std::fs::write(root_path.join("typeshed/stdlib/VERSIONS").as_std_path(), "")?;
            std::fs::write(
-                context.join_project_path("bar.py").as_std_path(),
-                "import sub.a",
-            )?;
-            std::fs::create_dir_all(context.join_root_path("typeshed/stdlib").as_std_path())?;
-            std::fs::write(
-                context
-                    .join_root_path("typeshed/stdlib/VERSIONS")
-                    .as_std_path(),
-                "",
-            )?;
-            std::fs::write(
-                context
-                    .join_root_path("typeshed/stdlib/os.pyi")
-                    .as_std_path(),
+                root_path.join("typeshed/stdlib/os.pyi").as_std_path(),
                "# not important",
            )?;

            Ok(())
        },
-        |context| {
+        |root_path, _project_path| {
            Some(Options {
                environment: Some(EnvironmentOptions {
-                    typeshed: Some(RelativePathBuf::cli(context.join_root_path("typeshed"))),
+                    typeshed: Some(RelativePathBuf::cli(root_path.join("typeshed"))),
                    ..EnvironmentOptions::default()
                }),
                ..Options::default()
@@ -1056,12 +1007,12 @@ fn changed_versions_file() -> anyhow::Result<()> {
 /// we're seeing is that Windows only emits a single event, similar to Linux.
 #[test]
 fn hard_links_in_project() -> anyhow::Result<()> {
-    let mut case = setup(|context: &SetupContext| {
-        let foo_path = context.join_project_path("foo.py");
+    let mut case = setup(|_root: &SystemPath, project: &SystemPath| {
+        let foo_path = project.join("foo.py");
        std::fs::write(foo_path.as_std_path(), "print('Version 1')")?;

        // Create a hardlink to `foo`
-        let bar_path = context.join_project_path("bar.py");
+        let bar_path = project.join("bar.py");
        std::fs::hard_link(foo_path.as_std_path(), bar_path.as_std_path())
            .context("Failed to create hard link from foo.py -> bar.py")?;

@@ -1127,12 +1078,12 @@ fn hard_links_in_project() -> anyhow::Result<()> {
    ignore = "windows doesn't support observing changes to hard linked files."
 )]
 fn hard_links_to_target_outside_project() -> anyhow::Result<()> {
-    let mut case = setup(|context: &SetupContext| {
-        let foo_path = context.join_root_path("foo.py");
+    let mut case = setup(|root: &SystemPath, project: &SystemPath| {
+        let foo_path = root.join("foo.py");
        std::fs::write(foo_path.as_std_path(), "print('Version 1')")?;

        // Create a hardlink to `foo`
-        let bar_path = context.join_project_path("bar.py");
+        let bar_path = project.join("bar.py");
        std::fs::hard_link(foo_path.as_std_path(), bar_path.as_std_path())
            .context("Failed to create hard link from foo.py -> bar.py")?;

@@ -1235,9 +1186,9 @@ mod unix {
        ignore = "FSEvents doesn't emit change events for symlinked directories outside of the watched paths."
    )]
    fn symlink_target_outside_watched_paths() -> anyhow::Result<()> {
-        let mut case = setup(|context: &SetupContext| {
+        let mut case = setup(|root: &SystemPath, project: &SystemPath| {
            // Set up the symlink target.
-            let link_target = context.join_root_path("bar");
+            let link_target = root.join("bar");
            std::fs::create_dir_all(link_target.as_std_path())
                .context("Failed to create link target directory")?;
            let baz_original = link_target.join("baz.py");
@@ -1245,7 +1196,7 @@ mod unix {
                .context("Failed to write link target file")?;

            // Create a symlink inside the project
-            let bar = context.join_project_path("bar");
+            let bar = project.join("bar");
            std::os::unix::fs::symlink(link_target.as_std_path(), bar.as_std_path())
                .context("Failed to create symlink to bar package")?;

@@ -1316,9 +1267,9 @@ mod unix {
    /// ```
    #[test]
    fn symlink_inside_project() -> anyhow::Result<()> {
-        let mut case = setup(|context: &SetupContext| {
+        let mut case = setup(|_root: &SystemPath, project: &SystemPath| {
            // Set up the symlink target.
-            let link_target = context.join_project_path("patched/bar");
+            let link_target = project.join("patched/bar");
            std::fs::create_dir_all(link_target.as_std_path())
                .context("Failed to create link target directory")?;
            let baz_original = link_target.join("baz.py");
@@ -1326,7 +1277,7 @@ mod unix {
                .context("Failed to write link target file")?;

            // Create a symlink inside site-packages
-            let bar_in_project = context.join_project_path("bar");
+            let bar_in_project = project.join("bar");
            std::os::unix::fs::symlink(link_target.as_std_path(), bar_in_project.as_std_path())
                .context("Failed to create symlink to bar package")?;

@@ -1407,9 +1358,9 @@ mod unix {
    #[test]
    fn symlinked_module_search_path() -> anyhow::Result<()> {
        let mut case = setup_with_options(
-            |context: &SetupContext| {
+            |root: &SystemPath, project: &SystemPath| {
                // Set up the symlink target.
-                let site_packages = context.join_root_path("site-packages");
+                let site_packages = root.join("site-packages");
                let bar = site_packages.join("bar");
                std::fs::create_dir_all(bar.as_std_path())
                    .context("Failed to create bar directory")?;
@@ -1418,8 +1369,7 @@ mod unix {
                    .context("Failed to write baz.py")?;

                // Symlink the site packages in the venv to the global site packages
-                let venv_site_packages =
-                    context.join_project_path(".venv/lib/python3.12/site-packages");
+                let venv_site_packages = project.join(".venv/lib/python3.12/site-packages");
                std::fs::create_dir_all(venv_site_packages.parent().unwrap())
                    .context("Failed to create .venv directory")?;
                std::os::unix::fs::symlink(
@@ -1430,7 +1380,7 @@ mod unix {

                Ok(())
            },
-            |_context| {
+            |_root, _project| {
                Some(Options {
                    environment: Some(EnvironmentOptions {
                        extra_paths: Some(vec![RelativePathBuf::cli(
@@ -1500,9 +1450,9 @@ mod unix {

 #[test]
 fn nested_projects_delete_root() -> anyhow::Result<()> {
-    let mut case = setup(|context: &SetupContext| {
+    let mut case = setup(|root: &SystemPath, project_root: &SystemPath| {
        std::fs::write(
-            context.join_project_path("pyproject.toml").as_std_path(),
+            project_root.join("pyproject.toml").as_std_path(),
            r#"
            [project]
            name = "inner"
@@ -1512,7 +1462,7 @@ fn nested_projects_delete_root() -> anyhow::Result<()> {
        )?;

        std::fs::write(
-            context.join_root_path("pyproject.toml").as_std_path(),
+            root.join("pyproject.toml").as_std_path(),
            r#"
            [project]
            name = "outer"
@@ -1537,79 +1487,3 @@ fn nested_projects_delete_root() -> anyhow::Result<()> {

    Ok(())
 }
-
-#[test]
-fn changes_to_user_configuration() -> anyhow::Result<()> {
-    let mut _config_dir_override: Option<UserConfigDirectoryOverrideGuard> = None;
-
-    let mut case = setup(|context: &SetupContext| {
-        std::fs::write(
-            context.join_project_path("pyproject.toml").as_std_path(),
-            r#"
-            [project]
-            name = "test"
-            "#,
-        )?;
-
-        std::fs::write(
-            context.join_project_path("foo.py").as_std_path(),
-            "a = 10 / 0",
-        )?;
-
-        let config_directory = context.join_root_path("home/.config");
-        std::fs::create_dir_all(config_directory.join("knot").as_std_path())?;
-        std::fs::write(
-            config_directory.join("knot/knot.toml").as_std_path(),
-            r#"
-            [rules]
-            division-by-zero = "ignore"
-            "#,
-        )?;
-
-        _config_dir_override = Some(
-            context
-                .system()
-                .with_user_config_directory(Some(config_directory)),
-        );
-
-        Ok(())
-    })?;
-
-    let foo = case
-        .system_file(case.project_path("foo.py"))
-        .expect("foo.py to exist");
-    let diagnostics = case
-        .db()
-        .check_file(foo)
-        .context("Failed to check project.")?;
-
-    assert!(
-        diagnostics.is_empty(),
-        "Expected no diagnostics but got: {diagnostics:#?}"
-    );
-
-    // Enable division-by-zero in the user configuration with warning severity
-    update_file(
-        case.root_path().join("home/.config/knot/knot.toml"),
-        r#"
-        [rules]
-        division-by-zero = "warn"
-        "#,
-    )?;
-
-    let changes = case.stop_watch(event_for_file("knot.toml"));
-
-    case.apply_changes(changes);
-
-    let diagnostics = case
-        .db()
-        .check_file(foo)
-        .context("Failed to check project.")?;
-
-    assert!(
-        diagnostics.len() == 1,
-        "Expected exactly one diagnostic but got: {diagnostics:#?}"
-    );
-
-    Ok(())
-}
--- a/crates/red_knot_project/Cargo.toml
+++ b/crates/red_knot_project/Cargo.toml
@@ -13,7 +13,7 @@ license.workspace = true

 [dependencies]
 ruff_cache = { workspace = true }
-ruff_db = { workspace = true, features = ["cache", "serde"] }
+ruff_db = { workspace = true, features = ["os", "cache", "serde"] }
 ruff_macros = { workspace = true }
 ruff_python_ast = { workspace = true, features = ["serde"] }
 ruff_text_size = { workspace = true }
@@ -24,11 +24,10 @@ anyhow = { workspace = true }
 crossbeam = { workspace = true }
 glob = { workspace = true }
 notify = { workspace = true }
-pep440_rs = { workspace = true, features = ["version-ranges"] }
+pep440_rs = { workspace = true }
 rayon = { workspace = true }
 rustc-hash = { workspace = true }
 salsa = { workspace = true }
-schemars = { workspace = true, optional = true }
 serde = { workspace = true }
 thiserror = { workspace = true }
 toml = { workspace = true }
@@ -41,9 +40,8 @@ insta = { workspace = true, features = ["redactions", "ron"] }

 [features]
 default = ["zstd"]
-deflate = ["red_knot_vendored/deflate"]
-schemars = ["dep:schemars", "ruff_db/schemars", "red_knot_python_semantic/schemars"]
 zstd = ["red_knot_vendored/zstd"]
+deflate = ["red_knot_vendored/deflate"]

 [lints]
 workspace = true
--- a/crates/red_knot_project/src/combine.rs
+++ b/crates/red_knot_project/src/combine.rs
@@ -1,8 +1,7 @@
 use std::{collections::HashMap, hash::BuildHasher};

-use red_knot_python_semantic::{PythonPlatform, SitePackages};
+use red_knot_python_semantic::{PythonPlatform, PythonVersion, SitePackages};
 use ruff_db::system::SystemPathBuf;
-use ruff_python_ast::PythonVersion;

 /// Combine two values, preferring the values in `self`.
 ///
--- a/crates/red_knot_project/src/db.rs
+++ b/crates/red_knot_project/src/db.rs
@@ -114,8 +114,8 @@ impl SemanticDb for ProjectDatabase {
        project.is_file_open(self, file)
    }

-    fn rule_selection(&self) -> Arc<RuleSelection> {
-        self.project().rules(self)
+    fn rule_selection(&self) -> &RuleSelection {
+        self.project().rule_selection(self)
    }

    fn lint_registry(&self) -> &LintRegistry {
@@ -186,6 +186,7 @@ pub(crate) mod tests {
        files: Files,
        system: TestSystem,
        vendored: VendoredFileSystem,
+        rule_selection: RuleSelection,
        project: Option<Project>,
    }

@@ -197,6 +198,7 @@ pub(crate) mod tests {
                vendored: red_knot_vendored::file_system().clone(),
                files: Files::default(),
                events: Arc::default(),
+                rule_selection: RuleSelection::from_registry(&DEFAULT_LINT_REGISTRY),
                project: None,
            };

@@ -268,8 +270,8 @@ pub(crate) mod tests {
            !file.path(self).is_vendored_path()
        }

-        fn rule_selection(&self) -> Arc<RuleSelection> {
-            self.project().rules(self)
+        fn rule_selection(&self) -> &RuleSelection {
+            &self.rule_selection
        }

        fn lint_registry(&self) -> &LintRegistry {
--- a/crates/red_knot_project/src/db/changes.rs
+++ b/crates/red_knot_project/src/db/changes.rs
@@ -8,7 +8,6 @@ use ruff_db::files::{system_path_to_file, File, Files};
 use ruff_db::system::walk_directory::WalkState;
 use ruff_db::system::SystemPath;
 use ruff_db::Db as _;
-use ruff_python_ast::PySourceType;
 use rustc_hash::FxHashSet;

 impl ProjectDatabase {
@@ -48,7 +47,7 @@ impl ProjectDatabase {
            if let Some(path) = change.system_path() {
                if matches!(
                    path.file_name(),
-                    Some(".gitignore" | ".ignore" | "knot.toml" | "pyproject.toml")
+                    Some(".gitignore" | ".ignore" | "ruff.toml" | ".ruff.toml" | "pyproject.toml")
                ) {
                    // Changes to ignore files or settings can change the project structure or add/remove files.
                    project_changed = true;
@@ -145,12 +144,6 @@ impl ProjectDatabase {
                        metadata.apply_cli_options(cli_options.clone());
                    }

-                    if let Err(error) = metadata.apply_configuration_files(self.system()) {
-                        tracing::error!(
-                            "Failed to apply configuration files, continuing without applying them: {error}"
-                        );
-                    }
-
                    let program_settings = metadata.to_program_settings(self.system());

                    let program = Program::get(self);
@@ -208,16 +201,9 @@ impl ProjectDatabase {
                        return WalkState::Continue;
                    }

-                    if entry
-                        .path()
-                        .extension()
-                        .and_then(PySourceType::try_from_extension)
-                        .is_some()
-                    {
-                        let mut paths = added_paths.lock().unwrap();
+                    let mut paths = added_paths.lock().unwrap();

-                        paths.push(entry.into_path());
-                    }
+                    paths.push(entry.into_path());

                    WalkState::Continue
                })
--- a/crates/red_knot_project/src/lib.rs
+++ b/crates/red_knot_project/src/lib.rs
@@ -3,18 +3,18 @@
 use crate::metadata::options::OptionDiagnostic;
 pub use db::{Db, ProjectDatabase};
 use files::{Index, Indexed, IndexedFiles};
-use metadata::settings::Settings;
 pub use metadata::{ProjectDiscoveryError, ProjectMetadata};
 use red_knot_python_semantic::lint::{LintRegistry, LintRegistryBuilder, RuleSelection};
 use red_knot_python_semantic::register_lints;
 use red_knot_python_semantic::types::check_types;
-use ruff_db::diagnostic::{Diagnostic, DiagnosticId, ParseDiagnostic, Severity, Span};
+use ruff_db::diagnostic::{Diagnostic, DiagnosticId, ParseDiagnostic, Severity};
 use ruff_db::files::{system_path_to_file, File};
 use ruff_db::parsed::parsed_module;
 use ruff_db::source::{source_text, SourceTextError};
 use ruff_db::system::walk_directory::WalkState;
 use ruff_db::system::{FileType, SystemPath};
 use ruff_python_ast::PySourceType;
+use ruff_text_size::TextRange;
 use rustc_hash::{FxBuildHasher, FxHashSet};
 use salsa::Durability;
 use salsa::Setter;
@@ -66,22 +66,12 @@ pub struct Project {
    /// The metadata describing the project, including the unresolved options.
    #[return_ref]
    pub metadata: ProjectMetadata,
-
-    /// The resolved project settings.
-    #[return_ref]
-    pub settings: Settings,
-
-    /// Diagnostics that were generated when resolving the project settings.
-    #[return_ref]
-    settings_diagnostics: Vec<OptionDiagnostic>,
 }

 #[salsa::tracked]
 impl Project {
    pub fn from_metadata(db: &dyn Db, metadata: ProjectMetadata) -> Self {
-        let (settings, settings_diagnostics) = metadata.options().to_settings(db);
-
-        Project::builder(metadata, settings, settings_diagnostics)
+        Project::builder(metadata)
            .durability(Durability::MEDIUM)
            .open_fileset_durability(Durability::LOW)
            .file_set_durability(Durability::LOW)
@@ -96,37 +86,30 @@ impl Project {
        self.metadata(db).name()
    }

-    /// Returns the resolved linter rules for the project.
-    ///
-    /// This is a salsa query to prevent re-computing queries if other, unrelated
-    /// settings change. For example, we don't want that changing the terminal settings
-    /// invalidates any type checking queries.
-    #[salsa::tracked]
-    pub fn rules(self, db: &dyn Db) -> Arc<RuleSelection> {
-        self.settings(db).to_rules()
-    }
-
    pub fn reload(self, db: &mut dyn Db, metadata: ProjectMetadata) {
        tracing::debug!("Reloading project");
        assert_eq!(self.root(db), metadata.root());

        if &metadata != self.metadata(db) {
-            let (settings, settings_diagnostics) = metadata.options().to_settings(db);
-
-            if self.settings(db) != &settings {
-                self.set_settings(db).to(settings);
-            }
-
-            if self.settings_diagnostics(db) != &settings_diagnostics {
-                self.set_settings_diagnostics(db).to(settings_diagnostics);
-            }
-
            self.set_metadata(db).to(metadata);
        }

        self.reload_files(db);
    }

+    pub fn rule_selection(self, db: &dyn Db) -> &RuleSelection {
+        let (selection, _) = self.rule_selection_with_diagnostics(db);
+        selection
+    }
+
+    #[salsa::tracked(return_ref)]
+    fn rule_selection_with_diagnostics(
+        self,
+        db: &dyn Db,
+    ) -> (RuleSelection, Vec<OptionDiagnostic>) {
+        self.metadata(db).options().to_rule_selection(db)
+    }
+
    /// Checks all open files in the project and its dependencies.
    pub(crate) fn check(self, db: &ProjectDatabase) -> Vec<Box<dyn Diagnostic>> {
        let project_span = tracing::debug_span!("Project::check");
@@ -135,7 +118,8 @@ impl Project {
        tracing::debug!("Checking project '{name}'", name = self.name(db));

        let mut diagnostics: Vec<Box<dyn Diagnostic>> = Vec::new();
-        diagnostics.extend(self.settings_diagnostics(db).iter().map(|diagnostic| {
+        let (_, options_diagnostics) = self.rule_selection_with_diagnostics(db);
+        diagnostics.extend(options_diagnostics.iter().map(|diagnostic| {
            let diagnostic: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
            diagnostic
        }));
@@ -167,8 +151,9 @@ impl Project {
    }

    pub(crate) fn check_file(self, db: &dyn Db, file: File) -> Vec<Box<dyn Diagnostic>> {
-        let mut file_diagnostics: Vec<_> = self
-            .settings_diagnostics(db)
+        let (_, options_diagnostics) = self.rule_selection_with_diagnostics(db);
+
+        let mut file_diagnostics: Vec<_> = options_diagnostics
            .iter()
            .map(|diagnostic| {
                let diagnostic: Box<dyn Diagnostic> = Box::new(diagnostic.clone());
@@ -344,13 +329,7 @@ fn check_file_impl(db: &dyn Db, file: File) -> Vec<Box<dyn Diagnostic>> {
        boxed
    }));

-    diagnostics.sort_unstable_by_key(|diagnostic| {
-        diagnostic
-            .span()
-            .and_then(|span| span.range())
-            .unwrap_or_default()
-            .start()
-    });
+    diagnostics.sort_unstable_by_key(|diagnostic| diagnostic.range().unwrap_or_default().start());

    diagnostics
 }
@@ -463,8 +442,12 @@ impl Diagnostic for IOErrorDiagnostic {
        self.error.to_string().into()
    }

-    fn span(&self) -> Option<Span> {
-        Some(Span::from(self.file))
+    fn file(&self) -> Option<File> {
+        Some(self.file)
+    }
+
+    fn range(&self) -> Option<TextRange> {
+        None
    }

    fn severity(&self) -> Severity {
--- a/crates/red_knot_project/src/metadata.rs
+++ b/crates/red_knot_project/src/metadata.rs
@@ -1,4 +1,3 @@
-use configuration_file::{ConfigurationFile, ConfigurationFileError};
 use red_knot_python_semantic::ProgramSettings;
 use ruff_db::system::{System, SystemPath, SystemPathBuf};
 use ruff_python_ast::name::Name;
@@ -6,15 +5,13 @@ use std::sync::Arc;
 use thiserror::Error;

 use crate::combine::Combine;
-use crate::metadata::pyproject::{Project, PyProject, PyProjectError, ResolveRequiresPythonError};
+use crate::metadata::pyproject::{Project, PyProject, PyProjectError};
 use crate::metadata::value::ValueSource;
 use options::KnotTomlError;
 use options::Options;

-mod configuration_file;
 pub mod options;
 pub mod pyproject;
-pub mod settings;
 pub mod value;

 #[derive(Debug, PartialEq, Eq)]
@@ -26,15 +23,6 @@ pub struct ProjectMetadata {

    /// The raw options
    pub(super) options: Options,
-
-    /// Paths of configurations other than the project's configuration that were combined into [`Self::options`].
-    ///
-    /// This field stores the paths of the configuration files, mainly for
-    /// knowing which files to watch for changes.
-    ///
-    /// The path ordering doesn't imply precedence.
-    #[cfg_attr(test, serde(skip_serializing_if = "Vec::is_empty"))]
-    pub(super) extra_configuration_paths: Vec<SystemPathBuf>,
 }

 impl ProjectMetadata {
@@ -43,16 +31,12 @@ impl ProjectMetadata {
        Self {
            name,
            root,
-            extra_configuration_paths: Vec::default(),
            options: Options::default(),
        }
    }

    /// Loads a project from a `pyproject.toml` file.
-    pub(crate) fn from_pyproject(
-        pyproject: PyProject,
-        root: SystemPathBuf,
-    ) -> Result<Self, ResolveRequiresPythonError> {
+    pub(crate) fn from_pyproject(pyproject: PyProject, root: SystemPathBuf) -> Self {
        Self::from_options(
            pyproject
                .tool
@@ -65,37 +49,21 @@ impl ProjectMetadata {

    /// Loads a project from a set of options with an optional pyproject-project table.
    pub(crate) fn from_options(
-        mut options: Options,
+        options: Options,
        root: SystemPathBuf,
        project: Option<&Project>,
-    ) -> Result<Self, ResolveRequiresPythonError> {
+    ) -> Self {
        let name = project
-            .and_then(|project| project.name.as_deref())
-            .map(|name| Name::new(&**name))
+            .and_then(|project| project.name.as_ref())
+            .map(|name| Name::new(&***name))
            .unwrap_or_else(|| Name::new(root.file_name().unwrap_or("root")));

-        // If the `options` don't specify a python version but the `project.requires-python` field is set,
-        // use that as a lower bound instead.
-        if let Some(project) = project {
-            if !options
-                .environment
-                .as_ref()
-                .is_some_and(|env| env.python_version.is_some())
-            {
-                if let Some(requires_python) = project.resolve_requires_python_lower_bound()? {
-                    let mut environment = options.environment.unwrap_or_default();
-                    environment.python_version = Some(requires_python);
-                    options.environment = Some(environment);
-                }
-            }
-        }
-
-        Ok(Self {
+        // TODO(https://github.com/astral-sh/ruff/issues/15491): Respect requires-python
+        Self {
            name,
            root,
            options,
-            extra_configuration_paths: Vec::new(),
-        })
+        }
    }

    /// Discovers the closest project at `path` and returns its metadata.
@@ -163,34 +131,19 @@ impl ProjectMetadata {
                }

                tracing::debug!("Found project at '{}'", project_root);
-
-                let metadata = ProjectMetadata::from_options(
+                return Ok(ProjectMetadata::from_options(
                    options,
                    project_root.to_path_buf(),
                    pyproject
                        .as_ref()
                        .and_then(|pyproject| pyproject.project.as_ref()),
-                )
-                .map_err(|err| {
-                    ProjectDiscoveryError::InvalidRequiresPythonConstraint {
-                        source: err,
-                        path: pyproject_path,
-                    }
-                })?;
-
-                return Ok(metadata);
+                ));
            }

            if let Some(pyproject) = pyproject {
                let has_knot_section = pyproject.knot().is_some();
                let metadata =
-                    ProjectMetadata::from_pyproject(pyproject, project_root.to_path_buf())
-                        .map_err(
-                            |err| ProjectDiscoveryError::InvalidRequiresPythonConstraint {
-                                source: err,
-                                path: pyproject_path,
-                            },
-                        )?;
+                    ProjectMetadata::from_pyproject(pyproject, project_root.to_path_buf());

                if has_knot_section {
                    tracing::debug!("Found project at '{}'", project_root);
@@ -238,10 +191,6 @@ impl ProjectMetadata {
        &self.options
    }

-    pub fn extra_configuration_paths(&self) -> &[SystemPathBuf] {
-        &self.extra_configuration_paths
-    }
-
    pub fn to_program_settings(&self, system: &dyn System) -> ProgramSettings {
        self.options.to_program_settings(self.root(), system)
    }
@@ -251,31 +200,9 @@ impl ProjectMetadata {
        self.options = options.combine(std::mem::take(&mut self.options));
    }

-    /// Applies the options from the configuration files to the project's options.
-    ///
-    /// This includes:
-    ///
-    /// * The user-level configuration
-    pub fn apply_configuration_files(
-        &mut self,
-        system: &dyn System,
-    ) -> Result<(), ConfigurationFileError> {
-        if let Some(user) = ConfigurationFile::user(system)? {
-            tracing::debug!(
-                "Applying user-level configuration loaded from `{path}`.",
-                path = user.path()
-            );
-            self.apply_configuration_file(user);
-        }
-
-        Ok(())
-    }
-
-    /// Applies a lower-precedence configuration files to the project's options.
-    fn apply_configuration_file(&mut self, options: ConfigurationFile) {
-        self.extra_configuration_paths
-            .push(options.path().to_owned());
-        self.options.combine_with(options.into_options());
+    /// Combine the project options with the user options where project options take precedence.
+    pub fn apply_user_options(&mut self, options: Options) {
+        self.options.combine_with(options);
    }
 }

@@ -295,22 +222,16 @@ pub enum ProjectDiscoveryError {
        source: Box<KnotTomlError>,
        path: SystemPathBuf,
    },
-
-    #[error("Invalid `requires-python` version specifier (`{path}`): {source}")]
-    InvalidRequiresPythonConstraint {
-        source: ResolveRequiresPythonError,
-        path: SystemPathBuf,
-    },
 }

