Fix is_airflow_* function, add docs

* `airflow.providers_manager.ProvidersManager.dataset_factories` → `airflow.providers_manager.ProvidersManager.asset_factories`
* `airflow.providers_manager.ProvidersManager.dataset_uri_handlers` → `airflow.providers_manager.ProvidersManager.asset_uri_handlers`
* `airflow.providers_manager.ProvidersManager.dataset_to_openlineage_converters` → `airflow.providers_manager.ProvidersManager.asset_to_openlineage_converters`
* `airflow.lineage.hook.DatasetLineageInfo.dataset`  → `airflow.lineage.hook.AssetLineageInfo.asset`

.github/renovate.json5

@@ -45,7 +45,7 @@
       groupName: "Artifact GitHub Actions dependencies",
       matchManagers: ["github-actions"],
       matchDatasources: ["gitea-tags", "github-tags"],
-      matchPackageNames: ["actions/.*-artifact"],
+      matchPackagePatterns: ["actions/.*-artifact"],
       description: "Weekly update of artifact-related GitHub Actions dependencies",
     },
     {
@@ -61,7 +61,7 @@
     {
       // Disable updates of `zip-rs`; intentionally pinned for now due to ownership change
       // See: https://github.com/astral-sh/uv/issues/3642
-      matchPackageNames: ["zip"],
+      matchPackagePatterns: ["zip"],
       matchManagers: ["cargo"],
       enabled: false,
     },
@@ -70,7 +70,7 @@
       // with `mkdocs-material-insider`.
       // See: https://squidfunk.github.io/mkdocs-material/insiders/upgrade/
       matchManagers: ["pip_requirements"],
-      matchPackageNames: ["mkdocs-material"],
+      matchPackagePatterns: ["mkdocs-material"],
       enabled: false,
     },
     {
@@ -87,13 +87,13 @@
     {
       groupName: "Monaco",
       matchManagers: ["npm"],
-      matchPackageNames: ["monaco"],
+      matchPackagePatterns: ["monaco"],
       description: "Weekly update of the Monaco editor",
     },
     {
       groupName: "strum",
       matchManagers: ["cargo"],
-      matchPackageNames: ["strum"],
+      matchPackagePatterns: ["strum"],
       description: "Weekly update of strum dependencies",
     },
     {

.github/workflows/build-docker.yml

@@ -48,13 +48,11 @@ jobs:
 
       - name: Check tag consistency
         if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
-        env:
-          TAG: ${{ inputs.plan != '' && fromJson(inputs.plan).announcement_tag || 'dry-run' }}
         run: |
           version=$(grep "version = " pyproject.toml | sed -e 's/version = "\(.*\)"/\1/g')
-          if [ "${TAG}" != "${version}" ]; then
+          if [ "${{ fromJson(inputs.plan).announcement_tag }}" != "${version}" ]; then
             echo "The input tag does not match the version from pyproject.toml:" >&2
-            echo "${TAG}" >&2
+            echo "${{ fromJson(inputs.plan).announcement_tag }}" >&2
             echo "${version}" >&2
             exit 1
           else
@@ -177,8 +175,6 @@ jobs:
 
       - name: Generate Dynamic Dockerfile Tags
         shell: bash
-        env:
-          TAG_VALUE: ${{ fromJson(inputs.plan).announcement_tag }}
         run: |
           set -euo pipefail
 
@@ -199,8 +195,8 @@ jobs:
           # Loop through all base tags and append its docker metadata pattern to the list
           # Order is on purpose such that the label org.opencontainers.image.version has the first pattern with the full version
           IFS=','; for TAG in ${BASE_TAGS}; do
-            TAG_PATTERNS="${TAG_PATTERNS}type=pep440,pattern={{ version }},suffix=-${TAG},value=${TAG_VALUE}\n"
-            TAG_PATTERNS="${TAG_PATTERNS}type=pep440,pattern={{ major }}.{{ minor }},suffix=-${TAG},value=${TAG_VALUE}\n"
+            TAG_PATTERNS="${TAG_PATTERNS}type=pep440,pattern={{ version }},suffix=-${TAG},value=${{ fromJson(inputs.plan).announcement_tag }}\n"
+            TAG_PATTERNS="${TAG_PATTERNS}type=pep440,pattern={{ major }}.{{ minor }},suffix=-${TAG},value=${{ fromJson(inputs.plan).announcement_tag }}\n"
             TAG_PATTERNS="${TAG_PATTERNS}type=raw,value=${TAG}\n"
           done
 

.github/workflows/ci.yaml

@@ -386,7 +386,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup component add rustfmt
       - uses: Swatinem/rust-cache@v2
-      - run: ./scripts/add_rule.py --name DoTheThing --prefix F --code 999 --linter pyflakes
+      - run: ./scripts/add_rule.py --name DoTheThing --prefix PL --code C0999 --linter pylint
       - run: cargo check
       - run: cargo fmt --all --check
       - run: |

.github/workflows/daily_fuzz.yaml

@@ -73,6 +73,6 @@ jobs:
               owner: "astral-sh",
               repo: "ruff",
               title: `Daily parser fuzz failed on ${new Date().toDateString()}`,
-              body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
+              body: "Runs listed here: https://github.com/astral-sh/ruff/actions/workflows/daily_fuzz.yml",
               labels: ["bug", "parser", "fuzzer"],
             })

.github/workflows/daily_property_tests.yaml

@@ -1,71 +0,0 @@
-name: Daily property test run
-
-on:
-  workflow_dispatch:
-  schedule:
-    - cron: "0 12 * * *"
-  pull_request:
-    paths:
-      - ".github/workflows/daily_property_tests.yaml"
-
-permissions:
-  contents: read
-
-concurrency:
-  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
-  cancel-in-progress: true
-
-env:
-  CARGO_INCREMENTAL: 0
-  CARGO_NET_RETRY: 10
-  CARGO_TERM_COLOR: always
-  RUSTUP_MAX_RETRIES: 10
-  FORCE_COLOR: 1
-
-jobs:
-  property_tests:
-    name: Property tests
-    runs-on: ubuntu-latest
-    timeout-minutes: 20
-    # Don't run the cron job on forks:
-    if: ${{ github.repository == 'astral-sh/ruff' || github.event_name != 'schedule' }}
-    steps:
-      - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
-      - name: "Install Rust toolchain"
-        run: rustup show
-      - name: "Install mold"
-        uses: rui314/setup-mold@v1
-      - uses: Swatinem/rust-cache@v2
-      - name: Build Red Knot
-        # A release build takes longer (2 min vs 1 min), but the property tests run much faster in release
-        # mode (1.5 min vs 14 min), so the overall time is shorter with a release build.
-        run: cargo build --locked --release --package red_knot_python_semantic --tests
-      - name: Run property tests
-        shell: bash
-        run: |
-          export QUICKCHECK_TESTS=100000
-          for _ in {1..5}; do
-            cargo test --locked --release --package red_knot_python_semantic -- --ignored types::property_tests::stable
-          done
-
-  create-issue-on-failure:
-    name: Create an issue if the daily property test run surfaced any bugs
-    runs-on: ubuntu-latest
-    needs: property_tests
-    if: ${{ github.repository == 'astral-sh/ruff' && always() && github.event_name == 'schedule' && needs.property_tests.result == 'failure' }}
-    permissions:
-      issues: write
-    steps:
-      - uses: actions/github-script@v7
-        with:
-          github-token: ${{ secrets.GITHUB_TOKEN }}
-          script: |
-            await github.rest.issues.create({
-              owner: "astral-sh",
-              repo: "ruff",
-              title: `Daily property test run failed on ${new Date().toDateString()}`,
-              body: "Run listed here: https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}",
-              labels: ["bug", "red-knot", "testing"],
-            })

.github/workflows/publish-docs.yml

@@ -33,9 +33,8 @@ jobs:
           python-version: 3.12
 
       - name: "Set docs version"
-        env:
-          version: ${{ (inputs.plan != '' && fromJson(inputs.plan).announcement_tag) || inputs.ref }}
         run: |
+          version="${{ (inputs.plan != '' && fromJson(inputs.plan).announcement_tag) || inputs.ref }}"
           # if version is missing, use 'latest'
           if [ -z "$version" ]; then
             echo "Using 'latest' as version"

.github/zizmor.yml

@@ -1,12 +1,6 @@
 # Configuration for the zizmor static analysis tool, run via pre-commit in CI
 # https://woodruffw.github.io/zizmor/configuration/
-#
-# TODO: can we remove the ignores here so that our workflows are more secure?
 rules:
   dangerous-triggers:
     ignore:
       - pr-comment.yaml
-  cache-poisoning:
-    ignore:
-      - build-docker.yml
-      - publish-playground.yml

.pre-commit-config.yaml

@@ -59,7 +59,7 @@ repos:
           - black==24.10.0
 
   - repo: https://github.com/crate-ci/typos
-    rev: v1.29.4
+    rev: v1.28.4
     hooks:
       - id: typos
 
@@ -73,7 +73,7 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.8.6
+    rev: v0.8.4
     hooks:
       - id: ruff-format
       - id: ruff
@@ -91,7 +91,7 @@ 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: v1.0.0
+    rev: v0.10.0
     hooks:
       - id: zizmor
 
@@ -103,7 +103,7 @@ repos:
   # `actionlint` hook, for verifying correct syntax in GitHub Actions workflows.
   # Some additional configuration for `actionlint` can be found in `.github/actionlint.yaml`.
   - repo: https://github.com/rhysd/actionlint
-    rev: v1.7.6
+    rev: v1.7.5
     hooks:
       - id: actionlint
         stages:

BREAKING_CHANGES.md

@@ -1,9 +1,5 @@
 # Breaking Changes
 
-## 0.9.0
-
-Ruff now formats your code according to the 2025 style guide. As a result, your code might now get formatted differently. See the [changelog](./CHANGELOG.md#090) for a detailed list of changes.
-
 ## 0.8.0
 
 - **Default to Python 3.9**

CHANGELOG.md

@@ -1,180 +1,5 @@
 # Changelog
 
-## 0.9.1
-
-### Preview features
-
-- \[`pycodestyle`\] Run `too-many-newlines-at-end-of-file` on each cell in notebooks (`W391`) ([#15308](https://github.com/astral-sh/ruff/pull/15308))
-- \[`ruff`\] Omit diagnostic for shadowed private function parameters in `used-dummy-variable` (`RUF052`) ([#15376](https://github.com/astral-sh/ruff/pull/15376))
-
-### Rule changes
-
-- \[`flake8-bugbear`\] Improve `assert-raises-exception` message (`B017`) ([#15389](https://github.com/astral-sh/ruff/pull/15389))
-
-### Formatter
-
-- Preserve trailing end-of line comments for the last string literal in implicitly concatenated strings ([#15378](https://github.com/astral-sh/ruff/pull/15378))
-
-### Server
-
-- Fix a bug where the server and client notebooks were out of sync after reordering cells ([#15398](https://github.com/astral-sh/ruff/pull/15398))
-
-### Bug fixes
-
-- \[`flake8-pie`\] Correctly remove wrapping parentheses (`PIE800`) ([#15394](https://github.com/astral-sh/ruff/pull/15394))
-- \[`pyupgrade`\] Handle comments and multiline expressions correctly (`UP037`) ([#15337](https://github.com/astral-sh/ruff/pull/15337))
-
-## 0.9.0
-
-Check out the [blog post](https://astral.sh/blog/ruff-v0.9.0) for a migration guide and overview of the changes!
-
-### Breaking changes
-
-Ruff now formats your code according to the 2025 style guide. As a result, your code might now get formatted differently. See the formatter section for a detailed list of changes.
-
-This release doesn’t remove or remap any existing stable rules.
-
-### Stabilization
-
-The following rules have been stabilized and are no longer in preview:
-
-- [`stdlib-module-shadowing`](https://docs.astral.sh/ruff/rules/stdlib-module-shadowing/) (`A005`).
-    This rule has also been renamed: previously, it was called `builtin-module-shadowing`.
-- [`builtin-lambda-argument-shadowing`](https://docs.astral.sh/ruff/rules/builtin-lambda-argument-shadowing/) (`A006`)
-- [`slice-to-remove-prefix-or-suffix`](https://docs.astral.sh/ruff/rules/slice-to-remove-prefix-or-suffix/) (`FURB188`)
-- [`boolean-chained-comparison`](https://docs.astral.sh/ruff/rules/boolean-chained-comparison/) (`PLR1716`)
-- [`decimal-from-float-literal`](https://docs.astral.sh/ruff/rules/decimal-from-float-literal/) (`RUF032`)
-- [`post-init-default`](https://docs.astral.sh/ruff/rules/post-init-default/) (`RUF033`)
-- [`useless-if-else`](https://docs.astral.sh/ruff/rules/useless-if-else/) (`RUF034`)
-
-The following behaviors have been stabilized:
-
-- [`pytest-parametrize-names-wrong-type`](https://docs.astral.sh/ruff/rules/pytest-parametrize-names-wrong-type/) (`PT006`): Detect [`pytest.parametrize`](https://docs.pytest.org/en/7.1.x/how-to/parametrize.html#parametrize) calls outside decorators and calls with keyword arguments.
-- [`module-import-not-at-top-of-file`](https://docs.astral.sh/ruff/rules/module-import-not-at-top-of-file/) (`E402`): Ignore [`pytest.importorskip`](https://docs.pytest.org/en/7.1.x/reference/reference.html#pytest-importorskip) calls between import statements.
-- [`mutable-dataclass-default`](https://docs.astral.sh/ruff/rules/mutable-dataclass-default/) (`RUF008`) and [`function-call-in-dataclass-default-argument`](https://docs.astral.sh/ruff/rules/function-call-in-dataclass-default-argument/) (`RUF009`): Add support for [`attrs`](https://www.attrs.org/en/stable/).
-- [`bad-version-info-comparison`](https://docs.astral.sh/ruff/rules/bad-version-info-comparison/) (`PYI006`): Extend the rule to check non-stub files.
-
-The following fixes or improvements to fixes have been stabilized:
-
-- [`redundant-numeric-union`](https://docs.astral.sh/ruff/rules/redundant-numeric-union/) (`PYI041`)
-- [`duplicate-union-members`](https://docs.astral.sh/ruff/rules/duplicate-union-member/) (`PYI016`)
-
-### Formatter
-
-This release introduces the new 2025 stable style ([#13371](https://github.com/astral-sh/ruff/issues/13371)), stabilizing the following changes:
-
-- Format expressions in f-string elements ([#7594](https://github.com/astral-sh/ruff/issues/7594))
-- Alternate quotes for strings inside f-strings ([#13860](https://github.com/astral-sh/ruff/pull/13860))
-- Preserve the casing of hex codes in f-string debug expressions ([#14766](https://github.com/astral-sh/ruff/issues/14766))
-- Choose the quote style for each string literal in an implicitly concatenated f-string rather than for the entire string ([#13539](https://github.com/astral-sh/ruff/pull/13539))
-- Automatically join an implicitly concatenated string into a single string literal if it fits on a single line ([#9457](https://github.com/astral-sh/ruff/issues/9457))
-- Remove the [`ISC001`](https://docs.astral.sh/ruff/rules/single-line-implicit-string-concatenation/) incompatibility warning ([#15123](https://github.com/astral-sh/ruff/pull/15123))
-- Prefer parenthesizing the `assert` message over breaking the assertion expression ([#9457](https://github.com/astral-sh/ruff/issues/9457))
-- Automatically parenthesize over-long `if` guards in `match` `case` clauses ([#13513](https://github.com/astral-sh/ruff/pull/13513))
-- More consistent formatting for `match` `case` patterns ([#6933](https://github.com/astral-sh/ruff/issues/6933))
-- Avoid unnecessary parentheses around return type annotations ([#13381](https://github.com/astral-sh/ruff/pull/13381))
-- Keep the opening parentheses on the same line as the `if` keyword for comprehensions where the condition has a leading comment ([#12282](https://github.com/astral-sh/ruff/pull/12282))
-- More consistent formatting for `with` statements with a single context manager for Python 3.8 or older ([#10276](https://github.com/astral-sh/ruff/pull/10276))
-- Correctly calculate the line-width for code blocks in docstrings when using `max-doc-code-line-length = "dynamic"` ([#13523](https://github.com/astral-sh/ruff/pull/13523))
-
-### Preview features
-
-- \[`flake8-bugbear`\] Implement `class-as-data-structure` (`B903`) ([#9601](https://github.com/astral-sh/ruff/pull/9601))
-- \[`flake8-type-checking`\] Apply `quoted-type-alias` more eagerly in `TYPE_CHECKING` blocks and ignore it in stubs (`TC008`) ([#15180](https://github.com/astral-sh/ruff/pull/15180))
-- \[`pylint`\] Ignore `eq-without-hash` in stub files (`PLW1641`) ([#15310](https://github.com/astral-sh/ruff/pull/15310))
-- \[`pyupgrade`\] Split `UP007` into two individual rules: `UP007` for `Union` and `UP045` for `Optional` (`UP007`, `UP045`) ([#15313](https://github.com/astral-sh/ruff/pull/15313))
-- \[`ruff`\] New rule that detects classes that are both an enum and a `dataclass` (`RUF049`) ([#15299](https://github.com/astral-sh/ruff/pull/15299))
-- \[`ruff`\] Recode `RUF025` to `RUF037` (`RUF037`) ([#15258](https://github.com/astral-sh/ruff/pull/15258))
-
-### Rule changes
-
-- \[`flake8-builtins`\] Ignore [`stdlib-module-shadowing`](https://docs.astral.sh/ruff/rules/stdlib-module-shadowing/) in stub files(`A005`) ([#15350](https://github.com/astral-sh/ruff/pull/15350))
-- \[`flake8-return`\] Add support for functions returning `typing.Never` (`RET503`) ([#15298](https://github.com/astral-sh/ruff/pull/15298))
-
-### Server
-
-- Improve the observability by removing the need for the ["trace" value](https://microsoft.github.io/language-server-protocol/specifications/lsp/3.17/specification/#traceValue) to turn on or off logging. The server logging is solely controlled using the [`logLevel` server setting](https://docs.astral.sh/ruff/editors/settings/#loglevel)
-    which defaults to `info`. This addresses the issue where users were notified about an error and told to consult the log, but it didn’t contain any messages. ([#15232](https://github.com/astral-sh/ruff/pull/15232))
-- Ignore diagnostics from other sources for code action requests ([#15373](https://github.com/astral-sh/ruff/pull/15373))
-
-### CLI
-
-- Improve the error message for `--config key=value` when the `key` is for a table and it’s a simple `value`
-
-### Bug fixes
-
-- \[`eradicate`\] Ignore metadata blocks directly followed by normal blocks (`ERA001`) ([#15330](https://github.com/astral-sh/ruff/pull/15330))
-- \[`flake8-django`\] Recognize other magic methods (`DJ012`) ([#15365](https://github.com/astral-sh/ruff/pull/15365))
-- \[`pycodestyle`\] Avoid false positives related to type aliases (`E252`) ([#15356](https://github.com/astral-sh/ruff/pull/15356))
-- \[`pydocstyle`\] Avoid treating newline-separated sections as sub-sections (`D405`) ([#15311](https://github.com/astral-sh/ruff/pull/15311))
-- \[`pyflakes`\] Remove call when removing final argument from `format` (`F523`) ([#15309](https://github.com/astral-sh/ruff/pull/15309))
-- \[`refurb`\] Mark fix as unsafe when the right-hand side is a string (`FURB171`) ([#15273](https://github.com/astral-sh/ruff/pull/15273))
-- \[`ruff`\] Treat `)` as a regex metacharacter (`RUF043`, `RUF055`) ([#15318](https://github.com/astral-sh/ruff/pull/15318))
-- \[`ruff`\] Parenthesize the `int`-call argument when removing the `int` call would change semantics (`RUF046`) ([#15277](https://github.com/astral-sh/ruff/pull/15277))
-
-## 0.8.6
-
-### Preview features
-
-- \[`format`\]: Preserve multiline implicit concatenated strings in docstring positions ([#15126](https://github.com/astral-sh/ruff/pull/15126))
-- \[`ruff`\] Add rule to detect empty literal in deque call (`RUF025`) ([#15104](https://github.com/astral-sh/ruff/pull/15104))
-- \[`ruff`\] Avoid reporting when `ndigits` is possibly negative (`RUF057`) ([#15234](https://github.com/astral-sh/ruff/pull/15234))
-
-### Rule changes
-
-- \[`flake8-todos`\] remove issue code length restriction (`TD003`) ([#15175](https://github.com/astral-sh/ruff/pull/15175))
-- \[`pyflakes`\] Ignore errors in `@no_type_check` string annotations (`F722`, `F821`) ([#15215](https://github.com/astral-sh/ruff/pull/15215))
-
-### CLI
-
-- Show errors for attempted fixes only when passed `--verbose` ([#15237](https://github.com/astral-sh/ruff/pull/15237))
-
-### Bug fixes
-
-- \[`ruff`\] Avoid syntax error when removing int over multiple lines (`RUF046`) ([#15230](https://github.com/astral-sh/ruff/pull/15230))
-- \[`pyupgrade`\] Revert "Add all PEP-585 names to `UP006` rule" ([#15250](https://github.com/astral-sh/ruff/pull/15250))
-
-## 0.8.5
-
-### Preview features
-
-- \[`airflow`\] Extend names moved from core to provider (`AIR303`) ([#15145](https://github.com/astral-sh/ruff/pull/15145), [#15159](https://github.com/astral-sh/ruff/pull/15159), [#15196](https://github.com/astral-sh/ruff/pull/15196), [#15216](https://github.com/astral-sh/ruff/pull/15216))
-- \[`airflow`\] Extend rule to check class attributes, methods, arguments (`AIR302`) ([#15054](https://github.com/astral-sh/ruff/pull/15054), [#15083](https://github.com/astral-sh/ruff/pull/15083))
-- \[`fastapi`\] Update `FAST002` to check keyword-only arguments ([#15119](https://github.com/astral-sh/ruff/pull/15119))
-- \[`flake8-type-checking`\] Disable `TC006` and `TC007` in stub files ([#15179](https://github.com/astral-sh/ruff/pull/15179))
-- \[`pylint`\] Detect nested methods correctly (`PLW1641`) ([#15032](https://github.com/astral-sh/ruff/pull/15032))
-- \[`ruff`\] Detect more strict-integer expressions (`RUF046`) ([#14833](https://github.com/astral-sh/ruff/pull/14833))
-- \[`ruff`\] Implement `falsy-dict-get-fallback` (`RUF056`) ([#15160](https://github.com/astral-sh/ruff/pull/15160))
-- \[`ruff`\] Implement `unnecessary-round` (`RUF057`) ([#14828](https://github.com/astral-sh/ruff/pull/14828))
-
-### Rule changes
-
-- Visit PEP 764 inline `TypedDict` keys as non-type-expressions ([#15073](https://github.com/astral-sh/ruff/pull/15073))
-- \[`flake8-comprehensions`\] Skip `C416` if comprehension contains unpacking ([#14909](https://github.com/astral-sh/ruff/pull/14909))
-- \[`flake8-pie`\] Allow `cast(SomeType, ...)` (`PIE796`) ([#15141](https://github.com/astral-sh/ruff/pull/15141))
-- \[`flake8-simplify`\] More precise inference for dictionaries (`SIM300`) ([#15164](https://github.com/astral-sh/ruff/pull/15164))
-- \[`flake8-use-pathlib`\] Catch redundant joins in `PTH201` and avoid syntax errors ([#15177](https://github.com/astral-sh/ruff/pull/15177))
-- \[`pycodestyle`\] Preserve original value format (`E731`) ([#15097](https://github.com/astral-sh/ruff/pull/15097))
-- \[`pydocstyle`\] Split on first whitespace character (`D403`) ([#15082](https://github.com/astral-sh/ruff/pull/15082))
-- \[`pyupgrade`\] Add all PEP-585 names to `UP006` rule ([#5454](https://github.com/astral-sh/ruff/pull/5454))
-
-### Configuration
-
-- \[`flake8-type-checking`\] Improve flexibility of `runtime-evaluated-decorators` ([#15204](https://github.com/astral-sh/ruff/pull/15204))
-- \[`pydocstyle`\] Add setting to ignore missing documentation for `*args` and `**kwargs` parameters (`D417`) ([#15210](https://github.com/astral-sh/ruff/pull/15210))
-- \[`ruff`\] Add an allowlist for `unsafe-markup-use` (`RUF035`) ([#15076](https://github.com/astral-sh/ruff/pull/15076))
-
-### Bug fixes
-
-- Fix type subscript on older python versions ([#15090](https://github.com/astral-sh/ruff/pull/15090))
-- Use `TypeChecker` for detecting `fastapi` routes ([#15093](https://github.com/astral-sh/ruff/pull/15093))
-- \[`pycodestyle`\] Avoid false positives and negatives related to type parameter default syntax (`E225`, `E251`) ([#15214](https://github.com/astral-sh/ruff/pull/15214))
-
-### Documentation
-
-- Fix incorrect doc in `shebang-not-executable` (`EXE001`) and add git+windows solution to executable bit ([#15208](https://github.com/astral-sh/ruff/pull/15208))
-- Rename rules currently not conforming to naming convention ([#15102](https://github.com/astral-sh/ruff/pull/15102))
-
 ## 0.8.4
 