 #[cfg(test)]
 mod tests {
    //! Integration tests for project discovery

+    use crate::snapshot_project;
    use anyhow::{anyhow, Context};
    use insta::assert_ron_snapshot;
    use ruff_db::system::{SystemPathBuf, TestSystem};
-    use ruff_python_ast::PythonVersion;

    use crate::{ProjectDiscoveryError, ProjectMetadata};

@@ -329,15 +250,7 @@ mod tests {

        assert_eq!(project.root(), &*root);

-        with_escaped_paths(|| {
-            assert_ron_snapshot!(&project, @r#"
-                ProjectMetadata(
-                  name: Name("app"),
-                  root: "/app",
-                  options: Options(),
-                )
-            "#);
-        });
+        snapshot_project!(project);

        Ok(())
    }
@@ -366,16 +279,7 @@ mod tests {
            ProjectMetadata::discover(&root, &system).context("Failed to discover project")?;

        assert_eq!(project.root(), &*root);
-
-        with_escaped_paths(|| {
-            assert_ron_snapshot!(&project, @r#"
-                ProjectMetadata(
-                  name: Name("backend"),
-                  root: "/app",
-                  options: Options(),
-                )
-            "#);
-        });
+        snapshot_project!(project);

        // Discovering the same package from a subdirectory should give the same result
        let from_src = ProjectMetadata::discover(&root.join("db"), &system)
@@ -458,19 +362,7 @@ expected `.`, `]`

        let sub_project = ProjectMetadata::discover(&root.join("packages/a"), &system)?;

-        with_escaped_paths(|| {
-            assert_ron_snapshot!(sub_project, @r#"
-            ProjectMetadata(
-              name: Name("nested-project"),
-              root: "/app/packages/a",
-              options: Options(
-                src: Some(SrcOptions(
-                  root: Some("src"),
-                )),
-              ),
-            )
-            "#);
-        });
+        snapshot_project!(sub_project);

        Ok(())
    }
@@ -508,19 +400,7 @@ expected `.`, `]`

        let root = ProjectMetadata::discover(&root, &system)?;

-        with_escaped_paths(|| {
-            assert_ron_snapshot!(root, @r#"
-                              ProjectMetadata(
-                                name: Name("project-root"),
-                                root: "/app",
-                                options: Options(
-                                  src: Some(SrcOptions(
-                                    root: Some("src"),
-                                  )),
-                                ),
-                              )
-                              "#);
-        });
+        snapshot_project!(root);

        Ok(())
    }
@@ -552,15 +432,7 @@ expected `.`, `]`

        let sub_project = ProjectMetadata::discover(&root.join("packages/a"), &system)?;

-        with_escaped_paths(|| {
-            assert_ron_snapshot!(sub_project, @r#"
-            ProjectMetadata(
-              name: Name("nested-project"),
-              root: "/app/packages/a",
-              options: Options(),
-            )
-            "#);
-        });
+        snapshot_project!(sub_project);

        Ok(())
    }
@@ -595,19 +467,7 @@ expected `.`, `]`

        let root = ProjectMetadata::discover(&root.join("packages/a"), &system)?;

-        with_escaped_paths(|| {
-            assert_ron_snapshot!(root, @r#"
-            ProjectMetadata(
-              name: Name("project-root"),
-              root: "/app",
-              options: Options(
-                environment: Some(EnvironmentOptions(
-                  r#python-version: Some("3.10"),
-                )),
-              ),
-            )
-            "#);
-        });
+        snapshot_project!(root);

        Ok(())
    }
@@ -627,304 +487,27 @@ expected `.`, `]`
                (
                    root.join("pyproject.toml"),
                    r#"
-                    [project]
-                    name = "super-app"
-                    requires-python = ">=3.12"
+                        [project]
+                        name = "super-app"
+                        requires-python = ">=3.12"

-                    [tool.knot.src]
-                    root = "this_option_is_ignored"
-                    "#,
+                        [tool.knot.src]
+                        root = "this_option_is_ignored"
+                        "#,
                ),
                (
                    root.join("knot.toml"),
                    r#"
-                    [src]
-                    root = "src"
-                    "#,
+                        [src]
+                        root = "src"
+                        "#,
                ),
            ])
            .context("Failed to write files")?;

        let root = ProjectMetadata::discover(&root, &system)?;

-        with_escaped_paths(|| {
-            assert_ron_snapshot!(root, @r#"
-            ProjectMetadata(
-              name: Name("super-app"),
-              root: "/app",
-              options: Options(
-                environment: Some(EnvironmentOptions(
-                  r#python-version: Some("3.12"),
-                )),
-                src: Some(SrcOptions(
-                  root: Some("src"),
-                )),
-              ),
-            )
-            "#);
-        });
-
-        Ok(())
-    }
-    #[test]
-    fn requires_python_major_minor() -> anyhow::Result<()> {
-        let system = TestSystem::default();
-        let root = SystemPathBuf::from("/app");
-
-        system
-            .memory_file_system()
-            .write_file(
-                root.join("pyproject.toml"),
-                r#"
-                [project]
-                requires-python = ">=3.12"
-                "#,
-            )
-            .context("Failed to write file")?;
-
-        let root = ProjectMetadata::discover(&root, &system)?;
-
-        assert_eq!(
-            root.options
-                .environment
-                .unwrap_or_default()
-                .python_version
-                .as_deref(),
-            Some(&PythonVersion::PY312)
-        );
-
-        Ok(())
-    }
-
-    #[test]
-    fn requires_python_major_only() -> anyhow::Result<()> {
-        let system = TestSystem::default();
-        let root = SystemPathBuf::from("/app");
-
-        system
-            .memory_file_system()
-            .write_file(
-                root.join("pyproject.toml"),
-                r#"
-                [project]
-                requires-python = ">=3"
-                "#,
-            )
-            .context("Failed to write file")?;
-
-        let root = ProjectMetadata::discover(&root, &system)?;
-
-        assert_eq!(
-            root.options
-                .environment
-                .unwrap_or_default()
-                .python_version
-                .as_deref(),
-            Some(&PythonVersion::from((3, 0)))
-        );
-
-        Ok(())
-    }
-
-    /// A `requires-python` constraint with major, minor and patch can be simplified
-    /// to major and minor (e.g. 3.12.1 -> 3.12).
-    #[test]
-    fn requires_python_major_minor_patch() -> anyhow::Result<()> {
-        let system = TestSystem::default();
-        let root = SystemPathBuf::from("/app");
-
-        system
-            .memory_file_system()
-            .write_file(
-                root.join("pyproject.toml"),
-                r#"
-                [project]
-                requires-python = ">=3.12.8"
-                "#,
-            )
-            .context("Failed to write file")?;
-
-        let root = ProjectMetadata::discover(&root, &system)?;
-
-        assert_eq!(
-            root.options
-                .environment
-                .unwrap_or_default()
-                .python_version
-                .as_deref(),
-            Some(&PythonVersion::PY312)
-        );
-
-        Ok(())
-    }
-
-    #[test]
-    fn requires_python_beta_version() -> anyhow::Result<()> {
-        let system = TestSystem::default();
-        let root = SystemPathBuf::from("/app");
-
-        system
-            .memory_file_system()
-            .write_file(
-                root.join("pyproject.toml"),
-                r#"
-                [project]
-                requires-python = ">= 3.13.0b0"
-                "#,
-            )
-            .context("Failed to write file")?;
-
-        let root = ProjectMetadata::discover(&root, &system)?;
-
-        assert_eq!(
-            root.options
-                .environment
-                .unwrap_or_default()
-                .python_version
-                .as_deref(),
-            Some(&PythonVersion::PY313)
-        );
-
-        Ok(())
-    }
-
-    #[test]
-    fn requires_python_greater_than_major_minor() -> anyhow::Result<()> {
-        let system = TestSystem::default();
-        let root = SystemPathBuf::from("/app");
-
-        system
-            .memory_file_system()
-            .write_file(
-                root.join("pyproject.toml"),
-                r#"
-                [project]
-                # This is somewhat nonsensical because 3.12.1 > 3.12 is true.
-                # That's why simplifying the constraint to >= 3.12 is correct
-                requires-python = ">3.12"
-                "#,
-            )
-            .context("Failed to write file")?;
-
-        let root = ProjectMetadata::discover(&root, &system)?;
-
-        assert_eq!(
-            root.options
-                .environment
-                .unwrap_or_default()
-                .python_version
-                .as_deref(),
-            Some(&PythonVersion::PY312)
-        );
-
-        Ok(())
-    }
-
-    /// `python-version` takes precedence if both `requires-python` and `python-version` are configured.
-    #[test]
-    fn requires_python_and_python_version() -> anyhow::Result<()> {
-        let system = TestSystem::default();
-        let root = SystemPathBuf::from("/app");
-
-        system
-            .memory_file_system()
-            .write_file(
-                root.join("pyproject.toml"),
-                r#"
-                [project]
-                requires-python = ">=3.12"
-
-                [tool.knot.environment]
-                python-version = "3.10"
-                "#,
-            )
-            .context("Failed to write file")?;
-
-        let root = ProjectMetadata::discover(&root, &system)?;
-
-        assert_eq!(
-            root.options
-                .environment
-                .unwrap_or_default()
-                .python_version
-                .as_deref(),
-            Some(&PythonVersion::PY310)
-        );
-
-        Ok(())
-    }
-
-    #[test]
-    fn requires_python_less_than() -> anyhow::Result<()> {
-        let system = TestSystem::default();
-        let root = SystemPathBuf::from("/app");
-
-        system
-            .memory_file_system()
-            .write_file(
-                root.join("pyproject.toml"),
-                r#"
-                [project]
-                requires-python = "<3.12"
-                "#,
-            )
-            .context("Failed to write file")?;
-
-        let Err(error) = ProjectMetadata::discover(&root, &system) else {
-            return Err(anyhow!("Expected project discovery to fail because the `requires-python` doesn't specify a lower bound (it only specifies an upper bound)."));
-        };
-
-        assert_error_eq(&error, "Invalid `requires-python` version specifier (`/app/pyproject.toml`): value `<3.12` does not contain a lower bound. Add a lower bound to indicate the minimum compatible Python version (e.g., `>=3.13`) or specify a version in `environment.python-version`.");
-
-        Ok(())
-    }
-
-    #[test]
-    fn requires_python_no_specifiers() -> anyhow::Result<()> {
-        let system = TestSystem::default();
-        let root = SystemPathBuf::from("/app");
-
-        system
-            .memory_file_system()
-            .write_file(
-                root.join("pyproject.toml"),
-                r#"
-                [project]
-                requires-python = ""
-                "#,
-            )
-            .context("Failed to write file")?;
-
-        let Err(error) = ProjectMetadata::discover(&root, &system) else {
-            return Err(anyhow!("Expected project discovery to fail because the `requires-python` specifiers are empty and don't define a lower bound."));
-        };
-
-        assert_error_eq(&error, "Invalid `requires-python` version specifier (`/app/pyproject.toml`): value `` does not contain a lower bound. Add a lower bound to indicate the minimum compatible Python version (e.g., `>=3.13`) or specify a version in `environment.python-version`.");
-
-        Ok(())
-    }
-
-    #[test]
-    fn requires_python_too_large_major_version() -> anyhow::Result<()> {
-        let system = TestSystem::default();
-        let root = SystemPathBuf::from("/app");
-
-        system
-            .memory_file_system()
-            .write_file(
-                root.join("pyproject.toml"),
-                r#"
-                [project]
-                requires-python = ">=999.0"
-                "#,
-            )
-            .context("Failed to write file")?;
-
-        let Err(error) = ProjectMetadata::discover(&root, &system) else {
-            return Err(anyhow!("Expected project discovery to fail because of the requires-python major version that is larger than 255."));
-        };
-
-        assert_error_eq(&error, "Invalid `requires-python` version specifier (`/app/pyproject.toml`): The major version `999` is larger than the maximum supported value 255");
+        snapshot_project!(root);

        Ok(())
    }
@@ -934,12 +517,15 @@ expected `.`, `]`
        assert_eq!(error.to_string().replace('\\', "/"), message);
    }

-    fn with_escaped_paths<R>(f: impl FnOnce() -> R) -> R {
-        let mut settings = insta::Settings::clone_current();
-        settings.add_dynamic_redaction(".root", |content, _path| {
-            content.as_str().unwrap().replace('\\', "/")
+    /// Snapshots a project but with all paths using unix separators.
+    #[macro_export]
+    macro_rules! snapshot_project {
+    ($project:expr) => {{
+        assert_ron_snapshot!($project,{
+            ".root" => insta::dynamic_redaction(|content, _content_path| {
+                content.as_str().unwrap().replace("\\", "/")
+            }),
        });
-
-        settings.bind(f)
-    }
+    }};
+}
 }
--- a/crates/red_knot_project/src/metadata/configuration_file.rs
+++ b/crates/red_knot_project/src/metadata/configuration_file.rs
@@ -1,69 +0,0 @@
-use std::sync::Arc;
-
-use ruff_db::system::{System, SystemPath, SystemPathBuf};
-use thiserror::Error;
-
-use crate::metadata::value::ValueSource;
-
-use super::options::{KnotTomlError, Options};
-
-/// A `knot.toml` configuration file with the options it contains.
-pub(crate) struct ConfigurationFile {
-    path: SystemPathBuf,
-    options: Options,
-}
-
-impl ConfigurationFile {
-    /// Loads the user-level configuration file if it exists.
-    ///
-    /// Returns `None` if the file does not exist or if the concept of user-level configurations
-    /// doesn't exist on `system`.
-    pub(crate) fn user(system: &dyn System) -> Result<Option<Self>, ConfigurationFileError> {
-        let Some(configuration_directory) = system.user_config_directory() else {
-            return Ok(None);
-        };
-
-        let knot_toml_path = configuration_directory.join("knot").join("knot.toml");
-
-        tracing::debug!(
-            "Searching for a user-level configuration at `{path}`",
-            path = &knot_toml_path
-        );
-
-        let Ok(knot_toml_str) = system.read_to_string(&knot_toml_path) else {
-            return Ok(None);
-        };
-
-        match Options::from_toml_str(
-            &knot_toml_str,
-            ValueSource::File(Arc::new(knot_toml_path.clone())),
-        ) {
-            Ok(options) => Ok(Some(Self {
-                path: knot_toml_path,
-                options,
-            })),
-            Err(error) => Err(ConfigurationFileError::InvalidKnotToml {
-                source: Box::new(error),
-                path: knot_toml_path,
-            }),
-        }
-    }
-
-    /// Returns the path to the configuration file.
-    pub(crate) fn path(&self) -> &SystemPath {
-        &self.path
-    }
-
-    pub(crate) fn into_options(self) -> Options {
-        self.options
-    }
-}
-
-#[derive(Debug, Error)]
-pub enum ConfigurationFileError {
-    #[error("{path} is not a valid `knot.toml`: {source}")]
-    InvalidKnotToml {
-        source: Box<KnotTomlError>,
-        path: SystemPathBuf,
-    },
-}
--- a/crates/red_knot_project/src/metadata/options.rs
+++ b/crates/red_knot_project/src/metadata/options.rs
@@ -1,38 +1,32 @@
 use crate::metadata::value::{RangedValue, RelativePathBuf, ValueSource, ValueSourceGuard};
 use crate::Db;
 use red_knot_python_semantic::lint::{GetLintError, Level, LintSource, RuleSelection};
-use red_knot_python_semantic::{ProgramSettings, PythonPlatform, SearchPathSettings, SitePackages};
-use ruff_db::diagnostic::{Diagnostic, DiagnosticId, Severity, Span};
-use ruff_db::files::system_path_to_file;
+use red_knot_python_semantic::{
+    ProgramSettings, PythonPlatform, PythonVersion, SearchPathSettings, SitePackages,
+};
+use ruff_db::diagnostic::{Diagnostic, DiagnosticId, Severity};
+use ruff_db::files::{system_path_to_file, File};
 use ruff_db::system::{System, SystemPath};
 use ruff_macros::Combine;
-use ruff_python_ast::PythonVersion;
+use ruff_text_size::TextRange;
 use rustc_hash::FxHashMap;
 use serde::{Deserialize, Serialize};
 use std::borrow::Cow;
 use std::fmt::Debug;
 use thiserror::Error;

-use super::settings::{Settings, TerminalSettings};
-
 /// The options for the project.
 #[derive(Debug, Default, Clone, PartialEq, Eq, Combine, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
-#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 pub struct Options {
-    /// Configures the type checking environment.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub environment: Option<EnvironmentOptions>,

    #[serde(skip_serializing_if = "Option::is_none")]
    pub src: Option<SrcOptions>,

-    /// Configures the enabled lints and their severity.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub rules: Option<Rules>,
-
-    #[serde(skip_serializing_if = "Option::is_none")]
-    pub terminal: Option<TerminalOptions>,
 }

 impl Options {
@@ -113,22 +107,7 @@ impl Options {
    }

    #[must_use]
-    pub(crate) fn to_settings(&self, db: &dyn Db) -> (Settings, Vec<OptionDiagnostic>) {
-        let (rules, diagnostics) = self.to_rule_selection(db);
-
-        let mut settings = Settings::new(rules);
-
-        if let Some(terminal) = self.terminal.as_ref() {
-            settings.set_terminal(TerminalSettings {
-                error_on_warning: terminal.error_on_warning.unwrap_or_default(),
-            });
-        }
-
-        (settings, diagnostics)
-    }
-
-    #[must_use]
-    fn to_rule_selection(&self, db: &dyn Db) -> (RuleSelection, Vec<OptionDiagnostic>) {
+    pub(crate) fn to_rule_selection(&self, db: &dyn Db) -> (RuleSelection, Vec<OptionDiagnostic>) {
        let registry = db.lint_registry();
        let mut diagnostics = Vec::new();

@@ -187,14 +166,7 @@ impl Options {
                        ),
                    };

-                    let span = file.map(Span::from).map(|span| {
-                        if let Some(range) = rule_name.range() {
-                            span.with_range(range)
-                        } else {
-                            span
-                        }
-                    });
-                    diagnostics.push(diagnostic.with_span(span));
+                    diagnostics.push(diagnostic.with_file(file).with_range(rule_name.range()));
                }
            }
        }
@@ -205,22 +177,10 @@ impl Options {

 #[derive(Debug, Default, Clone, Eq, PartialEq, Combine, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
-#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 pub struct EnvironmentOptions {
-    /// Specifies the version of Python that will be used to execute the source code.
-    /// The version should be specified as a string in the format `M.m` where `M` is the major version
-    /// and `m` is the minor (e.g. "3.0" or "3.6").
-    /// If a version is provided, knot will generate errors if the source code makes use of language features
-    /// that are not supported in that version.
-    /// It will also tailor its use of type stub files, which conditionalizes type definitions based on the version.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub python_version: Option<RangedValue<PythonVersion>>,

-    /// Specifies the target platform that will be used to execute the source code.
-    /// If specified, Red Knot will tailor its use of type stub files,
-    /// which conditionalize type definitions based on the platform.
-    ///
-    /// If no platform is specified, knot will use `all` or the current platform in the LSP use case.
    #[serde(skip_serializing_if = "Option::is_none")]
    pub python_platform: Option<RangedValue<PythonPlatform>>,

@@ -244,7 +204,6 @@ pub struct EnvironmentOptions {

 #[derive(Debug, Default, Clone, Eq, PartialEq, Combine, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", deny_unknown_fields)]
-#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 pub struct SrcOptions {
    /// The root of the project, used for finding first-party modules.
    #[serde(skip_serializing_if = "Option::is_none")]
@@ -253,9 +212,7 @@ pub struct SrcOptions {

 #[derive(Debug, Default, Clone, Eq, PartialEq, Combine, Serialize, Deserialize)]
 #[serde(rename_all = "kebab-case", transparent)]
-#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 pub struct Rules {
-    #[cfg_attr(feature = "schemars", schemars(with = "schema::Rules"))]
    inner: FxHashMap<RangedValue<String>, RangedValue<Level>>,
 }

@@ -269,79 +226,6 @@ impl FromIterator<(RangedValue<String>, RangedValue<Level>)> for Rules {
    }
 }

-#[derive(Debug, Default, Clone, Eq, PartialEq, Combine, Serialize, Deserialize)]
-#[serde(rename_all = "kebab-case", deny_unknown_fields)]
-#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
-pub struct TerminalOptions {
-    /// Use exit code 1 if there are any warning-level diagnostics.
-    ///
-    /// Defaults to `false`.
-    pub error_on_warning: Option<bool>,
-}
-
-#[cfg(feature = "schemars")]
-mod schema {
-    use crate::DEFAULT_LINT_REGISTRY;
-    use red_knot_python_semantic::lint::Level;
-    use schemars::gen::SchemaGenerator;
-    use schemars::schema::{
-        InstanceType, Metadata, ObjectValidation, Schema, SchemaObject, SubschemaValidation,
-    };
-    use schemars::JsonSchema;
-
-    pub(super) struct Rules;
-
-    impl JsonSchema for Rules {
-        fn schema_name() -> String {
-            "Rules".to_string()
-        }
-
-        fn json_schema(gen: &mut SchemaGenerator) -> Schema {
-            let registry = &*DEFAULT_LINT_REGISTRY;
-
-            let level_schema = gen.subschema_for::<Level>();
-
-            let properties: schemars::Map<String, Schema> = registry
-                .lints()
-                .iter()
-                .map(|lint| {
-                    (
-                        lint.name().to_string(),
-                        Schema::Object(SchemaObject {
-                            metadata: Some(Box::new(Metadata {
-                                title: Some(lint.summary().to_string()),
-                                description: Some(lint.documentation()),
-                                deprecated: lint.status.is_deprecated(),
-                                default: Some(lint.default_level.to_string().into()),
-                                ..Metadata::default()
-                            })),
-                            subschemas: Some(Box::new(SubschemaValidation {
-                                one_of: Some(vec![level_schema.clone()]),
-                                ..Default::default()
-                            })),
-                            ..Default::default()
-                        }),
-                    )
-                })
-                .collect();
-
-            Schema::Object(SchemaObject {
-                instance_type: Some(InstanceType::Object.into()),
-                object: Some(Box::new(ObjectValidation {
-                    properties,
-                    // Allow unknown rules: Red Knot will warn about them.
-                    // It gives a better experience when using an older Red Knot version because
-                    // the schema will not deny rules that have been removed in newer versions.
-                    additional_properties: Some(Box::new(level_schema)),
-                    ..ObjectValidation::default()
-                })),
-
-                ..Default::default()
-            })
-        }
-    }
-}
-
 #[derive(Error, Debug)]
 pub enum KnotTomlError {
    #[error(transparent)]
@@ -353,7 +237,8 @@ pub struct OptionDiagnostic {
    id: DiagnosticId,
    message: String,
    severity: Severity,
-    span: Option<Span>,
+    file: Option<File>,
+    range: Option<TextRange>,
 }

 impl OptionDiagnostic {
@@ -362,13 +247,21 @@ impl OptionDiagnostic {
            id,
            message,
            severity,
-            span: None,
+            file: None,
+            range: None,
        }
    }

    #[must_use]
-    fn with_span(self, span: Option<Span>) -> Self {
-        OptionDiagnostic { span, ..self }
+    fn with_file(mut self, file: Option<File>) -> Self {
+        self.file = file;
+        self
+    }
+
+    #[must_use]
+    fn with_range(mut self, range: Option<TextRange>) -> Self {
+        self.range = range;
+        self
    }
 }

@@ -381,8 +274,12 @@ impl Diagnostic for OptionDiagnostic {
        Cow::Borrowed(&self.message)
    }

-    fn span(&self) -> Option<Span> {
-        self.span.clone()
+    fn file(&self) -> Option<File> {
+        self.file
+    }
+
+    fn range(&self) -> Option<TextRange> {
+        self.range
    }

    fn severity(&self) -> Severity {
--- a/crates/red_knot_project/src/metadata/pyproject.rs
+++ b/crates/red_knot_project/src/metadata/pyproject.rs
@@ -1,12 +1,11 @@
-use crate::metadata::options::Options;
-use crate::metadata::value::{RangedValue, ValueSource, ValueSourceGuard};
-use pep440_rs::{release_specifiers_to_ranges, Version, VersionSpecifiers};
-use ruff_python_ast::PythonVersion;
+use pep440_rs::{Version, VersionSpecifiers};
 use serde::{Deserialize, Deserializer, Serialize};
-use std::collections::Bound;
 use std::ops::Deref;
 use thiserror::Error;

+use crate::metadata::options::Options;
+use crate::metadata::value::{RangedValue, ValueSource, ValueSourceGuard};
+
 /// A `pyproject.toml` as specified in PEP 517.
 #[derive(Deserialize, Serialize, Debug, Default, Clone)]
 #[serde(rename_all = "kebab-case")]
@@ -56,73 +55,6 @@ pub struct Project {
    pub requires_python: Option<RangedValue<VersionSpecifiers>>,
 }