 ### Preview features

Cargo.lock

@@ -220,9 +220,9 @@ checksum = "7f839cdf7e2d3198ac6ca003fd8ebc61715755f41c1cad15ff13df67531e00ed"
 
 [[package]]
 name = "bstr"
-version = "1.11.3"
+version = "1.11.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "531a9155a481e2ee699d4f98f43c0ca4ff8ee1bfd55c31e9e98fb29d2b176fe0"
+checksum = "786a307d683a5bf92e6fd5fd69a7eb613751668d1d8d67d802846dfe367c62c8"
 dependencies = [
  "memchr",
  "regex-automata 0.4.8",
@@ -291,6 +291,12 @@ version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "cfg_aliases"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fd16c4719339c4530435d38e511904438d07cce7950afa3718a84ac36c10e89e"
+
 [[package]]
 name = "cfg_aliases"
 version = "0.2.1"
@@ -407,7 +413,7 @@ dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -418,15 +424,15 @@ checksum = "f46ad14479a25103f283c0f10005961cf086d8dc42205bb44c46ac563475dca6"
 
 [[package]]
 name = "clearscreen"
-version = "4.0.1"
+version = "3.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "8c41dc435a7b98e4608224bbf65282309f5403719df9113621b30f8b6f74e2f4"
+checksum = "2f8c93eb5f77c9050c7750e14f13ef1033a40a0aac70c6371535b6763a01438c"
 dependencies = [
- "nix",
+ "nix 0.28.0",
  "terminfo",
- "thiserror 2.0.9",
+ "thiserror 1.0.67",
  "which",
- "windows-sys 0.59.0",
+ "winapi",
 ]
 
 [[package]]
@@ -464,7 +470,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "117725a109d387c937a1533ce01b450cbde6b88abceea8473c4d7a85853cda3c"
 dependencies = [
  "lazy_static",
- "windows-sys 0.59.0",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -662,7 +668,7 @@ version = "3.4.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "90eeab0aa92f3f9b4e87f258c72b139c207d251f9cbc1080a0086b86a8870dd3"
 dependencies = [
- "nix",
+ "nix 0.29.0",
  "windows-sys 0.59.0",
 ]
 
@@ -687,7 +693,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "strsim 0.10.0",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -698,7 +704,7 @@ checksum = "a668eda54683121533a393014d8692171709ff57a7d61f187b6e782719f8933f"
 dependencies = [
  "darling_core",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -768,7 +774,16 @@ dependencies = [
  "glob",
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
+]
+
+[[package]]
+name = "dirs"
+version = "4.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ca3aa72a6f96ea37bbc5aa912f6788242832f75369bdfdadcb0e38423f100059"
+dependencies = [
+ "dirs-sys 0.3.7",
 ]
 
 [[package]]
@@ -777,7 +792,18 @@ version = "5.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "44c45a9d03d6676652bcb5e724c7e988de1acad23a711b5217ab9cbecbec2225"
 dependencies = [
- "dirs-sys",
+ "dirs-sys 0.4.1",
+]
+
+[[package]]
+name = "dirs-sys"
+version = "0.3.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1b1d1d91c932ef41c0f2663aa8b0ca0342d444d842c06914aa0a7e352d0bada6"
+dependencies = [
+ "libc",
+ "redox_users",
+ "winapi",
 ]
 
 [[package]]
@@ -800,7 +826,7 @@ checksum = "97369cbbc041bc366949bc74d34658d6cda5621039731c6310521892a3a20ae0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -849,12 +875,6 @@ dependencies = [
  "regex",
 ]
 
-[[package]]
-name = "env_home"
-version = "0.1.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c7f84e12ccf0a7ddc17a6c41c93326024c42920d7ee630d04950e6926645c0fe"
-
 [[package]]
 name = "env_logger"
 version = "0.11.6"
@@ -1226,7 +1246,7 @@ checksum = "1ec89e9337638ecdc08744df490b221a7399bf8d164eb52a665454e60e075ad6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -1345,14 +1365,14 @@ dependencies = [
 
 [[package]]
 name = "insta"
-version = "1.42.0"
+version = "1.41.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6513e4067e16e69ed1db5ab56048ed65db32d10ba5fc1217f5393f8f17d8b5a5"
+checksum = "7e9ffc4d4892617c50a928c52b2961cb5174b6fc6ebf252b2fac9d21955c48b8"
 dependencies = [
  "console",
  "globset",
+ "lazy_static",
  "linked-hash-map",
- "once_cell",
  "pest",
  "pest_derive",
  "regex",
@@ -1400,7 +1420,7 @@ dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -1442,15 +1462,6 @@ dependencies = [
  "either",
 ]
 
-[[package]]
-name = "itertools"
-version = "0.14.0"
-source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2b192c782037fadd9cfa75548310488aabdbf3d2da73885b31bd0abd03351285"
-dependencies = [
- "either",
-]
-
 [[package]]
 name = "itoa"
 version = "1.0.11"
@@ -1536,7 +1547,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2ae40017ac09cd2c6a53504cb3c871c7f2b41466eac5bc66ba63f39073b467b"
 dependencies = [
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -1636,9 +1647,9 @@ checksum = "2532096657941c2fea9c289d370a250971c689d4f143798ff67113ec042024a5"
 
 [[package]]
 name = "matchit"
-version = "0.8.6"
+version = "0.8.5"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2f926ade0c4e170215ae43342bf13b9310a437609c81f29f86c5df6657582ef9"
+checksum = "bd0aa4b8ca861b08d68afc8702af3250776898c1508b278e1da9d01e01d4b45c"
 
 [[package]]
 name = "memchr"
@@ -1708,6 +1719,18 @@ dependencies = [
  "uuid",
 ]
 
+[[package]]
+name = "nix"
+version = "0.28.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ab2156c4fce2f8df6c499cc1c763e4394b7482525bf2a9701c9d79d215f519e4"
+dependencies = [
+ "bitflags 2.6.0",
+ "cfg-if",
+ "cfg_aliases 0.1.1",
+ "libc",
+]
+
 [[package]]
 name = "nix"
 version = "0.29.0"
@@ -1716,7 +1739,7 @@ checksum = "71e2746dc3a24dd78b3cfcb7be93368c6de9963d30f43a6a73998a9cf4b17b46"
 dependencies = [
  "bitflags 2.6.0",
  "cfg-if",
- "cfg_aliases",
+ "cfg_aliases 0.2.1",
  "libc",
 ]
 
@@ -1992,7 +2015,7 @@ dependencies = [
  "pest_meta",
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -2270,7 +2293,7 @@ dependencies = [
  "hashbrown 0.15.2",
  "indexmap",
  "insta",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "memchr",
  "ordermap",
  "quickcheck",
@@ -2497,7 +2520,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.9.1"
+version = "0.8.4"
 dependencies = [
  "anyhow",
  "argfile",
@@ -2517,7 +2540,7 @@ dependencies = [
  "insta",
  "insta-cmd",
  "is-macro",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "log",
  "mimalloc",
  "notify",
@@ -2583,7 +2606,7 @@ dependencies = [
  "filetime",
  "glob",
  "globset",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "regex",
  "ruff_macros",
  "seahash",
@@ -2632,7 +2655,7 @@ dependencies = [
  "imara-diff",
  "indicatif",
  "indoc",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "libcst",
  "pretty_assertions",
  "rayon",
@@ -2716,7 +2739,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_linter"
-version = "0.9.1"
+version = "0.8.4"
 dependencies = [
  "aho-corasick",
  "annotate-snippets 0.9.2",
@@ -2732,7 +2755,7 @@ dependencies = [
  "insta",
  "is-macro",
  "is-wsl",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "libcst",
  "log",
  "memchr",
@@ -2745,7 +2768,6 @@ dependencies = [
  "regex",
  "ruff_cache",
  "ruff_diagnostics",
- "ruff_index",
  "ruff_macros",
  "ruff_notebook",
  "ruff_python_ast",
@@ -2780,11 +2802,11 @@ dependencies = [
 name = "ruff_macros"
 version = "0.0.0"
 dependencies = [
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "proc-macro2",
  "quote",
  "ruff_python_trivia",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -2792,7 +2814,7 @@ name = "ruff_notebook"
 version = "0.0.0"
 dependencies = [
  "anyhow",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "rand",
  "ruff_diagnostics",
  "ruff_source_file",
@@ -2813,7 +2835,7 @@ dependencies = [
  "bitflags 2.6.0",
  "compact_str",
  "is-macro",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "memchr",
  "ruff_cache",
  "ruff_macros",
@@ -2855,7 +2877,7 @@ dependencies = [
  "clap",
  "countme",
  "insta",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "memchr",
  "regex",
  "ruff_cache",
@@ -2893,7 +2915,7 @@ name = "ruff_python_literal"
 version = "0.0.0"
 dependencies = [
  "bitflags 2.6.0",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "ruff_python_ast",
  "unic-ucd-category",
 ]
@@ -2947,7 +2969,6 @@ dependencies = [
  "rustc-hash 2.1.0",
  "schemars",
  "serde",
- "smallvec",
 ]
 
 [[package]]
@@ -2962,7 +2983,7 @@ dependencies = [
 name = "ruff_python_trivia"
 version = "0.0.0"
 dependencies = [
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "ruff_source_file",
  "ruff_text_size",
  "unicode-ident",
@@ -3033,7 +3054,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_wasm"
-version = "0.9.1"
+version = "0.8.4"
 dependencies = [
  "console_error_panic_hook",
  "console_log",
@@ -3067,7 +3088,7 @@ dependencies = [
  "globset",
  "ignore",
  "is-macro",
- "itertools 0.14.0",
+ "itertools 0.13.0",
  "log",
  "matchit",
  "path-absolutize",
@@ -3175,7 +3196,7 @@ checksum = "e86697c916019a8588c99b5fac3cead74ec0b4b819707a682fd4d23fa0ce1ba1"
 [[package]]
 name = "salsa"
 version = "0.18.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=88a1d7774d78f048fbd77d40abca9ebd729fd1f0#88a1d7774d78f048fbd77d40abca9ebd729fd1f0"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=3c7f1694c9efba751dbeeacfbc93b227586e316a#3c7f1694c9efba751dbeeacfbc93b227586e316a"
 dependencies = [
  "append-only-vec",
  "arc-swap",
@@ -3183,6 +3204,7 @@ dependencies = [
  "dashmap 6.1.0",
  "hashlink",
  "indexmap",
+ "lazy_static",
  "parking_lot",
  "rayon",
  "rustc-hash 2.1.0",
@@ -3195,17 +3217,17 @@ dependencies = [
 [[package]]
 name = "salsa-macro-rules"
 version = "0.1.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=88a1d7774d78f048fbd77d40abca9ebd729fd1f0#88a1d7774d78f048fbd77d40abca9ebd729fd1f0"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=3c7f1694c9efba751dbeeacfbc93b227586e316a#3c7f1694c9efba751dbeeacfbc93b227586e316a"
 
 [[package]]
 name = "salsa-macros"
 version = "0.18.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=88a1d7774d78f048fbd77d40abca9ebd729fd1f0#88a1d7774d78f048fbd77d40abca9ebd729fd1f0"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=3c7f1694c9efba751dbeeacfbc93b227586e316a#3c7f1694c9efba751dbeeacfbc93b227586e316a"
 dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
  "synstructure",
 ]
 