-impl Project {
-    pub(super) fn resolve_requires_python_lower_bound(
-        &self,
-    ) -> Result<Option<RangedValue<PythonVersion>>, ResolveRequiresPythonError> {
-        let Some(requires_python) = self.requires_python.as_ref() else {
-            return Ok(None);
-        };
-
-        tracing::debug!("Resolving requires-python constraint: `{requires_python}`");
-
-        let ranges = release_specifiers_to_ranges((**requires_python).clone());
-        let Some((lower, _)) = ranges.bounding_range() else {
-            return Ok(None);
-        };
-
-        let version = match lower {
-            // Ex) `>=3.10.1` -> `>=3.10`
-            Bound::Included(version) => version,
-
-            // Ex) `>3.10.1` -> `>=3.10` or `>3.10` -> `>=3.10`
-            // The second example looks obscure at first but it is required because
-            // `3.10.1 > 3.10` is true but we only have two digits here. So including 3.10 is the
-            // right move. Overall, using `>` without a patch release is most likely bogus.
-            Bound::Excluded(version) => version,
-
-            // Ex) `<3.10` or ``
-            Bound::Unbounded => {
-                return Err(ResolveRequiresPythonError::NoLowerBound(
-                    requires_python.to_string(),
-                ))
-            }
-        };
-
-        // Take the major and minor version
-        let mut versions = version.release().iter().take(2);
-
-        let Some(major) = versions.next().copied() else {
-            return Ok(None);
-        };
-
-        let minor = versions.next().copied().unwrap_or_default();
-
-        tracing::debug!("Resolved requires-python constraint to: {major}.{minor}");
-
-        let major =
-            u8::try_from(major).map_err(|_| ResolveRequiresPythonError::TooLargeMajor(major))?;
-        let minor =
-            u8::try_from(minor).map_err(|_| ResolveRequiresPythonError::TooLargeMajor(minor))?;
-
-        Ok(Some(
-            requires_python
-                .clone()
-                .map_value(|_| PythonVersion::from((major, minor))),
-        ))
-    }
-}
-
-#[derive(Debug, Error)]
-pub enum ResolveRequiresPythonError {
-    #[error("The major version `{0}` is larger than the maximum supported value 255")]
-    TooLargeMajor(u64),
-    #[error("The minor version `{0}` is larger than the maximum supported value 255")]
-    TooLargeMinor(u64),
-    #[error("value `{0}` does not contain a lower bound. Add a lower bound to indicate the minimum compatible Python version (e.g., `>=3.13`) or specify a version in `environment.python-version`.")]
-    NoLowerBound(String),
-}
-
 #[derive(Deserialize, Serialize, Debug, Clone, PartialEq, Eq)]
 #[serde(rename_all = "kebab-case")]
 pub struct Tool {
--- a/crates/red_knot_project/src/metadata/settings.rs
+++ b/crates/red_knot_project/src/metadata/settings.rs
@@ -1,53 +0,0 @@
-use std::sync::Arc;
-
-use red_knot_python_semantic::lint::RuleSelection;
-
-/// The resolved [`super::Options`] for the project.
-///
-/// Unlike [`super::Options`], the struct has default values filled in and
-/// uses representations that are optimized for reads (instead of preserving the source representation).
-/// It's also not required that this structure precisely resembles the TOML schema, although
-/// it's encouraged to use a similar structure.
-///
-/// It's worth considering to adding a salsa query for specific settings to
-/// limit the blast radius when only some settings change. For example,
-/// changing the terminal settings shouldn't invalidate any core type-checking queries.
-/// This can be achieved by adding a salsa query for the type checking specific settings.
-///
-/// Settings that are part of [`red_knot_python_semantic::ProgramSettings`] are not included here.
-#[derive(Clone, Debug, Eq, PartialEq)]
-pub struct Settings {
-    rules: Arc<RuleSelection>,
-
-    terminal: TerminalSettings,
-}
-
-impl Settings {
-    pub fn new(rules: RuleSelection) -> Self {
-        Self {
-            rules: Arc::new(rules),
-            terminal: TerminalSettings::default(),
-        }
-    }
-
-    pub fn rules(&self) -> &RuleSelection {
-        &self.rules
-    }
-
-    pub fn to_rules(&self) -> Arc<RuleSelection> {
-        self.rules.clone()
-    }
-
-    pub fn terminal(&self) -> &TerminalSettings {
-        &self.terminal
-    }
-
-    pub fn set_terminal(&mut self, terminal: TerminalSettings) {
-        self.terminal = terminal;
-    }
-}
-
-#[derive(Debug, Clone, PartialEq, Eq, Default)]
-pub struct TerminalSettings {
-    pub error_on_warning: bool,
-}
--- a/crates/red_knot_project/src/metadata/value.rs
+++ b/crates/red_knot_project/src/metadata/value.rs
@@ -1,9 +1,8 @@
 use crate::combine::Combine;
 use crate::Db;
 use ruff_db::system::{System, SystemPath, SystemPathBuf};
-use ruff_macros::Combine;
 use ruff_text_size::{TextRange, TextSize};
-use serde::{Deserialize, Deserializer};
+use serde::{Deserialize, Deserializer, Serialize, Serializer};
 use std::cell::RefCell;
 use std::cmp::Ordering;
 use std::fmt;
@@ -71,19 +70,15 @@ impl Drop for ValueSourceGuard {
 ///
 /// This ensures that two resolved configurations are identical even if the position of a value has changed
 /// or if the values were loaded from different sources.
-#[derive(Clone, serde::Serialize)]
-#[serde(transparent)]
-#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
+#[derive(Clone)]
 pub struct RangedValue<T> {
    value: T,
-    #[serde(skip)]
    source: ValueSource,

    /// The byte range of `value` in `source`.
    ///
    /// Can be `None` because not all sources support a range.
    /// For example, arguments provided on the CLI won't have a range attached.
-    #[serde(skip)]
    range: Option<TextRange>,
 }

@@ -118,15 +113,6 @@ impl<T> RangedValue<T> {
        self
    }

-    #[must_use]
-    pub fn map_value<R>(self, f: impl FnOnce(T) -> R) -> RangedValue<R> {
-        RangedValue {
-            value: f(self.value),
-            source: self.source,
-            range: self.range,
-        }
-    }
-
    pub fn into_inner(self) -> T {
        self.value
    }
@@ -280,6 +266,18 @@ where
    }
 }

+impl<T> Serialize for RangedValue<T>
+where
+    T: Serialize,
+{
+    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
+    where
+        S: Serializer,
+    {
+        self.value.serialize(serializer)
+    }
+}
+
 /// A possibly relative path in a configuration file.
 ///
 /// Relative paths in configuration files or from CLI options
@@ -288,19 +286,9 @@ where
 /// * CLI: The path is relative to the current working directory
 /// * Configuration file: The path is relative to the project's root.
 #[derive(
-    Debug,
-    Clone,
-    serde::Serialize,
-    serde::Deserialize,
-    PartialEq,
-    Eq,
-    PartialOrd,
-    Ord,
-    Hash,
-    Combine,
+    Debug, Clone, serde::Serialize, serde::Deserialize, PartialEq, Eq, PartialOrd, Ord, Hash,
 )]
 #[serde(transparent)]
-#[cfg_attr(feature = "schemars", derive(schemars::JsonSchema))]
 pub struct RelativePathBuf(RangedValue<SystemPathBuf>);

 impl RelativePathBuf {
@@ -337,3 +325,13 @@ impl RelativePathBuf {
        SystemPath::absolute(&self.0, relative_to)
    }
 }
+
+impl Combine for RelativePathBuf {
+    fn combine(self, other: Self) -> Self {
+        Self(self.0.combine(other.0))
+    }
+
+    fn combine_with(&mut self, other: Self) {
+        self.0.combine_with(other.0);
+    }
+}
--- a/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__nested_projects_in_root_project.snap
+++ b/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__nested_projects_in_root_project.snap
@@ -0,0 +1,13 @@
+---
+source: crates/red_knot_project/src/metadata.rs
+expression: root
+---
+ProjectMetadata(
+  name: Name("project-root"),
+  root: "/app",
+  options: Options(
+    src: Some(SrcOptions(
+      root: Some("src"),
+    )),
+  ),
+)
--- a/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__nested_projects_in_sub_project.snap
+++ b/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__nested_projects_in_sub_project.snap
@@ -0,0 +1,13 @@
+---
+source: crates/red_knot_project/src/metadata.rs
+expression: sub_project
+---
+ProjectMetadata(
+  name: Name("nested-project"),
+  root: "/app/packages/a",
+  options: Options(
+    src: Some(SrcOptions(
+      root: Some("src"),
+    )),
+  ),
+)
--- a/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__nested_projects_with_outer_knot_section.snap
+++ b/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__nested_projects_with_outer_knot_section.snap
@@ -0,0 +1,13 @@
+---
+source: crates/red_knot_project/src/metadata.rs
+expression: root
+---
+ProjectMetadata(
+  name: Name("project-root"),
+  root: "/app",
+  options: Options(
+    environment: Some(EnvironmentOptions(
+      r#python-version: Some("3.10"),
+    )),
+  ),
+)
--- a/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__nested_projects_without_knot_sections.snap
+++ b/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__nested_projects_without_knot_sections.snap
@@ -0,0 +1,9 @@
+---
+source: crates/red_knot_project/src/metadata.rs
+expression: sub_project
+---
+ProjectMetadata(
+  name: Name("nested-project"),
+  root: "/app/packages/a",
+  options: Options(),
+)
--- a/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__project_with_knot_and_pyproject_toml.snap
+++ b/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__project_with_knot_and_pyproject_toml.snap
@@ -0,0 +1,13 @@
+---
+source: crates/red_knot_project/src/metadata.rs
+expression: root
+---
+ProjectMetadata(
+  name: Name("super-app"),
+  root: "/app",
+  options: Options(
+    src: Some(SrcOptions(
+      root: Some("src"),
+    )),
+  ),
+)
--- a/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__project_with_pyproject.snap
+++ b/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__project_with_pyproject.snap
@@ -0,0 +1,9 @@
+---
+source: crates/red_knot_project/src/metadata.rs
+expression: project
+---
+ProjectMetadata(
+  name: Name("backend"),
+  root: "/app",
+  options: Options(),
+)
--- a/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__project_without_pyproject.snap
+++ b/crates/red_knot_project/src/snapshots/red_knot_projectmetadatatests__project_without_pyproject.snap
@@ -0,0 +1,9 @@
+---
+source: crates/red_knot_project/src/metadata.rs
+expression: project
+---
+ProjectMetadata(
+  name: Name("app"),
+  root: "/app",
+  options: Options(),
+)
--- a/crates/red_knot_project/src/watch/project_watcher.rs
+++ b/crates/red_knot_project/src/watch/project_watcher.rs
@@ -73,13 +73,6 @@ impl ProjectWatcher {
            .canonicalize_path(&project_path)
            .unwrap_or(project_path);

-        let config_paths = db
-            .project()
-            .metadata(db)
-            .extra_configuration_paths()
-            .iter()
-            .cloned();
-
        // Find the non-overlapping module search paths and filter out paths that are already covered by the project.
        // Module search paths are already canonicalized.
        let unique_module_paths = ruff_db::system::deduplicate_nested_paths(
@@ -90,11 +83,8 @@ impl ProjectWatcher {
        .map(SystemPath::to_path_buf);

        // Now add the new paths, first starting with the project path and then
-        // adding the library search paths, and finally the paths for configurations.
-        for path in std::iter::once(project_path)
-            .chain(unique_module_paths)
-            .chain(config_paths)
-        {
+        // adding the library search paths.
+        for path in std::iter::once(project_path).chain(unique_module_paths) {
            // Log a warning. It's not worth aborting if registering a single folder fails because
            // Ruff otherwise stills works as expected.
            if let Err(error) = self.watcher.watch(&path) {
--- a/crates/red_knot_project/tests/check.rs
+++ b/crates/red_knot_project/tests/check.rs
@@ -270,8 +270,6 @@ impl SourceOrderVisitor<'_> for PullTypesVisitor<'_> {
 /// Whether or not the .py/.pyi version of this file is expected to fail
 #[rustfmt::skip]
 const KNOWN_FAILURES: &[(&str, bool, bool)] = &[
-    // related to circular references in nested functions
-    ("crates/ruff_linter/resources/test/fixtures/flake8_return/RET503.py", false, true),
    // related to circular references in class definitions
    ("crates/ruff_linter/resources/test/fixtures/pyflakes/F821_26.py", true, true),
    ("crates/ruff_linter/resources/test/fixtures/pyflakes/F821_27.py", true, true),
--- a/crates/red_knot_python_semantic/Cargo.toml
+++ b/crates/red_knot_python_semantic/Cargo.toml
@@ -12,9 +12,9 @@ license = { workspace = true }

 [dependencies]
 ruff_db = { workspace = true }
-ruff_index = { workspace = true, features = ["salsa"] }
+ruff_index = { workspace = true }
 ruff_macros = { workspace = true }
-ruff_python_ast = { workspace = true, features = ["salsa"] }
+ruff_python_ast = { workspace = true }
 ruff_python_parser = { workspace = true }
 ruff_python_stdlib = { workspace = true }
 ruff_source_file = { workspace = true }
@@ -31,12 +31,11 @@ drop_bomb = { workspace = true }
 indexmap = { workspace = true }
 itertools = { workspace = true }
 ordermap = { workspace = true }
-salsa = { workspace = true, features = ["compact_str"] }
+salsa = { workspace = true }
 thiserror = { workspace = true }
 tracing = { workspace = true }
 rustc-hash = { workspace = true }
 hashbrown = { workspace = true }
-schemars = { workspace = true, optional = true }
 serde = { workspace = true, optional = true }
 smallvec = { workspace = true }
 static_assertions = { workspace = true }
@@ -44,7 +43,7 @@ test-case = { workspace = true }
 memchr = { workspace = true }

 [dev-dependencies]
-ruff_db = { workspace = true, features = ["testing", "os"] }
+ruff_db = { workspace = true, features = ["os", "testing"] }
 ruff_python_parser = { workspace = true }
 red_knot_test = { workspace = true }
 red_knot_vendored = { workspace = true }
@@ -57,7 +56,7 @@ quickcheck = { version = "1.0.3", default-features = false }
 quickcheck_macros = { version = "1.0.0" }

 [features]
-serde = ["ruff_db/serde", "dep:serde", "ruff_python_ast/serde"]
+serde = ["ruff_db/serde", "dep:serde"]

 [lints]
 workspace = true
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/int_float_complex.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/int_float_complex.md
@@ -1,90 +0,0 @@
-# Special cases for int/float/complex in annotations
-
-In order to support common use cases, an annotation of `float` actually means `int | float`, and an
-annotation of `complex` actually means `int | float | complex`. See
-[the specification](https://typing.readthedocs.io/en/latest/spec/special-types.html#special-cases-for-float-and-complex)
-
-## float
-
-An annotation of `float` means `int | float`, so `int` is assignable to it:
-
-```py
-def takes_float(x: float):
-    pass
-
-def passes_int_to_float(x: int):
-    # no error!
-    takes_float(x)
-```
-
-It also applies to variable annotations:
-
-```py
-def assigns_int_to_float(x: int):
-    # no error!
-    y: float = x
-```
-
-It doesn't work the other way around:
-
-```py
-def takes_int(x: int):
-    pass
-
-def passes_float_to_int(x: float):
-    # error: [invalid-argument-type]
-    takes_int(x)
-
-def assigns_float_to_int(x: float):
-    # error: [invalid-assignment]
-    y: int = x
-```
-
-Unlike other type checkers, we choose not to obfuscate this special case by displaying `int | float`
-as just `float`; we display the actual type:
-
-```py
-def f(x: float):
-    reveal_type(x)  # revealed: int | float
-```
-
-## complex
-
-An annotation of `complex` means `int | float | complex`, so `int` and `float` are both assignable
-to it (but not the other way around):
-
-```py
-def takes_complex(x: complex):
-    pass
-
-def passes_to_complex(x: float, y: int):
-    # no errors!
-    takes_complex(x)
-    takes_complex(y)
-
-def assigns_to_complex(x: float, y: int):
-    # no errors!
-    a: complex = x
-    b: complex = y
-
-def takes_int(x: int):
-    pass
-
-def takes_float(x: float):
-    pass
-
-def passes_complex(x: complex):
-    # error: [invalid-argument-type]
-    takes_int(x)
-    # error: [invalid-argument-type]
-    takes_float(x)
-
-def assigns_complex(x: complex):
-    # error: [invalid-assignment]
-    y: int = x
-    # error: [invalid-assignment]
-    z: float = x
-
-def f(x: complex):
-    reveal_type(x)  # revealed: int | float | complex
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/literal_string.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/literal_string.md
@@ -73,12 +73,12 @@ qux = (foo, bar)
 reveal_type(qux)  # revealed: tuple[Literal["foo"], Literal["bar"]]

 # TODO: Infer "LiteralString"
-reveal_type(foo.join(qux))  # revealed: @Todo(decorated method)
+reveal_type(foo.join(qux))  # revealed: @Todo(Attribute access on `StringLiteral` types)

 template: LiteralString = "{}, {}"
 reveal_type(template)  # revealed: Literal["{}, {}"]
 # TODO: Infer `LiteralString`
-reveal_type(template.format(foo, bar))  # revealed: @Todo(decorated method)
+reveal_type(template.format(foo, bar))  # revealed: @Todo(Attribute access on `StringLiteral` types)
 ```

 ### Assignability
--- a/crates/red_knot_python_semantic/resources/mdtest/annotations/union.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/annotations/union.md
@@ -9,9 +9,9 @@ from typing import Union

 a: Union[int, str]
 a1: Union[int, bool]
-a2: Union[int, Union[bytes, str]]
+a2: Union[int, Union[float, str]]
 a3: Union[int, None]
-a4: Union[Union[bytes, str]]
+a4: Union[Union[float, str]]
 a5: Union[int]
 a6: Union[()]

@@ -21,11 +21,11 @@ def f():
    # Since bool is a subtype of int we simplify to int here. But we do allow assigning boolean values (see below).
    # revealed: int
    reveal_type(a1)
-    # revealed: int | bytes | str
+    # revealed: int | float | str
    reveal_type(a2)
    # revealed: int | None
    reveal_type(a3)
-    # revealed: bytes | str
+    # revealed: float | str
    reveal_type(a4)
    # revealed: int
    reveal_type(a5)
--- a/crates/red_knot_python_semantic/resources/mdtest/assignment/augmented.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/assignment/augmented.md
@@ -9,7 +9,7 @@ reveal_type(x)  # revealed: Literal[2]

 x = 1.0
 x /= 2
-reveal_type(x)  # revealed: int | float
+reveal_type(x)  # revealed: float
 ```

 ## Dunder methods
@@ -24,12 +24,12 @@ x -= 1
 reveal_type(x)  # revealed: str

 class C:
-    def __iadd__(self, other: str) -> int:
-        return 1
+    def __iadd__(self, other: str) -> float:
+        return 1.0

 x = C()
 x += "Hello"
-reveal_type(x)  # revealed: int
+reveal_type(x)  # revealed: float
 ```

 ## Unsupported types
@@ -40,7 +40,7 @@ class C:
        return 42

 x = C()
-# error: [unsupported-operator] "Operator `-=` is unsupported between objects of type `C` and `Literal[1]`"
+# error: [invalid-argument-type]
 x -= 1

 reveal_type(x)  # revealed: int
@@ -130,10 +130,10 @@ def _(flag: bool):
    if flag:
        f = Foo()
    else:
-        f = 42
+        f = 42.0
    f += 12

-    reveal_type(f)  # revealed: str | Literal[54]
+    reveal_type(f)  # revealed: str | float
 ```

 ## Partially bound target union with `__add__`
--- a/crates/red_knot_python_semantic/resources/mdtest/attributes.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/attributes.md
@@ -30,11 +30,7 @@ reveal_type(c_instance.inferred_from_value)  # revealed: Unknown | Literal[1, "a
 # TODO: Same here. This should be `Unknown | Literal[1, "a"]`
 reveal_type(c_instance.inferred_from_other_attribute)  # revealed: Unknown

-# There is no special handling of attributes that are (directly) assigned to a declared parameter,
-# which means we union with `Unknown` here, since the attribute itself is not declared. This is
-# something that we might want to change in the future.
-#
-# See https://github.com/astral-sh/ruff/issues/15960 for a related discussion.
+# TODO: should be `int | None`
 reveal_type(c_instance.inferred_from_param)  # revealed: Unknown | int | None

 reveal_type(c_instance.declared_only)  # revealed: bytes
@@ -49,10 +45,10 @@ reveal_type(c_instance.possibly_undeclared_unbound)  # revealed: str
 c_instance.inferred_from_value = "value set on instance"

 # This assignment is also fine:
-c_instance.declared_and_bound = False
+c_instance.inferred_from_param = None

-# error: [invalid-assignment] "Object of type `Literal["incompatible"]` is not assignable to attribute `declared_and_bound` of type `bool`"
-c_instance.declared_and_bound = "incompatible"
+# TODO: this should be an error (incompatible types in assignment)
+c_instance.inferred_from_param = "incompatible"

 # TODO: we already show an error here but the message might be improved?
 # mypy shows no error here, but pyright raises "reportAttributeAccessIssue"
@@ -185,6 +181,7 @@ reveal_type(c_instance.inferred_from_value)  # revealed: Unknown | Literal[1, "a
 # TODO: Should be `Unknown | Literal[1, "a"]`
 reveal_type(c_instance.inferred_from_other_attribute)  # revealed: Unknown

+# TODO: Should be `int | None`
 reveal_type(c_instance.inferred_from_param)  # revealed: Unknown | int | None

 reveal_type(c_instance.declared_only)  # revealed: bytes
@@ -235,36 +232,6 @@ reveal_type(c_instance.y)  # revealed: int
 reveal_type(c_instance.z)  # revealed: int
 ```

-#### Attributes defined in multi-target assignments
-
-```py
-class C:
-    def __init__(self) -> None:
-        self.a = self.b = 1
-
-c_instance = C()
-
-reveal_type(c_instance.a)  # revealed: Unknown | Literal[1]
-reveal_type(c_instance.b)  # revealed: Unknown | Literal[1]
-```
-
-#### Augmented assignments
-
-```py
-class Weird:
-    def __iadd__(self, other: None) -> str:
-        return "a"
-
-class C:
-    def __init__(self) -> None:
-        self.w = Weird()
-        self.w += None
-
-# TODO: Mypy and pyright do not support this, but it would be great if we could
-# infer `Unknown | str` or at least `Unknown | Weird | str` here.
-reveal_type(C().w)  # revealed: Unknown | Weird
-```
-
 #### Attributes defined in tuple unpackings

 ```py
@@ -286,24 +253,19 @@ reveal_type(c_instance.b1)  # revealed: Unknown | Literal["a"]
 reveal_type(c_instance.c1)  # revealed: Unknown | int
 reveal_type(c_instance.d1)  # revealed: Unknown | str

-reveal_type(c_instance.a2)  # revealed: Unknown | Literal[1]
+# TODO: This should be supported (no error; type should be: `Unknown | Literal[1]`)
+# error: [unresolved-attribute]
+reveal_type(c_instance.a2)  # revealed: Unknown

-reveal_type(c_instance.b2)  # revealed: Unknown | Literal["a"]
+# TODO: This should be supported (no error; type should be: `Unknown | Literal["a"]`)
+# error: [unresolved-attribute]
+reveal_type(c_instance.b2)  # revealed: Unknown

-reveal_type(c_instance.c2)  # revealed: Unknown | int
-reveal_type(c_instance.d2)  # revealed: Unknown | str
-```
-
-#### Starred assignments
-
-```py
-class C:
-    def __init__(self) -> None:
-        self.a, *self.b = (1, 2, 3)
-
-c_instance = C()
-reveal_type(c_instance.a)  # revealed: Unknown | Literal[1]
-reveal_type(c_instance.b)  # revealed: Unknown | @Todo(starred unpacking)
+# TODO: Similar for these two (should be `Unknown | int` and `Unknown | str`, respectively)
+# error: [unresolved-attribute]
+reveal_type(c_instance.c2)  # revealed: Unknown
+# error: [unresolved-attribute]
+reveal_type(c_instance.d2)  # revealed: Unknown
 ```

 #### Attributes defined in for-loop (unpacking)
@@ -325,8 +287,6 @@ class TupleIterable:
    def __iter__(self) -> TupleIterator:
        return TupleIterator()

-class NonIterable: ...
-
 class C:
    def __init__(self):
        for self.x in IntIterable():
@@ -335,54 +295,14 @@ class C:
        for _, self.y in TupleIterable():
            pass

-        # TODO: We should emit a diagnostic here
-        for self.z in NonIterable():
-            pass
+# TODO: Pyright fully supports these, mypy detects the presence of the attributes,
+# but infers type `Any` for both of them. We should infer `int` and `str` here:

-reveal_type(C().x)  # revealed: Unknown | int
-
-reveal_type(C().y)  # revealed: Unknown | str
-```
-
-#### Attributes defined in `with` statements
-
-```py
-class ContextManager:
-    def __enter__(self) -> int | None: ...
-    def __exit__(self, exc_type, exc_value, traceback) -> None: ...
-
-class C:
-    def __init__(self) -> None:
-        with ContextManager() as self.x:
-            pass
-
-c_instance = C()
-
-# TODO: Should be `Unknown | int | None`
 # error: [unresolved-attribute]
-reveal_type(c_instance.x)  # revealed: Unknown
-```
+reveal_type(C().x)  # revealed: Unknown

-#### Attributes defined in comprehensions
-
-```py
-class IntIterator:
-    def __next__(self) -> int:
-        return 1
-
-class IntIterable:
-    def __iter__(self) -> IntIterator:
-        return IntIterator()
-
-class C:
-    def __init__(self) -> None:
-        [... for self.a in IntIterable()]
-
-c_instance = C()
-
-# TODO: Should be `Unknown | int`
 # error: [unresolved-attribute]
-reveal_type(c_instance.a)  # revealed: Unknown
+reveal_type(C().y)  # revealed: Unknown
 ```

 #### Conditionally declared / bound attributes
@@ -473,6 +393,8 @@ reveal_type(D().x)  # revealed: Unknown | Literal[1]

 If `staticmethod` is something else, that should not influence the behavior:

+`other.py`:
+
 ```py
 def staticmethod(f):
    return f
@@ -487,6 +409,8 @@ reveal_type(C().x)  # revealed: Unknown | Literal[1]

 And if `staticmethod` is fully qualified, that should also be recognized:

+`fully_qualified.py`:
+
 ```py
 import builtins

@@ -523,15 +447,6 @@ class C:
 reveal_type(C().x)  # revealed: str
 ```

-#### Diagnostics are reported for the right-hand side of attribute assignments
-
-```py
-class C:
-    def __init__(self) -> None:
-        # error: [too-many-positional-arguments]
-        self.x: int = len(1, 2, 3)
-```
-
 ### Pure class variables (`ClassVar`)

 #### Annotated with `ClassVar` type qualifier
@@ -807,67 +722,6 @@ def _(flag: bool, flag1: bool, flag2: bool):
    reveal_type(C.x)  # revealed: Unknown | Literal[1, 2, 3]
 ```

-### Attribute possibly unbound on a subclass but not on a superclass
-
-```py
-def _(flag: bool):
-    class Foo:
-        x = 1
-
-    class Bar(Foo):
-        if flag:
-            x = 2
-
-    reveal_type(Bar.x)  # revealed: Unknown | Literal[2, 1]
-```
-
-### Attribute possibly unbound on a subclass and on a superclass
-
-```py
-def _(flag: bool):
-    class Foo:
-        if flag:
-            x = 1
-
-    class Bar(Foo):
-        if flag:
-            x = 2
-
-    # error: [possibly-unbound-attribute]
-    reveal_type(Bar.x)  # revealed: Unknown | Literal[2, 1]
-```
-
-### Attribute access on `Any`
-
-The union of the set of types that `Any` could materialise to is equivalent to `object`. It follows
-from this that attribute access on `Any` resolves to `Any` if the attribute does not exist on
-`object` -- but if the attribute *does* exist on `object`, the type of the attribute is
-`<type as it exists on object> & Any`.
-
-```py
-from typing import Any
-
-class Foo(Any): ...
-
-reveal_type(Foo.bar)  # revealed: Any
-reveal_type(Foo.__repr__)  # revealed: Literal[__repr__] & Any
-```
-
-Similar principles apply if `Any` appears in the middle of an inheritance hierarchy:
-
-```py
-from typing import ClassVar, Literal
-
-class A:
-    x: ClassVar[Literal[1]] = 1
-
-class B(Any): ...
-class C(B, A): ...
-
-reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Literal[B], Any, Literal[A], Literal[object]]
-reveal_type(C.x)  # revealed: Literal[1] & Any
-```
-
 ### Unions with all paths unbound

 If the symbol is unbound in all elements of the union, we detect that:
@@ -995,6 +849,8 @@ outer.nested.inner.Outer.Nested.Inner.attr = "a"
 Most attribute accesses on function-literal types are delegated to `types.FunctionType`, since all
 functions are instances of that class:

+`a.py`:
+
 ```py
 def f(): ...

@@ -1004,9 +860,13 @@ reveal_type(f.__kwdefaults__)  # revealed: @Todo(generics) | None

 Some attributes are special-cased, however:

+`b.py`:
+
 ```py
-reveal_type(f.__get__)  # revealed: <method-wrapper `__get__` of `f`>
-reveal_type(f.__call__)  # revealed: <bound method `__call__` of `Literal[f]`>
+def f(): ...
+
+reveal_type(f.__get__)  # revealed: @Todo(`__get__` method on functions)
+reveal_type(f.__call__)  # revealed: @Todo(`__call__` method on functions)
 ```

 ### Int-literal attributes
@@ -1014,13 +874,17 @@ reveal_type(f.__call__)  # revealed: <bound method `__call__` of `Literal[f]`>
 Most attribute accesses on int-literal types are delegated to `builtins.int`, since all literal
 integers are instances of that class:

+`a.py`:
+
 ```py
-reveal_type((2).bit_length)  # revealed: <bound method `bit_length` of `Literal[2]`>
+reveal_type((2).bit_length)  # revealed: @Todo(bound method)
 reveal_type((2).denominator)  # revealed: @Todo(@property)
 ```

 Some attributes are special-cased, however:

+`b.py`:
+
 ```py
 reveal_type((2).numerator)  # revealed: Literal[2]
 reveal_type((2).real)  # revealed: Literal[2]
@@ -1029,15 +893,19 @@ reveal_type((2).real)  # revealed: Literal[2]
 ### Bool-literal attributes

 Most attribute accesses on bool-literal types are delegated to `builtins.bool`, since all literal
-bools are instances of that class:
+bols are instances of that class:
+
+`a.py`:

 ```py
-reveal_type(True.__and__)  # revealed: @Todo(decorated method)
-reveal_type(False.__or__)  # revealed: @Todo(decorated method)
+reveal_type(True.__and__)  # revealed: @Todo(bound method)
+reveal_type(False.__or__)  # revealed: @Todo(bound method)
 ```

 Some attributes are special-cased, however:

+`b.py`:
+
 ```py
 reveal_type(True.numerator)  # revealed: Literal[1]
 reveal_type(False.real)  # revealed: Literal[0]
@@ -1045,11 +913,11 @@ reveal_type(False.real)  # revealed: Literal[0]

 ### Bytes-literal attributes

-All attribute access on literal `bytes` types is currently delegated to `builtins.bytes`:
+All attribute access on literal `bytes` types is currently delegated to `buitins.bytes`:

 ```py
-reveal_type(b"foo".join)  # revealed: <bound method `join` of `Literal[b"foo"]`>
-reveal_type(b"foo".endswith)  # revealed: <bound method `endswith` of `Literal[b"foo"]`>
+reveal_type(b"foo".join)  # revealed: @Todo(bound method)
+reveal_type(b"foo".endswith)  # revealed: @Todo(bound method)
 ```

 ## Instance attribute edge cases
@@ -1136,40 +1004,6 @@ class C:
 reveal_type(C().x)  # revealed: Unknown
 ```

-### Builtin types attributes
-
-This test can probably be removed eventually, but we currently include it because we do not yet
-understand generic bases and protocols, and we want to make sure that we can still use builtin types
-in our tests in the meantime. See the corresponding TODO in `Type::static_member` for more
-information.
-
-```py
-class C:
-    a_int: int = 1
-    a_str: str = "a"
-    a_bytes: bytes = b"a"
-    a_bool: bool = True
-    a_float: float = 1.0
-    a_complex: complex = 1 + 1j
-    a_tuple: tuple[int] = (1,)
-    a_range: range = range(1)
-    a_slice: slice = slice(1)
-    a_type: type = int
-    a_none: None = None
-
-reveal_type(C.a_int)  # revealed: int
-reveal_type(C.a_str)  # revealed: str
-reveal_type(C.a_bytes)  # revealed: bytes
-reveal_type(C.a_bool)  # revealed: bool
-reveal_type(C.a_float)  # revealed: int | float
-reveal_type(C.a_complex)  # revealed: int | float | complex
-reveal_type(C.a_tuple)  # revealed: tuple[int]
-reveal_type(C.a_range)  # revealed: range
-reveal_type(C.a_slice)  # revealed: slice
-reveal_type(C.a_type)  # revealed: type
-reveal_type(C.a_none)  # revealed: None
-```
-
 ## References

 Some of the tests in the *Class and instance variables* section draw inspiration from
--- a/crates/red_knot_python_semantic/resources/mdtest/binary/booleans.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/binary/booleans.md
@@ -56,7 +56,7 @@ def _(a: bool):
        reveal_type(x - a)  # revealed: int
        reveal_type(x * a)  # revealed: int
        reveal_type(x // a)  # revealed: int
-        reveal_type(x / a)  # revealed: int | float
+        reveal_type(x / a)  # revealed: float
        reveal_type(x % a)  # revealed: int

    def rhs_is_int(x: int):
@@ -64,7 +64,7 @@ def _(a: bool):
        reveal_type(a - x)  # revealed: int
        reveal_type(a * x)  # revealed: int
        reveal_type(a // x)  # revealed: int
-        reveal_type(a / x)  # revealed: int | float
+        reveal_type(a / x)  # revealed: float
        reveal_type(a % x)  # revealed: int

    def lhs_is_bool(x: bool):
@@ -72,7 +72,7 @@ def _(a: bool):
        reveal_type(x - a)  # revealed: int
        reveal_type(x * a)  # revealed: int
        reveal_type(x // a)  # revealed: int
-        reveal_type(x / a)  # revealed: int | float
+        reveal_type(x / a)  # revealed: float
        reveal_type(x % a)  # revealed: int

    def rhs_is_bool(x: bool):
@@ -80,7 +80,7 @@ def _(a: bool):
        reveal_type(a - x)  # revealed: int
        reveal_type(a * x)  # revealed: int
        reveal_type(a // x)  # revealed: int
-        reveal_type(a / x)  # revealed: int | float
+        reveal_type(a / x)  # revealed: float
        reveal_type(a % x)  # revealed: int

    def both_are_bool(x: bool, y: bool):
@@ -88,6 +88,6 @@ def _(a: bool):
        reveal_type(x - y)  # revealed: int
        reveal_type(x * y)  # revealed: int
        reveal_type(x // y)  # revealed: int
-        reveal_type(x / y)  # revealed: int | float
+        reveal_type(x / y)  # revealed: float
        reveal_type(x % y)  # revealed: int
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/binary/instances.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/binary/instances.md
@@ -244,7 +244,10 @@ class B:
    def __rsub__(self, other: A) -> B:
        return B()

-reveal_type(A() - B())  # revealed: B
+# TODO: this should be `B` (the return annotation of `B.__rsub__`),
+# because `A.__sub__` is annotated as only accepting `A`,
+# but `B.__rsub__` will accept `A`.
+reveal_type(A() - B())  # revealed: A
 ```

 ## Callable instances as dunders
@@ -260,31 +263,31 @@ class B:
    __add__ = A()

 # TODO: this could be `int` if we declare `B.__add__` using a `Callable` type
-# TODO: Should not be an error: `A` instance is not a method descriptor, don't prepend `self` arg.
-#   Revealed type should be `Unknown | int`.
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `B` and `B`"
-reveal_type(B() + B())  # revealed: Unknown
+reveal_type(B() + B())  # revealed: Unknown | int
 ```

 ## Integration test: numbers from typeshed

-We get less precise results from binary operations on float/complex literals due to the special case
-for annotations of `float` or `complex`, which applies also to return annotations for typeshed
-dunder methods. Perhaps we could have a special-case on the special-case, to exclude these typeshed
-return annotations from the widening, and preserve a bit more precision here?
-
 ```py
-reveal_type(3j + 3.14)  # revealed: int | float | complex
-reveal_type(4.2 + 42)  # revealed: int | float
-reveal_type(3j + 3)  # revealed: int | float | complex
-reveal_type(3.14 + 3j)  # revealed: int | float | complex
-reveal_type(42 + 4.2)  # revealed: int | float
-reveal_type(3 + 3j)  # revealed: int | float | complex
+reveal_type(3j + 3.14)  # revealed: complex
+reveal_type(4.2 + 42)  # revealed: float
+reveal_type(3j + 3)  # revealed: complex
+
+# TODO should be complex, need to check arg type and fall back to `rhs.__radd__`
+reveal_type(3.14 + 3j)  # revealed: float
+
+# TODO should be float, need to check arg type and fall back to `rhs.__radd__`
+reveal_type(42 + 4.2)  # revealed: int
+
+# TODO should be complex, need to check arg type and fall back to `rhs.__radd__`
+reveal_type(3 + 3j)  # revealed: int

 def _(x: bool, y: int):
    reveal_type(x + y)  # revealed: int
-    reveal_type(4.2 + x)  # revealed: int | float
-    reveal_type(y + 4.12)  # revealed: int | float
+    reveal_type(4.2 + x)  # revealed: float
+
+    # TODO should be float, need to check arg type and fall back to `rhs.__radd__`
+    reveal_type(y + 4.12)  # revealed: int
 ```

 ## With literal types
@@ -301,7 +304,8 @@ class A:
        return self

 reveal_type(A() + 1)  # revealed: A
-reveal_type(1 + A())  # revealed: A
+# TODO should be `A` since `int.__add__` doesn't support `A` instances
+reveal_type(1 + A())  # revealed: int

 reveal_type(A() + "foo")  # revealed: A
 # TODO should be `A` since `str.__add__` doesn't support `A` instances
--- a/crates/red_knot_python_semantic/resources/mdtest/binary/integers.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/binary/integers.md
@@ -10,16 +10,16 @@ reveal_type(-3 // 3)  # revealed: Literal[-1]
 reveal_type(-3 / 3)  # revealed: float
 reveal_type(5 % 3)  # revealed: Literal[2]

-# TODO: Should emit `unsupported-operator` but we don't understand the bases of `str`, so we think
-#       it inherits `Unknown`, so we think `str.__radd__` is `Unknown` instead of nonexistent.
-reveal_type(2 + "f")  # revealed: Unknown
+# TODO: We don't currently verify that the actual parameter to int.__add__ matches the declared
+# formal parameter type.
+reveal_type(2 + "f")  # revealed: int

 def lhs(x: int):
    reveal_type(x + 1)  # revealed: int
    reveal_type(x - 4)  # revealed: int
    reveal_type(x * -1)  # revealed: int
    reveal_type(x // 3)  # revealed: int
-    reveal_type(x / 3)  # revealed: int | float
+    reveal_type(x / 3)  # revealed: float
    reveal_type(x % 3)  # revealed: int

 def rhs(x: int):
@@ -27,7 +27,7 @@ def rhs(x: int):
    reveal_type(3 - x)  # revealed: int
    reveal_type(3 * x)  # revealed: int
    reveal_type(-3 // x)  # revealed: int
-    reveal_type(-3 / x)  # revealed: int | float
+    reveal_type(-3 / x)  # revealed: float
    reveal_type(5 % x)  # revealed: int

 def both(x: int):
@@ -35,7 +35,7 @@ def both(x: int):
    reveal_type(x - x)  # revealed: int
    reveal_type(x * x)  # revealed: int
    reveal_type(x // x)  # revealed: int
-    reveal_type(x / x)  # revealed: int | float
+    reveal_type(x / x)  # revealed: float
    reveal_type(x % x)  # revealed: int
 ```

@@ -80,20 +80,24 @@ c = 3 % 0  # error: "Cannot reduce object of type `Literal[3]` modulo zero"
 reveal_type(c)  # revealed: int

 # error: "Cannot divide object of type `int` by zero"
-reveal_type(int() / 0)  # revealed: int | float
+# revealed: float
+reveal_type(int() / 0)

 # error: "Cannot divide object of type `Literal[1]` by zero"
-reveal_type(1 / False)  # revealed: float
+# revealed: float
+reveal_type(1 / False)
 # error: [division-by-zero] "Cannot divide object of type `Literal[True]` by zero"
 True / False
 # error: [division-by-zero] "Cannot divide object of type `Literal[True]` by zero"
 bool(1) / False

 # error: "Cannot divide object of type `float` by zero"
-reveal_type(1.0 / 0)  # revealed: int | float
+# revealed: float
+reveal_type(1.0 / 0)

 class MyInt(int): ...

 # No error for a subclass of int
-reveal_type(MyInt(3) / 0)  # revealed: int | float
+# revealed: float
+reveal_type(MyInt(3) / 0)
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/call/callable_instance.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/callable_instance.md
@@ -4,14 +4,14 @@

 ```py
 class Multiplier:
-    def __init__(self, factor: int):
+    def __init__(self, factor: float):
        self.factor = factor

-    def __call__(self, number: int) -> int:
+    def __call__(self, number: float) -> float:
        return number * self.factor

-a = Multiplier(2)(3)
-reveal_type(a)  # revealed: int
+a = Multiplier(2.0)(3.0)
+reveal_type(a)  # revealed: float

 class Unit: ...

@@ -52,7 +52,7 @@ class NonCallable:
    __call__ = 1

 a = NonCallable()
-# error: [call-non-callable] "Object of type `Literal[1]` is not callable"
+# error: "Object of type `Unknown | Literal[1]` is not callable (due to union element `Literal[1]`)"
 reveal_type(a())  # revealed: Unknown
 ```

@@ -67,8 +67,8 @@ def _(flag: bool):
            def __call__(self) -> int: ...

    a = NonCallable()
-    # error: [call-non-callable] "Object of type `Literal[1]` is not callable"
-    reveal_type(a())  # revealed: int | Unknown
+    # error: "Object of type `Literal[1] | Literal[__call__]` is not callable (due to union element `Literal[1]`)"
+    reveal_type(a())  # revealed: Unknown | int
 ```

 ## Call binding errors
@@ -99,26 +99,3 @@ c = C()
 # error: 13 [invalid-argument-type] "Object of type `C` cannot be assigned to parameter 1 (`self`) of function `__call__`; expected type `int`"
 reveal_type(c())  # revealed: int
 ```
-
-## Union over callables
-
-### Possibly unbound `__call__`
-
-```py
-def outer(cond1: bool):
-    class Test:
-        if cond1:
-            def __call__(self): ...
-
-    class Other:
-        def __call__(self): ...
-
-    def inner(cond2: bool):
-        if cond2:
-            a = Test()
-        else:
-            a = Other()
-
-            # error: [call-non-callable] "Object of type `Test` is not callable (possibly unbound `__call__` method)"
-        a()
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/call/function.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/function.md
@@ -278,10 +278,10 @@ proper diagnostics in case of missing or superfluous arguments.
 from typing_extensions import reveal_type

 # error: [missing-argument] "No argument provided for required parameter `obj` of function `reveal_type`"
-reveal_type()
+reveal_type()  # revealed: Unknown

 # error: [too-many-positional-arguments] "Too many positional arguments to function `reveal_type`: expected 1, got 2"
-reveal_type(1, 2)
+reveal_type(1, 2)  # revealed: Literal[1]
 ```

 ### `static_assert`
@@ -290,6 +290,7 @@ reveal_type(1, 2)
 from knot_extensions import static_assert

 # error: [missing-argument] "No argument provided for required parameter `condition` of function `static_assert`"
+# error: [static-assert-error]
 static_assert()

 # error: [too-many-positional-arguments] "Too many positional arguments to function `static_assert`: expected 2, got 3"
--- a/crates/red_knot_python_semantic/resources/mdtest/call/getattr_static.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/getattr_static.md
@@ -1,133 +0,0 @@
-# `inspect.getattr_static`
-
-## Basic usage
-
-`inspect.getattr_static` is a function that returns attributes of an object without invoking the
-descriptor protocol (for caveats, see the [official documentation]).
-
-Consider the following example:
-
-```py
-import inspect
-
-class Descriptor:
-    def __get__(self, instance, owner) -> str:
-        return 1
-
-class C:
-    normal: int = 1
-    descriptor: Descriptor = Descriptor()
-```
-
-If we access attributes on an instance of `C` as usual, the descriptor protocol is invoked, and we
-get a type of `str` for the `descriptor` attribute:
-
-```py
-c = C()
-
-reveal_type(c.normal)  # revealed: int
-reveal_type(c.descriptor)  # revealed: str
-```
-
-However, if we use `inspect.getattr_static`, we can see the underlying `Descriptor` type:
-
-```py
-reveal_type(inspect.getattr_static(c, "normal"))  # revealed: int
-reveal_type(inspect.getattr_static(c, "descriptor"))  # revealed: Descriptor
-```
-
-For non-existent attributes, a default value can be provided:
-
-```py
-reveal_type(inspect.getattr_static(C, "normal", "default-arg"))  # revealed: int
-reveal_type(inspect.getattr_static(C, "non_existent", "default-arg"))  # revealed: Literal["default-arg"]
-```
-
-When a non-existent attribute is accessed without a default value, the runtime raises an
-`AttributeError`. We could emit a diagnostic for this case, but that is currently not supported:
-
-```py
-# TODO: we could emit a diagnostic here
-reveal_type(inspect.getattr_static(C, "non_existent"))  # revealed: Never
-```
-
-We can access attributes on objects of all kinds:
-
-```py
-import sys
-
-reveal_type(inspect.getattr_static(sys, "platform"))  # revealed: LiteralString
-reveal_type(inspect.getattr_static(inspect, "getattr_static"))  # revealed: Literal[getattr_static]
-
-reveal_type(inspect.getattr_static(1, "real"))  # revealed: Literal[1]
-```
-
-(Implicit) instance attributes can also be accessed through `inspect.getattr_static`:
-
-```py
-class D:
-    def __init__(self) -> None:
-        self.instance_attr: int = 1
-
-reveal_type(inspect.getattr_static(D(), "instance_attr"))  # revealed: int
-```
-
-## Error cases
-
-We can only infer precise types if the attribute is a literal string. In all other cases, we fall
-back to `Any`:
-
-```py
-import inspect
-
-class C:
-    x: int = 1
-
-def _(attr_name: str):
-    reveal_type(inspect.getattr_static(C(), attr_name))  # revealed: Any
-    reveal_type(inspect.getattr_static(C(), attr_name, 1))  # revealed: Any
-```
-
-But we still detect errors in the number or type of arguments:
-
-```py
-# error: [missing-argument] "No arguments provided for required parameters `obj`, `attr` of function `getattr_static`"
-inspect.getattr_static()
-
-# error: [missing-argument] "No argument provided for required parameter `attr`"
-inspect.getattr_static(C())
-
-# error: [invalid-argument-type] "Object of type `Literal[1]` cannot be assigned to parameter 2 (`attr`) of function `getattr_static`; expected type `str`"
-inspect.getattr_static(C(), 1)
-
-# error: [too-many-positional-arguments] "Too many positional arguments to function `getattr_static`: expected 3, got 4"
-inspect.getattr_static(C(), "x", "default-arg", "one too many")
-```
-
-## Possibly unbound attributes
-
-```py
-import inspect
-
-def _(flag: bool):
-    class C:
-        if flag:
-            x: int = 1
-
-    reveal_type(inspect.getattr_static(C, "x", "default"))  # revealed: int | Literal["default"]
-```
-
-## Gradual types
-
-```py
-import inspect
-from typing import Any
-
-def _(a: Any, tuple_of_any: tuple[Any]):
-    reveal_type(inspect.getattr_static(a, "x", "default"))  # revealed: Any | Literal["default"]
-
-    # TODO: Ideally, this would just be `Literal[index]`
-    reveal_type(inspect.getattr_static(tuple_of_any, "index", "default"))  # revealed: Literal[index] | Literal["default"]
-```
-
-[official documentation]: https://docs.python.org/3/library/inspect.html#inspect.getattr_static
--- a/crates/red_knot_python_semantic/resources/mdtest/call/methods.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/methods.md
@@ -1,258 +0,0 @@
-# Methods
-
-## Background: Functions as descriptors
-
-> Note: See also this related section in the descriptor guide: [Functions and methods].
-
-Say we have a simple class `C` with a function definition `f` inside its body:
-
-```py
-class C:
-    def f(self, x: int) -> str:
-        return "a"
-```
-
-Whenever we access the `f` attribute through the class object itself (`C.f`) or through an instance
-(`C().f`), this access happens via the descriptor protocol. Functions are (non-data) descriptors
-because they implement a `__get__` method. This is crucial in making sure that method calls work as
-expected. In general, the signature of the `__get__` method in the descriptor protocol is
-`__get__(self, instance, owner)`. The `self` argument is the descriptor object itself (`f`). The
-passed value for the `instance` argument depends on whether the attribute is accessed from the class
-object (in which case it is `None`), or from an instance (in which case it is the instance of type
-`C`). The `owner` argument is the class itself (`C` of type `Literal[C]`). To summarize:
-
- `C.f` is equivalent to `getattr_static(C, "f").__get__(None, C)`
- `C().f` is equivalent to `getattr_static(C, "f").__get__(C(), C)`
-
-Here, `inspect.getattr_static` is used to bypass the descriptor protocol and directly access the
-function attribute. The way the special `__get__` method *on functions* works is as follows. In the
-former case, if the `instance` argument is `None`, `__get__` simply returns the function itself. In
-the latter case, it returns a *bound method* object:
-
-```py
-from inspect import getattr_static
-
-reveal_type(getattr_static(C, "f"))  # revealed: Literal[f]
-
-reveal_type(getattr_static(C, "f").__get__)  # revealed: <method-wrapper `__get__` of `f`>
-
-reveal_type(getattr_static(C, "f").__get__(None, C))  # revealed: Literal[f]
-reveal_type(getattr_static(C, "f").__get__(C(), C))  # revealed: <bound method `f` of `C`>
-```
-
-In conclusion, this is why we see the following two types when accessing the `f` attribute on the
-class object `C` and on an instance `C()`:
-
-```py
-reveal_type(C.f)  # revealed: Literal[f]
-reveal_type(C().f)  # revealed: <bound method `f` of `C`>
-```
-
-A bound method is a callable object that contains a reference to the `instance` that it was called
-on (can be inspected via `__self__`), and the function object that it refers to (can be inspected
-via `__func__`):
-
-```py
-bound_method = C().f
-
-reveal_type(bound_method.__self__)  # revealed: C
-reveal_type(bound_method.__func__)  # revealed: Literal[f]
-```
-
-When we call the bound method, the `instance` is implicitly passed as the first argument (`self`):
-
-```py
-reveal_type(C().f(1))  # revealed: str
-reveal_type(bound_method(1))  # revealed: str
-```
-
-When we call the function object itself, we need to pass the `instance` explicitly:
-
-```py
-C.f(1)  # error: [missing-argument]
-
-reveal_type(C.f(C(), 1))  # revealed: str
-```
-
-When we access methods from derived classes, they will be bound to instances of the derived class:
-
-```py
-class D(C):
-    pass
-
-reveal_type(D().f)  # revealed: <bound method `f` of `D`>
-```
-
-If we access an attribute on a bound method object itself, it will defer to `types.MethodType`:
-
-```py
-reveal_type(bound_method.__hash__)  # revealed: <bound method `__hash__` of `MethodType`>
-```
-
-If an attribute is not available on the bound method object, it will be looked up on the underlying
-function object. We model this explicitly, which means that we can access `__kwdefaults__` on bound
-methods, even though it is not available on `types.MethodType`:
-
-```py
-reveal_type(bound_method.__kwdefaults__)  # revealed: @Todo(generics) | None
-```
-
-## Basic method calls on class objects and instances
-
-```py
-class Base:
-    def method_on_base(self, x: int | None) -> str:
-        return "a"
-
-class Derived(Base):
-    def method_on_derived(self, x: bytes) -> tuple[int, str]:
-        return (1, "a")
-
-reveal_type(Base().method_on_base(1))  # revealed: str
-reveal_type(Base.method_on_base(Base(), 1))  # revealed: str
-
-Base().method_on_base("incorrect")  # error: [invalid-argument-type]
-Base().method_on_base()  # error: [missing-argument]
-Base().method_on_base(1, 2)  # error: [too-many-positional-arguments]
-
-reveal_type(Derived().method_on_base(1))  # revealed: str
-reveal_type(Derived().method_on_derived(b"abc"))  # revealed: tuple[int, str]
-reveal_type(Derived.method_on_base(Derived(), 1))  # revealed: str
-reveal_type(Derived.method_on_derived(Derived(), b"abc"))  # revealed: tuple[int, str]
-```
-
-## Method calls on literals
-
-### Boolean literals
-
-```py
-reveal_type(True.bit_length())  # revealed: int
-reveal_type(True.as_integer_ratio())  # revealed: tuple[int, Literal[1]]
-```
-
-### Integer literals
-
-```py
-reveal_type((42).bit_length())  # revealed: int
-```
-
-### String literals
-
-```py
-reveal_type("abcde".find("abc"))  # revealed: int
-reveal_type("foo".encode(encoding="utf-8"))  # revealed: bytes
-
-"abcde".find(123)  # error: [invalid-argument-type]
-```
-
-### Bytes literals
-
-```py
-reveal_type(b"abcde".startswith(b"abc"))  # revealed: bool
-```
-
-## Method calls on `LiteralString`
-
-```py
-from typing_extensions import LiteralString
-
-def f(s: LiteralString) -> None:
-    reveal_type(s.find("a"))  # revealed: int
-```
-
-## Method calls on `tuple`
-
-```py
-def f(t: tuple[int, str]) -> None:
-    reveal_type(t.index("a"))  # revealed: int
-```
-
-## Method calls on unions
-
-```py
-from typing import Any
-
-class A:
-    def f(self) -> int:
-        return 1
-
-class B:
-    def f(self) -> str:
-        return "a"
-
-def f(a_or_b: A | B, any_or_a: Any | A):
-    reveal_type(a_or_b.f)  # revealed: <bound method `f` of `A`> | <bound method `f` of `B`>
-    reveal_type(a_or_b.f())  # revealed: int | str
-
-    reveal_type(any_or_a.f)  # revealed: Any | <bound method `f` of `A`>
-    reveal_type(any_or_a.f())  # revealed: Any | int
-```
-
-## Method calls on `KnownInstance` types
-
-```toml
-[environment]
-python-version = "3.12"
-```
-
-```py
-type IntOrStr = int | str
-
-reveal_type(IntOrStr.__or__)  # revealed: <bound method `__or__` of `typing.TypeAliasType`>
-```
-
-## Error cases: Calling `__get__` for methods
-
-The `__get__` method on `types.FunctionType` has the following overloaded signature in typeshed:
-
-```py
-from types import FunctionType, MethodType
-from typing import overload
-
-@overload
-def __get__(self, instance: None, owner: type, /) -> FunctionType: ...
-@overload
-def __get__(self, instance: object, owner: type | None = None, /) -> MethodType: ...
-```
-
-Here, we test that this signature is enforced correctly:
-
-```py
-from inspect import getattr_static
-
-class C:
-    def f(self, x: int) -> str:
-        return "a"
-
-method_wrapper = getattr_static(C, "f").__get__
-
-reveal_type(method_wrapper)  # revealed: <method-wrapper `__get__` of `f`>
-
-# All of these are fine:
-method_wrapper(C(), C)
-method_wrapper(C())
-method_wrapper(C(), None)
-method_wrapper(None, C)
-
-# Passing `None` without an `owner` argument is an
-# error: [missing-argument] "No argument provided for required parameter `owner`"
-method_wrapper(None)
-
-# Passing something that is not assignable to `type` as the `owner` argument is an
-# error: [invalid-argument-type] "Object of type `Literal[1]` cannot be assigned to parameter 2 (`owner`); expected type `type`"
-method_wrapper(None, 1)
-
-# Passing `None` as the `owner` argument when `instance` is `None` is an
-# error: [invalid-argument-type] "Object of type `None` cannot be assigned to parameter 2 (`owner`); expected type `type`"
-method_wrapper(None, None)
-
-# Calling `__get__` without any arguments is an
-# error: [missing-argument] "No argument provided for required parameter `instance`"
-method_wrapper()
-
-# Calling `__get__` with too many positional arguments is an
-# error: [too-many-positional-arguments] "Too many positional arguments: expected 2, got 3"
-method_wrapper(C(), C, "one too many")
-```
-
-[functions and methods]: https://docs.python.org/3/howto/descriptor.html#functions-and-methods
--- a/crates/red_knot_python_semantic/resources/mdtest/call/union.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/call/union.md
@@ -39,8 +39,8 @@ def _(flag: bool):
    else:
        def f() -> int:
            return 1
-    x = f()  # error: [call-non-callable] "Object of type `Literal[1]` is not callable"
-    reveal_type(x)  # revealed: int | Unknown
+    x = f()  # error: "Object of type `Literal[1] | Literal[f]` is not callable (due to union element `Literal[1]`)"
+    reveal_type(x)  # revealed: Unknown | int
 ```

 ## Multiple non-callable elements in a union
@@ -56,8 +56,8 @@ def _(flag: bool, flag2: bool):
    else:
        def f() -> int:
            return 1
-    # error: [call-non-callable] "Object of type `Literal[1]` is not callable"
-    # revealed: int | Unknown
+    # error: "Object of type `Literal[1, "foo"] | Literal[f]` is not callable (due to union elements Literal[1], Literal["foo"])"
+    # revealed: Unknown | int
    reveal_type(f())
 ```