@@ -3239,7 +3261,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "serde_derive_internals",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3288,7 +3310,7 @@ checksum = "5a9bf7cf98d04a2b28aead066b7496853d4779c9cc183c440dbac457641e19a0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3299,7 +3321,7 @@ checksum = "330f01ce65a3a5fe59a60c82f3c9a024b573b8a6e875bd233fe5f934e71d54e3"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3322,7 +3344,7 @@ checksum = "6c64451ba24fc7a6a2d60fc75dd9c83c90903b19028d4eff35e88fc1e86564e9"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3363,7 +3385,7 @@ dependencies = [
  "darling",
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3392,7 +3414,7 @@ version = "3.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "da03fa3b94cc19e3ebfc88c4229c49d8f08cdbd1228870a45f0ffdf84988e14b"
 dependencies = [
- "dirs",
+ "dirs 5.0.1",
 ]
 
 [[package]]
@@ -3477,7 +3499,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "rustversion",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3499,9 +3521,9 @@ dependencies = [
 
 [[package]]
 name = "syn"
-version = "2.0.95"
+version = "2.0.93"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46f71c0377baf4ef1cc3e3402ded576dccc315800fbc62dfc7fe04b009773b4a"
+checksum = "9c786062daee0d6db1132800e623df74274a0a87322d8e183338e01b3d98d058"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3516,7 +3538,7 @@ checksum = "c8af7666ab7b6390ab78131fb5b0fce11d6b7a6951602017c35fa82800708971"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3544,10 +3566,11 @@ dependencies = [
 
 [[package]]
 name = "terminfo"
-version = "0.9.0"
+version = "0.8.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d4ea810f0692f9f51b382fff5893887bb4580f5fa246fde546e0b13e7fcee662"
+checksum = "666cd3a6681775d22b200409aad3b089c5b99fb11ecdd8a204d9d62f8148498f"
 dependencies = [
+ "dirs 4.0.0",
  "fnv",
  "nom",
  "phf",
@@ -3578,7 +3601,7 @@ dependencies = [
  "cfg-if",
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3589,7 +3612,7 @@ checksum = "5c89e72a01ed4c579669add59014b9a524d609c0c88c6a585ce37485879f6ffb"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
  "test-case-core",
 ]
 
@@ -3619,7 +3642,7 @@ checksum = "b607164372e89797d78b8e23a6d67d5d1038c1c65efd52e1389ef8b77caba2a6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3630,7 +3653,7 @@ checksum = "7b50fa271071aae2e6ee85f842e2e28ba8cd2c5fb67f11fcb1fd70b276f9e7d4"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -3752,7 +3775,7 @@ checksum = "395ae124c09f9e6918a2310af6038fba074bcf474ac352496d5910dd59a2226d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -4022,7 +4045,7 @@ checksum = "6b91f57fe13a38d0ce9e28a03463d8d3c2468ed03d75375110ec71d93b449a08"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -4117,7 +4140,7 @@ dependencies = [
  "once_cell",
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
  "wasm-bindgen-shared",
 ]
 
@@ -4152,7 +4175,7 @@ checksum = "98c9ae5a76e46f4deecd0f0255cc223cfa18dc9b261213b8aa0c7b36f61b3f1d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
@@ -4186,7 +4209,7 @@ checksum = "222ebde6ea87fbfa6bdd2e9f1fd8a91d60aee5db68792632176c4e16a74fc7d8"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -4220,12 +4243,12 @@ dependencies = [
 
 [[package]]
 name = "which"
-version = "7.0.1"
+version = "6.0.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fb4a9e33648339dc1642b0e36e21b3385e6148e289226f657c809dee59df5028"
+checksum = "8211e4f58a2b2805adfbefbc07bab82958fc91e3836339b1ab7ae32465dce0d7"
 dependencies = [
  "either",
- "env_home",
+ "home",
  "rustix",
  "winsafe",
 ]
@@ -4489,7 +4512,7 @@ checksum = "28cc31741b18cb6f1d5ff12f5b7523e3d6eb0852bbbad19d73905511d9849b95"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
  "synstructure",
 ]
 
@@ -4510,7 +4533,7 @@ checksum = "9ce1b18ccd8e73a9321186f97e46f9f04b778851177567b1975109d26a08d2a6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]
@@ -4530,7 +4553,7 @@ checksum = "0ea7b4a3637ea8669cedf0f1fd5c286a17f3de97b8dd5a70a6c167a1730e63a5"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
  "synstructure",
 ]
 
@@ -4559,7 +4582,7 @@ checksum = "6eafa6dfb17584ea3e2bd6e76e0cc15ad7af12b09abdd1ca55961bed9b1063c6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn 2.0.95",
+ "syn 2.0.93",
 ]
 
 [[package]]

Cargo.toml

@@ -55,7 +55,7 @@ camino = { version = "1.1.7" }
 chrono = { version = "0.4.35", default-features = false, features = ["clock"] }
 clap = { version = "4.5.3", features = ["derive"] }
 clap_complete_command = { version = "0.6.0" }
-clearscreen = { version = "4.0.0" }
+clearscreen = { version = "3.0.0" }
 codspeed-criterion-compat = { version = "2.6.0", default-features = false }
 colored = { version = "2.1.0" }
 console_error_panic_hook = { version = "0.1.7" }
@@ -89,7 +89,7 @@ insta = { version = "1.35.1" }
 insta-cmd = { version = "0.6.0" }
 is-macro = { version = "0.3.5" }
 is-wsl = { version = "0.4.0" }
-itertools = { version = "0.14.0" }
+itertools = { version = "0.13.0" }
 js-sys = { version = "0.3.69" }
 jod-thread = { version = "0.1.2" }
 libc = { version = "0.2.153" }
@@ -119,7 +119,7 @@ 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 = "88a1d7774d78f048fbd77d40abca9ebd729fd1f0" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "3c7f1694c9efba751dbeeacfbc93b227586e316a" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }

README.md

@@ -116,21 +116,12 @@ For more, see the [documentation](https://docs.astral.sh/ruff/).
 
 ### Installation
 
-Ruff is available as [`ruff`](https://pypi.org/project/ruff/) on PyPI.
-
-Invoke Ruff directly with [`uvx`](https://docs.astral.sh/uv/):
-
-```shell
-uvx ruff check   # Lint all files in the current directory.
-uvx ruff format  # Format all files in the current directory.
-```
-
-Or install Ruff with `uv` (recommended), `pip`, or `pipx`:
+Ruff is available as [`ruff`](https://pypi.org/project/ruff/) on PyPI:
 
 ```shell
 # With uv.
-uv tool install ruff@latest  # Install Ruff globally.
-uv add --dev ruff            # Or add Ruff to your project.
+uv add --dev ruff     # to add ruff to your project
+uv tool install ruff  # to install ruff globally
 
 # With pip.
 pip install ruff
@@ -149,8 +140,8 @@ 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/0.9.1/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.9.1/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.8.4/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.8.4/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 +174,7 @@ 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: v0.9.1
+  rev: v0.8.4
   hooks:
     # Run the linter.
     - id: ruff
@@ -205,7 +196,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/ruff-action@v3
+      - uses: astral-sh/ruff-action@v1
 ```
 
 ### Configuration<a id="configuration"></a>

crates/red_knot_python_semantic/resources/mdtest/annotations/literal.md

@@ -9,6 +9,8 @@ from typing import Literal
 from enum import Enum
 
 mode: Literal["w", "r"]
+mode2: Literal["w"] | Literal["r"]
+union_var: Literal[Literal[Literal[1, 2, 3], "foo"], 5, None]
 a1: Literal[26]
 a2: Literal[0x1A]
 a3: Literal[-4]
@@ -17,6 +19,7 @@ a5: Literal[b"hello world"]
 a6: Literal[True]
 a7: Literal[None]
 a8: Literal[Literal[1]]
+a9: Literal[Literal["w"], Literal["r"], Literal[Literal["w+"]]]
 
 class Color(Enum):
     RED = 0
@@ -27,6 +30,9 @@ b1: Literal[Color.RED]
 
 def f():
     reveal_type(mode)  # revealed: Literal["w", "r"]
+    reveal_type(mode2)  # revealed: Literal["w", "r"]
+    # TODO: should be revealed: Literal[1, 2, 3, "foo", 5] | None
+    reveal_type(union_var)  # revealed: Literal[1, 2, 3, 5] | Literal["foo"] | None
     reveal_type(a1)  # revealed: Literal[26]
     reveal_type(a2)  # revealed: Literal[26]
     reveal_type(a3)  # revealed: Literal[-4]
@@ -35,6 +41,7 @@ def f():
     reveal_type(a6)  # revealed: Literal[True]
     reveal_type(a7)  # revealed: None
     reveal_type(a8)  # revealed: Literal[1]
+    reveal_type(a9)  # revealed: Literal["w", "r", "w+"]
     # TODO: This should be Color.RED
     reveal_type(b1)  # revealed: Literal[0]
 
@@ -54,63 +61,6 @@ invalid4: Literal[
 ]
 ```
 
-## Shortening unions of literals
-
-When a Literal is parameterized with more than one value, it’s treated as exactly to equivalent to
-the union of those types.
-
-```py
-from typing import Literal
-
-def x(
-    a1: Literal[Literal[Literal[1, 2, 3], "foo"], 5, None],
-    a2: Literal["w"] | Literal["r"],
-    a3: Literal[Literal["w"], Literal["r"], Literal[Literal["w+"]]],
-    a4: Literal[True] | Literal[1, 2] | Literal["foo"],
-):
-    reveal_type(a1)  # revealed: Literal[1, 2, 3, "foo", 5] | None
-    reveal_type(a2)  # revealed: Literal["w", "r"]
-    reveal_type(a3)  # revealed: Literal["w", "r", "w+"]
-    reveal_type(a4)  # revealed: Literal[True, 1, 2, "foo"]
-```
-
-## Display of heterogeneous unions of literals
-
-```py
-from typing import Literal, Union
-
-def foo(x: int) -> int:
-    return x + 1
-
-def bar(s: str) -> str:
-    return s
-
-class A: ...
-class B: ...
-
-def union_example(
-    x: Union[
-        # unknown type
-        # error: [unresolved-reference]
-        y,
-        Literal[-1],
-        Literal["A"],
-        Literal[b"A"],
-        Literal[b"\x00"],
-        Literal[b"\x07"],
-        Literal[0],
-        Literal[1],
-        Literal["B"],
-        Literal["foo"],
-        Literal["bar"],
-        Literal["B"],
-        Literal[True],
-        None,
-    ]
-):
-    reveal_type(x)  # revealed: Unknown | Literal[-1, "A", b"A", b"\x00", b"\x07", 0, 1, "B", "foo", "bar", True] | None
-```
-
 ## Detecting Literal outside typing and typing_extensions
 
 Only Literal that is defined in typing and typing_extension modules is detected as the special

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

@@ -107,7 +107,7 @@ def _(flag: bool):
     qux_2: Literal["qux"] = baz_2  # error: [invalid-assignment]
 
     baz_3 = "foo" if flag else 1
-    reveal_type(baz_3)  # revealed: Literal["foo", 1]
+    reveal_type(baz_3)  # revealed: Literal["foo"] | Literal[1]
     qux_3: LiteralString = baz_3  # error: [invalid-assignment]
 ```
 

crates/red_knot_python_semantic/resources/mdtest/annotations/string.md

@@ -105,7 +105,7 @@ def f1(
 from typing import Literal
 
 def f(v: Literal["a", r"b", b"c", "d" "e", "\N{LATIN SMALL LETTER F}", "\x67", """h"""]):
-    reveal_type(v)  # revealed: Literal["a", "b", b"c", "de", "f", "g", "h"]
+    reveal_type(v)  # revealed: Literal["a", "b", "de", "f", "g", "h"] | Literal[b"c"]
 ```
 
 ## Class variables

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

@@ -122,10 +122,3 @@ class Foo: ...
 x = Foo()
 reveal_type(x)  # revealed: Foo
 ```
-
-## Annotated assignments in stub files are inferred correctly
-
-```pyi path=main.pyi
-x: int = 1
-reveal_type(x) # revealed: Literal[1]
-```

crates/red_knot_python_semantic/resources/mdtest/assignment/augmented.md

@@ -40,9 +40,9 @@ class C:
         return 42
 
 x = C()
-# error: [invalid-argument-type]
 x -= 1
 
+# TODO: should error, once operand type check is implemented
 reveal_type(x)  # revealed: int
 ```
 

crates/red_knot_python_semantic/resources/mdtest/binary/booleans.md

@@ -46,50 +46,3 @@ reveal_type(a | b)  # revealed: Literal[True]
 reveal_type(b | a)  # revealed: Literal[True]
 reveal_type(b | b)  # revealed: Literal[False]
 ```
-
-## Arithmetic with a variable
-
-```py
-a = True
-b = False
-
-def lhs_is_int(x: int):
-    reveal_type(x + a)  # revealed: int
-    reveal_type(x - a)  # revealed: int
-    reveal_type(x * a)  # revealed: int
-    reveal_type(x // a)  # revealed: int
-    reveal_type(x / a)  # revealed: float
-    reveal_type(x % a)  # revealed: int
-
-def rhs_is_int(x: int):
-    reveal_type(a + x)  # revealed: int
-    reveal_type(a - x)  # revealed: int
-    reveal_type(a * x)  # revealed: int
-    reveal_type(a // x)  # revealed: int
-    reveal_type(a / x)  # revealed: float
-    reveal_type(a % x)  # revealed: int
-
-def lhs_is_bool(x: 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
-    reveal_type(x / a)  # revealed: float
-    reveal_type(x % a)  # revealed: int
-
-def rhs_is_bool(x: 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
-    reveal_type(a / x)  # revealed: float
-    reveal_type(a % x)  # revealed: int
-
-def both_are_bool(x: bool, y: 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
-    reveal_type(x / y)  # revealed: float
-    reveal_type(x % y)  # revealed: int
-```

crates/red_knot_python_semantic/resources/mdtest/binary/classes.md

@@ -1,27 +0,0 @@
-# Binary operations on classes
-
-## Union of two classes
-
-Unioning two classes via the `|` operator is only available in Python 3.10 and later.
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-class A: ...
-class B: ...
-
-reveal_type(A | B)  # revealed: UnionType
-```
-
-## Union of two classes (prior to 3.10)
-
-```py
-class A: ...
-class B: ...
-
-# error: "Operator `|` is unsupported between objects of type `Literal[A]` and `Literal[B]`"
-reveal_type(A | B)  # revealed: Unknown
-```

crates/red_knot_python_semantic/resources/mdtest/binary/custom.md

@@ -1,371 +0,0 @@
-# Custom binary operations
-
-## Class instances
-
-```py
-class Yes:
-    def __add__(self, other) -> Literal["+"]:
-        return "+"
-
-    def __sub__(self, other) -> Literal["-"]:
-        return "-"
-
-    def __mul__(self, other) -> Literal["*"]:
-        return "*"
-
-    def __matmul__(self, other) -> Literal["@"]:
-        return "@"
-
-    def __truediv__(self, other) -> Literal["/"]:
-        return "/"
-
-    def __mod__(self, other) -> Literal["%"]:
-        return "%"
-
-    def __pow__(self, other) -> Literal["**"]:
-        return "**"
-
-    def __lshift__(self, other) -> Literal["<<"]:
-        return "<<"
-
-    def __rshift__(self, other) -> Literal[">>"]:
-        return ">>"
-
-    def __or__(self, other) -> Literal["|"]:
-        return "|"
-
-    def __xor__(self, other) -> Literal["^"]:
-        return "^"
-
-    def __and__(self, other) -> Literal["&"]:
-        return "&"
-
-    def __floordiv__(self, other) -> Literal["//"]:
-        return "//"
-
-class Sub(Yes): ...
-class No: ...
-
-# Yes implements all of the dunder methods.
-reveal_type(Yes() + Yes())  # revealed: Literal["+"]
-reveal_type(Yes() - Yes())  # revealed: Literal["-"]
-reveal_type(Yes() * Yes())  # revealed: Literal["*"]
-reveal_type(Yes() @ Yes())  # revealed: Literal["@"]
-reveal_type(Yes() / Yes())  # revealed: Literal["/"]
-reveal_type(Yes() % Yes())  # revealed: Literal["%"]
-reveal_type(Yes() ** Yes())  # revealed: Literal["**"]
-reveal_type(Yes() << Yes())  # revealed: Literal["<<"]
-reveal_type(Yes() >> Yes())  # revealed: Literal[">>"]
-reveal_type(Yes() | Yes())  # revealed: Literal["|"]
-reveal_type(Yes() ^ Yes())  # revealed: Literal["^"]
-reveal_type(Yes() & Yes())  # revealed: Literal["&"]
-reveal_type(Yes() // Yes())  # revealed: Literal["//"]
-
-# Sub inherits Yes's implementation of the dunder methods.
-reveal_type(Sub() + Sub())  # revealed: Literal["+"]
-reveal_type(Sub() - Sub())  # revealed: Literal["-"]
-reveal_type(Sub() * Sub())  # revealed: Literal["*"]
-reveal_type(Sub() @ Sub())  # revealed: Literal["@"]
-reveal_type(Sub() / Sub())  # revealed: Literal["/"]
-reveal_type(Sub() % Sub())  # revealed: Literal["%"]
-reveal_type(Sub() ** Sub())  # revealed: Literal["**"]
-reveal_type(Sub() << Sub())  # revealed: Literal["<<"]
-reveal_type(Sub() >> Sub())  # revealed: Literal[">>"]
-reveal_type(Sub() | Sub())  # revealed: Literal["|"]
-reveal_type(Sub() ^ Sub())  # revealed: Literal["^"]
-reveal_type(Sub() & Sub())  # revealed: Literal["&"]
-reveal_type(Sub() // Sub())  # revealed: Literal["//"]
-
-# No does not implement any of the dunder methods.
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `No` and `No`"
-reveal_type(No() + No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `-` is unsupported between objects of type `No` and `No`"
-reveal_type(No() - No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `*` is unsupported between objects of type `No` and `No`"
-reveal_type(No() * No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `@` is unsupported between objects of type `No` and `No`"
-reveal_type(No() @ No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `/` is unsupported between objects of type `No` and `No`"
-reveal_type(No() / No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `%` is unsupported between objects of type `No` and `No`"
-reveal_type(No() % No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `**` is unsupported between objects of type `No` and `No`"
-reveal_type(No() ** No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `<<` is unsupported between objects of type `No` and `No`"
-reveal_type(No() << No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>>` is unsupported between objects of type `No` and `No`"
-reveal_type(No() >> No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `|` is unsupported between objects of type `No` and `No`"
-reveal_type(No() | No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `^` is unsupported between objects of type `No` and `No`"
-reveal_type(No() ^ No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `&` is unsupported between objects of type `No` and `No`"
-reveal_type(No() & No())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `//` is unsupported between objects of type `No` and `No`"
-reveal_type(No() // No())  # revealed: Unknown
-
-# Yes does not implement any of the reflected dunder methods.
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() + Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `-` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() - Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `*` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() * Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `@` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() @ Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `/` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() / Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `%` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() % Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `**` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() ** Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `<<` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() << Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>>` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() >> Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `|` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() | Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `^` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() ^ Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `&` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() & Yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `//` is unsupported between objects of type `No` and `Yes`"
-reveal_type(No() // Yes())  # revealed: Unknown
-```
-
-## Subclass reflections override superclass dunders
-
-```py
-class Yes:
-    def __add__(self, other) -> Literal["+"]:
-        return "+"
-
-    def __sub__(self, other) -> Literal["-"]:
-        return "-"
-
-    def __mul__(self, other) -> Literal["*"]:
-        return "*"
-
-    def __matmul__(self, other) -> Literal["@"]:
-        return "@"
-
-    def __truediv__(self, other) -> Literal["/"]:
-        return "/"
-
-    def __mod__(self, other) -> Literal["%"]:
-        return "%"
-
-    def __pow__(self, other) -> Literal["**"]:
-        return "**"
-
-    def __lshift__(self, other) -> Literal["<<"]:
-        return "<<"
-
-    def __rshift__(self, other) -> Literal[">>"]:
-        return ">>"
-
-    def __or__(self, other) -> Literal["|"]:
-        return "|"
-
-    def __xor__(self, other) -> Literal["^"]:
-        return "^"
-
-    def __and__(self, other) -> Literal["&"]:
-        return "&"
-
-    def __floordiv__(self, other) -> Literal["//"]:
-        return "//"
-
-class Sub(Yes):
-    def __radd__(self, other) -> Literal["r+"]:
-        return "r+"
-
-    def __rsub__(self, other) -> Literal["r-"]:
-        return "r-"
-
-    def __rmul__(self, other) -> Literal["r*"]:
-        return "r*"
-
-    def __rmatmul__(self, other) -> Literal["r@"]:
-        return "r@"
-
-    def __rtruediv__(self, other) -> Literal["r/"]:
-        return "r/"
-
-    def __rmod__(self, other) -> Literal["r%"]:
-        return "r%"
-
-    def __rpow__(self, other) -> Literal["r**"]:
-        return "r**"
-
-    def __rlshift__(self, other) -> Literal["r<<"]:
-        return "r<<"
-
-    def __rrshift__(self, other) -> Literal["r>>"]:
-        return "r>>"
-
-    def __ror__(self, other) -> Literal["r|"]:
-        return "r|"
-
-    def __rxor__(self, other) -> Literal["r^"]:
-        return "r^"
-
-    def __rand__(self, other) -> Literal["r&"]:
-        return "r&"
-
-    def __rfloordiv__(self, other) -> Literal["r//"]:
-        return "r//"
-
-class No:
-    def __radd__(self, other) -> Literal["r+"]:
-        return "r+"
-
-    def __rsub__(self, other) -> Literal["r-"]:
-        return "r-"
-
-    def __rmul__(self, other) -> Literal["r*"]:
-        return "r*"
-
-    def __rmatmul__(self, other) -> Literal["r@"]:
-        return "r@"
-
-    def __rtruediv__(self, other) -> Literal["r/"]:
-        return "r/"
-
-    def __rmod__(self, other) -> Literal["r%"]:
-        return "r%"
-
-    def __rpow__(self, other) -> Literal["r**"]:
-        return "r**"
-
-    def __rlshift__(self, other) -> Literal["r<<"]:
-        return "r<<"
-
-    def __rrshift__(self, other) -> Literal["r>>"]:
-        return "r>>"
-
-    def __ror__(self, other) -> Literal["r|"]:
-        return "r|"
-
-    def __rxor__(self, other) -> Literal["r^"]:
-        return "r^"
-
-    def __rand__(self, other) -> Literal["r&"]:
-        return "r&"
-
-    def __rfloordiv__(self, other) -> Literal["r//"]:
-        return "r//"
-
-# Subclass reflected dunder methods take precedence over the superclass's regular dunders.
-reveal_type(Yes() + Sub())  # revealed: Literal["r+"]
-reveal_type(Yes() - Sub())  # revealed: Literal["r-"]
-reveal_type(Yes() * Sub())  # revealed: Literal["r*"]
-reveal_type(Yes() @ Sub())  # revealed: Literal["r@"]
-reveal_type(Yes() / Sub())  # revealed: Literal["r/"]
-reveal_type(Yes() % Sub())  # revealed: Literal["r%"]
-reveal_type(Yes() ** Sub())  # revealed: Literal["r**"]
-reveal_type(Yes() << Sub())  # revealed: Literal["r<<"]
-reveal_type(Yes() >> Sub())  # revealed: Literal["r>>"]
-reveal_type(Yes() | Sub())  # revealed: Literal["r|"]
-reveal_type(Yes() ^ Sub())  # revealed: Literal["r^"]
-reveal_type(Yes() & Sub())  # revealed: Literal["r&"]
-reveal_type(Yes() // Sub())  # revealed: Literal["r//"]
-
-# But for an unrelated class, the superclass regular dunders are used.
-reveal_type(Yes() + No())  # revealed: Literal["+"]
-reveal_type(Yes() - No())  # revealed: Literal["-"]
-reveal_type(Yes() * No())  # revealed: Literal["*"]
-reveal_type(Yes() @ No())  # revealed: Literal["@"]
-reveal_type(Yes() / No())  # revealed: Literal["/"]
-reveal_type(Yes() % No())  # revealed: Literal["%"]
-reveal_type(Yes() ** No())  # revealed: Literal["**"]
-reveal_type(Yes() << No())  # revealed: Literal["<<"]
-reveal_type(Yes() >> No())  # revealed: Literal[">>"]
-reveal_type(Yes() | No())  # revealed: Literal["|"]
-reveal_type(Yes() ^ No())  # revealed: Literal["^"]
-reveal_type(Yes() & No())  # revealed: Literal["&"]
-reveal_type(Yes() // No())  # revealed: Literal["//"]
-```
-
-## Classes
-
-Dunder methods defined in a class are available to instances of that class, but not to the class
-itself. (For these operators to work on the class itself, they would have to be defined on the
-class's type, i.e. `type`.)
-
-```py
-class Yes:
-    def __add__(self, other) -> Literal["+"]:
-        return "+"
-
-class Sub(Yes): ...
-class No: ...
-
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `Literal[Yes]` and `Literal[Yes]`"
-reveal_type(Yes + Yes)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `Literal[Sub]` and `Literal[Sub]`"
-reveal_type(Sub + Sub)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `Literal[No]` and `Literal[No]`"
-reveal_type(No + No)  # revealed: Unknown
-```
-
-## Subclass
-
-```py
-class Yes:
-    def __add__(self, other) -> Literal["+"]:
-        return "+"
-
-class Sub(Yes): ...
-class No: ...
-
-def yes() -> type[Yes]:
-    return Yes
-
-def sub() -> type[Sub]:
-    return Sub
-
-def no() -> type[No]:
-    return No
-
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `type[Yes]` and `type[Yes]`"
-reveal_type(yes() + yes())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `type[Sub]` and `type[Sub]`"
-reveal_type(sub() + sub())  # revealed: Unknown
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `type[No]` and `type[No]`"
-reveal_type(no() + no())  # revealed: Unknown
-```
-
-## Function literals
-
-```py
-def f():
-    pass
-
-# error: [unsupported-operator] "Operator `+` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f + f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `-` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f - f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `*` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f * f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `@` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f @ f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `/` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f / f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `%` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f % f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `**` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f**f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `<<` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f << f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>>` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f >> f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `|` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f | f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `^` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f ^ f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `&` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f & f)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `//` is unsupported between objects of type `Literal[f]` and `Literal[f]`"
-reveal_type(f // f)  # revealed: Unknown
-```

crates/red_knot_python_semantic/resources/mdtest/binary/integers.md

@@ -9,34 +9,6 @@ reveal_type(3 * -1)  # revealed: Literal[-3]
 reveal_type(-3 // 3)  # revealed: Literal[-1]
 reveal_type(-3 / 3)  # revealed: float
 reveal_type(5 % 3)  # revealed: Literal[2]
-
-# 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: float
-    reveal_type(x % 3)  # revealed: int
-
-def rhs(x: int):
-    reveal_type(2 + x)  # revealed: int
-    reveal_type(3 - x)  # revealed: int
-    reveal_type(3 * x)  # revealed: int
-    reveal_type(-3 // x)  # revealed: int
-    reveal_type(-3 / x)  # revealed: float
-    reveal_type(5 % x)  # revealed: int
-
-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
-    reveal_type(x / x)  # revealed: float
-    reveal_type(x % x)  # revealed: int
 ```
 
 ## Power
@@ -49,11 +21,6 @@ largest_u32 = 4_294_967_295
 reveal_type(2**2)  # revealed: Literal[4]
 reveal_type(1 ** (largest_u32 + 1))  # revealed: int
 reveal_type(2**largest_u32)  # revealed: int
-
-def variable(x: int):
-    reveal_type(x**2)  # revealed: @Todo(return type)
-    reveal_type(2**x)  # revealed: @Todo(return type)
-    reveal_type(x**x)  # revealed: @Todo(return type)
 ```
 
 ## Division by Zero

crates/red_knot_python_semantic/resources/mdtest/call/callable_instance.md

@@ -70,32 +70,3 @@ def _(flag: bool):
     # 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
-
-### Wrong argument type
-
-```py
-class C:
-    def __call__(self, x: int) -> int:
-        return 1
-
-c = C()
-
-# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter 2 (`x`) of function `__call__`; expected type `int`"
-reveal_type(c("foo"))  # revealed: int
-```
-
-### Wrong argument type on `self`
-
-```py
-class C:
-    # TODO this definition should also be an error; `C` must be assignable to type of `self`
-    def __call__(self: int) -> int:
-        return 1
-
-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
-```

crates/red_knot_python_semantic/resources/mdtest/call/function.md

@@ -64,260 +64,3 @@ def _(flag: bool):
     # error: [possibly-unresolved-reference]
     reveal_type(foo())  # revealed: int
 ```
-
-## Wrong argument type
-
-### Positional argument, positional-or-keyword parameter
-
-```py
-def f(x: int) -> int:
-    return 1
-
-# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter 1 (`x`) of function `f`; expected type `int`"
-reveal_type(f("foo"))  # revealed: int
-```
-
-### Positional argument, positional-only parameter
-
-```py
-def f(x: int, /) -> int:
-    return 1
-
-# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter 1 (`x`) of function `f`; expected type `int`"
-reveal_type(f("foo"))  # revealed: int
-```
-
-### Positional argument, variadic parameter
-
-```py
-def f(*args: int) -> int:
-    return 1
-
-# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter `*args` of function `f`; expected type `int`"
-reveal_type(f("foo"))  # revealed: int
-```
-
-### Keyword argument, positional-or-keyword parameter
-
-```py
-def f(x: int) -> int:
-    return 1
-
-# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter `x` of function `f`; expected type `int`"
-reveal_type(f(x="foo"))  # revealed: int
-```
-
-### Keyword argument, keyword-only parameter
-
-```py
-def f(*, x: int) -> int:
-    return 1
-
-# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter `x` of function `f`; expected type `int`"
-reveal_type(f(x="foo"))  # revealed: int
-```
-
-### Keyword argument, keywords parameter
-
-```py
-def f(**kwargs: int) -> int:
-    return 1
-
-# error: 15 [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter `**kwargs` of function `f`; expected type `int`"
-reveal_type(f(x="foo"))  # revealed: int
-```
-
-### Correctly match keyword out-of-order
-
-```py
-def f(x: int = 1, y: str = "foo") -> int:
-    return 1
-
-# error: 15 [invalid-argument-type] "Object of type `Literal[2]` cannot be assigned to parameter `y` of function `f`; expected type `str`"
-# error: 20 [invalid-argument-type] "Object of type `Literal["bar"]` cannot be assigned to parameter `x` of function `f`; expected type `int`"
-reveal_type(f(y=2, x="bar"))  # revealed: int
-```
-
-## Too many positional arguments
-
-### One too many
-
-```py
-def f() -> int:
-    return 1
-
-# error: 15 [too-many-positional-arguments] "Too many positional arguments to function `f`: expected 0, got 1"
-reveal_type(f("foo"))  # revealed: int
-```
-
-### Two too many
-
-```py
-def f() -> int:
-    return 1
-
-# error: 15 [too-many-positional-arguments] "Too many positional arguments to function `f`: expected 0, got 2"
-reveal_type(f("foo", "bar"))  # revealed: int
-```
-
-### No too-many-positional if variadic is taken
-
-```py
-def f(*args: int) -> int:
-    return 1
-
-reveal_type(f(1, 2, 3))  # revealed: int
-```
-
-## Missing arguments
-
-### No defaults or variadic
-
-```py
-def f(x: int) -> int:
-    return 1
-
-# error: 13 [missing-argument] "No argument provided for required parameter `x` of function `f`"
-reveal_type(f())  # revealed: int
-```
-
-### With default
-
-```py
-def f(x: int, y: str = "foo") -> int:
-    return 1
-
-# error: 13 [missing-argument] "No argument provided for required parameter `x` of function `f`"
-reveal_type(f())  # revealed: int
-```
-
-### Defaulted argument is not required
-
-```py
-def f(x: int = 1) -> int:
-    return 1
-
-reveal_type(f())  # revealed: int
-```
-
-### With variadic
-
-```py
-def f(x: int, *y: str) -> int:
-    return 1
-
-# error: 13 [missing-argument] "No argument provided for required parameter `x` of function `f`"
-reveal_type(f())  # revealed: int
-```
-
-### Variadic argument is not required
-
-```py
-def f(*args: int) -> int:
-    return 1
-
-reveal_type(f())  # revealed: int
-```
-
-### Keywords argument is not required
-
-```py
-def f(**kwargs: int) -> int:
-    return 1
-
-reveal_type(f())  # revealed: int
-```
-
-### Multiple
-
-```py
-def f(x: int, y: int) -> int:
-    return 1
-
-# error: 13 [missing-argument] "No arguments provided for required parameters `x`, `y` of function `f`"
-reveal_type(f())  # revealed: int
-```
-
-## Unknown argument
-
-```py
-def f(x: int) -> int:
-    return 1
-
-# error: 20 [unknown-argument] "Argument `y` does not match any known parameter of function `f`"
-reveal_type(f(x=1, y=2))  # revealed: int
-```
-
-## Parameter already assigned
-
-```py
-def f(x: int) -> int:
-    return 1
-
-# error: 18 [parameter-already-assigned] "Multiple values provided for parameter `x` of function `f`"
-reveal_type(f(1, x=2))  # revealed: int
-```
-
-## Special functions
-
-Some functions require special handling in type inference. Here, we make sure that we still emit
-proper diagnostics in case of missing or superfluous arguments.
-
-### `reveal_type`
-
-```py
-from typing_extensions import reveal_type
-
-# error: [missing-argument] "No argument provided for required parameter `obj` of function `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)  # revealed: Literal[1]
-```
-
-### `static_assert`
-
-```py
-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"
-static_assert(True, 2, 3)
-```
-
-### `len`
-
-```py
-# error: [missing-argument] "No argument provided for required parameter `obj` of function `len`"
-len()
-
-# error: [too-many-positional-arguments] "Too many positional arguments to function `len`: expected 1, got 2"
-len([], 1)
-```
-
-### Type API predicates
-
-```py
-from knot_extensions import is_subtype_of, is_fully_static
-
-# error: [missing-argument]
-is_subtype_of()
-
-# error: [missing-argument]
-is_subtype_of(int)
-
-# error: [too-many-positional-arguments]
-is_subtype_of(int, int, int)
-
-# error: [too-many-positional-arguments]
-is_subtype_of(int, int, int, int)
-
-# error: [missing-argument]
-is_fully_static()
-
-# error: [too-many-positional-arguments]
-is_fully_static(int, int)
-```

crates/red_knot_python_semantic/resources/mdtest/call/invalid_syntax.md

@@ -1,44 +0,0 @@
-# Invalid signatures
-
-## Multiple arguments with the same name
-
-We always map a keyword argument to the first parameter of that name.
-
-```py
-# error: [invalid-syntax] "Duplicate parameter "x""
-def f(x: int, x: str) -> int:
-    return 1
-
-# error: 13 [missing-argument] "No argument provided for required parameter `x` of function `f`"
-# error: 18 [parameter-already-assigned] "Multiple values provided for parameter `x` of function `f`"
-reveal_type(f(1, x=2))  # revealed: int
-```
-
-## Positional after non-positional
-
-When parameter kinds are given in an invalid order, we emit a diagnostic and implicitly reorder them
-to the valid order:
-
-```py
-# error: [invalid-syntax] "Parameter cannot follow var-keyword parameter"
-def f(**kw: int, x: str) -> int:
-    return 1
-
-# error: 15 [invalid-argument-type] "Object of type `Literal[1]` cannot be assigned to parameter 1 (`x`) of function `f`; expected type `str`"
-reveal_type(f(1))  # revealed: int
-```
-
-## Non-defaulted after defaulted
-
-We emit a syntax diagnostic for this, but it doesn't cause any problems for binding.
-
-```py
-# error: [invalid-syntax] "Parameter without a default cannot follow a parameter with a default"
-def f(x: int = 1, y: str) -> int:
-    return 1
-
-reveal_type(f(y="foo"))  # revealed: int
-# error: [invalid-argument-type] "Object of type `Literal["foo"]` cannot be assigned to parameter 1 (`x`) of function `f`; expected type `int`"
-# error: [missing-argument] "No argument provided for required parameter `y` of function `f`"
-reveal_type(f("foo"))  # revealed: int
-```

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

@@ -56,7 +56,7 @@ def _(flag: bool, flag2: bool):
     else:
         def f() -> int:
             return 1
-    # error: "Object of type `Literal[1, "foo"] | Literal[f]` is not callable (due to union elements Literal[1], Literal["foo"])"
+    # error: "Object of type `Literal[1] | Literal["foo"] | Literal[f]` is not callable (due to union elements Literal[1], Literal["foo"])"
     # revealed: Unknown | int
     reveal_type(f())
 ```
@@ -72,6 +72,6 @@ def _(flag: bool):
     else:
         f = "foo"
 