@@ -72,39 +72,6 @@ def _(flag: bool):
    else:
        f = "foo"

-    x = f()  # error: [call-non-callable] "Object of type `Literal[1, "foo"]` is not callable"
-    reveal_type(x)  # revealed: Unknown
-```
-
-## Mismatching signatures
-
-Calling a union where the arguments don't match the signature of all variants.
-
-```py
-def f1(a: int) -> int: ...
-def f2(a: str) -> str: ...
-def _(flag: bool):
-    if flag:
-        f = f1
-    else:
-        f = f2
-
-    # error: [invalid-argument-type] "Object of type `Literal[3]` cannot be assigned to parameter 1 (`a`) of function `f2`; expected type `str`"
-    x = f(3)
-    reveal_type(x)  # revealed: int | str
-```
-
-## Any non-callable variant
-
-```py
-def f1(a: int): ...
-def _(flag: bool):
-    if flag:
-        f = f1
-    else:
-        f = "This is a string literal"
-
-    # error: [call-non-callable] "Object of type `Literal["This is a string literal"]` is not callable"
-    x = f(3)
+    x = f()  # error: "Object of type `Literal[1, "foo"]` is not callable"
    reveal_type(x)  # revealed: Unknown
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/instances/membership_test.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/instances/membership_test.md
@@ -21,9 +21,8 @@ class A:

 reveal_type("hello" in A())  # revealed: bool
 reveal_type("hello" not in A())  # revealed: bool
-# error: [unsupported-operator] "Operator `in` is not supported for types `int` and `A`, in comparing `Literal[42]` with `A`"
+# TODO: should emit diagnostic, need to check arg type, will fail
 reveal_type(42 in A())  # revealed: bool
-# error: [unsupported-operator] "Operator `not in` is not supported for types `int` and `A`, in comparing `Literal[42]` with `A`"
 reveal_type(42 not in A())  # revealed: bool
 ```

@@ -127,9 +126,9 @@ class A:

 reveal_type(CheckContains() in A())  # revealed: bool

-# error: [unsupported-operator] "Operator `in` is not supported for types `CheckIter` and `A`"
+# TODO: should emit diagnostic, need to check arg type,
+# should not fall back to __iter__ or __getitem__
 reveal_type(CheckIter() in A())  # revealed: bool
-# error: [unsupported-operator] "Operator `in` is not supported for types `CheckGetItem` and `A`"
 reveal_type(CheckGetItem() in A())  # revealed: bool

 class B:
@@ -155,8 +154,7 @@ class A:
    def __getitem__(self, key: str) -> str:
        return "foo"

-# error: [unsupported-operator] "Operator `in` is not supported for types `int` and `A`, in comparing `Literal[42]` with `A`"
+# TODO should emit a diagnostic
 reveal_type(42 in A())  # revealed: bool
-# error: [unsupported-operator] "Operator `in` is not supported for types `str` and `A`, in comparing `Literal["hello"]` with `A`"
 reveal_type("hello" in A())  # revealed: bool
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/instances/rich_comparison.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/instances/rich_comparison.md
@@ -16,38 +16,31 @@ most common case involves implementing these methods for the same type:
 ```py
 from __future__ import annotations

-class EqReturnType: ...
-class NeReturnType: ...
-class LtReturnType: ...
-class LeReturnType: ...
-class GtReturnType: ...
-class GeReturnType: ...
-
 class A:
-    def __eq__(self, other: A) -> EqReturnType:
-        return EqReturnType()
+    def __eq__(self, other: A) -> int:
+        return 42

-    def __ne__(self, other: A) -> NeReturnType:
-        return NeReturnType()
+    def __ne__(self, other: A) -> float:
+        return 42.0

-    def __lt__(self, other: A) -> LtReturnType:
-        return LtReturnType()
+    def __lt__(self, other: A) -> str:
+        return "42"

-    def __le__(self, other: A) -> LeReturnType:
-        return LeReturnType()
+    def __le__(self, other: A) -> bytes:
+        return b"42"

-    def __gt__(self, other: A) -> GtReturnType:
-        return GtReturnType()
+    def __gt__(self, other: A) -> list:
+        return [42]

-    def __ge__(self, other: A) -> GeReturnType:
-        return GeReturnType()
+    def __ge__(self, other: A) -> set:
+        return {42}

-reveal_type(A() == A())  # revealed: EqReturnType
-reveal_type(A() != A())  # revealed: NeReturnType
-reveal_type(A() < A())  # revealed: LtReturnType
-reveal_type(A() <= A())  # revealed: LeReturnType
-reveal_type(A() > A())  # revealed: GtReturnType
-reveal_type(A() >= A())  # revealed: GeReturnType
+reveal_type(A() == A())  # revealed: int
+reveal_type(A() != A())  # revealed: float
+reveal_type(A() < A())  # revealed: str
+reveal_type(A() <= A())  # revealed: bytes
+reveal_type(A() > A())  # revealed: list
+reveal_type(A() >= A())  # revealed: set
 ```

 ## Rich Comparison Dunder Implementations for Other Class
@@ -58,40 +51,33 @@ type:
 ```py
 from __future__ import annotations

-class EqReturnType: ...
-class NeReturnType: ...
-class LtReturnType: ...
-class LeReturnType: ...
-class GtReturnType: ...
-class GeReturnType: ...
-
 class A:
-    def __eq__(self, other: B) -> EqReturnType:
-        return EqReturnType()
+    def __eq__(self, other: B) -> int:
+        return 42

-    def __ne__(self, other: B) -> NeReturnType:
-        return NeReturnType()
+    def __ne__(self, other: B) -> float:
+        return 42.0

-    def __lt__(self, other: B) -> LtReturnType:
-        return LtReturnType()
+    def __lt__(self, other: B) -> str:
+        return "42"

-    def __le__(self, other: B) -> LeReturnType:
-        return LeReturnType()
+    def __le__(self, other: B) -> bytes:
+        return b"42"

-    def __gt__(self, other: B) -> GtReturnType:
-        return GtReturnType()
+    def __gt__(self, other: B) -> list:
+        return [42]

-    def __ge__(self, other: B) -> GeReturnType:
-        return GeReturnType()
+    def __ge__(self, other: B) -> set:
+        return {42}

 class B: ...

-reveal_type(A() == B())  # revealed: EqReturnType
-reveal_type(A() != B())  # revealed: NeReturnType
-reveal_type(A() < B())  # revealed: LtReturnType
-reveal_type(A() <= B())  # revealed: LeReturnType
-reveal_type(A() > B())  # revealed: GtReturnType
-reveal_type(A() >= B())  # revealed: GeReturnType
+reveal_type(A() == B())  # revealed: int
+reveal_type(A() != B())  # revealed: float
+reveal_type(A() < B())  # revealed: str
+reveal_type(A() <= B())  # revealed: bytes
+reveal_type(A() > B())  # revealed: list
+reveal_type(A() >= B())  # revealed: set
 ```

 ## Reflected Comparisons
@@ -103,64 +89,58 @@ these methods will be ignored here because they require a mismatched operand typ
 ```py
 from __future__ import annotations

-class EqReturnType: ...
-class NeReturnType: ...
-class LtReturnType: ...
-class LeReturnType: ...
-class GtReturnType: ...
-class GeReturnType: ...
-
 class A:
-    def __eq__(self, other: B) -> EqReturnType:
-        return EqReturnType()
+    def __eq__(self, other: B) -> int:
+        return 42

-    def __ne__(self, other: B) -> NeReturnType:
-        return NeReturnType()
+    def __ne__(self, other: B) -> float:
+        return 42.0

-    def __lt__(self, other: B) -> LtReturnType:
-        return LtReturnType()
+    def __lt__(self, other: B) -> str:
+        return "42"

-    def __le__(self, other: B) -> LeReturnType:
-        return LeReturnType()
+    def __le__(self, other: B) -> bytes:
+        return b"42"

-    def __gt__(self, other: B) -> GtReturnType:
-        return GtReturnType()
+    def __gt__(self, other: B) -> list:
+        return [42]

-    def __ge__(self, other: B) -> GeReturnType:
-        return GeReturnType()
-
-class Unrelated: ...
+    def __ge__(self, other: B) -> set:
+        return {42}

 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: str) -> B:
        return B()

-    def __ne__(self, other: Unrelated) -> B:
+    def __ne__(self, other: str) -> B:
        return B()

+# TODO: should be `int` and `float`.
+# Need to check arg type and fall back to `rhs.__eq__` and `rhs.__ne__`.
+#
 # Because `object.__eq__` and `object.__ne__` accept `object` in typeshed,
 # this can only happen with an invalid override of these methods,
 # but we still support it.
-reveal_type(B() == A())  # revealed: EqReturnType
-reveal_type(B() != A())  # revealed: NeReturnType
+reveal_type(B() == A())  # revealed: B
+reveal_type(B() != A())  # revealed: B

-reveal_type(B() < A())  # revealed: GtReturnType
-reveal_type(B() <= A())  # revealed: GeReturnType
+reveal_type(B() < A())  # revealed: list
+reveal_type(B() <= A())  # revealed: set

-reveal_type(B() > A())  # revealed: LtReturnType
-reveal_type(B() >= A())  # revealed: LeReturnType
+reveal_type(B() > A())  # revealed: str
+reveal_type(B() >= A())  # revealed: bytes

 class C:
-    def __gt__(self, other: C) -> EqReturnType:
+    def __gt__(self, other: C) -> int:
        return 42

-    def __ge__(self, other: C) -> NeReturnType:
-        return NeReturnType()
+    def __ge__(self, other: C) -> float:
+        return 42.0

-reveal_type(C() < C())  # revealed: EqReturnType
-reveal_type(C() <= C())  # revealed: NeReturnType
+reveal_type(C() < C())  # revealed: int
+reveal_type(C() <= C())  # revealed: float
 ```

 ## Reflected Comparisons with Subclasses
@@ -172,13 +152,6 @@ than `A`.
 ```py
 from __future__ import annotations

-class EqReturnType: ...
-class NeReturnType: ...
-class LtReturnType: ...
-class LeReturnType: ...
-class GtReturnType: ...
-class GeReturnType: ...
-
 class A:
    def __eq__(self, other: A) -> A:
        return A()
@@ -199,32 +172,32 @@ class A:
        return A()

 class B(A):
-    def __eq__(self, other: A) -> EqReturnType:
-        return EqReturnType()
+    def __eq__(self, other: A) -> int:
+        return 42

-    def __ne__(self, other: A) -> NeReturnType:
-        return NeReturnType()
+    def __ne__(self, other: A) -> float:
+        return 42.0

-    def __lt__(self, other: A) -> LtReturnType:
-        return LtReturnType()
+    def __lt__(self, other: A) -> str:
+        return "42"

-    def __le__(self, other: A) -> LeReturnType:
-        return LeReturnType()
+    def __le__(self, other: A) -> bytes:
+        return b"42"

-    def __gt__(self, other: A) -> GtReturnType:
-        return GtReturnType()
+    def __gt__(self, other: A) -> list:
+        return [42]

-    def __ge__(self, other: A) -> GeReturnType:
-        return GeReturnType()
+    def __ge__(self, other: A) -> set:
+        return {42}

-reveal_type(A() == B())  # revealed: EqReturnType
-reveal_type(A() != B())  # revealed: NeReturnType
+reveal_type(A() == B())  # revealed: int
+reveal_type(A() != B())  # revealed: float

-reveal_type(A() < B())  # revealed: GtReturnType
-reveal_type(A() <= B())  # revealed: GeReturnType
+reveal_type(A() < B())  # revealed: list
+reveal_type(A() <= B())  # revealed: set

-reveal_type(A() > B())  # revealed: LtReturnType
-reveal_type(A() >= B())  # revealed: LeReturnType
+reveal_type(A() > B())  # revealed: str
+reveal_type(A() >= B())  # revealed: bytes
 ```

 ## Reflected Comparisons with Subclass But Falls Back to LHS
@@ -249,8 +222,9 @@ class B(A):
    def __gt__(self, other: int) -> B:
        return B()

-reveal_type(A() < B())  # revealed: A
-reveal_type(A() > B())  # revealed: A
+# TODO: should be `A`, need to check argument type and fall back to LHS method
+reveal_type(A() < B())  # revealed: B
+reveal_type(A() > B())  # revealed: B
 ```

 ## Operations involving instances of classes inheriting from `Any`
@@ -298,8 +272,9 @@ class A:
    def __ne__(self, other: int) -> A:
        return A()

-reveal_type(A() == A())  # revealed: bool
-reveal_type(A() != A())  # revealed: bool
+# TODO: it should be `bool`, need to check arg type and fall back to `is` and `is not`
+reveal_type(A() == A())  # revealed: A
+reveal_type(A() != A())  # revealed: A
 ```

 ## Object Comparisons with Typeshed
@@ -330,14 +305,12 @@ reveal_type(1 >= 1.0)  # revealed: bool
 reveal_type(1 == 2j)  # revealed: bool
 reveal_type(1 != 2j)  # revealed: bool

-# error: [unsupported-operator] "Operator `<` is not supported for types `int` and `complex`, in comparing `Literal[1]` with `complex`"
-reveal_type(1 < 2j)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `<=` is not supported for types `int` and `complex`, in comparing `Literal[1]` with `complex`"
-reveal_type(1 <= 2j)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>` is not supported for types `int` and `complex`, in comparing `Literal[1]` with `complex`"
-reveal_type(1 > 2j)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>=` is not supported for types `int` and `complex`, in comparing `Literal[1]` with `complex`"
-reveal_type(1 >= 2j)  # revealed: Unknown
+# TODO: should be Unknown and emit diagnostic,
+# need to check arg type and should be failed
+reveal_type(1 < 2j)  # revealed: bool
+reveal_type(1 <= 2j)  # revealed: bool
+reveal_type(1 > 2j)  # revealed: bool
+reveal_type(1 >= 2j)  # revealed: bool

 def f(x: bool, y: int):
    reveal_type(x < y)  # revealed: bool
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/integers.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/integers.md
@@ -12,8 +12,8 @@ reveal_type(1 is 1)  # revealed: bool
 reveal_type(1 is not 1)  # revealed: bool
 reveal_type(1 is 2)  # revealed: Literal[False]
 reveal_type(1 is not 7)  # revealed: Literal[True]
-# error: [unsupported-operator] "Operator `<=` is not supported for types `int` and `str`, in comparing `Literal[1]` with `Literal[""]`"
-reveal_type(1 <= "" and 0 < 1)  # revealed: Unknown & ~AlwaysTruthy | Literal[True]
+# TODO: should be Unknown, and emit diagnostic, once we check call argument types
+reveal_type(1 <= "" and 0 < 1)  # revealed: bool
 ```

 ## Integer instance
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/intersections.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/intersections.md
@@ -8,9 +8,7 @@ types, we can infer that the result for the intersection type is also true/false
 ```py
 from typing import Literal

-class Base:
-    def __gt__(self, other) -> bool:
-        return False
+class Base: ...

 class Child1(Base):
    def __eq__(self, other) -> Literal[True]:
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/non_bool_returns.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/non_bool_returns.md
@@ -23,7 +23,6 @@ from __future__ import annotations

 class A:
    def __lt__(self, other) -> A: ...
-    def __gt__(self, other) -> bool: ...

 class B:
    def __lt__(self, other) -> B: ...
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/tuples.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/tuples.md
@@ -33,6 +33,8 @@ reveal_type(a >= b)  # revealed: Literal[False]

 Even when tuples have different lengths, comparisons should be handled appropriately.

+`different_length.py`:
+
 ```py
 a = (1, 2, 3)
 b = (1, 2, 3, 4)
@@ -92,19 +94,18 @@ reveal_type(a == b)  # revealed: bool
 # TODO: should be Literal[True], once we implement (in)equality for mismatched literals
 reveal_type(a != b)  # revealed: bool

-# error: [unsupported-operator] "Operator `<` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
-reveal_type(a < b)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `<=` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
-reveal_type(a <= b)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
-reveal_type(a > b)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>=` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
-reveal_type(a >= b)  # revealed: Unknown
+# TODO: should be Unknown and add more informative diagnostics
+reveal_type(a < b)  # revealed: bool
+reveal_type(a <= b)  # revealed: bool
+reveal_type(a > b)  # revealed: bool
+reveal_type(a >= b)  # revealed: bool
 ```

 However, if the lexicographic comparison completes without reaching a point where str and int are
 compared, Python will still produce a result based on the prior elements.

+`short_circuit.py`:
+
 ```py
 a = (1, 2)
 b = (999999, "hello")
@@ -147,40 +148,33 @@ of the dunder methods.)
 ```py
 from __future__ import annotations

-class EqReturnType: ...
-class NeReturnType: ...
-class LtReturnType: ...
-class LeReturnType: ...
-class GtReturnType: ...
-class GeReturnType: ...
-
 class A:
-    def __eq__(self, o: object) -> EqReturnType:
-        return EqReturnType()
+    def __eq__(self, o: object) -> str:
+        return "hello"

-    def __ne__(self, o: object) -> NeReturnType:
-        return NeReturnType()
+    def __ne__(self, o: object) -> bytes:
+        return b"world"

-    def __lt__(self, o: A) -> LtReturnType:
-        return LtReturnType()
+    def __lt__(self, o: A) -> float:
+        return 3.14

-    def __le__(self, o: A) -> LeReturnType:
-        return LeReturnType()
+    def __le__(self, o: A) -> complex:
+        return complex(0.5, -0.5)

-    def __gt__(self, o: A) -> GtReturnType:
-        return GtReturnType()
+    def __gt__(self, o: A) -> tuple:
+        return (1, 2, 3)

-    def __ge__(self, o: A) -> GeReturnType:
-        return GeReturnType()
+    def __ge__(self, o: A) -> list:
+        return [1, 2, 3]

 a = (A(), A())

 reveal_type(a == a)  # revealed: bool
 reveal_type(a != a)  # revealed: bool
-reveal_type(a < a)  # revealed: LtReturnType | Literal[False]
-reveal_type(a <= a)  # revealed: LeReturnType | Literal[True]
-reveal_type(a > a)  # revealed: GtReturnType | Literal[False]
-reveal_type(a >= a)  # revealed: GeReturnType | Literal[True]
+reveal_type(a < a)  # revealed: float | Literal[False]
+reveal_type(a <= a)  # revealed: complex | Literal[True]
+reveal_type(a > a)  # revealed: tuple | Literal[False]
+reveal_type(a >= a)  # revealed: list | Literal[True]

 # If lexicographic comparison is finished before comparing A()
 b = ("1_foo", A())
@@ -193,13 +187,11 @@ reveal_type(b <= c)  # revealed: Literal[True]
 reveal_type(b > c)  # revealed: Literal[False]
 reveal_type(b >= c)  # revealed: Literal[False]

-class LtReturnTypeOnB: ...
-
 class B:
-    def __lt__(self, o: B) -> LtReturnTypeOnB:
+    def __lt__(self, o: B) -> set:
        return set()

-reveal_type((A(), B()) < (A(), B()))  # revealed: LtReturnType | LtReturnTypeOnB | Literal[False]
+reveal_type((A(), B()) < (A(), B()))  # revealed: float | set | Literal[False]
 ```

 #### Special Handling of Eq and NotEq in Lexicographic Comparisons
--- a/crates/red_knot_python_semantic/resources/mdtest/comparison/unsupported.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comparison/unsupported.md
@@ -9,22 +9,28 @@ def _(flag: bool, flag1: bool, flag2: bool):
    b = 0 not in 10  # error: "Operator `not in` is not supported for types `Literal[0]` and `Literal[10]`"
    reveal_type(b)  # revealed: bool

-    # error: [unsupported-operator] "Operator `<` is not supported for types `object` and `int`, in comparing `object` with `Literal[5]`"
+    # TODO: should error, once operand type check is implemented
+    # ("Operator `<` is not supported for types `object` and `int`")
    c = object() < 5
-    reveal_type(c)  # revealed: Unknown
+    # TODO: should be Unknown, once operand type check is implemented
+    reveal_type(c)  # revealed: bool

-    # error: [unsupported-operator] "Operator `<` is not supported for types `int` and `object`, in comparing `Literal[5]` with `object`"
+    # TODO: should error, once operand type check is implemented
+    # ("Operator `<` is not supported for types `int` and `object`")
    d = 5 < object()
-    reveal_type(d)  # revealed: Unknown
+    # TODO: should be Unknown, once operand type check is implemented
+    reveal_type(d)  # revealed: bool

    int_literal_or_str_literal = 1 if flag else "foo"
    # error: "Operator `in` is not supported for types `Literal[42]` and `Literal[1]`, in comparing `Literal[42]` with `Literal[1, "foo"]`"
    e = 42 in int_literal_or_str_literal
    reveal_type(e)  # revealed: bool

-    # error: [unsupported-operator] "Operator `<` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`"
+    # TODO: should error, need to check if __lt__ signature is valid for right operand
+    # error may be "Operator `<` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`
    f = (1, 2) < (1, "hello")
-    reveal_type(f)  # revealed: Unknown
+    # TODO: should be Unknown, once operand type check is implemented
+    reveal_type(f)  # revealed: bool

    # error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`, in comparing `tuple[bool, A]` with `tuple[bool, A]`"
    g = (flag1, A()) < (flag2, A())
--- a/crates/red_knot_python_semantic/resources/mdtest/comprehensions/basic.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/comprehensions/basic.md
@@ -43,7 +43,8 @@ class IntIterable:
    def __iter__(self) -> IntIterator:
        return IntIterator()

-# revealed: tuple[int, int]
+# TODO: This could be a `tuple[int, int]` if we model that `y` can not be modified in the outer comprehension scope
+# revealed: tuple[int, Unknown | int]
 [[reveal_type((x, y)) for x in IntIterable()] for y in IntIterable()]
 ```

@@ -66,7 +67,8 @@ class IterableOfIterables:
    def __iter__(self) -> IteratorOfIterables:
        return IteratorOfIterables()

-# revealed: tuple[int, IntIterable]
+# TODO: This could be a `tuple[int, int]` (see above)
+# revealed: tuple[int, Unknown | IntIterable]
 [[reveal_type((x, y)) for x in y] for y in IterableOfIterables()]
 ```

--- a/crates/red_knot_python_semantic/resources/mdtest/descriptor_protocol.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/descriptor_protocol.md
@@ -22,26 +22,22 @@ class Ten:
        pass

 class C:
-    ten: Ten = Ten()
+    ten = Ten()

 c = C()