-    x = f()  # error: "Object of type `Literal[1, "foo"]` is not callable"
+    x = f()  # error: "Object of type `Literal[1] | Literal["foo"]` is not callable"
     reveal_type(x)  # revealed: Unknown
 ```

crates/red_knot_python_semantic/resources/mdtest/comparison/unsupported.md

@@ -22,7 +22,7 @@ def _(flag: bool, flag1: bool, flag2: bool):
     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"]`"
+    # error: "Operator `in` is not supported for types `Literal[42]` and `Literal[1]`, in comparing `Literal[42]` with `Literal[1] | Literal["foo"]`"
     e = 42 in int_literal_or_str_literal
     reveal_type(e)  # revealed: bool
 

crates/red_knot_python_semantic/resources/mdtest/conditional/if_statement.md

@@ -115,35 +115,3 @@ def _(flag: bool, flag2: bool):
 
     reveal_type(y)  # revealed: Literal[2, 3, 4]
 ```
-
-## if-elif with assignment expressions in tests
-
-```py
-def check(x: int) -> bool:
-    return bool(x)
-
-if check(x := 1):
-    x = 2
-elif check(x := 3):
-    x = 4
-
-reveal_type(x)  # revealed: Literal[2, 3, 4]
-```
-
-## constraints apply to later test expressions
-
-```py
-def check(x) -> bool:
-    return bool(x)
-
-def _(flag: bool):
-    x = 1 if flag else None
-    y = 0
-
-    if x is None:
-        pass
-    elif check(y := x):
-        pass
-
-    reveal_type(y)  # revealed: Literal[0, 1]
-```

crates/red_knot_python_semantic/resources/mdtest/directives/assert_type.md

@@ -1,145 +0,0 @@
-# `assert_type`
-
-## Basic
-
-```py
-from typing_extensions import assert_type
-
-def _(x: int):
-    assert_type(x, int)  # fine
-    assert_type(x, str)  # error: [type-assertion-failure]
-```
-
-## Narrowing
-
-The asserted type is checked against the inferred type, not the declared type.
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-from typing_extensions import assert_type
-
-def _(x: int | str):
-    if isinstance(x, int):
-        reveal_type(x)  # revealed: int
-        assert_type(x, int)  # fine
-```
-
-## Equivalence
-
-The actual type must match the asserted type precisely.
-
-```py
-from typing import Any, Type, Union
-from typing_extensions import assert_type
-
-# Subtype does not count
-def _(x: bool):
-    assert_type(x, int)  # error: [type-assertion-failure]
-
-def _(a: type[int], b: type[Any]):
-    assert_type(a, type[Any])  # error: [type-assertion-failure]
-    assert_type(b, type[int])  # error: [type-assertion-failure]
-
-# The expression constructing the type is not taken into account
-def _(a: type[int]):
-    assert_type(a, Type[int])  # fine
-```
-
-## Gradual types
-
-```py
-from typing import Any
-from typing_extensions import Literal, assert_type
-
-from knot_extensions import Unknown
-
-# Any and Unknown are considered equivalent
-def _(a: Unknown, b: Any):
-    reveal_type(a)  # revealed: Unknown
-    assert_type(a, Any)  # fine
-
-    reveal_type(b)  # revealed: Any
-    assert_type(b, Unknown)  # fine
-
-def _(a: type[Unknown], b: type[Any]):
-    # TODO: Should be `type[Unknown]`
-    reveal_type(a)  # revealed: @Todo(unsupported type[X] special form)
-    # TODO: Should be fine
-    assert_type(a, type[Any])  # error: [type-assertion-failure]
-
-    reveal_type(b)  # revealed: type[Any]
-    # TODO: Should be fine
-    assert_type(b, type[Unknown])  # error: [type-assertion-failure]
-```
-
-## Tuples
-
-Tuple types with the same elements are the same.
-
-```py
-from typing_extensions import assert_type
-
-from knot_extensions import Unknown
-
-def _(a: tuple[int, str, bytes]):
-    assert_type(a, tuple[int, str, bytes])  # fine
-
-    assert_type(a, tuple[int, str])  # error: [type-assertion-failure]
-    assert_type(a, tuple[int, str, bytes, None])  # error: [type-assertion-failure]
-    assert_type(a, tuple[int, bytes, str])  # error: [type-assertion-failure]
-
-def _(a: tuple[Any, ...], b: tuple[Unknown, ...]):
-    assert_type(a, tuple[Any, ...])  # fine
-    assert_type(a, tuple[Unknown, ...])  # fine
-
-    assert_type(b, tuple[Unknown, ...])  # fine
-    assert_type(b, tuple[Any, ...])  # fine
-```
-
-## Unions
-
-Unions with the same elements are the same, regardless of order.
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-from typing_extensions import assert_type
-
-def _(a: str | int):
-    assert_type(a, str | int)  # fine
-
-    # TODO: Order-independent union handling in type equivalence
-    assert_type(a, int | str)  # error: [type-assertion-failure]
-```
-
-## Intersections
-
-Intersections are the same when their positive and negative parts are respectively the same,
-regardless of order.
-
-```py
-from typing_extensions import assert_type
-
-from knot_extensions import Intersection, Not
-
-class A: ...
-class B: ...
-class C: ...
-class D: ...
-
-def _(a: A):
-    if isinstance(a, B) and not isinstance(a, C) and not isinstance(a, D):
-        reveal_type(a)  # revealed: A & B & ~C & ~D
-
-        assert_type(a, Intersection[A, B, Not[C], Not[D]])  # fine
-
-        # TODO: Order-independent intersection handling in type equivalence
-        assert_type(a, Intersection[B, A, Not[D], Not[C]])  # error: [type-assertion-failure]
-```

crates/red_knot_python_semantic/resources/mdtest/expression/attribute.md

@@ -17,7 +17,7 @@ def _(flag: bool):
 
     reveal_type(A.always_bound)  # revealed: Literal[1]
 
-    reveal_type(A.union)  # revealed: Literal[1, "abc"]
+    reveal_type(A.union)  # revealed: Literal[1] | Literal["abc"]
 
     # error: [possibly-unbound-attribute] "Attribute `possibly_unbound` on type `Literal[A]` is possibly unbound"
     reveal_type(A.possibly_unbound)  # revealed: Literal["abc"]

crates/red_knot_python_semantic/resources/mdtest/expression/if.md

@@ -31,9 +31,9 @@ The test inside an if expression should not affect code outside of the expressio
 def _(flag: bool):
     x: Literal[42, "hello"] = 42 if flag else "hello"
 
-    reveal_type(x)  # revealed: Literal[42, "hello"]
+    reveal_type(x)  # revealed: Literal[42] | Literal["hello"]
 
     _ = ... if isinstance(x, str) else ...
 
-    reveal_type(x)  # revealed: Literal[42, "hello"]
+    reveal_type(x)  # revealed: Literal[42] | Literal["hello"]
 ```

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

@@ -119,7 +119,7 @@ class ZeroOrStr:
 reveal_type(len(Zero()))  # revealed: Literal[0]
 reveal_type(len(ZeroOrOne()))  # revealed: Literal[0, 1]
 reveal_type(len(ZeroOrTrue()))  # revealed: Literal[0, 1]
-reveal_type(len(OneOrFalse()))  # revealed: Literal[1, 0]
+reveal_type(len(OneOrFalse()))  # revealed: Literal[0, 1]
 
 # TODO: Emit a diagnostic
 reveal_type(len(OneOrFoo()))  # revealed: int

crates/red_knot_python_semantic/resources/mdtest/intersection_types.md

@@ -1,747 +0,0 @@
-# Intersection types
-
-## Introduction
-
-This test suite covers certain properties of intersection types and makes sure that we can apply
-various simplification strategies. We use `Intersection` (`&`) and `Not` (`~`) to construct
-intersection types (note that we display negative contributions at the end; the order does not
-matter):
-
-```py
-from knot_extensions import Intersection, Not
-
-class P: ...
-class Q: ...
-
-def _(
-    i1: Intersection[P, Q],
-    i2: Intersection[P, Not[Q]],
-    i3: Intersection[Not[P], Q],
-    i4: Intersection[Not[P], Not[Q]],
-) -> None:
-    reveal_type(i1)  # revealed: P & Q
-    reveal_type(i2)  # revealed: P & ~Q
-    reveal_type(i3)  # revealed: Q & ~P
-    reveal_type(i4)  # revealed: ~P & ~Q
-```
-
-## Notation
-
-Throughout this document, we use the following types as representatives for certain equivalence
-classes.
-
-### Non-disjoint types
-
-We use `P`, `Q`, `R`, … to denote types that are non-disjoint:
-
-```py
-from knot_extensions import static_assert, is_disjoint_from
-
-class P: ...
-class Q: ...
-class R: ...
-
-static_assert(not is_disjoint_from(P, Q))
-static_assert(not is_disjoint_from(P, R))
-static_assert(not is_disjoint_from(Q, R))
-```
-
-Although `P` is not a subtype of `Q` and `Q` is not a subtype of `P`, the two types are not disjoint
-because it would be possible to create a class `S` that inherits from both `P` and `Q` using
-multiple inheritance. An instance of `S` would be a member of the `P` type _and_ the `Q` type.
-
-### Disjoint types
-
-We use `Literal[1]`, `Literal[2]`, … as examples of pairwise-disjoint types, and `int` as a joint
-supertype of these:
-
-```py
-from knot_extensions import static_assert, is_disjoint_from, is_subtype_of
-from typing import Literal
-
-static_assert(is_disjoint_from(Literal[1], Literal[2]))
-static_assert(is_disjoint_from(Literal[1], Literal[3]))
-static_assert(is_disjoint_from(Literal[2], Literal[3]))
-
-static_assert(is_subtype_of(Literal[1], int))
-static_assert(is_subtype_of(Literal[2], int))
-static_assert(is_subtype_of(Literal[3], int))
-```
-
-### Subtypes
-
-Finally, we use `A <: B <: C` and `A <: B1`, `A <: B2` to denote hierarchies of (proper) subtypes:
-
-```py
-from knot_extensions import static_assert, is_subtype_of, is_disjoint_from
-
-class A: ...
-class B(A): ...
-class C(B): ...
-
-static_assert(is_subtype_of(B, A))
-static_assert(is_subtype_of(C, B))
-static_assert(is_subtype_of(C, A))
-
-static_assert(not is_subtype_of(A, B))
-static_assert(not is_subtype_of(B, C))
-static_assert(not is_subtype_of(A, C))
-
-class B1(A): ...
-class B2(A): ...
-
-static_assert(is_subtype_of(B1, A))
-static_assert(is_subtype_of(B2, A))
-
-static_assert(not is_subtype_of(A, B1))
-static_assert(not is_subtype_of(A, B2))
-
-static_assert(not is_subtype_of(B1, B2))
-static_assert(not is_subtype_of(B2, B1))
-```
-
-## Structural properties
-
-This section covers structural properties of intersection types and documents some decisions on how
-to represent mixtures of intersections and unions.
-
-### Single-element unions
-
-If we have a union of a single element, we can simplify to that element. Similarly, we show an
-intersection with a single negative contribution as just the negation of that element.
-
-```py
-from knot_extensions import Intersection, Not
-
-class P: ...
-
-def _(
-    i1: Intersection[P],
-    i2: Intersection[Not[P]],
-) -> None:
-    reveal_type(i1)  # revealed: P
-    reveal_type(i2)  # revealed: ~P
-```
-
-### Flattening of nested intersections
-
-We eagerly flatten nested intersections types.
-
-```py
-from knot_extensions import Intersection, Not
-
-class P: ...
-class Q: ...
-class R: ...
-class S: ...
-
-def positive_contributions(
-    i1: Intersection[P, Intersection[Q, R]],
-    i2: Intersection[Intersection[P, Q], R],
-) -> None:
-    reveal_type(i1)  # revealed: P & Q & R
-    reveal_type(i2)  # revealed: P & Q & R
-
-def negative_contributions(
-    i1: Intersection[Not[P], Intersection[Not[Q], Not[R]]],
-    i2: Intersection[Intersection[Not[P], Not[Q]], Not[R]],
-) -> None:
-    reveal_type(i1)  # revealed: ~P & ~Q & ~R
-    reveal_type(i2)  # revealed: ~P & ~Q & ~R
-
-def mixed(
-    i1: Intersection[P, Intersection[Not[Q], R]],
-    i2: Intersection[Intersection[P, Not[Q]], R],
-    i3: Intersection[Not[P], Intersection[Q, Not[R]]],
-    i4: Intersection[Intersection[Q, Not[R]], Not[P]],
-) -> None:
-    reveal_type(i1)  # revealed: P & R & ~Q
-    reveal_type(i2)  # revealed: P & R & ~Q
-    reveal_type(i3)  # revealed: Q & ~P & ~R
-    reveal_type(i4)  # revealed: Q & ~R & ~P
-
-def multiple(
-    i1: Intersection[Intersection[P, Q], Intersection[R, S]],
-):
-    reveal_type(i1)  # revealed: P & Q & R & S
-
-def nested(
-    i1: Intersection[Intersection[Intersection[P, Q], R], S],
-    i2: Intersection[P, Intersection[Q, Intersection[R, S]]],
-):
-    reveal_type(i1)  # revealed: P & Q & R & S
-    reveal_type(i2)  # revealed: P & Q & R & S
-```
-
-### Union of intersections
-
-We always normalize our representation to a _union of intersections_, so when we add a _union to an
-intersection_, we distribute the union over the respective elements:
-
-```py
-from knot_extensions import Intersection, Not
-
-class P: ...
-class Q: ...
-class R: ...
-class S: ...
-
-def _(
-    i1: Intersection[P, Q | R | S],
-    i2: Intersection[P | Q | R, S],
-    i3: Intersection[P | Q, R | S],
-) -> None:
-    reveal_type(i1)  # revealed: P & Q | P & R | P & S
-    reveal_type(i2)  # revealed: P & S | Q & S | R & S
-    reveal_type(i3)  # revealed: P & R | Q & R | P & S | Q & S
-
-def simplifications_for_same_elements(
-    i1: Intersection[P, Q | P],
-    i2: Intersection[Q, P | Q],
-    i3: Intersection[P | Q, Q | R],
-    i4: Intersection[P | Q, P | Q],
-    i5: Intersection[P | Q, Q | P],
-) -> None:
-    #   P & (Q | P)
-    # = P & Q | P & P
-    # = P & Q | P
-    # = P
-    # (because P is a supertype of P & Q)
-    reveal_type(i1)  # revealed: P
-    # similar here:
-    reveal_type(i2)  # revealed: Q
-
-    #   (P | Q) & (Q | R)
-    # = P & Q | P & R | Q & Q | Q & R
-    # = P & Q | P & R | Q | Q & R
-    # = Q | P & R
-    # (again, because Q is a supertype of P & Q and of Q & R)
-    reveal_type(i3)  # revealed: Q | P & R
-
-    #   (P | Q) & (P | Q)
-    # = P & P | P & Q | Q & P | Q & Q
-    # = P | P & Q | Q
-    # = P | Q
-    reveal_type(i4)  # revealed: P | Q
-```
-
-### Negation distributes over union
-
-Distribution also applies to a negation operation. This is a manifestation of one of
-[De Morgan's laws], namely `~(P | Q) = ~P & ~Q`:
-
-```py
-from knot_extensions import Not
-from typing import Literal
-
-class P: ...
-class Q: ...
-class R: ...
-
-def _(i1: Not[P | Q], i2: Not[P | Q | R]) -> None:
-    reveal_type(i1)  # revealed: ~P & ~Q
-    reveal_type(i2)  # revealed: ~P & ~Q & ~R
-
-def example_literals(i: Not[Literal[1, 2]]) -> None:
-    reveal_type(i)  # revealed: ~Literal[1] & ~Literal[2]
-```
-
-### Negation of intersections
-
-The other of [De Morgan's laws], `~(P & Q) = ~P | ~Q`, also holds:
-
-```py
-from knot_extensions import Intersection, Not
-
-class P: ...
-class Q: ...
-class R: ...
-
-def _(
-    i1: Not[Intersection[P, Q]],
-    i2: Not[Intersection[P, Q, R]],
-) -> None:
-    reveal_type(i1)  # revealed: ~P | ~Q
-    reveal_type(i2)  # revealed: ~P | ~Q | ~R
-```
-
-### `Never` is dual to `object`
-
-`Never` represents the empty set of values, while `object` represents the set of all values, so
-`~Never` is equivalent to `object`, and `~object` is equivalent to `Never`. This is a manifestation
-of the [complement laws] of set theory.
-
-```py
-from knot_extensions import Intersection, Not
-from typing_extensions import Never
-
-def _(
-    not_never: Not[Never],
-    not_object: Not[object],
-) -> None:
-    reveal_type(not_never)  # revealed: object
-    reveal_type(not_object)  # revealed: Never
-```
-
-### Intersection of a type and its negation
-
-Continuing with more [complement laws], if we see both `P` and `~P` in an intersection, we can
-simplify to `Never`, even in the presence of other types:
-
-```py
-from knot_extensions import Intersection, Not
-from typing import Any
-
-class P: ...
-class Q: ...
-
-def _(
-    i1: Intersection[P, Not[P]],
-    i2: Intersection[Not[P], P],
-    i3: Intersection[P, Q, Not[P]],
-    i4: Intersection[Not[P], Q, P],
-    i5: Intersection[P, Any, Not[P]],
-    i6: Intersection[Not[P], Any, P],
-) -> None:
-    reveal_type(i1)  # revealed: Never
-    reveal_type(i2)  # revealed: Never
-    reveal_type(i3)  # revealed: Never
-    reveal_type(i4)  # revealed: Never
-    reveal_type(i5)  # revealed: Never
-    reveal_type(i6)  # revealed: Never
-```
-
-### Union of a type and its negation
-
-Similarly, if we have both `P` and `~P` in a _union_, we could simplify that to `object`. However,
-this is a rather costly operation which would require us to build the negation of each type that we
-add to a union, so this is not implemented at the moment.
-
-```py
-from knot_extensions import Intersection, Not
-
-class P: ...
-
-def _(
-    i1: P | Not[P],
-    i2: Not[P] | P,
-) -> None:
-    # These could be simplified to `object`
-    reveal_type(i1)  # revealed: P | ~P
-    reveal_type(i2)  # revealed: ~P | P
-```
-
-### Negation is an involution
-
-The final of the [complement laws] states that negating twice is equivalent to not negating at all:
-
-```py
-from knot_extensions import Not
-
-class P: ...
-
-def _(
-    i1: Not[P],
-    i2: Not[Not[P]],
-    i3: Not[Not[Not[P]]],
-    i4: Not[Not[Not[Not[P]]]],
-) -> None:
-    reveal_type(i1)  # revealed: ~P
-    reveal_type(i2)  # revealed: P
-    reveal_type(i3)  # revealed: ~P
-    reveal_type(i4)  # revealed: P
-```
-
-## Simplification strategies
-
-In this section, we present various simplification strategies that go beyond the structure of the
-representation.
-
-### `Never` in intersections
-
-If we intersect with `Never`, we can simplify the whole intersection to `Never`, even if there are
-dynamic types involved:
-
-```py
-from knot_extensions import Intersection, Not
-from typing_extensions import Never, Any
-
-class P: ...
-class Q: ...
-
-def _(
-    i1: Intersection[P, Never],
-    i2: Intersection[Never, P],
-    i3: Intersection[Any, Never],
-    i4: Intersection[Never, Not[Any]],
-) -> None:
-    reveal_type(i1)  # revealed: Never
-    reveal_type(i2)  # revealed: Never
-    reveal_type(i3)  # revealed: Never
-    reveal_type(i4)  # revealed: Never
-```
-
-### Simplifications using disjointness
-
-#### Positive contributions
-
-If we intersect disjoint types, we can simplify to `Never`, even in the presence of other types:
-
-```py
-from knot_extensions import Intersection, Not
-from typing import Literal, Any
-
-class P: ...
-
-def _(
-    i01: Intersection[Literal[1], Literal[2]],
-    i02: Intersection[Literal[2], Literal[1]],
-    i03: Intersection[Literal[1], Literal[2], P],
-    i04: Intersection[Literal[1], P, Literal[2]],
-    i05: Intersection[P, Literal[1], Literal[2]],
-    i06: Intersection[Literal[1], Literal[2], Any],
-    i07: Intersection[Literal[1], Any, Literal[2]],
-    i08: Intersection[Any, Literal[1], Literal[2]],
-) -> None:
-    reveal_type(i01)  # revealed: Never
-    reveal_type(i02)  # revealed: Never
-    reveal_type(i03)  # revealed: Never
-    reveal_type(i04)  # revealed: Never
-    reveal_type(i05)  # revealed: Never
-    reveal_type(i06)  # revealed: Never
-    reveal_type(i07)  # revealed: Never
-    reveal_type(i08)  # revealed: Never
-
-# `bool` is final and can not be subclassed, so `type[bool]` is equivalent to `Literal[bool]`, which
-# is disjoint from `type[str]`:
-def example_type_bool_type_str(
-    i: Intersection[type[bool], type[str]],
-) -> None:
-    reveal_type(i)  # revealed: Never
-```
-
-#### Positive and negative contributions
-
-If we intersect a type `X` with the negation of a disjoint type `Y`, we can remove the negative
-contribution `~Y`, as it necessarily overlaps with the positive contribution `X`:
-
-```py
-from knot_extensions import Intersection, Not
-from typing import Literal
-
-def _(
-    i1: Intersection[Literal[1], Not[Literal[2]]],
-    i2: Intersection[Not[Literal[2]], Literal[1]],
-    i3: Intersection[Literal[1], Not[Literal[2]], int],
-    i4: Intersection[Literal[1], int, Not[Literal[2]]],
-    i5: Intersection[int, Literal[1], Not[Literal[2]]],
-) -> None:
-    reveal_type(i1)  # revealed: Literal[1]
-    reveal_type(i2)  # revealed: Literal[1]
-    reveal_type(i3)  # revealed: Literal[1]
-    reveal_type(i4)  # revealed: Literal[1]
-    reveal_type(i5)  # revealed: Literal[1]
-
-# None is disjoint from int, so this simplification applies here
-def example_none(
-    i1: Intersection[int, Not[None]],
-    i2: Intersection[Not[None], int],
-) -> None:
-    reveal_type(i1)  # revealed: int
-    reveal_type(i2)  # revealed: int
-```
-
-### Simplifications using subtype relationships
-
-#### Positive type and positive subtype
-
-Subtypes are contained within their supertypes, so we can simplify intersections by removing
-superfluous supertypes:
-
-```py
-from knot_extensions import Intersection, Not
-from typing import Any
-
-class A: ...
-class B(A): ...
-class C(B): ...
-class Unrelated: ...
-
-def _(
-    i01: Intersection[A, B],
-    i02: Intersection[B, A],
-    i03: Intersection[A, C],
-    i04: Intersection[C, A],
-    i05: Intersection[B, C],
-    i06: Intersection[C, B],
-    i07: Intersection[A, B, C],
-    i08: Intersection[C, B, A],
-    i09: Intersection[B, C, A],
-    i10: Intersection[A, B, Unrelated],
-    i11: Intersection[B, A, Unrelated],
-    i12: Intersection[B, Unrelated, A],
-    i13: Intersection[A, Unrelated, B],
-    i14: Intersection[Unrelated, A, B],
-    i15: Intersection[Unrelated, B, A],
-    i16: Intersection[A, B, Any],
-    i17: Intersection[B, A, Any],
-    i18: Intersection[B, Any, A],
-    i19: Intersection[A, Any, B],
-    i20: Intersection[Any, A, B],
-    i21: Intersection[Any, B, A],
-) -> None:
-    reveal_type(i01)  # revealed: B
-    reveal_type(i02)  # revealed: B
-    reveal_type(i03)  # revealed: C
-    reveal_type(i04)  # revealed: C
-    reveal_type(i05)  # revealed: C
-    reveal_type(i06)  # revealed: C
-    reveal_type(i07)  # revealed: C
-    reveal_type(i08)  # revealed: C
-    reveal_type(i09)  # revealed: C
-    reveal_type(i10)  # revealed: B & Unrelated
-    reveal_type(i11)  # revealed: B & Unrelated
-    reveal_type(i12)  # revealed: B & Unrelated
-    reveal_type(i13)  # revealed: Unrelated & B
-    reveal_type(i14)  # revealed: Unrelated & B
-    reveal_type(i15)  # revealed: Unrelated & B
-    reveal_type(i16)  # revealed: B & Any
-    reveal_type(i17)  # revealed: B & Any
-    reveal_type(i18)  # revealed: B & Any
-    reveal_type(i19)  # revealed: Any & B
-    reveal_type(i20)  # revealed: Any & B
-    reveal_type(i21)  # revealed: Any & B
-```
-
-#### Negative type and negative subtype
-
-For negative contributions, this property is reversed. Here we can get remove superfluous
-_subtypes_:
-
-```py
-from knot_extensions import Intersection, Not
-from typing import Any
-
-class A: ...
-class B(A): ...
-class C(B): ...
-class Unrelated: ...
-
-def _(
-    i01: Intersection[Not[B], Not[A]],
-    i02: Intersection[Not[A], Not[B]],
-    i03: Intersection[Not[A], Not[C]],
-    i04: Intersection[Not[C], Not[A]],
-    i05: Intersection[Not[B], Not[C]],
-    i06: Intersection[Not[C], Not[B]],
-    i07: Intersection[Not[A], Not[B], Not[C]],
-    i08: Intersection[Not[C], Not[B], Not[A]],
-    i09: Intersection[Not[B], Not[C], Not[A]],
-    i10: Intersection[Not[B], Not[A], Unrelated],
-    i11: Intersection[Not[A], Not[B], Unrelated],
-    i12: Intersection[Not[A], Unrelated, Not[B]],
-    i13: Intersection[Not[B], Unrelated, Not[A]],
-    i14: Intersection[Unrelated, Not[A], Not[B]],
-    i15: Intersection[Unrelated, Not[B], Not[A]],
-    i16: Intersection[Not[B], Not[A], Any],
-    i17: Intersection[Not[A], Not[B], Any],
-    i18: Intersection[Not[A], Any, Not[B]],
-    i19: Intersection[Not[B], Any, Not[A]],
-    i20: Intersection[Any, Not[A], Not[B]],
-    i21: Intersection[Any, Not[B], Not[A]],
-) -> None:
-    reveal_type(i01)  # revealed: ~A
-    reveal_type(i02)  # revealed: ~A
-    reveal_type(i03)  # revealed: ~A
-    reveal_type(i04)  # revealed: ~A
-    reveal_type(i05)  # revealed: ~B
-    reveal_type(i06)  # revealed: ~B
-    reveal_type(i07)  # revealed: ~A
-    reveal_type(i08)  # revealed: ~A
-    reveal_type(i09)  # revealed: ~A
-    reveal_type(i10)  # revealed: Unrelated & ~A
-    reveal_type(i11)  # revealed: Unrelated & ~A
-    reveal_type(i12)  # revealed: Unrelated & ~A
-    reveal_type(i13)  # revealed: Unrelated & ~A
-    reveal_type(i14)  # revealed: Unrelated & ~A
-    reveal_type(i15)  # revealed: Unrelated & ~A
-    reveal_type(i16)  # revealed: Any & ~A
-    reveal_type(i17)  # revealed: Any & ~A
-    reveal_type(i18)  # revealed: Any & ~A
-    reveal_type(i19)  # revealed: Any & ~A
-    reveal_type(i20)  # revealed: Any & ~A
-    reveal_type(i21)  # revealed: Any & ~A
-```
-
-#### Negative type and multiple negative subtypes
-
-If there are multiple negative subtypes, all of them can be removed:
-
-```py
-from knot_extensions import Intersection, Not
-
-class A: ...
-class B1(A): ...
-class B2(A): ...
-
-def _(
-    i1: Intersection[Not[A], Not[B1], Not[B2]],
-    i2: Intersection[Not[A], Not[B2], Not[B1]],
-    i3: Intersection[Not[B1], Not[A], Not[B2]],
-    i4: Intersection[Not[B1], Not[B2], Not[A]],
-    i5: Intersection[Not[B2], Not[A], Not[B1]],
-    i6: Intersection[Not[B2], Not[B1], Not[A]],
-) -> None:
-    reveal_type(i1)  # revealed: ~A
-    reveal_type(i2)  # revealed: ~A
-    reveal_type(i3)  # revealed: ~A
-    reveal_type(i4)  # revealed: ~A
-    reveal_type(i5)  # revealed: ~A
-    reveal_type(i6)  # revealed: ~A
-```
-
-#### Negative type and positive subtype
-
-When `A` is a supertype of `B`, its negation `~A` is disjoint from `B`, so we can simplify the
-intersection to `Never`:
-
-```py
-from knot_extensions import Intersection, Not
-from typing import Any
-
-class A: ...
-class B(A): ...
-class C(B): ...
-class Unrelated: ...
-
-def _(
-    i1: Intersection[Not[A], B],
-    i2: Intersection[B, Not[A]],
-    i3: Intersection[Not[A], C],
-    i4: Intersection[C, Not[A]],
-    i5: Intersection[Unrelated, Not[A], B],
-    i6: Intersection[B, Not[A], Not[Unrelated]],
-    i7: Intersection[Any, Not[A], B],
-    i8: Intersection[B, Not[A], Not[Any]],
-) -> None:
-    reveal_type(i1)  # revealed: Never
-    reveal_type(i2)  # revealed: Never
-    reveal_type(i3)  # revealed: Never
-    reveal_type(i4)  # revealed: Never
-    reveal_type(i5)  # revealed: Never
-    reveal_type(i6)  # revealed: Never
-    reveal_type(i7)  # revealed: Never
-    reveal_type(i8)  # revealed: Never
-```
-
-## Non fully-static types
-
-### Negation of dynamic types
-
-`Any` represents the dynamic type, an unknown set of runtime values. The negation of that, `~Any`,
-is still an unknown set of runtime values, so `~Any` is equivalent to `Any`. We therefore eagerly
-simplify `~Any` to `Any` in intersections. The same applies to `Unknown`.
-
-```py
-from knot_extensions import Intersection, Not, Unknown
-from typing_extensions import Any, Never
-
-class P: ...
-
-def any(
-    i1: Not[Any],
-    i2: Intersection[P, Not[Any]],
-    i3: Intersection[Never, Not[Any]],
-) -> None:
-    reveal_type(i1)  # revealed: Any
-    reveal_type(i2)  # revealed: P & Any
-    reveal_type(i3)  # revealed: Never
-
-def unknown(
-    i1: Not[Unknown],
-    i2: Intersection[P, Not[Unknown]],
-    i3: Intersection[Never, Not[Unknown]],
-) -> None:
-    reveal_type(i1)  # revealed: Unknown
-    reveal_type(i2)  # revealed: P & Unknown
-    reveal_type(i3)  # revealed: Never
-```
-
-### Collapsing of multiple `Any`/`Unknown` contributions
-
-The intersection of an unknown set of runtime values with (another) unknown set of runtime values is
-still an unknown set of runtime values:
-
-```py
-from knot_extensions import Intersection, Not, Unknown
-from typing_extensions import Any
-
-class P: ...
-
-def any(
-    i1: Intersection[Any, Any],
-    i2: Intersection[P, Any, Any],
-    i3: Intersection[Any, P, Any],
-    i4: Intersection[Any, Any, P],
-) -> None:
-    reveal_type(i1)  # revealed: Any
-    reveal_type(i2)  # revealed: P & Any
-    reveal_type(i3)  # revealed: Any & P
-    reveal_type(i4)  # revealed: Any & P
-
-def unknown(
-    i1: Intersection[Unknown, Unknown],
-    i2: Intersection[P, Unknown, Unknown],
-    i3: Intersection[Unknown, P, Unknown],
-    i4: Intersection[Unknown, Unknown, P],
-) -> None:
-    reveal_type(i1)  # revealed: Unknown
-    reveal_type(i2)  # revealed: P & Unknown
-    reveal_type(i3)  # revealed: Unknown & P
-    reveal_type(i4)  # revealed: Unknown & P
-```
-
-### No self-cancellation
-
-Dynamic types do not cancel each other out. Intersecting an unknown set of values with the negation
-of another unknown set of values is not necessarily empty, so we keep the positive contribution:
-
-```py
-from knot_extensions import Intersection, Not, Unknown
-
-def any(
-    i1: Intersection[Any, Not[Any]],
-    i2: Intersection[Not[Any], Any],
-) -> None:
-    reveal_type(i1)  # revealed: Any
-    reveal_type(i2)  # revealed: Any
-
-def unknown(
-    i1: Intersection[Unknown, Not[Unknown]],
-    i2: Intersection[Not[Unknown], Unknown],
-) -> None:
-    reveal_type(i1)  # revealed: Unknown
-    reveal_type(i2)  # revealed: Unknown
-```
-
-### Mixed dynamic types
-
-We currently do not simplify mixed dynamic types, but might consider doing so in the future:
-
-```py
-from knot_extensions import Intersection, Not, Unknown
-
-def mixed(
-    i1: Intersection[Any, Unknown],
-    i2: Intersection[Any, Not[Unknown]],
-    i3: Intersection[Not[Any], Unknown],
-    i4: Intersection[Not[Any], Not[Unknown]],
-) -> None:
-    reveal_type(i1)  # revealed: Any & Unknown
-    reveal_type(i2)  # revealed: Any & Unknown
-    reveal_type(i3)  # revealed: Any & Unknown
-    reveal_type(i4)  # revealed: Any & Unknown
-```
-
-[complement laws]: https://en.wikipedia.org/wiki/Complement_(set_theory)
-[de morgan's laws]: https://en.wikipedia.org/wiki/De_Morgan%27s_laws

crates/red_knot_python_semantic/resources/mdtest/loops/for.md

@@ -98,7 +98,7 @@ reveal_type(x)
 for x in (1, "a", b"foo"):
     pass
 
-# revealed: Literal[1, "a", b"foo"]
+# revealed: Literal[1] | Literal["a"] | Literal[b"foo"]
 # error: [possibly-unresolved-reference]
 reveal_type(x)
 ```

crates/red_knot_python_semantic/resources/mdtest/loops/while_loop.md

@@ -41,7 +41,7 @@ def _(flag: bool, flag2: bool):
         x = 3
 
     reveal_type(x)  # revealed: Literal[2, 3]
-    reveal_type(y)  # revealed: Literal[4, 1, 2]
+    reveal_type(y)  # revealed: Literal[1, 2, 4]
 ```
 
 ## Nested `while` loops

crates/red_knot_python_semantic/resources/mdtest/metaclass.md

@@ -170,35 +170,8 @@ def f(*args, **kwargs) -> int: ...
 
 class A(metaclass=f): ...
 
-# TODO: Should be `int`
-reveal_type(A)  # revealed: Literal[A]
-reveal_type(A.__class__)  # revealed: type[int]
-
-def _(n: int):
-    # error: [invalid-metaclass]
-    class B(metaclass=n): ...
-    # TODO: Should be `Unknown`
-    reveal_type(B)  # revealed: Literal[B]
-    reveal_type(B.__class__)  # revealed: type[Unknown]
-
-def _(flag: bool):
-    m = f if flag else 42
-
-    # error: [invalid-metaclass]
-    class C(metaclass=m): ...
-    # TODO: Should be `int | Unknown`
-    reveal_type(C)  # revealed: Literal[C]
-    reveal_type(C.__class__)  # revealed: type[Unknown]
-
-class SignatureMismatch: ...
-
-# TODO: Emit a diagnostic
-class D(metaclass=SignatureMismatch): ...
-
-# TODO: Should be `Unknown`
-reveal_type(D)  # revealed: Literal[D]
-# TODO: Should be `type[Unknown]`
-reveal_type(D.__class__)  # revealed: Literal[SignatureMismatch]
+# TODO should be `type[int]`
+reveal_type(A.__class__)  # revealed: @Todo(metaclass not a class)
 ```
 
 ## Cyclic

crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/is.md

@@ -56,7 +56,7 @@ def _(x_flag: bool, y_flag: bool):
 def _(flag1: bool, flag2: bool):
     x = None if flag1 else (1 if flag2 else True)
 