-reveal_type(c.ten)  # revealed: Literal[10]
+# TODO: this should be `Literal[10]`
+reveal_type(c.ten)  # revealed: Unknown | Ten

-reveal_type(C.ten)  # revealed: Literal[10]
+# TODO: This should `Literal[10]`
+reveal_type(C.ten)  # revealed: Unknown | Ten

 # These are fine:
-# TODO: This should not be an error
-c.ten = 10  # error: [invalid-assignment]
+c.ten = 10
 C.ten = 10

-# TODO: This should be an error (as the wrong type is being implicitly passed to `Ten.__set__`),
-# but the error message is misleading.
-# error: [invalid-assignment] "Object of type `Literal[11]` is not assignable to attribute `ten` of type `Ten`"
+# TODO: Both of these should be errors
 c.ten = 11
-
-# TODO: same as above
-# error: [invalid-assignment] "Object of type `Literal[11]` is not assignable to attribute `ten` of type `Literal[10]`"
 C.ten = 11
 ```

@@ -61,86 +57,24 @@ class FlexibleInt:
        self._value = int(value)

 class C:
-    flexible_int: FlexibleInt = FlexibleInt()
+    flexible_int = FlexibleInt()

 c = C()

-reveal_type(c.flexible_int)  # revealed: int | None
+# TODO: should be `int | None`
+reveal_type(c.flexible_int)  # revealed: Unknown | FlexibleInt

-# TODO: These should not be errors
-# error: [invalid-assignment]
 c.flexible_int = 42  # okay
-# error: [invalid-assignment]
 c.flexible_int = "42"  # also okay!

-reveal_type(c.flexible_int)  # revealed: int | None
+# TODO: should be `int | None`
+reveal_type(c.flexible_int)  # revealed: Unknown | FlexibleInt

-# TODO: This should be an error, but the message needs to be improved.
-# error: [invalid-assignment] "Object of type `None` is not assignable to attribute `flexible_int` of type `FlexibleInt`"
+# TODO: should be an error
 c.flexible_int = None  # not okay

-reveal_type(c.flexible_int)  # revealed: int | None
-```
-
-## Data and non-data descriptors
-
-Descriptors that define `__set__` or `__delete__` are called *data descriptors*. An example\
-of a data descriptor is a `property` with a setter and/or a deleter.\
-Descriptors that only define `__get__`, meanwhile, are called *non-data descriptors*. Examples
-include\
-functions, `classmethod` or `staticmethod`).
-
-The precedence chain for attribute access is (1) data descriptors, (2) instance attributes, and (3)
-non-data descriptors.
-
-```py
-from typing import Literal
-
-class DataDescriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> Literal["data"]:
-        return "data"
-
-    def __set__(self, instance: int, value) -> None:
-        pass
-
-class NonDataDescriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> Literal["non-data"]:
-        return "non-data"
-
-class C:
-    data_descriptor = DataDescriptor()
-    non_data_descriptor = NonDataDescriptor()
-
-    def f(self):
-        # This explains why data descriptors come first in the precedence chain. If
-        # instance attributes would take priority, we would override the descriptor
-        # here. Instead, this calls `DataDescriptor.__set__`, i.e. it does not affect
-        # the type of the `data_descriptor` attribute.
-        self.data_descriptor = 1
-
-        # However, for non-data descriptors, instance attributes do take precedence.
-        # So it is possible to override them.
-        self.non_data_descriptor = 1
-
-c = C()
-
-# TODO: This should ideally be `Unknown | Literal["data"]`.
-#
-#     - Pyright also wrongly shows `int | Literal['data']` here
-#     - Mypy shows Literal["data"] here, but also shows Literal["non-data"] below.
-#
-reveal_type(c.data_descriptor)  # revealed: Unknown | Literal["data", 1]
-
-reveal_type(c.non_data_descriptor)  # revealed: Unknown | Literal["non-data", 1]
-
-reveal_type(C.data_descriptor)  # revealed: Unknown | Literal["data"]
-
-reveal_type(C.non_data_descriptor)  # revealed: Unknown | Literal["non-data"]
-
-# It is possible to override data descriptors via class objects. The following
-# assignment does not call `DataDescriptor.__set__`. For this reason, we infer
-# `Unknown | …` for all (descriptor) attributes.
-C.data_descriptor = "something else"  # This is okay
+# TODO: should be `int | None`
+reveal_type(c.flexible_int)  # revealed: Unknown | FlexibleInt
 ```

 ## Built-in `property` descriptor
@@ -167,7 +101,7 @@ c = C()
 reveal_type(c._name)  # revealed: str | None

 # Should be `str`
-reveal_type(c.name)  # revealed: @Todo(decorated method)
+reveal_type(c.name)  # revealed: @Todo(bound method)

 # Should be `builtins.property`
 reveal_type(C.name)  # revealed: Literal[name]
@@ -208,7 +142,7 @@ reveal_type(c1)  # revealed: @Todo(return type)
 reveal_type(C.get_name())  # revealed: @Todo(return type)

 # TODO: should be `str`
-reveal_type(C("42").get_name())  # revealed: @Todo(decorated method)
+reveal_type(C("42").get_name())  # revealed: @Todo(bound method)
 ```

 ## Descriptors only work when used as class variables
@@ -226,10 +160,9 @@ class Ten:

 class C:
    def __init__(self):
-        self.ten: Ten = Ten()
+        self.ten = Ten()

-# TODO: Should be Ten
-reveal_type(C().ten)  # revealed: Literal[10]
+reveal_type(C().ten)  # revealed: Unknown | Ten
 ```

 ## Descriptors distinguishing between class and instance access
@@ -253,166 +186,13 @@ class Descriptor:
            return "called on class object"

 class C:
-    d: Descriptor = Descriptor()
+    d = Descriptor()

 # TODO: should be `Literal["called on class object"]
-reveal_type(C.d)  # revealed: LiteralString
+reveal_type(C.d)  # revealed: Unknown | Descriptor

 # TODO: should be `Literal["called on instance"]
-reveal_type(C().d)  # revealed: LiteralString
-```
-
-## Undeclared descriptor arguments
-
-If a descriptor attribute is not declared, we union with `Unknown`, just like for regular
-attributes, since that attribute could be overwritten externally. Even a data descriptor with a
-`__set__` method can be overwritten when accessed through a class object.
-
-```py
-class Descriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> int:
-        return 1
-
-    def __set__(self, instance: object, value: int) -> None:
-        pass
-
-class C:
-    descriptor = Descriptor()
-
-C.descriptor = "something else"
-
-# This could also be `Literal["something else"]` if we support narrowing of attribute types based on assignments
-reveal_type(C.descriptor)  # revealed: Unknown | int
-```
-
-## Descriptors with incorrect `__get__` signature
-
-```py
-class Descriptor:
-    # `__get__` method with missing parameters:
-    def __get__(self) -> int:
-        return 1
-
-class C:
-    descriptor: Descriptor = Descriptor()
-
-# TODO: This should be an error
-reveal_type(C.descriptor)  # revealed: Descriptor
-```
-
-## Possibly-unbound `__get__` method
-
-```py
-def _(flag: bool):
-    class MaybeDescriptor:
-        if flag:
-            def __get__(self, instance: object, owner: type | None = None) -> int:
-                return 1
-
-    class C:
-        descriptor: MaybeDescriptor = MaybeDescriptor()
-
-    # TODO: This should be `MaybeDescriptor | int`
-    reveal_type(C.descriptor)  # revealed: int
-```
-
-## Dunder methods
-
-Dunder methods are looked up on the meta type, but we still need to invoke the descriptor protocol:
-
-```py
-class SomeCallable:
-    def __call__(self, x: int) -> str:
-        return "a"
-
-class Descriptor:
-    def __get__(self, instance: object, owner: type | None = None) -> SomeCallable:
-        return SomeCallable()
-
-class B:
-    __call__: Descriptor = Descriptor()
-
-b_instance = B()
-reveal_type(b_instance(1))  # revealed: str
-
-b_instance("bla")  # error: [invalid-argument-type]
-```
-
-## Functions as descriptors
-
-Functions are descriptors because they implement a `__get__` method. This is crucial in making sure
-that method calls work as expected. See [this test suite](./call/methods.md) for more information.
-Here, we only demonstrate how `__get__` works on functions:
-
-```py
-from inspect import getattr_static
-
-def f(x: object) -> str:
-    return "a"
-
-reveal_type(f)  # revealed: Literal[f]
-reveal_type(f.__get__)  # revealed: <method-wrapper `__get__` of `f`>
-reveal_type(f.__get__(None, type(f)))  # revealed: Literal[f]
-reveal_type(f.__get__(None, type(f))(1))  # revealed: str
-
-wrapper_descriptor = getattr_static(f, "__get__")
-
-reveal_type(wrapper_descriptor)  # revealed: <wrapper-descriptor `__get__` of `function` objects>
-reveal_type(wrapper_descriptor(f, None, type(f)))  # revealed: Literal[f]
-
-# Attribute access on the method-wrapper `f.__get__` falls back to `MethodWrapperType`:
-reveal_type(f.__get__.__hash__)  # revealed: <bound method `__hash__` of `MethodWrapperType`>
-
-# Attribute access on the wrapper-descriptor falls back to `WrapperDescriptorType`:
-reveal_type(wrapper_descriptor.__qualname__)  # revealed: @Todo(@property)
-```
-
-We can also bind the free function `f` to an instance of a class `C`:
-
-```py
-class C: ...
-
-bound_method = wrapper_descriptor(f, C(), C)
-
-reveal_type(bound_method)  # revealed: <bound method `f` of `C`>
-```
-
-We can then call it, and the instance of `C` is implicitly passed to the first parameter of `f`
-(`x`):
-
-```py
-reveal_type(bound_method())  # revealed: str
-```
-
-Finally, we test some error cases for the call to the wrapper descriptor:
-
-```py
-# Calling the wrapper descriptor without any arguments is an
-# error: [missing-argument] "No arguments provided for required parameters `self`, `instance`"
-wrapper_descriptor()
-
-# Calling it without the `instance` argument is an also an
-# error: [missing-argument] "No argument provided for required parameter `instance`"
-wrapper_descriptor(f)
-
-# Calling it without the `owner` argument if `instance` is not `None` is an
-# error: [missing-argument] "No argument provided for required parameter `owner`"
-wrapper_descriptor(f, None)
-
-# But calling it with an instance is fine (in this case, the `owner` argument is optional):
-wrapper_descriptor(f, C())
-
-# Calling it with something that is not a `FunctionType` as the first argument is an
-# error: [invalid-argument-type] "Object of type `Literal[1]` cannot be assigned to parameter 1 (`self`); expected type `FunctionType`"
-wrapper_descriptor(1, None, type(f))
-
-# Calling it with something that is not a `type` as the `owner` argument is an
-# error: [invalid-argument-type] "Object of type `Literal[f]` cannot be assigned to parameter 3 (`owner`); expected type `type`"
-wrapper_descriptor(f, None, f)
-
-# Calling it with too many positional arguments is an
-# error: [too-many-positional-arguments] "Too many positional arguments: expected 3, got 4"
-wrapper_descriptor(f, None, type(f), "one too many")
+reveal_type(C().d)  # revealed: Unknown | Descriptor
 ```

 [descriptors]: https://docs.python.org/3/howto/descriptor.html
--- a/crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
@@ -1,184 +0,0 @@
-# Invalid argument type diagnostics
-
-<!-- snapshot-diagnostics -->
-
-## Basic
-
-This is a basic test demonstrating that a diagnostic points to the function definition corresponding
-to the invalid argument.
-
-```py
-def foo(x: int) -> int:
-    return x * x
-
-foo("hello")  # error: [invalid-argument-type]
-```
-
-## Different source order
-
-This is like the basic test, except we put the call site above the function definition.
-
-```py
-def bar():
-    foo("hello")  # error: [invalid-argument-type]
-
-def foo(x: int) -> int:
-    return x * x
-```
-
-## Different files
-
-This tests that a diagnostic can point to a function definition in a different file in which an
-invalid call site was found.
-
-`package.py`:
-
-```py
-def foo(x: int) -> int:
-    return x * x
-```
-
-```py
-import package
-
-package.foo("hello")  # error: [invalid-argument-type]
-```
-
-## Many parameters
-
-This checks that a diagnostic renders reasonably when there are multiple parameters.
-
-```py
-def foo(x: int, y: int, z: int) -> int:
-    return x * y * z
-
-foo(1, "hello", 3)  # error: [invalid-argument-type]
-```
-
-## Many parameters across multiple lines
-
-This checks that a diagnostic renders reasonably when there are multiple parameters spread out
-across multiple lines.
-
-```py
-def foo(
-    x: int,
-    y: int,
-    z: int,
-) -> int:
-    return x * y * z
-
-foo(1, "hello", 3)  # error: [invalid-argument-type]
-```
-
-## Many parameters with multiple invalid arguments
-
-This checks that a diagnostic renders reasonably when there are multiple parameters and multiple
-invalid argument types.
-
-```py
-def foo(x: int, y: int, z: int) -> int:
-    return x * y * z
-
-# error: [invalid-argument-type]
-# error: [invalid-argument-type]
-# error: [invalid-argument-type]
-foo("a", "b", "c")
-```
-
-At present (2025-02-18), this renders three different diagnostic messages. But arguably, these could
-all be folded into one diagnostic. Fixing this requires at least better support for multi-spans in
-the diagnostic model and possibly also how diagnostics are emitted by the type checker itself.
-
-## Test calling a function whose type is vendored from `typeshed`
-
-This tests that diagnostic rendering is reasonable when the function being called is from the
-standard library.
-
-```py
-import json
-
-json.loads(5)  # error: [invalid-argument-type]
-```
-
-## Tests for a variety of argument types
-
-These tests check that diagnostic output is reasonable regardless of the kinds of arguments used in
-a function definition.
-
-### Only positional
-
-Tests a function definition with only positional parameters.
-
-```py
-def foo(x: int, y: int, z: int, /) -> int:
-    return x * y * z
-
-foo(1, "hello", 3)  # error: [invalid-argument-type]
-```
-
-### Variadic arguments
-
-Tests a function definition with variadic arguments.
-
-```py
-def foo(*numbers: int) -> int:
-    return len(numbers)
-
-foo(1, 2, 3, "hello", 5)  # error: [invalid-argument-type]
-```
-
-### Keyword only arguments
-
-Tests a function definition with keyword-only arguments.
-
-```py
-def foo(x: int, y: int, *, z: int = 0) -> int:
-    return x * y * z
-
-foo(1, 2, z="hello")  # error: [invalid-argument-type]
-```
-
-### One keyword argument
-
-Tests a function definition with keyword-only arguments.
-
-```py
-def foo(x: int, y: int, z: int = 0) -> int:
-    return x * y * z
-
-foo(1, 2, "hello")  # error: [invalid-argument-type]
-```
-
-### Variadic keyword arguments
-
-```py
-def foo(**numbers: int) -> int:
-    return len(numbers)
-
-foo(a=1, b=2, c=3, d="hello", e=5)  # error: [invalid-argument-type]
-```
-
-### Mix of arguments
-
-Tests a function definition with multiple different kinds of arguments.
-
-```py
-def foo(x: int, /, y: int, *, z: int = 0) -> int:
-    return x * y * z
-
-foo(1, 2, z="hello")  # error: [invalid-argument-type]
-```
-
-### Synthetic arguments
-
-Tests a function call with synthetic arguments.
-
-```py
-class C:
-    def __call__(self, x: int) -> int:
-        return 1
-
-c = C()
-c("wrong")  # error: [invalid-argument-type]
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/diagnostics/unpacking.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/diagnostics/unpacking.md
@@ -1,21 +0,0 @@
-# Unpacking
-
-<!-- snapshot-diagnostics -->
-
-## Right hand side not iterable
-
-```py
-a, b = 1  # error: [not-iterable]
-```
-
-## Too many values to unpack
-
-```py
-a, b = (1, 2, 3)  # error: [invalid-assignment]
-```
-
-## Too few values to unpack
-
-```py
-a, b = (1,)  # error: [invalid-assignment]
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/doc/README.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/doc/README.md
@@ -1,2 +0,0 @@
-This directory contains user-facing documentation, but also doubles as an extended test suite that
-makes sure that our documentation stays up to date.
--- a/crates/red_knot_python_semantic/resources/mdtest/doc/public_type_undeclared_symbols.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/doc/public_type_undeclared_symbols.md
@@ -1,125 +0,0 @@
-# Public type of undeclared symbols
-
-## Summary
-
-One major deviation from the behavior of existing Python type checkers is our handling of 'public'
-types for undeclared symbols. This is best illustrated with an example:
-
-```py
-class Wrapper:
-    value = None
-
-wrapper = Wrapper()
-
-reveal_type(wrapper.value)  # revealed: Unknown | None
-
-wrapper.value = 1
-```
-
-Mypy and Pyright both infer a type of `None` for the type of `wrapper.value`. Consequently, both
-tools emit an error when trying to assign `1` to `wrapper.value`. But there is nothing wrong with
-this program. Emitting an error here violates the [gradual guarantee] which states that *"Removing
-type annotations (making the program more dynamic) should not result in additional static type
-errors."*: If `value` were annotated with `int | None` here, Mypy and Pyright would not emit any
-errors.
-
-By inferring `Unknown | None` instead, we allow arbitrary values to be assigned to `wrapper.value`.
-This is a deliberate choice to prevent false positive errors on untyped code.
-
-More generally, we infer `Unknown | T_inferred` for undeclared symbols, where `T_inferred` is the
-inferred type of the right-hand side of the assignment. This gradual type represents an *unknown*
-fully-static type that is *at least as large as* `T_inferred`. It accurately describes our static
-knowledge about this type. In the example above, we don't know what values `wrapper.value` could
-possibly contain, but we *do know* that `None` is a possibility. This allows us to catch errors
-where `wrapper.value` is used in a way that is incompatible with `None`:
-
-```py
-def accepts_int(i: int) -> None:
-    pass
-
-def f(w: Wrapper) -> None:
-    # This is fine
-    v: int | None = w.value
-
-    # This function call is incorrect, because `w.value` could be `None`. We therefore emit the following
-    # error: "`Unknown | None` cannot be assigned to parameter 1 (`i`) of function `accepts_int`; expected type `int`"
-    c = accepts_int(w.value)
-```
-
-## Explicit lack of knowledge
-
-The following example demonstrates how Mypy and Pyright's type inference of fully-static types in
-these situations can lead to false-negatives, even though everything appears to be (statically)
-typed. To make this a bit more realistic, imagine that `OptionalInt` is imported from an external,
-untyped module:
-
-`optional_int.py`:
-
-```py
-class OptionalInt:
-    value = 10
-
-def reset(o):
-    o.value = None
-```
-
-It is then used like this:
-
-```py
-from optional_int import OptionalInt, reset
-
-o = OptionalInt()
-reset(o)  # Oh no...
-
-# Mypy and Pyright infer a fully-static type of `int` here, which appears to make the
-# subsequent division operation safe -- but it is not. We infer the following type:
-reveal_type(o.value)  # revealed: Unknown | Literal[10]
-
-print(o.value // 2)  # Runtime error!
-```
-
-We do not catch this mistake either, but we accurately reflect our lack of knowledge about
-`o.value`. Together with a possible future type-checker mode that would detect the prevalence of
-dynamic types, this could help developers catch such mistakes.
-
-## Stricter behavior
-
-Users can always opt in to stricter behavior by adding type annotations. For the `OptionalInt`
-class, this would probably be:
-
-```py
-class OptionalInt:
-    value: int | None = 10
-
-o = OptionalInt()
-
-# The following public type is now
-# revealed: int | None
-reveal_type(o.value)
-
-# Incompatible assignments are now caught:
-# error: "Object of type `Literal["a"]` is not assignable to attribute `value` of type `int | None`"
-o.value = "a"
-```
-
-## What is meant by 'public' type?
-
-We apply different semantics depending on whether a symbol is accessed from the same scope in which
-it was originally defined, or whether it is accessed from an external scope. External scopes will
-see the symbol's "public type", which has been discussed above. But within the same scope the symbol
-was defined in, we use a narrower type of `T_inferred` for undeclared symbols. This is because, from
-the perspective of this scope, there is no way that the value of the symbol could have been
-reassigned from external scopes. For example:
-
-```py
-class Wrapper:
-    value = None
-
-    # Type as seen from the same scope:
-    reveal_type(value)  # revealed: None
-
-# Type as seen from another scope:
-reveal_type(Wrapper.value)  # revealed: Unknown | None
-```
-
-[gradual guarantee]: https://typing.readthedocs.io/en/latest/spec/concepts.html#the-gradual-guarantee
--- a/crates/red_knot_python_semantic/resources/mdtest/exception/basic.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/exception/basic.md
@@ -124,49 +124,42 @@ def _(e: Exception | type[Exception] | None):
 ## Exception cause is not an exception

 ```py
-def _():
-    try:
-        raise EOFError() from GeneratorExit  # fine
-    except:
-        ...
+try:
+    raise EOFError() from GeneratorExit  # fine
+except:
+    ...

-def _():
-    try:
-        raise StopIteration from MemoryError()  # fine
-    except:
-        ...
+try:
+    raise StopIteration from MemoryError()  # fine
+except:
+    ...

-def _():
-    try:
-        raise BufferError() from None  # fine
-    except:
-        ...
+try:
+    raise BufferError() from None  # fine
+except:
+    ...

-def _():
-    try:
-        raise ZeroDivisionError from False  # error: [invalid-raise]
-    except:
-        ...
+try:
+    raise ZeroDivisionError from False  # error: [invalid-raise]
+except:
+    ...

-def _():
-    try:
-        raise SystemExit from bool()  # error: [invalid-raise]
-    except:
-        ...
+try:
+    raise SystemExit from bool()  # error: [invalid-raise]
+except:
+    ...

-def _():
-    try:
-        raise
-    except KeyboardInterrupt as e:  # fine
-        reveal_type(e)  # revealed: KeyboardInterrupt
-        raise LookupError from e  # fine
+try:
+    raise
+except KeyboardInterrupt as e:  # fine
+    reveal_type(e)  # revealed: KeyboardInterrupt
+    raise LookupError from e  # fine

-def _():
-    try:
-        raise
-    except int as e:  # error: [invalid-exception-caught]
-        reveal_type(e)  # revealed: Unknown
-        raise KeyError from e
+try:
+    raise
+except int as e:  # error: [invalid-exception-caught]
+    reveal_type(e)  # revealed: Unknown
+    raise KeyError from e

 def _(e: Exception | type[Exception]):
    raise ModuleNotFoundError from e  # fine
--- a/crates/red_knot_python_semantic/resources/mdtest/exception/control_flow.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/exception/control_flow.md
@@ -29,6 +29,8 @@ completing. The type of `x` at the beginning of the `except` suite in this examp
 `x = could_raise_returns_str()` redefinition, but we *also* could have jumped to the `except` suite
 *after* that redefinition.

+`union_type_inferred.py`:
+
 ```py
 def could_raise_returns_str() -> str:
    return "foo"
@@ -50,7 +52,12 @@ reveal_type(x)  # revealed: str | Literal[2]
 If `x` has the same type at the end of both branches, however, the branches unify and `x` is not
 inferred as having a union type following the `try`/`except` block:

+`branches_unify_to_non_union_type.py`:
+
 ```py
+def could_raise_returns_str() -> str:
+    return "foo"
+
 x = 1

 try:
@@ -130,6 +137,8 @@ the `except` suite:
 - At the end of `else`, `x == 3`
 - At the end of `except`, `x == 2`

+`single_except.py`:
+
 ```py
 def could_raise_returns_str() -> str:
    return "foo"
@@ -158,6 +167,9 @@ been executed in its entirety, or the `try` suite and the `else` suite must both
 in their entireties:

 ```py
+def could_raise_returns_str() -> str:
+    return "foo"
+
 x = 1

 try:
@@ -186,6 +198,8 @@ A `finally` suite is *always* executed. As such, if we reach the `reveal_type` c
 this example, we know that `x` *must* have been reassigned to `2` during the `finally` suite. The
 type of `x` at the end of the example is therefore `Literal[2]`:

+`redef_in_finally.py`:
+
 ```py
 def could_raise_returns_str() -> str:
    return "foo"
@@ -211,7 +225,12 @@ at this point than there were when we were inside the `finally` block.
 (Our current model does *not* correctly infer the types *inside* `finally` suites, however; this is
 still a TODO item for us.)

+`no_redef_in_finally.py`:
+
 ```py
+def could_raise_returns_str() -> str:
+    return "foo"
+
 x = 1

 try:
@@ -240,35 +259,33 @@ suites:
    exception raised in the `except` suite to cause us to jump to the `finally` suite before the
    `except` suite ran to completion

+`redef_in_finally.py`:
+
 ```py
-class A: ...
-class B: ...
-class C: ...
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_A() -> A:
-    return A()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_B() -> B:
-    return B()
-
-def could_raise_returns_C() -> C:
-    return C()
+def could_raise_returns_bool() -> bool:
+    return True

 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 finally:
-    # TODO: should be `Literal[1] | A | B | C`
-    reveal_type(x)  # revealed: A | C
+    # TODO: should be `Literal[1] | str | bytes | bool`
+    reveal_type(x)  # revealed: str | bool
    x = 2
    reveal_type(x)  # revealed: Literal[2]

@@ -281,61 +298,80 @@ itself. (In some control-flow possibilities, some exceptions were merely *suspen
 `finally` suite; these lead to the scope's termination following the conclusion of the `finally`
 suite.)

+`no_redef_in_finally.py`:
+
 ```py
+def could_raise_returns_str() -> str:
+    return "foo"
+
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"
+
+def could_raise_returns_bool() -> bool:
+    return True
+
 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 finally:
-    # TODO: should be `Literal[1] | A | B | C`
-    reveal_type(x)  # revealed: A | C
+    # TODO: should be `Literal[1] | str | bytes | bool`
+    reveal_type(x)  # revealed: str | bool

-reveal_type(x)  # revealed: A | C
+reveal_type(x)  # revealed: str | bool
 ```

 An example with multiple `except` branches and a `finally` branch:

+`multiple_except_branches.py`:
+
 ```py
-class D: ...
-class E: ...
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_D() -> D:
-    return D()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_E() -> E:
-    return E()
+def could_raise_returns_bool() -> bool:
+    return True
+
+def could_raise_returns_memoryview() -> memoryview:
+    return memoryview(b"")
+
+def could_raise_returns_float() -> float:
+    return 3.14

 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 except ValueError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_D()
-    reveal_type(x)  # revealed: D
-    x = could_raise_returns_E()
-    reveal_type(x)  # revealed: E
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_memoryview()
+    reveal_type(x)  # revealed: memoryview
+    x = could_raise_returns_float()
+    reveal_type(x)  # revealed: float
 finally:
-    # TODO: should be `Literal[1] | A | B | C | D | E`
-    reveal_type(x)  # revealed: A | C | E
+    # TODO: should be `Literal[1] | str | bytes | bool | memoryview | float`
+    reveal_type(x)  # revealed: str | bool | float

-reveal_type(x)  # revealed: A | C | E
+reveal_type(x)  # revealed: str | bool | float
 ```

 ## Combining `except`, `else` and `finally` branches
@@ -344,94 +380,104 @@ If the exception handler has an `else` branch, we must also take into account th
 control flow could have jumped to the `finally` suite from partway through the `else` suite due to
 an exception raised *there*.

+`single_except_branch.py`:
+
 ```py
-class A: ...
-class B: ...
-class C: ...
-class D: ...
-class E: ...
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_A() -> A:
-    return A()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_B() -> B:
-    return B()
+def could_raise_returns_bool() -> bool:
+    return True

-def could_raise_returns_C() -> C:
-    return C()
+def could_raise_returns_memoryview() -> memoryview:
+    return memoryview(b"")

-def could_raise_returns_D() -> D:
-    return D()
-
-def could_raise_returns_E() -> E:
-    return E()
+def could_raise_returns_float() -> float:
+    return 3.14

 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 else:
-    reveal_type(x)  # revealed: A
-    x = could_raise_returns_D()
-    reveal_type(x)  # revealed: D
-    x = could_raise_returns_E()
-    reveal_type(x)  # revealed: E
+    reveal_type(x)  # revealed: str
+    x = could_raise_returns_memoryview()
+    reveal_type(x)  # revealed: memoryview
+    x = could_raise_returns_float()
+    reveal_type(x)  # revealed: float
 finally:
-    # TODO: should be `Literal[1] | A | B | C | D | E`
-    reveal_type(x)  # revealed: C | E
+    # TODO: should be `Literal[1] | str | bytes | bool | memoryview | float`
+    reveal_type(x)  # revealed: bool | float

-reveal_type(x)  # revealed: C | E
+reveal_type(x)  # revealed: bool | float
 ```

 The same again, this time with multiple `except` branches:

+`multiple_except_branches.py`:
+
 ```py
-class F: ...
-class G: ...
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_F() -> F:
-    return F()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_G() -> G:
-    return G()
+def could_raise_returns_bool() -> bool:
+    return True
+
+def could_raise_returns_memoryview() -> memoryview:
+    return memoryview(b"")
+
+def could_raise_returns_float() -> float:
+    return 3.14
+
+def could_raise_returns_range() -> range:
+    return range(42)
+
+def could_raise_returns_slice() -> slice:
+    return slice(None)

 x = 1

 try:
    reveal_type(x)  # revealed: Literal[1]
-    x = could_raise_returns_A()
-    reveal_type(x)  # revealed: A
+    x = could_raise_returns_str()
+    reveal_type(x)  # revealed: str
 except TypeError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_B()
-    reveal_type(x)  # revealed: B
-    x = could_raise_returns_C()
-    reveal_type(x)  # revealed: C
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_bytes()
+    reveal_type(x)  # revealed: bytes
+    x = could_raise_returns_bool()
+    reveal_type(x)  # revealed: bool
 except ValueError:
-    reveal_type(x)  # revealed: Literal[1] | A
-    x = could_raise_returns_D()
-    reveal_type(x)  # revealed: D
-    x = could_raise_returns_E()
-    reveal_type(x)  # revealed: E
+    reveal_type(x)  # revealed: Literal[1] | str
+    x = could_raise_returns_memoryview()
+    reveal_type(x)  # revealed: memoryview
+    x = could_raise_returns_float()
+    reveal_type(x)  # revealed: float
 else:
-    reveal_type(x)  # revealed: A
-    x = could_raise_returns_F()
-    reveal_type(x)  # revealed: F
-    x = could_raise_returns_G()
-    reveal_type(x)  # revealed: G
+    reveal_type(x)  # revealed: str
+    x = could_raise_returns_range()
+    reveal_type(x)  # revealed: range
+    x = could_raise_returns_slice()
+    reveal_type(x)  # revealed: slice
 finally:
-    # TODO: should be `Literal[1] | A | B | C | D | E | F | G`
-    reveal_type(x)  # revealed: C | E | G
+    # TODO: should be `Literal[1] | str | bytes | bool | memoryview | float | range | slice`
+    reveal_type(x)  # revealed: bool | float | slice

-reveal_type(x)  # revealed: C | E | G
+reveal_type(x)  # revealed: bool | float | slice
 ```

 ## Nested `try`/`except` blocks
@@ -445,101 +491,92 @@ a suite containing statements that could possibly raise exceptions, which would
 jumping out of that suite prior to the suite running to completion.

 ```py
-class A: ...
-class B: ...
-class C: ...
-class D: ...
-class E: ...
-class F: ...
-class G: ...
-class H: ...
-class I: ...
-class J: ...
-class K: ...
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_A() -> A:
-    return A()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_B() -> B:
-    return B()
+def could_raise_returns_bool() -> bool:
+    return True

-def could_raise_returns_C() -> C:
-    return C()
+def could_raise_returns_memoryview() -> memoryview:
+    return memoryview(b"")

-def could_raise_returns_D() -> D:
-    return D()
+def could_raise_returns_float() -> float:
+    return 3.14

-def could_raise_returns_E() -> E:
-    return E()
+def could_raise_returns_range() -> range:
+    return range(42)

-def could_raise_returns_F() -> F:
-    return F()
+def could_raise_returns_slice() -> slice:
+    return slice(None)

-def could_raise_returns_G() -> G:
-    return G()
+def could_raise_returns_complex() -> complex:
+    return 3j

-def could_raise_returns_H() -> H:
-    return H()
+def could_raise_returns_bytearray() -> bytearray:
+    return bytearray()

-def could_raise_returns_I() -> I:
-    return I()
+class Foo: ...
+class Bar: ...

-def could_raise_returns_J() -> J:
-    return J()
+def could_raise_returns_Foo() -> Foo:
+    return Foo()

-def could_raise_returns_K() -> K:
-    return K()
+def could_raise_returns_Bar() -> Bar:
+    return Bar()

 x = 1

 try:
    try:
        reveal_type(x)  # revealed: Literal[1]
-        x = could_raise_returns_A()
-        reveal_type(x)  # revealed: A
+        x = could_raise_returns_str()
+        reveal_type(x)  # revealed: str
    except TypeError:
-        reveal_type(x)  # revealed: Literal[1] | A
-        x = could_raise_returns_B()
-        reveal_type(x)  # revealed: B
-        x = could_raise_returns_C()
-        reveal_type(x)  # revealed: C
+        reveal_type(x)  # revealed: Literal[1] | str
+        x = could_raise_returns_bytes()
+        reveal_type(x)  # revealed: bytes
+        x = could_raise_returns_bool()
+        reveal_type(x)  # revealed: bool
    except ValueError:
-        reveal_type(x)  # revealed: Literal[1] | A
-        x = could_raise_returns_D()
-        reveal_type(x)  # revealed: D
-        x = could_raise_returns_E()
-        reveal_type(x)  # revealed: E
+        reveal_type(x)  # revealed: Literal[1] | str
+        x = could_raise_returns_memoryview()
+        reveal_type(x)  # revealed: memoryview
+        x = could_raise_returns_float()
+        reveal_type(x)  # revealed: float
    else:
-        reveal_type(x)  # revealed: A
-        x = could_raise_returns_F()
-        reveal_type(x)  # revealed: F
-        x = could_raise_returns_G()
-        reveal_type(x)  # revealed: G
+        reveal_type(x)  # revealed: str
+        x = could_raise_returns_range()
+        reveal_type(x)  # revealed: range
+        x = could_raise_returns_slice()
+        reveal_type(x)  # revealed: slice
    finally:
-        # TODO: should be `Literal[1] | A | B | C | D | E | F | G`
-        reveal_type(x)  # revealed: C | E | G
+        # TODO: should be `Literal[1] | str | bytes | bool | memoryview | float | range | slice`
+        reveal_type(x)  # revealed: bool | float | slice
        x = 2
        reveal_type(x)  # revealed: Literal[2]
    reveal_type(x)  # revealed: Literal[2]
 except:
-    reveal_type(x)  # revealed: Literal[1, 2] | A | B | C | D | E | F | G
-    x = could_raise_returns_H()
-    reveal_type(x)  # revealed: H
-    x = could_raise_returns_I()
-    reveal_type(x)  # revealed: I
+    reveal_type(x)  # revealed: Literal[1, 2] | str | bytes | bool | memoryview | float | range | slice
+    x = could_raise_returns_complex()
+    reveal_type(x)  # revealed: complex
+    x = could_raise_returns_bytearray()
+    reveal_type(x)  # revealed: bytearray
 else:
    reveal_type(x)  # revealed: Literal[2]
-    x = could_raise_returns_J()
-    reveal_type(x)  # revealed: J
-    x = could_raise_returns_K()
-    reveal_type(x)  # revealed: K
+    x = could_raise_returns_Foo()
+    reveal_type(x)  # revealed: Foo
+    x = could_raise_returns_Bar()
+    reveal_type(x)  # revealed: Bar
 finally:
-    # TODO: should be `Literal[1, 2] | A | B | C | D | E | F | G | H | I | J | K`
-    reveal_type(x)  # revealed: I | K
+    # TODO: should be `Literal[1, 2] | str | bytes | bool | memoryview | float | range | slice | complex | bytearray | Foo | Bar`
+    reveal_type(x)  # revealed: bytearray | Bar

 # Either one `except` branch or the `else`
 # must have been taken and completed to get here:
-reveal_type(x)  # revealed: I | K
+reveal_type(x)  # revealed: bytearray | Bar
 ```

 ## Nested scopes inside `try` blocks
@@ -548,56 +585,50 @@ Shadowing a variable in an inner scope has no effect on type inference of the va
 in the outer scope:

 ```py
-class A: ...
-class B: ...
-class C: ...
-class D: ...
-class E: ...
+def could_raise_returns_str() -> str:
+    return "foo"

-def could_raise_returns_A() -> A:
-    return A()
+def could_raise_returns_bytes() -> bytes:
+    return b"foo"

-def could_raise_returns_B() -> B:
-    return B()
+def could_raise_returns_range() -> range:
+    return range(42)

-def could_raise_returns_C() -> C:
-    return C()
+def could_raise_returns_bytearray() -> bytearray:
+    return bytearray()

-def could_raise_returns_D() -> D:
-    return D()
-
-def could_raise_returns_E() -> E:
-    return E()
+def could_raise_returns_float() -> float:
+    return 3.14

 x = 1

 try:

-    def foo(param=could_raise_returns_A()):
-        x = could_raise_returns_A()
+    def foo(param=could_raise_returns_str()):
+        x = could_raise_returns_str()

        try:
-            reveal_type(x)  # revealed: A
-            x = could_raise_returns_B()
-            reveal_type(x)  # revealed: B
+            reveal_type(x)  # revealed: str
+            x = could_raise_returns_bytes()
+            reveal_type(x)  # revealed: bytes
        except:
-            reveal_type(x)  # revealed: A | B
-            x = could_raise_returns_C()
-            reveal_type(x)  # revealed: C
-            x = could_raise_returns_D()
-            reveal_type(x)  # revealed: D
+            reveal_type(x)  # revealed: str | bytes
+            x = could_raise_returns_bytearray()
+            reveal_type(x)  # revealed: bytearray
+            x = could_raise_returns_float()
+            reveal_type(x)  # revealed: float
        finally:
-            # TODO: should be `A | B | C | D`
-            reveal_type(x)  # revealed: B | D
-        reveal_type(x)  # revealed: B | D
+            # TODO: should be `str | bytes | bytearray | float`
+            reveal_type(x)  # revealed: bytes | float
+        reveal_type(x)  # revealed: bytes | float
    x = foo
    reveal_type(x)  # revealed: Literal[foo]
 except:
    reveal_type(x)  # revealed: Literal[1] | Literal[foo]

    class Bar:
-        x = could_raise_returns_E()
-        reveal_type(x)  # revealed: E
+        x = could_raise_returns_range()
+        reveal_type(x)  # revealed: range

    x = Bar
    reveal_type(x)  # revealed: Literal[Bar]
--- a/crates/red_knot_python_semantic/resources/mdtest/import/conventions.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/import/conventions.md
@@ -1,371 +0,0 @@
-# Import conventions
-
-This document describes the conventions for importing symbols.
-
-Reference:
-
- <https://typing.readthedocs.io/en/latest/spec/distributing.html#import-conventions>
-
-## Builtins scope
-
-When looking up for a name, red knot will fallback to using the builtins scope if the name is not
-found in the global scope. The `builtins.pyi` file, that will be used to resolve any symbol in the
-builtins scope, contains multiple symbols from other modules (e.g., `typing`) but those are not
-re-exported.
-
-```py
-# These symbols are being imported in `builtins.pyi` but shouldn't be considered as being
-# available in the builtins scope.
-
-# error: "Name `Literal` used when not defined"
-reveal_type(Literal)  # revealed: Unknown
-
-# error: "Name `sys` used when not defined"
-reveal_type(sys)  # revealed: Unknown
-```
-
-## Builtins import
-
-Similarly, trying to import the symbols from the builtins module which aren't re-exported should
-also raise an error.
-
-```py
-# error: "Module `builtins` has no member `Literal`"
-# error: "Module `builtins` has no member `sys`"
-from builtins import Literal, sys
-
-reveal_type(Literal)  # revealed: Unknown
-reveal_type(sys)  # revealed: Unknown
-
-# error: "Module `math` has no member `Iterable`"
-from math import Iterable
-
-reveal_type(Iterable)  # revealed: Unknown
-```
-
-## Re-exported symbols in stub files
-
-When a symbol is re-exported, importing it should not raise an error. This tests both `import ...`
-and `from ... import ...` forms.
-
-Note: Submodule imports in `import ...` form doesn't work because it's a syntax error. For example,
-in `import os.path as os.path` the `os.path` is not a valid identifier.
-
-```py
-from b import Any, Literal, foo
-
-reveal_type(Any)  # revealed: typing.Any
-reveal_type(Literal)  # revealed: typing.Literal
-reveal_type(foo)  # revealed: <module 'foo'>
-```
-
-`b.pyi`:
-
-```pyi
-import foo as foo
-from typing import Any as Any, Literal as Literal
-```
-
-`foo.py`:
-
-```py
-```
-
-## Non-exported symbols in stub files
-
-Here, none of the symbols are being re-exported in the stub file.
-
-```py
-# error: 15 [unresolved-import] "Module `b` has no member `foo`"
-# error: 20 [unresolved-import] "Module `b` has no member `Any`"
-# error: 25 [unresolved-import] "Module `b` has no member `Literal`"
-from b import foo, Any, Literal
-
-reveal_type(Any)  # revealed: Unknown
-reveal_type(Literal)  # revealed: Unknown
-reveal_type(foo)  # revealed: Unknown
-```
-
-`b.pyi`:
-
-```pyi
-import foo
-from typing import Any, Literal
-```
-
-`foo.pyi`:
-
-```pyi
-```
-
-## Nested non-exports
-
-Here, a chain of modules all don't re-export an import.
-
-```py
-# error: "Module `a` has no member `Any`"
-from a import Any
-
-reveal_type(Any)  # revealed: Unknown
-```
-
-`a.pyi`:
-
-```pyi
-# error: "Module `b` has no member `Any`"
-from b import Any
-
-reveal_type(Any)  # revealed: Unknown
-```
-
-`b.pyi`:
-
-```pyi
-# error: "Module `c` has no member `Any`"
-from c import Any
-
-reveal_type(Any)  # revealed: Unknown
-```
-
-`c.pyi`:
-
-```pyi
-from typing import Any
-
-reveal_type(Any)  # revealed: typing.Any
-```
-
-## Nested mixed re-export and not
-
-But, if the symbol is being re-exported explicitly in one of the modules in the chain, it should not
-raise an error at that step in the chain.
-
-```py
-# error: "Module `a` has no member `Any`"
-from a import Any
-
-reveal_type(Any)  # revealed: Unknown
-```
-
-`a.pyi`:
-
-```pyi
-from b import Any
-
-reveal_type(Any)  # revealed: Unknown
-```
-
-`b.pyi`:
-
-```pyi
-# error: "Module `c` has no member `Any`"
-from c import Any as Any
-
-reveal_type(Any)  # revealed: Unknown
-```
-
-`c.pyi`:
-
-```pyi
-from typing import Any
-
-reveal_type(Any)  # revealed: typing.Any
-```
-
-## Exported as different name
-
-The re-export convention only works when the aliased name is exactly the same as the original name.
-
-```py
-# error: "Module `a` has no member `Foo`"
-from a import Foo
-
-reveal_type(Foo)  # revealed: Unknown
-```
-
-`a.pyi`:
-
-```pyi
-from b import AnyFoo as Foo
-
-reveal_type(Foo)  # revealed: Literal[AnyFoo]
-```
-
-`b.pyi`:
-
-```pyi
-class AnyFoo: ...
-```
-
-## Exported using `__all__`
-
-Here, the symbol is re-exported using the `__all__` variable.
-
-```py
-# TODO: This should *not* be an error but we don't understand `__all__` yet.
-# error: "Module `a` has no member `Foo`"
-from a import Foo
-```
-
-`a.pyi`:
-
-```pyi
-from b import Foo
-
-__all__ = ['Foo']
-```
-
-`b.pyi`:
-
-```pyi
-class Foo: ...
-```
-
-## Re-exports in `__init__.pyi`
-
-Similarly, for an `__init__.pyi` (stub) file, importing a non-exported name should raise an error
-but the inference would be `Unknown`.
-
-```py
-# error: 15 "Module `a` has no member `Foo`"
-# error: 20 "Module `a` has no member `c`"
-from a import Foo, c, foo
-
-reveal_type(Foo)  # revealed: Unknown
-reveal_type(c)  # revealed: Unknown
-reveal_type(foo)  # revealed: <module 'a.foo'>
-```
-
-`a/__init__.pyi`:
-
-```pyi
-from .b import c
-from .foo import Foo
-```
-
-`a/foo.pyi`:
-
-```pyi
-class Foo: ...
-```
-
-`a/b/__init__.pyi`:
-
-```pyi
-```
-
-`a/b/c.pyi`:
-
-```pyi
-```
-
-## Conditional re-export in stub file
-
-The following scenarios are when a re-export happens conditionally in a stub file.
-
-### Global import
-
-```py
-# error: "Member `Foo` of module `a` is possibly unbound"
-from a import Foo
-
-reveal_type(Foo)  # revealed: str
-```
-
-`a.pyi`:
-
-```pyi
-from b import Foo
-
-def coinflip() -> bool: ...
-
-if coinflip():
-    Foo: str = ...
-
-reveal_type(Foo)  # revealed: Literal[Foo] | str
-```
-
-`b.pyi`:
-
-```pyi
-class Foo: ...
-```
-
-### Both branch is an import
-
-Here, both the branches of the condition are import statements where one of them re-exports while
-the other does not.
-
-```py
-# error: "Member `Foo` of module `a` is possibly unbound"
-from a import Foo
-
-reveal_type(Foo)  # revealed: Literal[Foo]
-```
-
-`a.pyi`:
-
-```pyi
-def coinflip() -> bool: ...
-
-if coinflip():
-    from b import Foo
-else:
-    from b import Foo as Foo
-
-reveal_type(Foo)  # revealed: Literal[Foo]
-```
-
-`b.pyi`:
-
-```pyi
-class Foo: ...
-```
-
-### Re-export in one branch
-
-```py
-# error: "Member `Foo` of module `a` is possibly unbound"
-from a import Foo
-
-reveal_type(Foo)  # revealed: Literal[Foo]
-```
-
-`a.pyi`:
-
-```pyi
-def coinflip() -> bool: ...
-
-if coinflip():
-    from b import Foo as Foo
-```
-
-`b.pyi`:
-
-```pyi
-class Foo: ...
-```
-
-### Non-export in one branch
-
-```py
-# error: "Module `a` has no member `Foo`"
-from a import Foo
-
-reveal_type(Foo)  # revealed: Unknown
-```
-
-`a.pyi`:
-
-```pyi
-def coinflip() -> bool: ...
-
-if coinflip():
-    from b import Foo
-```
-
-`b.pyi`:
-
-```pyi
-class Foo: ...
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/import/relative.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/import/relative.md
@@ -218,21 +218,3 @@ import package
 # error: [unresolved-attribute] "Type `<module 'package'>` has no attribute `foo`"
 reveal_type(package.foo.X)  # revealed: Unknown
 ```
-
-## Relative imports at the top of a search path
-
-Relative imports at the top of a search path result in a runtime error:
-`ImportError: attempted relative import with no known parent package`. That's why Red Knot should
-disallow them.
-
-`parser.py`:
-
-```py
-X: int = 42
-```
-
-`__main__.py`:
-
-```py
-from .parser import X  # error: [unresolved-import]
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/loops/for.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/loops/for.md
@@ -183,32 +183,25 @@ for x in Test():
 ## Union type as iterable and union type as iterator

 ```py
-class Result1A: ...
-class Result1B: ...
-class Result2A: ...
-class Result2B: ...
-class Result3: ...
-class Result4: ...
-
-class TestIter1:
-    def __next__(self) -> Result1A | Result1B:
-        return Result1B()
+class TestIter:
+    def __next__(self) -> int | Exception:
+        return 42

 class TestIter2:
-    def __next__(self) -> Result2A | Result2B:
-        return Result2B()
+    def __next__(self) -> str | tuple[int, int]:
+        return "42"

 class TestIter3:
-    def __next__(self) -> Result3:
-        return Result3()
+    def __next__(self) -> bytes:
+        return b"42"

 class TestIter4:
-    def __next__(self) -> Result4:
-        return Result4()
+    def __next__(self) -> memoryview:
+        return memoryview(b"42")

 class Test:
-    def __iter__(self) -> TestIter1 | TestIter2:
-        return TestIter1()
+    def __iter__(self) -> TestIter | TestIter2:
+        return TestIter()

 class Test2:
    def __iter__(self) -> TestIter3 | TestIter4:
@@ -216,7 +209,7 @@ class Test2:

 def _(flag: bool):
    for x in Test() if flag else Test2():
-        reveal_type(x)  # revealed: Result1A | Result1B | Result2A | Result2B | Result3 | Result4
+        reveal_type(x)  # revealed: int | Exception | str | tuple[int, int] | bytes | memoryview
 ```

 ## Union type as iterable where one union element has no `__iter__` method
@@ -252,10 +245,9 @@ class Test2:
        return 42

 def _(flag: bool):
-    # TODO: Improve error message to state which union variant isn't iterable (https://github.com/astral-sh/ruff/issues/13989)
    # error: "Object of type `Test | Test2` is not iterable"
    for x in Test() if flag else Test2():
-        reveal_type(x)  # revealed: int
+        reveal_type(x)  # revealed: Unknown
 ```