-    reveal_type(x)  # revealed: None | Literal[1, True]
+    reveal_type(x)  # revealed: None | Literal[1] | Literal[True]
     if x is None:
         reveal_type(x)  # revealed: None
     elif x is True:

crates/red_knot_python_semantic/resources/mdtest/narrow/isinstance.md

@@ -17,7 +17,7 @@ def _(flag: bool):
             reveal_type(x)  # revealed: Never
 
     if isinstance(x, (int, object)):
-        reveal_type(x)  # revealed: Literal[1, "a"]
+        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
 ```
 
 ## `classinfo` is a tuple of types
@@ -30,7 +30,7 @@ def _(flag: bool, flag1: bool, flag2: bool):
     x = 1 if flag else "a"
 
     if isinstance(x, (int, str)):
-        reveal_type(x)  # revealed: Literal[1, "a"]
+        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
     else:
         reveal_type(x)  # revealed: Never
 
@@ -43,19 +43,19 @@ def _(flag: bool, flag1: bool, flag2: bool):
     # No narrowing should occur if a larger type is also
     # one of the possibilities:
     if isinstance(x, (int, object)):
-        reveal_type(x)  # revealed: Literal[1, "a"]
+        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
     else:
         reveal_type(x)  # revealed: Never
 
     y = 1 if flag1 else "a" if flag2 else b"b"
     if isinstance(y, (int, str)):
-        reveal_type(y)  # revealed: Literal[1, "a"]
+        reveal_type(y)  # revealed: Literal[1] | Literal["a"]
 
     if isinstance(y, (int, bytes)):
-        reveal_type(y)  # revealed: Literal[1, b"b"]
+        reveal_type(y)  # revealed: Literal[1] | Literal[b"b"]
 
     if isinstance(y, (str, bytes)):
-        reveal_type(y)  # revealed: Literal["a", b"b"]
+        reveal_type(y)  # revealed: Literal["a"] | Literal[b"b"]
 ```
 
 ## `classinfo` is a nested tuple of types
@@ -107,7 +107,7 @@ def _(flag: bool):
     x = 1 if flag else "foo"
 
     if isinstance(x, t):
-        reveal_type(x)  # revealed: Literal[1, "foo"]
+        reveal_type(x)  # revealed: Literal[1] | Literal["foo"]
 ```
 
 ## Do not use custom `isinstance` for narrowing
@@ -119,7 +119,7 @@ def _(flag: bool):
     x = 1 if flag else "a"
 
     if isinstance(x, int):
-        reveal_type(x)  # revealed: Literal[1, "a"]
+        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
 ```
 
 ## Do support narrowing if `isinstance` is aliased
@@ -155,12 +155,12 @@ def _(flag: bool):
     # TODO: this should cause us to emit a diagnostic during
     # type checking
     if isinstance(x, "a"):
-        reveal_type(x)  # revealed: Literal[1, "a"]
+        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
 
     # TODO: this should cause us to emit a diagnostic during
     # type checking
     if isinstance(x, "int"):
-        reveal_type(x)  # revealed: Literal[1, "a"]
+        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
 ```
 
 ## Do not narrow if there are keyword arguments
@@ -169,15 +169,8 @@ def _(flag: bool):
 def _(flag: bool):
     x = 1 if flag else "a"
 
-    # error: [unknown-argument]
+    # TODO: this should cause us to emit a diagnostic
+    # (`isinstance` has no `foo` parameter)
     if isinstance(x, int, foo="bar"):
-        reveal_type(x)  # revealed: Literal[1, "a"]
-```
-
-## `type[]` types are narrowed as well as class-literal types
-
-```py
-def _(x: object, y: type[int]):
-    if isinstance(x, y):
-        reveal_type(x)  # revealed: int
+        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
 ```

crates/red_knot_python_semantic/resources/mdtest/narrow/issubclass.md

@@ -90,7 +90,7 @@ def _(t: type[object]):
         if issubclass(t, B):
             reveal_type(t)  # revealed: type[A] & type[B]
     else:
-        reveal_type(t)  # revealed: type & ~type[A]
+        reveal_type(t)  # revealed: type[object] & ~type[A]
 ```
 
 ### Handling of `None`
@@ -146,7 +146,7 @@ class A: ...
 
 t = object()
 
-# error: [invalid-argument-type]
+# TODO: we should emit a diagnostic here
 if issubclass(t, A):
     reveal_type(t)  # revealed: type[A]
 ```
@@ -160,7 +160,7 @@ branch:
 ```py
 t = 1
 
-# error: [invalid-argument-type]
+# TODO: we should emit a diagnostic here
 if issubclass(t, int):
     reveal_type(t)  # revealed: Never
 ```
@@ -234,15 +234,8 @@ def flag() -> bool: ...
 
 t = int if flag() else str
 
-# error: [unknown-argument]
+# TODO: this should cause us to emit a diagnostic
+# (`issubclass` has no `foo` parameter)
 if issubclass(t, int, foo="bar"):
     reveal_type(t)  # revealed: Literal[int, str]
 ```
-
-### `type[]` types are narrowed as well as class-literal types
-
-```py
-def _(x: type, y: type[int]):
-    if issubclass(x, y):
-        reveal_type(x)  # revealed: type[int]
-```

crates/red_knot_python_semantic/resources/mdtest/narrow/match.md

@@ -16,48 +16,3 @@ def _(flag: bool):
 
     reveal_type(y)  # revealed: Literal[0] | None
 ```
-
-## Class patterns
-
-```py
-def get_object() -> object: ...
-
-class A: ...
-class B: ...
-
-x = get_object()
-
-reveal_type(x)  # revealed: object
-
-match x:
-    case A():
-        reveal_type(x)  # revealed: A
-    case B():
-        # TODO could be `B & ~A`
-        reveal_type(x)  # revealed: B
-
-reveal_type(x)  # revealed: object
-```
-
-## Class pattern with guard
-
-```py
-def get_object() -> object: ...
-
-class A:
-    def y() -> int: ...
-
-class B: ...
-
-x = get_object()
-
-reveal_type(x)  # revealed: object
-
-match x:
-    case A() if reveal_type(x):  # revealed: A
-        pass
-    case B() if reveal_type(x):  # revealed: B
-        pass
-
-reveal_type(x)  # revealed: object
-```

crates/red_knot_python_semantic/resources/mdtest/narrow/truthiness.md

@@ -9,39 +9,39 @@ def foo() -> Literal[0, -1, True, False, "", "foo", b"", b"bar", None] | tuple[(
 x = foo()
 
 if x:
-    reveal_type(x)  # revealed: Literal[-1, True, "foo", b"bar"]
+    reveal_type(x)  # revealed: Literal[-1] | Literal[True] | Literal["foo"] | Literal[b"bar"]
 else:
-    reveal_type(x)  # revealed: Literal[0, False, "", b""] | None | tuple[()]
+    reveal_type(x)  # revealed: Literal[0] | Literal[False] | Literal[""] | Literal[b""] | None | tuple[()]
 
 if not x:
-    reveal_type(x)  # revealed: Literal[0, False, "", b""] | None | tuple[()]
+    reveal_type(x)  # revealed: Literal[0] | Literal[False] | Literal[""] | Literal[b""] | None | tuple[()]
 else:
-    reveal_type(x)  # revealed: Literal[-1, True, "foo", b"bar"]
+    reveal_type(x)  # revealed: Literal[-1] | Literal[True] | Literal["foo"] | Literal[b"bar"]
 
 if x and not x:
     reveal_type(x)  # revealed: Never
 else:
-    reveal_type(x)  # revealed: Literal[0, "", b"", -1, "foo", b"bar"] | bool | None | tuple[()]
+    reveal_type(x)  # revealed: Literal[-1, 0] | bool | Literal["", "foo"] | Literal[b"", b"bar"] | None | tuple[()]
 
 if not (x and not x):
-    reveal_type(x)  # revealed: Literal[0, "", b"", -1, "foo", b"bar"] | bool | None | tuple[()]
+    reveal_type(x)  # revealed: Literal[-1, 0] | bool | Literal["", "foo"] | Literal[b"", b"bar"] | None | tuple[()]
 else:
     reveal_type(x)  # revealed: Never
 
 if x or not x:
-    reveal_type(x)  # revealed: Literal[-1, "foo", b"bar", 0, "", b""] | bool | None | tuple[()]
+    reveal_type(x)  # revealed: Literal[-1, 0] | bool | Literal["foo", ""] | Literal[b"bar", b""] | None | tuple[()]
 else:
     reveal_type(x)  # revealed: Never
 
 if not (x or not x):
     reveal_type(x)  # revealed: Never
 else:
-    reveal_type(x)  # revealed: Literal[-1, "foo", b"bar", 0, "", b""] | bool | None | tuple[()]
+    reveal_type(x)  # revealed: Literal[-1, 0] | bool | Literal["foo", ""] | Literal[b"bar", b""] | None | tuple[()]
 
 if (isinstance(x, int) or isinstance(x, str)) and x:
-    reveal_type(x)  # revealed: Literal[-1, True, "foo"]
+    reveal_type(x)  # revealed: Literal[-1] | Literal[True] | Literal["foo"]
 else:
-    reveal_type(x)  # revealed: Literal[b"", b"bar", 0, False, ""] | None | tuple[()]
+    reveal_type(x)  # revealed: Literal[b"", b"bar"] | None | tuple[()] | Literal[0] | Literal[False] | Literal[""]
 ```
 
 ## Function Literals
@@ -166,16 +166,16 @@ y = literals()
 
 if isinstance(x, str) and not isinstance(x, B):
     reveal_type(x)  # revealed: A & str & ~B
-    reveal_type(y)  # revealed: Literal[0, 42, "", "hello"]
+    reveal_type(y)  # revealed: Literal[0, 42] | Literal["", "hello"]
 
     z = x if flag() else y
 
-    reveal_type(z)  # revealed: A & str & ~B | Literal[0, 42, "", "hello"]
+    reveal_type(z)  # revealed: A & str & ~B | Literal[0, 42] | Literal["", "hello"]
 
     if z:
-        reveal_type(z)  # revealed: A & str & ~B & ~AlwaysFalsy | Literal[42, "hello"]
+        reveal_type(z)  # revealed: A & str & ~B & ~AlwaysFalsy | Literal[42] | Literal["hello"]
     else:
-        reveal_type(z)  # revealed: A & str & ~B & ~AlwaysTruthy | Literal[0, ""]
+        reveal_type(z)  # revealed: A & str & ~B & ~AlwaysTruthy | Literal[0] | Literal[""]
 ```
 
 ## Narrowing Multiple Variables

crates/red_knot_python_semantic/resources/mdtest/scopes/unbound.md

@@ -37,7 +37,7 @@ class C:
     # error: [possibly-unresolved-reference]
     y = x
 
-reveal_type(C.y)  # revealed: Literal[1, "abc"]
+reveal_type(C.y)  # revealed: Literal[1] | Literal["abc"]
 ```
 
 ## Unbound function local

crates/red_knot_python_semantic/resources/mdtest/slots.md

@@ -167,7 +167,7 @@ class A:
     __slots__ = ()
     __slots__ += ("a", "b")
 
-reveal_type(A.__slots__)  # revealed: @Todo(return type)
+reveal_type(A.__slots__)  # revealed: @Todo(Support for more binary expressions)
 
 class B:
     __slots__ = ("c", "d")

crates/red_knot_python_semantic/resources/mdtest/stubs/ellipsis.md

@@ -1,78 +0,0 @@
-# Ellipsis
-
-## Function and methods
-
-The ellipsis literal `...` can be used as a placeholder default value for a function parameter, in a
-stub file only, regardless of the type of the parameter.
-
-```py path=test.pyi
-def f(x: int = ...) -> None:
-    reveal_type(x)  # revealed: int
-
-def f2(x: str = ...) -> None:
-    reveal_type(x)  # revealed: str
-```
-
-## Class and module symbols
-
-The ellipsis literal can be assigned to a class or module symbol, regardless of its declared type,
-in a stub file only.
-
-```py path=test.pyi
-y: bytes = ...
-reveal_type(y)  # revealed: bytes
-x = ...
-reveal_type(x)  # revealed: Unknown
-
-class Foo:
-    y: int = ...
-
-reveal_type(Foo.y)  # revealed: int
-```
-
-## Unpacking ellipsis literal in assignment
-
-No diagnostic is emitted if an ellipsis literal is "unpacked" in a stub file as part of an
-assignment statement:
-
-```py path=test.pyi
-x, y = ...
-reveal_type(x)  # revealed: Unknown
-reveal_type(y)  # revealed: Unknown
-```
-
-## Unpacking ellipsis literal in for loops
-
-Iterating over an ellipsis literal as part of a `for` loop in a stub is invalid, however, and
-results in a diagnostic:
-
-```py path=test.pyi
-# error: [not-iterable] "Object of type `ellipsis` is not iterable"
-for a, b in ...:
-    reveal_type(a)  # revealed: Unknown
-    reveal_type(b)  # revealed: Unknown
-```
-
-## Ellipsis usage in non stub file
-
-In a non-stub file, there's no special treatment of ellipsis literals. An ellipsis literal can only
-be assigned if `EllipsisType` is actually assignable to the annotated type.
-
-```py
-# error: 7 [invalid-parameter-default] "Default value of type `ellipsis` is not assignable to annotated parameter type `int`"
-def f(x: int = ...) -> None: ...
-
-# error: 1 [invalid-assignment] "Object of type `ellipsis` is not assignable to `int`"
-a: int = ...
-b = ...
-reveal_type(b)  # revealed: ellipsis
-```
-
-## Use of `Ellipsis` symbol
-
-There is no special treatment of the builtin name `Ellipsis` in stubs, only of `...` literals.
-
-```py path=test.pyi
-# error: 7 [invalid-parameter-default] "Default value of type `ellipsis` is not assignable to annotated parameter type `int`"
-def f(x: int = Ellipsis) -> None: ...
-```

crates/red_knot_python_semantic/resources/mdtest/type_api.md

@@ -1,352 +0,0 @@
-# Type API (`knot_extensions`)
-
-This document describes the internal `knot_extensions` API for creating and manipulating types as
-well as testing various type system properties.
-
-## Type extensions
-
-The Python language itself allows us to perform a variety of operations on types. For example, we
-can build a union of types like `int | None`, or we can use type constructors such as `list[int]`
-and `type[int]` to create new types. But some type-level operations that we rely on in Red Knot,
-like intersections, cannot yet be expressed in Python. The `knot_extensions` module provides the
-`Intersection` and `Not` type constructors (special forms) which allow us to construct these types
-directly.
-
-### Negation
-
-```py
-from knot_extensions import Not, static_assert
-
-def negate(n1: Not[int], n2: Not[Not[int]], n3: Not[Not[Not[int]]]) -> None:
-    reveal_type(n1)  # revealed: ~int
-    reveal_type(n2)  # revealed: int
-    reveal_type(n3)  # revealed: ~int
-
-def static_truthiness(not_one: Not[Literal[1]]) -> None:
-    static_assert(not_one != 1)
-    static_assert(not (not_one == 1))
-
-# error: "Special form `knot_extensions.Not` expected exactly one type parameter"
-n: Not[int, str]
-```
-
-### Intersection
-
-```py
-from knot_extensions import Intersection, Not, is_subtype_of, static_assert
-from typing_extensions import Never
-
-class S: ...
-class T: ...
-
-def x(x1: Intersection[S, T], x2: Intersection[S, Not[T]]) -> None:
-    reveal_type(x1)  # revealed: S & T
-    reveal_type(x2)  # revealed: S & ~T
-
-def y(y1: Intersection[int, object], y2: Intersection[int, bool], y3: Intersection[int, Never]) -> None:
-    reveal_type(y1)  # revealed: int
-    reveal_type(y2)  # revealed: bool
-    reveal_type(y3)  # revealed: Never
-
-def z(z1: Intersection[int, Not[Literal[1]], Not[Literal[2]]]) -> None:
-    reveal_type(z1)  # revealed: int & ~Literal[1] & ~Literal[2]
-
-class A: ...
-class B: ...
-class C: ...
-
-type ABC = Intersection[A, B, C]
-
-static_assert(is_subtype_of(ABC, A))
-static_assert(is_subtype_of(ABC, B))
-static_assert(is_subtype_of(ABC, C))
-
-class D: ...
-
-static_assert(not is_subtype_of(ABC, D))
-```
-
-### Unknown type
-
-The `Unknown` type is a special type that we use to represent actually unknown types (no
-annotation), as opposed to `Any` which represents an explicitly unknown type.
-
-```py
-from knot_extensions import Unknown, static_assert, is_assignable_to, is_fully_static
-
-static_assert(is_assignable_to(Unknown, int))
-static_assert(is_assignable_to(int, Unknown))
-
-static_assert(not is_fully_static(Unknown))
-
-def explicit_unknown(x: Unknown, y: tuple[str, Unknown], z: Unknown = 1) -> None:
-    reveal_type(x)  # revealed: Unknown
-    reveal_type(y)  # revealed: tuple[str, Unknown]
-    reveal_type(z)  # revealed: Unknown | Literal[1]
-
-# Unknown can be subclassed, just like Any
-class C(Unknown): ...
-
-# revealed: tuple[Literal[C], Unknown, Literal[object]]
-reveal_type(C.__mro__)
-
-# error: "Special form `knot_extensions.Unknown` expected no type parameter"
-u: Unknown[str]
-```
-
-## Static assertions
-
-### Basics
-
-The `knot_extensions` module provides a `static_assert` function that can be used to enforce
-properties at type-check time. The function takes an arbitrary expression and raises a type error if
-the expression is not of statically known truthiness.
-
-```py
-from knot_extensions import static_assert
-from typing import TYPE_CHECKING
-import sys
-
-static_assert(True)
-static_assert(False)  # error: "Static assertion error: argument evaluates to `False`"
-
-static_assert(False or True)
-static_assert(True and True)
-static_assert(False or False)  # error: "Static assertion error: argument evaluates to `False`"
-static_assert(False and True)  # error: "Static assertion error: argument evaluates to `False`"
-
-static_assert(1 + 1 == 2)
-static_assert(1 + 1 == 3)  # error: "Static assertion error: argument evaluates to `False`"
-
-static_assert("a" in "abc")
-static_assert("d" in "abc")  # error: "Static assertion error: argument evaluates to `False`"
-
-n = None
-static_assert(n is None)
-
-static_assert(TYPE_CHECKING)
-
-static_assert(sys.version_info >= (3, 6))
-```
-
-### Narrowing constraints
-
-Static assertions can be used to enforce narrowing constraints:
-
-```py
-from knot_extensions import static_assert
-
-def f(x: int) -> None:
-    if x != 0:
-        static_assert(x != 0)
-    else:
-        # `int` can be subclassed, so we cannot assert that `x == 0` here:
-        # error: "Static assertion error: argument of type `bool` has an ambiguous static truthiness"
-        static_assert(x == 0)
-```
-
-### Truthy expressions
-
-See also: <https://docs.python.org/3/library/stdtypes.html#truth-value-testing>
-
-```py
-from knot_extensions import static_assert
-
-static_assert(True)
-static_assert(False)  # error: "Static assertion error: argument evaluates to `False`"
-
-static_assert(None)  # error: "Static assertion error: argument of type `None` is statically known to be falsy"
-
-static_assert(1)
-static_assert(0)  # error: "Static assertion error: argument of type `Literal[0]` is statically known to be falsy"
-
-static_assert((0,))
-static_assert(())  # error: "Static assertion error: argument of type `tuple[()]` is statically known to be falsy"
-
-static_assert("a")
-static_assert("")  # error: "Static assertion error: argument of type `Literal[""]` is statically known to be falsy"
-
-static_assert(b"a")
-static_assert(b"")  # error: "Static assertion error: argument of type `Literal[b""]` is statically known to be falsy"
-```
-
-### Error messages
-
-We provide various tailored error messages for wrong argument types to `static_assert`:
-
-```py
-from knot_extensions import static_assert
-
-static_assert(2 * 3 == 6)
-
-# error: "Static assertion error: argument evaluates to `False`"
-static_assert(2 * 3 == 7)
-
-# error: "Static assertion error: argument of type `bool` has an ambiguous static truthiness"
-static_assert(int(2.0 * 3.0) == 6)
-
-class InvalidBoolDunder:
-    def __bool__(self) -> int:
-        return 1
-
-# error: "Static assertion error: argument of type `InvalidBoolDunder` has an ambiguous static truthiness"
-static_assert(InvalidBoolDunder())
-```
-
-### Custom error messages
-
-Alternatively, users can provide custom error messages:
-
-```py
-from knot_extensions import static_assert
-
-# error: "Static assertion error: I really want this to be true"
-static_assert(1 + 1 == 3, "I really want this to be true")
-
-error_message = "A custom message "
-error_message += "constructed from multiple string literals"
-# error: "Static assertion error: A custom message constructed from multiple string literals"
-static_assert(False, error_message)
-
-# There are limitations to what we can still infer as a string literal. In those cases,
-# we simply fall back to the default message.
-shouted_message = "A custom message".upper()
-# error: "Static assertion error: argument evaluates to `False`"
-static_assert(False, shouted_message)
-```
-
-## Type predicates
-
-The `knot_extensions` module also provides predicates to test various properties of types. These are
-implemented as functions that return `Literal[True]` or `Literal[False]` depending on the result of
-the test.
-
-### Equivalence
-
-```py
-from knot_extensions import is_equivalent_to, static_assert
-from typing_extensions import Never, Union
-
-static_assert(is_equivalent_to(type, type[object]))
-static_assert(is_equivalent_to(tuple[int, Never], Never))
-static_assert(is_equivalent_to(int | str, Union[int, str]))
-
-static_assert(not is_equivalent_to(int, str))
-static_assert(not is_equivalent_to(int | str, int | str | bytes))
-```
-
-### Subtyping
-
-```py
-from knot_extensions import is_subtype_of, static_assert
-
-static_assert(is_subtype_of(bool, int))
-static_assert(not is_subtype_of(str, int))
-
-static_assert(is_subtype_of(bool, int | str))
-static_assert(is_subtype_of(str, int | str))
-static_assert(not is_subtype_of(bytes, int | str))
-
-class Base: ...
-class Derived(Base): ...
-class Unrelated: ...
-
-static_assert(is_subtype_of(Derived, Base))
-static_assert(not is_subtype_of(Base, Derived))
-static_assert(is_subtype_of(Base, Base))
-
-static_assert(not is_subtype_of(Unrelated, Base))
-static_assert(not is_subtype_of(Base, Unrelated))
-```
-
-### Assignability
-
-```py
-from knot_extensions import is_assignable_to, static_assert
-from typing import Any
-
-static_assert(is_assignable_to(int, Any))
-static_assert(is_assignable_to(Any, str))
-static_assert(not is_assignable_to(int, str))
-```
-
-### Disjointness
-
-```py
-from knot_extensions import is_disjoint_from, static_assert
-
-static_assert(is_disjoint_from(None, int))
-static_assert(not is_disjoint_from(Literal[2] | str, int))
-```
-
-### Fully static types
-
-```py
-from knot_extensions import is_fully_static, static_assert
-from typing import Any
-
-static_assert(is_fully_static(int | str))
-static_assert(is_fully_static(type[int]))
-
-static_assert(not is_fully_static(int | Any))
-static_assert(not is_fully_static(type[Any]))
-```
-
-### Singleton types
-
-```py
-from knot_extensions import is_singleton, static_assert
-
-static_assert(is_singleton(None))
-static_assert(is_singleton(Literal[True]))
-
-static_assert(not is_singleton(int))
-static_assert(not is_singleton(Literal["a"]))
-```
-
-### Single-valued types
-
-```py
-from knot_extensions import is_single_valued, static_assert
-
-static_assert(is_single_valued(None))
-static_assert(is_single_valued(Literal[True]))
-static_assert(is_single_valued(Literal["a"]))
-
-static_assert(not is_single_valued(int))
-static_assert(not is_single_valued(Literal["a"] | Literal["b"]))
-```
-
-## `TypeOf`
-
-We use `TypeOf` to get the inferred type of an expression. This is useful when we want to refer to
-it in a type expression. For example, if we want to make sure that the class literal type `str` is a
-subtype of `type[str]`, we can not use `is_subtype_of(str, type[str])`, as that would test if the
-type `str` itself is a subtype of `type[str]`. Instead, we can use `TypeOf[str]` to get the type of
-the expression `str`:
-
-```py
-from knot_extensions import TypeOf, is_subtype_of, static_assert
-
-# This is incorrect and therefore fails with ...
-# error: "Static assertion error: argument evaluates to `False`"
-static_assert(is_subtype_of(str, type[str]))
-
-# Correct, returns True:
-static_assert(is_subtype_of(TypeOf[str], type[str]))
-
-class Base: ...
-class Derived(Base): ...
-
-# `TypeOf` can be used in annotations:
-def type_of_annotation() -> None:
-    t1: TypeOf[Base] = Base
-    t2: TypeOf[Base] = Derived  # error: [invalid-assignment]
-
-    # Note how this is different from `type[…]` which includes subclasses:
-    s1: type[Base] = Base
-    s2: type[Base] = Derived  # no error here
-
-# error: "Special form `knot_extensions.TypeOf` expected exactly one type parameter"
-t: TypeOf[int, str, bytes]
-```

crates/red_knot_python_semantic/resources/mdtest/type_of/basic.md

@@ -142,25 +142,3 @@ class Foo(type[int]): ...
 # TODO: should be `tuple[Literal[Foo], Literal[type], Literal[object]]
 reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
 ```
-
-## `@final` classes
-
-`type[]` types are eagerly converted to class-literal types if a class decorated with `@final` is
-used as the type argument. This applies to standard-library classes and user-defined classes:
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-from types import EllipsisType
-from typing import final
-
-@final
-class Foo: ...
-
-def _(x: type[Foo], y: type[EllipsisType]):
-    reveal_type(x)  # revealed: Literal[Foo]
-    reveal_type(y)  # revealed: Literal[EllipsisType]
-```