 ## Union type as iterator where one union element has no `__next__` method
@@ -271,5 +263,5 @@ class Test:

 # error: [not-iterable] "Object of type `Test` is not iterable"
 for x in Test():
-    reveal_type(x)  # revealed: int
+    reveal_type(x)  # revealed: Unknown
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/is.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/is.md
@@ -64,39 +64,3 @@ def _(flag1: bool, flag2: bool):
    else:
        reveal_type(x)  # revealed: Literal[1]
 ```
-
-## `is` for `EllipsisType` (Python 3.10+)
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-from types import EllipsisType
-
-def _(x: int | EllipsisType):
-    if x is ...:
-        reveal_type(x)  # revealed: EllipsisType
-    else:
-        reveal_type(x)  # revealed: int
-```
-
-## `is` for `EllipsisType` (Python 3.9 and below)
-
-```toml
-[environment]
-python-version = "3.9"
-```
-
-```py
-def _(flag: bool):
-    x = ... if flag else 42
-
-    reveal_type(x)  # revealed: ellipsis | Literal[42]
-
-    if x is ...:
-        reveal_type(x)  # revealed: ellipsis
-    else:
-        reveal_type(x)  # revealed: Literal[42]
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/protocols.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/protocols.md
@@ -1,15 +0,0 @@
-# Protocols
-
-We do not support protocols yet, but to avoid false positives, we *partially* support some known
-protocols.
-
-## `typing.SupportsIndex`
-
-```py
-from typing import SupportsIndex, Literal
-
-def _(some_int: int, some_literal_int: Literal[1], some_indexable: SupportsIndex):
-    a: SupportsIndex = some_int
-    b: SupportsIndex = some_literal_int
-    c: SupportsIndex = some_indexable
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/scopes/eager.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/scopes/eager.md
@@ -1,382 +0,0 @@
-# Eager scopes
-
-Some scopes are executed eagerly: references to variables defined in enclosing scopes are resolved
-_immediately_. This is in constrast to (for instance) function scopes, where those references are
-resolved when the function is called.
-
-## Function definitions
-
-Function definitions are evaluated lazily.
-
-```py
-x = 1
-
-def f():
-    reveal_type(x)  # revealed: Unknown | Literal[2]
-
-x = 2
-```
-
-## Class definitions
-
-Class definitions are evaluated eagerly.
-
-```py
-def _():
-    x = 1
-
-    class A:
-        reveal_type(x)  # revealed: Literal[1]
-
-        y = x
-
-    x = 2
-
-    reveal_type(A.y)  # revealed: Unknown | Literal[1]
-```
-
-## List comprehensions
-
-List comprehensions are evaluated eagerly.
-
-```py
-def _():
-    x = 1
-
-    # revealed: Literal[1]
-    [reveal_type(x) for a in range(1)]
-
-    x = 2
-```
-
-## Set comprehensions
-
-Set comprehensions are evaluated eagerly.
-
-```py
-def _():
-    x = 1
-
-    # revealed: Literal[1]
-    {reveal_type(x) for a in range(1)}
-
-    x = 2
-```
-
-## Dict comprehensions
-
-Dict comprehensions are evaluated eagerly.
-
-```py
-def _():
-    x = 1
-
-    # revealed: Literal[1]
-    {a: reveal_type(x) for a in range(1)}
-
-    x = 2
-```
-
-## Generator expressions
-
-Generator expressions don't necessarily run eagerly, but in practice usually they do, so assuming
-they do is the better default.
-
-```py
-def _():
-    x = 1
-
-    # revealed: Literal[1]
-    list(reveal_type(x) for a in range(1))
-
-    x = 2
-```
-
-But that does lead to incorrect results when the generator expression isn't run immediately:
-
-```py
-def evaluated_later():
-    x = 1
-
-    # revealed: Literal[1]
-    y = (reveal_type(x) for a in range(1))
-
-    x = 2
-
-    # The generator isn't evaluated until here, so at runtime, `x` will evaluate to 2, contradicting
-    # our inferred type.
-    print(next(y))
-```
-
-Though note that “the iterable expression in the leftmost `for` clause is immediately evaluated”
-\[[spec][generators]\]:
-
-```py
-def iterable_evaluated_eagerly():
-    x = 1
-
-    # revealed: Literal[1]
-    y = (a for a in [reveal_type(x)])
-
-    x = 2
-
-    # Even though the generator isn't evaluated until here, the first iterable was evaluated
-    # immediately, so our inferred type is correct.
-    print(next(y))
-```
-
-## Top-level eager scopes
-
-All of the above examples behave identically when the eager scopes are directly nested in the global
-scope.
-
-### Class definitions
-
-```py
-x = 1
-
-class A:
-    reveal_type(x)  # revealed: Literal[1]
-
-    y = x
-
-x = 2
-
-reveal_type(A.y)  # revealed: Unknown | Literal[1]
-```
-
-### List comprehensions
-
-```py
-x = 1
-
-# revealed: Literal[1]
-[reveal_type(x) for a in range(1)]
-
-x = 2
-```
-
-### Set comprehensions
-
-```py
-x = 1
-
-# revealed: Literal[1]
-{reveal_type(x) for a in range(1)}
-
-x = 2
-```
-
-### Dict comprehensions
-
-```py
-x = 1
-
-# revealed: Literal[1]
-{a: reveal_type(x) for a in range(1)}
-
-x = 2
-```
-
-### Generator expressions
-
-```py
-x = 1
-
-# revealed: Literal[1]
-list(reveal_type(x) for a in range(1))
-
-x = 2
-```
-
-`evaluated_later.py`:
-
-```py
-x = 1
-
-# revealed: Literal[1]
-y = (reveal_type(x) for a in range(1))
-
-x = 2
-
-# The generator isn't evaluated until here, so at runtime, `x` will evaluate to 2, contradicting
-# our inferred type.
-print(next(y))
-```
-
-`iterable_evaluated_eagerly.py`:
-
-```py
-x = 1
-
-# revealed: Literal[1]
-y = (a for a in [reveal_type(x)])
-
-x = 2
-
-# Even though the generator isn't evaluated until here, the first iterable was evaluated
-# immediately, so our inferred type is correct.
-print(next(y))
-```
-
-## Lazy scopes are "sticky"
-
-As we look through each enclosing scope when resolving a reference, lookups become lazy as soon as
-we encounter any lazy scope, even if there are other eager scopes that enclose it.
-
-### Eager scope within eager scope
-
-If we don't encounter a lazy scope, lookup remains eager. The resolved binding is not necessarily in
-the immediately enclosing scope. Here, the list comprehension and class definition are both eager
-scopes, and we immediately resolve the use of `x` to (only) the `x = 1` binding.
-
-```py
-def _():
-    x = 1
-
-    class A:
-        # revealed: Literal[1]
-        [reveal_type(x) for a in range(1)]
-
-    x = 2
-```
-
-### Class definition bindings are not visible in nested scopes
-
-Class definitions are eager scopes, but any bindings in them are explicitly not visible to any
-nested scopes. (Those nested scopes are typically (lazy) function definitions, but the rule also
-applies to nested eager scopes like comprehensions and other class definitions.)
-
-```py
-def _():
-    x = 1
-
-    class A:
-        x = 4
-
-        # revealed: Literal[1]
-        [reveal_type(x) for a in range(1)]
-
-        class B:
-            # revealed: Literal[1]
-            [reveal_type(x) for a in range(1)]
-
-    x = 2
-```
-
-### Eager scope within a lazy scope
-
-The list comprehension is an eager scope, and it is enclosed within a function definition, which is
-a lazy scope. Because we pass through this lazy scope before encountering any bindings or
-definitions, the lookup is lazy.
-
-```py
-def _():
-    x = 1
-
-    def f():
-        # revealed: Unknown | Literal[2]
-        [reveal_type(x) for a in range(1)]
-    x = 2
-```
-
-### Lazy scope within an eager scope
-
-The function definition is a lazy scope, and it is enclosed within a class definition, which is an
-eager scope. Even though we pass through an eager scope before encountering any bindings or
-definitions, the lookup remains lazy.
-
-```py
-def _():
-    x = 1
-
-    class A:
-        def f():
-            # revealed: Unknown | Literal[2]
-            reveal_type(x)
-
-    x = 2
-```
-
-### Lazy scope within a lazy scope
-
-No matter how many lazy scopes we pass through before encountering a binding or definition, the
-lookup remains lazy.
-
-```py
-def _():
-    x = 1
-
-    def f():
-        def g():
-            # revealed: Unknown | Literal[2]
-            reveal_type(x)
-    x = 2
-```
-
-### Eager scope within a lazy scope within another eager scope
-
-We have a list comprehension (eager scope), enclosed within a function definition (lazy scope),
-enclosed within a class definition (eager scope), all of which we must pass through before
-encountering any binding of `x`. Even though the last scope we pass through is eager, the lookup is
-lazy, since we encountered a lazy scope on the way.
-
-```py
-def _():
-    x = 1
-
-    class A:
-        def f():
-            # revealed: Unknown | Literal[2]
-            [reveal_type(x) for a in range(1)]
-
-    x = 2
-```
-
-## Annotations
-
-Type annotations are sometimes deferred. When they are, the types that are referenced in an
-annotation are looked up lazily, even if they occur in an eager scope.
-
-### Eager annotations in a Python file
-
-```py
-x = int
-
-class C:
-    var: x
-
-reveal_type(C.var)  # revealed: int
-
-x = str
-```
-
-### Deferred annotations in a Python file
-
-```py
-from __future__ import annotations
-
-x = int
-
-class C:
-    var: x
-
-reveal_type(C.var)  # revealed: Unknown | str
-
-x = str
-```
-
-### Deferred annotations in a stub file
-
-```pyi
-x = int
-
-class C:
-    var: x
-
-reveal_type(C.var)  # revealed: Unknown | str
-
-x = str
-```
-
-[generators]: https://docs.python.org/3/reference/expressions.html#generator-expressions
--- a/crates/red_knot_python_semantic/resources/mdtest/scopes/moduletype_attrs.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/scopes/moduletype_attrs.md
@@ -9,7 +9,7 @@ is unbound.
 ```py
 reveal_type(__name__)  # revealed: str
 reveal_type(__file__)  # revealed: str | None
-reveal_type(__loader__)  # revealed: @Todo(instance attribute on class with dynamic base) | None
+reveal_type(__loader__)  # revealed: LoaderProtocol | None
 reveal_type(__package__)  # revealed: str | None
 reveal_type(__doc__)  # revealed: str | None

@@ -29,6 +29,8 @@ def foo():
 However, three attributes on `types.ModuleType` are not present as implicit module globals; these
 are excluded:

+`unbound_dunders.py`:
+
 ```py
 # error: [unresolved-reference]
 # revealed: Unknown
@@ -54,10 +56,10 @@ inside the module:
 import typing

 reveal_type(typing.__name__)  # revealed: str
-reveal_type(typing.__init__)  # revealed: <bound method `__init__` of `ModuleType`>
+reveal_type(typing.__init__)  # revealed: @Todo(bound method)

 # These come from `builtins.object`, not `types.ModuleType`:
-reveal_type(typing.__eq__)  # revealed: <bound method `__eq__` of `ModuleType`>
+reveal_type(typing.__eq__)  # revealed: @Todo(bound method)

 reveal_type(typing.__class__)  # revealed: Literal[ModuleType]

@@ -70,7 +72,11 @@ Typeshed includes a fake `__getattr__` method in the stub for `types.ModuleType`
 dynamic imports; but we ignore that for module-literal types where we know exactly which module
 we're dealing with:

+`__getattr__.py`:
+
 ```py
+import typing
+
 # error: [unresolved-attribute]
 reveal_type(typing.__getattr__)  # revealed: Unknown
 ```
--- a/crates/red_knot_python_semantic/resources/mdtest/shadowing/function.md
+++ b/crates/red_knot_python_semantic/resources/mdtest/shadowing/function.md
@@ -5,6 +5,8 @@
 Parameter `x` of type `str` is shadowed and reassigned with a new `int` value inside the function.
 No diagnostics should be generated.

+`a.py`:
+
 ```py
 def f(x: str):
    x: int = int(x)
@@ -12,6 +14,8 @@ def f(x: str):

 ## Implicit error

+`a.py`:
+
 ```py
 def f(): ...

@@ -20,6 +24,8 @@ f = 1  # error: "Implicit shadowing of function `f`; annotate to make it explici

 ## Explicit shadowing

+`a.py`:
+
 ```py
 def f(): ...

--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_module_import.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_module_import.snap
@@ -9,7 +9,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/import/basic.md

 # Python source files

-## mdtest_snippet.py
+## mdtest_snippet__1.py

 ```
 1 | import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve import `zqzqzqzqzqzqzq`"
@@ -19,7 +19,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/import/basic.md

 ```
 error: lint:unresolved-import
- --> /src/mdtest_snippet.py:1:8
+ --> /src/mdtest_snippet__1.py:1:8
  |
 1 | import zqzqzqzqzqzqzq  # error: [unresolved-import] "Cannot resolve import `zqzqzqzqzqzqzq`"
  |        ^^^^^^^^^^^^^^ Cannot resolve import `zqzqzqzqzqzqzq`
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_submodule_imports.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/basic.md_-_Structures_-_Unresolvable_submodule_imports.snap
@@ -9,7 +9,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/import/basic.md

 # Python source files

-## mdtest_snippet.py
+## mdtest_snippet__1.py

 ```
 1 | # Topmost component resolvable, submodule not resolvable:
@@ -28,7 +28,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/import/basic.md

 ```
 error: lint:unresolved-import
- --> /src/mdtest_snippet.py:2:8
+ --> /src/mdtest_snippet__1.py:2:8
  |
 1 | # Topmost component resolvable, submodule not resolvable:
 2 | import a.foo  # error: [unresolved-import] "Cannot resolve import `a.foo`"
@@ -41,7 +41,7 @@ error: lint:unresolved-import

 ```
 error: lint:unresolved-import
- --> /src/mdtest_snippet.py:5:8
+ --> /src/mdtest_snippet__1.py:5:8
  |
 4 | # Topmost component unresolvable:
 5 | import b.foo  # error: [unresolved-import] "Cannot resolve import `b.foo`"
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Basic.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Basic.snap
@@ -1,39 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Basic
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(x: int) -> int:
-2 |     return x * x
-3 | 
-4 | foo("hello")  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:4:5
-  |
-2 |     return x * x
-3 |
-4 | foo("hello")  # error: [invalid-argument-type]
-  |     ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter 1 (`x`) of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:9
-  |
-1 | def foo(x: int) -> int:
-  |         ------ info: parameter declared in function definition here
-2 |     return x * x
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Different_files.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Different_files.snap
@@ -1,45 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Different files
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## package.py
-
-```
-1 | def foo(x: int) -> int:
-2 |     return x * x
-```
-
-## mdtest_snippet.py
-
-```
-1 | import package
-2 | 
-3 | package.foo("hello")  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:3:13
-  |
-1 | import package
-2 |
-3 | package.foo("hello")  # error: [invalid-argument-type]
-  |             ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter 1 (`x`) of function `foo`; expected type `int`
-  |
- ::: /src/package.py:1:9
-  |
-1 | def foo(x: int) -> int:
-  |         ------ info: parameter declared in function definition here
-2 |     return x * x
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Different_source_order.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Different_source_order.snap
@@ -1,43 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Different source order
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def bar():
-2 |     foo("hello")  # error: [invalid-argument-type]
-3 | 
-4 | def foo(x: int) -> int:
-5 |     return x * x
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:2:9
-  |
-1 | def bar():
-2 |     foo("hello")  # error: [invalid-argument-type]
-  |         ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter 1 (`x`) of function `foo`; expected type `int`
-3 |
-4 | def foo(x: int) -> int:
-  |
- ::: /src/mdtest_snippet.py:4:9
-  |
-2 |     foo("hello")  # error: [invalid-argument-type]
-3 |
-4 | def foo(x: int) -> int:
-  |         ------ info: parameter declared in function definition here
-5 |     return x * x
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Many_parameters.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Many_parameters.snap
@@ -1,39 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Many parameters
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(x: int, y: int, z: int) -> int:
-2 |     return x * y * z
-3 | 
-4 | foo(1, "hello", 3)  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:4:8
-  |
-2 |     return x * y * z
-3 |
-4 | foo(1, "hello", 3)  # error: [invalid-argument-type]
-  |        ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter 2 (`y`) of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:17
-  |
-1 | def foo(x: int, y: int, z: int) -> int:
-  |                 ------ info: parameter declared in function definition here
-2 |     return x * y * z
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Many_parameters_across_multiple_lines.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Many_parameters_across_multiple_lines.snap
@@ -1,46 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Many parameters across multiple lines
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(
-2 |     x: int,
-3 |     y: int,
-4 |     z: int,
-5 | ) -> int:
-6 |     return x * y * z
-7 | 
-8 | foo(1, "hello", 3)  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:8:8
-  |
-6 |     return x * y * z
-7 |
-8 | foo(1, "hello", 3)  # error: [invalid-argument-type]
-  |        ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter 2 (`y`) of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:3:5
-  |
-1 | def foo(
-2 |     x: int,
-3 |     y: int,
-  |     ------ info: parameter declared in function definition here
-4 |     z: int,
-5 | ) -> int:
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Many_parameters_with_multiple_invalid_arguments.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Many_parameters_with_multiple_invalid_arguments.snap
@@ -1,78 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Many parameters with multiple invalid arguments
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(x: int, y: int, z: int) -> int:
-2 |     return x * y * z
-3 | 
-4 | # error: [invalid-argument-type]
-5 | # error: [invalid-argument-type]
-6 | # error: [invalid-argument-type]
-7 | foo("a", "b", "c")
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:7:5
-  |
-5 | # error: [invalid-argument-type]
-6 | # error: [invalid-argument-type]
-7 | foo("a", "b", "c")
-  |     ^^^ Object of type `Literal["a"]` cannot be assigned to parameter 1 (`x`) of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:9
-  |
-1 | def foo(x: int, y: int, z: int) -> int:
-  |         ------ info: parameter declared in function definition here
-2 |     return x * y * z
-  |
-
-```
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:7:10
-  |
-5 | # error: [invalid-argument-type]
-6 | # error: [invalid-argument-type]
-7 | foo("a", "b", "c")
-  |          ^^^ Object of type `Literal["b"]` cannot be assigned to parameter 2 (`y`) of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:17
-  |
-1 | def foo(x: int, y: int, z: int) -> int:
-  |                 ------ info: parameter declared in function definition here
-2 |     return x * y * z
-  |
-
-```
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:7:15
-  |
-5 | # error: [invalid-argument-type]
-6 | # error: [invalid-argument-type]
-7 | foo("a", "b", "c")
-  |               ^^^ Object of type `Literal["c"]` cannot be assigned to parameter 3 (`z`) of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:25
-  |
-1 | def foo(x: int, y: int, z: int) -> int:
-  |                         ------ info: parameter declared in function definition here
-2 |     return x * y * z
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Test_calling_a_function_whose_type_is_vendored_from_`typeshed`.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Test_calling_a_function_whose_type_is_vendored_from_`typeshed`.snap
@@ -1,41 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Test calling a function whose type is vendored from `typeshed`
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | import json
-2 | 
-3 | json.loads(5)  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
-  --> /src/mdtest_snippet.py:3:12
-   |
- 1 | import json
- 2 |
- 3 | json.loads(5)  # error: [invalid-argument-type]
-   |            ^ Object of type `Literal[5]` cannot be assigned to parameter 1 (`s`) of function `loads`; expected type `str | bytes | bytearray`
-   |
-  ::: vendored://stdlib/json/__init__.pyi:40:5
-   |
-38 | ) -> None: ...
-39 | def loads(
-40 |     s: str | bytes | bytearray,
-   |     -------------------------- info: parameter declared in function definition here
-41 |     *,
-42 |     cls: type[JSONDecoder] | None = None,
-   |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Keyword_only_arguments.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Keyword_only_arguments.snap
@@ -1,39 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Tests for a variety of argument types - Keyword only arguments
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(x: int, y: int, *, z: int = 0) -> int:
-2 |     return x * y * z
-3 | 
-4 | foo(1, 2, z="hello")  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:4:11
-  |
-2 |     return x * y * z
-3 |
-4 | foo(1, 2, z="hello")  # error: [invalid-argument-type]
-  |           ^^^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter `z` of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:28
-  |
-1 | def foo(x: int, y: int, *, z: int = 0) -> int:
-  |                            ---------- info: parameter declared in function definition here
-2 |     return x * y * z
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Mix_of_arguments.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Mix_of_arguments.snap
@@ -1,39 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Tests for a variety of argument types - Mix of arguments
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(x: int, /, y: int, *, z: int = 0) -> int:
-2 |     return x * y * z
-3 | 
-4 | foo(1, 2, z="hello")  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:4:11
-  |
-2 |     return x * y * z
-3 |
-4 | foo(1, 2, z="hello")  # error: [invalid-argument-type]
-  |           ^^^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter `z` of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:31
-  |
-1 | def foo(x: int, /, y: int, *, z: int = 0) -> int:
-  |                               ---------- info: parameter declared in function definition here
-2 |     return x * y * z
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_One_keyword_argument.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_One_keyword_argument.snap
@@ -1,39 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Tests for a variety of argument types - One keyword argument
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(x: int, y: int, z: int = 0) -> int:
-2 |     return x * y * z
-3 | 
-4 | foo(1, 2, "hello")  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:4:11
-  |
-2 |     return x * y * z
-3 |
-4 | foo(1, 2, "hello")  # error: [invalid-argument-type]
-  |           ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter 3 (`z`) of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:25
-  |
-1 | def foo(x: int, y: int, z: int = 0) -> int:
-  |                         ---------- info: parameter declared in function definition here
-2 |     return x * y * z
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Only_positional.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Only_positional.snap
@@ -1,39 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Tests for a variety of argument types - Only positional
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(x: int, y: int, z: int, /) -> int:
-2 |     return x * y * z
-3 | 
-4 | foo(1, "hello", 3)  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:4:8
-  |
-2 |     return x * y * z
-3 |
-4 | foo(1, "hello", 3)  # error: [invalid-argument-type]
-  |        ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter 2 (`y`) of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:17
-  |
-1 | def foo(x: int, y: int, z: int, /) -> int:
-  |                 ------ info: parameter declared in function definition here
-2 |     return x * y * z
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Synthetic_arguments.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Synthetic_arguments.snap
@@ -1,41 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Tests for a variety of argument types - Synthetic arguments
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | class C:
-2 |     def __call__(self, x: int) -> int:
-3 |         return 1
-4 | 
-5 | c = C()
-6 | c("wrong")  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:6:3
-  |
-5 | c = C()
-6 | c("wrong")  # error: [invalid-argument-type]
-  |   ^^^^^^^ Object of type `Literal["wrong"]` cannot be assigned to parameter 2 (`x`) of function `__call__`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:2:24
-  |
-1 | class C:
-2 |     def __call__(self, x: int) -> int:
-  |                        ------ info: parameter declared in function definition here
-3 |         return 1
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Variadic_arguments.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Variadic_arguments.snap
@@ -1,39 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Tests for a variety of argument types - Variadic arguments
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(*numbers: int) -> int:
-2 |     return len(numbers)
-3 | 
-4 | foo(1, 2, 3, "hello", 5)  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:4:14
-  |
-2 |     return len(numbers)
-3 |
-4 | foo(1, 2, 3, "hello", 5)  # error: [invalid-argument-type]
-  |              ^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter `*numbers` of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:9
-  |
-1 | def foo(*numbers: int) -> int:
-  |         ------------- info: parameter declared in function definition here
-2 |     return len(numbers)
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Variadic_keyword_arguments.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/invalid_argument_type.md_-_Invalid_argument_type_diagnostics_-_Tests_for_a_variety_of_argument_types_-_Variadic_keyword_arguments.snap
@@ -1,39 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: invalid_argument_type.md - Invalid argument type diagnostics - Tests for a variety of argument types - Variadic keyword arguments
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/invalid_argument_type.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | def foo(**numbers: int) -> int:
-2 |     return len(numbers)
-3 | 
-4 | foo(a=1, b=2, c=3, d="hello", e=5)  # error: [invalid-argument-type]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-argument-type
- --> /src/mdtest_snippet.py:4:20
-  |
-2 |     return len(numbers)
-3 |
-4 | foo(a=1, b=2, c=3, d="hello", e=5)  # error: [invalid-argument-type]
-  |                    ^^^^^^^^^ Object of type `Literal["hello"]` cannot be assigned to parameter `**numbers` of function `foo`; expected type `int`
-  |
- ::: /src/mdtest_snippet.py:1:9
-  |
-1 | def foo(**numbers: int) -> int:
-  |         -------------- info: parameter declared in function definition here
-2 |     return len(numbers)
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/unpacking.md_-_Unpacking_-_Right_hand_side_not_iterable.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/unpacking.md_-_Unpacking_-_Right_hand_side_not_iterable.snap
@@ -1,28 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: unpacking.md - Unpacking - Right hand side not iterable
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unpacking.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | a, b = 1  # error: [not-iterable]
-```
-
-# Diagnostics
-
-```
-error: lint:not-iterable
- --> /src/mdtest_snippet.py:1:8
-  |
-1 | a, b = 1  # error: [not-iterable]
-  |        ^ Object of type `Literal[1]` is not iterable
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/unpacking.md_-_Unpacking_-_Too_few_values_to_unpack.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/unpacking.md_-_Unpacking_-_Too_few_values_to_unpack.snap
@@ -1,28 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: unpacking.md - Unpacking - Too few values to unpack
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unpacking.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | a, b = (1,)  # error: [invalid-assignment]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-assignment
- --> /src/mdtest_snippet.py:1:1
-  |
-1 | a, b = (1,)  # error: [invalid-assignment]
-  | ^^^^ Not enough values to unpack (expected 2, got 1)
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/unpacking.md_-_Unpacking_-_Too_many_values_to_unpack.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/unpacking.md_-_Unpacking_-_Too_many_values_to_unpack.snap
@@ -1,28 +0,0 @@
---
-source: crates/red_knot_test/src/lib.rs
-expression: snapshot
---
---
-mdtest name: unpacking.md - Unpacking - Too many values to unpack
-mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unpacking.md
---
-
-# Python source files
-
-## mdtest_snippet.py
-
-```
-1 | a, b = (1, 2, 3)  # error: [invalid-assignment]
-```
-
-# Diagnostics
-
-```
-error: lint:invalid-assignment
- --> /src/mdtest_snippet.py:1:1
-  |
-1 | a, b = (1, 2, 3)  # error: [invalid-assignment]
-  | ^^^^ Too many values to unpack (expected 2, got 3)
-  |
-
-```
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_An_unresolvable_import_that_does_not_use_`from`.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_An_unresolvable_import_that_does_not_use_`from`.snap
@@ -9,7 +9,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unreso

 # Python source files

-## mdtest_snippet.py
+## mdtest_snippet__1.py

 ```
 1 | import does_not_exist  # error: [unresolved-import]
@@ -21,7 +21,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unreso

 ```
 error: lint:unresolved-import
- --> /src/mdtest_snippet.py:1:8
+ --> /src/mdtest_snippet__1.py:1:8
  |
 1 | import does_not_exist  # error: [unresolved-import]
  |        ^^^^^^^^^^^^^^ Cannot resolve import `does_not_exist`
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_a_resolvable_module_but_unresolvable_item.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_a_resolvable_module_but_unresolvable_item.snap
@@ -16,7 +16,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unreso
 2 | does_exist2 = 2
 ```

-## mdtest_snippet.py
+## mdtest_snippet__1.py

 ```
 1 | from a import does_exist1, does_not_exist, does_exist2  # error: [unresolved-import]
@@ -26,7 +26,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unreso

 ```
 error: lint:unresolved-import
- --> /src/mdtest_snippet.py:1:28
+ --> /src/mdtest_snippet__1.py:1:28
  |
 1 | from a import does_exist1, does_not_exist, does_exist2  # error: [unresolved-import]
  |                            ^^^^^^^^^^^^^^ Module `a` has no member `does_not_exist`
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_an_unknown_current_module.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_an_unknown_current_module.snap
@@ -9,7 +9,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unreso

 # Python source files

-## mdtest_snippet.py
+## mdtest_snippet__1.py

 ```
 1 | from .does_not_exist import add  # error: [unresolved-import]
@@ -21,7 +21,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unreso

 ```
 error: lint:unresolved-import
- --> /src/mdtest_snippet.py:1:7
+ --> /src/mdtest_snippet__1.py:1:7
  |
 1 | from .does_not_exist import add  # error: [unresolved-import]
  |       ^^^^^^^^^^^^^^ Cannot resolve import `.does_not_exist`
--- a/crates/red_knot_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_an_unknown_nested_module.snap
+++ b/crates/red_knot_python_semantic/resources/mdtest/snapshots/unresolved_import.md_-_Unresolved_import_diagnostics_-_Using_`from`_with_an_unknown_nested_module.snap
@@ -9,7 +9,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unreso

 # Python source files

-## mdtest_snippet.py
+## mdtest_snippet__1.py

 ```
 1 | from .does_not_exist.foo.bar import add  # error: [unresolved-import]
@@ -21,7 +21,7 @@ mdtest path: crates/red_knot_python_semantic/resources/mdtest/diagnostics/unreso

 ```
 error: lint:unresolved-import
- --> /src/mdtest_snippet.py:1:7
+ --> /src/mdtest_snippet__1.py:1:7
  |
 1 | from .does_not_exist.foo.bar import add  # error: [unresolved-import]
  |       ^^^^^^^^^^^^^^^^^^^^^^ Cannot resolve import `.does_not_exist.foo.bar`
--- a/Show More
+++ b/Show More