crates/red_knot_python_semantic/resources/mdtest/type_of/dynamic.md

@@ -47,8 +47,9 @@ x: type = A()  # error: [invalid-assignment]
 
 ```py
 def f(x: type[object]):
-    reveal_type(x)  # revealed: type
-    reveal_type(x.__repr__)  # revealed: @Todo(instance attributes)
+    reveal_type(x)  # revealed: type[object]
+    # TODO: bound method types
+    reveal_type(x.__repr__)  # revealed: Literal[__repr__]
 
 class A: ...
 

crates/red_knot_python_semantic/resources/mdtest/type_properties/is_assignable_to.md

@@ -1,352 +0,0 @@
-# Assignable-to relation
-
-The `is_assignable_to(S, T)` relation below checks if type `S` is assignable to type `T` (target).
-This allows us to check if a type `S` can be used in a context where a type `T` is expected
-(function arguments, variable assignments). See the [typing documentation] for a precise definition
-of this concept.
-
-## Basic types
-
-### Fully static
-
-Fully static types participate in subtyping. If a type `S` is a subtype of `T`, `S` will also be
-assignable to `T`. Two equivalent types are subtypes of each other:
-
-```py
-from knot_extensions import static_assert, is_assignable_to
-
-class Parent: ...
-class Child1(Parent): ...
-class Child2(Parent): ...
-class Grandchild(Child1, Child2): ...
-class Unrelated: ...
-
-static_assert(is_assignable_to(int, int))
-static_assert(is_assignable_to(Parent, Parent))
-static_assert(is_assignable_to(Child1, Parent))
-static_assert(is_assignable_to(Grandchild, Parent))
-static_assert(is_assignable_to(Unrelated, Unrelated))
-
-static_assert(not is_assignable_to(str, int))
-static_assert(not is_assignable_to(object, int))
-static_assert(not is_assignable_to(Parent, Child1))
-static_assert(not is_assignable_to(Unrelated, Parent))
-static_assert(not is_assignable_to(Child1, Child2))
-```
-
-### Gradual types
-
-Gradual types do not participate in subtyping, but can still be assignable to other types (and
-static types can be assignable to gradual types):
-
-```py
-from knot_extensions import static_assert, is_assignable_to, Unknown
-from typing import Any
-
-static_assert(is_assignable_to(Unknown, Literal[1]))
-static_assert(is_assignable_to(Any, Literal[1]))
-static_assert(is_assignable_to(Literal[1], Unknown))
-static_assert(is_assignable_to(Literal[1], Any))
-```
-
-## Literal types
-
-### Boolean literals
-
-`Literal[True]` and `Literal[False]` are both subtypes of (and therefore assignable to) `bool`,
-which is in turn a subtype of `int`:
-
-```py
-from knot_extensions import static_assert, is_assignable_to
-from typing import Literal
-
-static_assert(is_assignable_to(Literal[True], Literal[True]))
-static_assert(is_assignable_to(Literal[True], bool))
-static_assert(is_assignable_to(Literal[True], int))
-
-static_assert(not is_assignable_to(Literal[True], Literal[False]))
-static_assert(not is_assignable_to(bool, Literal[True]))
-```
-
-### Integer literals
-
-```py
-from knot_extensions import static_assert, is_assignable_to
-from typing import Literal
-
-static_assert(is_assignable_to(Literal[1], Literal[1]))
-static_assert(is_assignable_to(Literal[1], int))
-
-static_assert(not is_assignable_to(Literal[1], Literal[2]))
-static_assert(not is_assignable_to(int, Literal[1]))
-static_assert(not is_assignable_to(Literal[1], str))
-```
-
-### String literals and `LiteralString`
-
-All string-literal types are subtypes of (and therefore assignable to) `LiteralString`, which is in
-turn a subtype of `str`:
-
-```py
-from knot_extensions import static_assert, is_assignable_to
-from typing_extensions import Literal, LiteralString
-
-static_assert(is_assignable_to(Literal["foo"], Literal["foo"]))
-static_assert(is_assignable_to(Literal["foo"], LiteralString))
-static_assert(is_assignable_to(Literal["foo"], str))
-
-static_assert(is_assignable_to(LiteralString, str))
-
-static_assert(not is_assignable_to(Literal["foo"], Literal["bar"]))
-static_assert(not is_assignable_to(str, Literal["foo"]))
-static_assert(not is_assignable_to(str, LiteralString))
-```
-
-### Byte literals
-
-```py
-from knot_extensions import static_assert, is_assignable_to
-from typing_extensions import Literal, LiteralString
-
-static_assert(is_assignable_to(Literal[b"foo"], bytes))
-static_assert(is_assignable_to(Literal[b"foo"], Literal[b"foo"]))
-
-static_assert(not is_assignable_to(Literal[b"foo"], str))
-static_assert(not is_assignable_to(Literal[b"foo"], LiteralString))
-static_assert(not is_assignable_to(Literal[b"foo"], Literal[b"bar"]))
-static_assert(not is_assignable_to(Literal[b"foo"], Literal["foo"]))
-static_assert(not is_assignable_to(Literal["foo"], Literal[b"foo"]))
-```
-
-## `type[…]` and class literals
-
-In the following tests, `TypeOf[str]` is a singleton type with a single inhabitant, the class `str`.
-This contrasts with `type[str]`, which represents "all possible subclasses of `str`".
-
-Both `TypeOf[str]` and `type[str]` are subtypes of `type` and `type[object]`, which both represent
-"all possible instances of `type`"; therefore both `type[str]` and `TypeOf[str]` are assignable to
-`type`. `type[Any]`, on the other hand, represents a type of unknown size or inhabitants, but which
-is known to be no larger than the set of possible objects represented by `type`.
-
-```py
-from knot_extensions import static_assert, is_assignable_to, Unknown, TypeOf
-from typing import Any
-
-static_assert(is_assignable_to(type, type))
-static_assert(is_assignable_to(type[object], type[object]))
-
-static_assert(is_assignable_to(type, type[object]))
-static_assert(is_assignable_to(type[object], type))
-
-static_assert(is_assignable_to(type[str], type[object]))
-static_assert(is_assignable_to(TypeOf[str], type[object]))
-static_assert(is_assignable_to(type[str], type))
-static_assert(is_assignable_to(TypeOf[str], type))
-
-static_assert(is_assignable_to(type[str], type[str]))
-static_assert(is_assignable_to(TypeOf[str], type[str]))
-
-static_assert(not is_assignable_to(TypeOf[int], type[str]))
-static_assert(not is_assignable_to(type, type[str]))
-static_assert(not is_assignable_to(type[object], type[str]))
-
-static_assert(is_assignable_to(type[Any], type[Any]))
-static_assert(is_assignable_to(type[Any], type[object]))
-static_assert(is_assignable_to(type[object], type[Any]))
-static_assert(is_assignable_to(type, type[Any]))
-static_assert(is_assignable_to(type[Any], type[str]))
-static_assert(is_assignable_to(type[str], type[Any]))
-static_assert(is_assignable_to(TypeOf[str], type[Any]))
-
-static_assert(is_assignable_to(type[Unknown], type[Unknown]))
-static_assert(is_assignable_to(type[Unknown], type[object]))
-static_assert(is_assignable_to(type[object], type[Unknown]))
-static_assert(is_assignable_to(type, type[Unknown]))
-static_assert(is_assignable_to(type[Unknown], type[str]))
-static_assert(is_assignable_to(type[str], type[Unknown]))
-static_assert(is_assignable_to(TypeOf[str], type[Unknown]))
-
-static_assert(is_assignable_to(type[Unknown], type[Any]))
-static_assert(is_assignable_to(type[Any], type[Unknown]))
-
-static_assert(not is_assignable_to(object, type[Any]))
-static_assert(not is_assignable_to(str, type[Any]))
-
-class Meta(type): ...
-
-static_assert(is_assignable_to(type[Any], Meta))
-static_assert(is_assignable_to(type[Unknown], Meta))
-static_assert(is_assignable_to(Meta, type[Any]))
-static_assert(is_assignable_to(Meta, type[Unknown]))
-```
-
-## Tuple types
-
-```py
-from knot_extensions import static_assert, is_assignable_to
-from typing import Literal, Any
-
-static_assert(is_assignable_to(tuple[()], tuple[()]))
-static_assert(is_assignable_to(tuple[int], tuple[int]))
-static_assert(is_assignable_to(tuple[int], tuple[Any]))
-static_assert(is_assignable_to(tuple[Any], tuple[int]))
-static_assert(is_assignable_to(tuple[int, str], tuple[int, str]))
-static_assert(is_assignable_to(tuple[Literal[1], Literal[2]], tuple[int, int]))
-static_assert(is_assignable_to(tuple[Any, Literal[2]], tuple[int, int]))
-static_assert(is_assignable_to(tuple[Literal[1], Any], tuple[int, int]))
-
-static_assert(not is_assignable_to(tuple[()], tuple[int]))
-static_assert(not is_assignable_to(tuple[int], tuple[str]))
-static_assert(not is_assignable_to(tuple[int], tuple[int, str]))
-static_assert(not is_assignable_to(tuple[int, str], tuple[int]))
-static_assert(not is_assignable_to(tuple[int, int], tuple[Literal[1], int]))
-static_assert(not is_assignable_to(tuple[Any, Literal[2]], tuple[int, str]))
-```
-
-## Union types
-
-```py
-from knot_extensions import static_assert, is_assignable_to, Unknown
-from typing import Literal, Any
-
-static_assert(is_assignable_to(int, int | str))
-static_assert(is_assignable_to(str, int | str))
-static_assert(is_assignable_to(int | str, int | str))
-static_assert(is_assignable_to(str | int, int | str))
-static_assert(is_assignable_to(Literal[1], int | str))
-static_assert(is_assignable_to(Literal[1], Unknown | str))
-static_assert(is_assignable_to(Literal[1] | Literal[2], Literal[1] | Literal[2]))
-static_assert(is_assignable_to(Literal[1] | Literal[2], int))
-static_assert(is_assignable_to(Literal[1] | None, int | None))
-static_assert(is_assignable_to(Any, int | str))
-static_assert(is_assignable_to(Any | int, int))
-static_assert(is_assignable_to(str, int | Any))
-
-static_assert(not is_assignable_to(int | None, int))
-static_assert(not is_assignable_to(int | None, str | None))
-static_assert(not is_assignable_to(Literal[1] | None, int))
-static_assert(not is_assignable_to(Literal[1] | None, str | None))
-static_assert(not is_assignable_to(Any | int | str, int))
-```
-
-## Intersection types
-
-```py
-from knot_extensions import static_assert, is_assignable_to, Intersection, Not
-from typing_extensions import Any, Literal
-
-class Parent: ...
-class Child1(Parent): ...
-class Child2(Parent): ...
-class Grandchild(Child1, Child2): ...
-class Unrelated: ...
-
-static_assert(is_assignable_to(Intersection[Child1, Child2], Child1))
-static_assert(is_assignable_to(Intersection[Child1, Child2], Child2))
-static_assert(is_assignable_to(Intersection[Child1, Child2], Parent))
-static_assert(is_assignable_to(Intersection[Child1, Parent], Parent))
-
-static_assert(is_assignable_to(Intersection[Parent, Unrelated], Parent))
-static_assert(is_assignable_to(Intersection[Child1, Unrelated], Child1))
-
-static_assert(is_assignable_to(Intersection[Child1, Not[Child2]], Child1))
-static_assert(is_assignable_to(Intersection[Child1, Not[Child2]], Parent))
-static_assert(is_assignable_to(Intersection[Child1, Not[Grandchild]], Parent))
-
-static_assert(is_assignable_to(Intersection[Child1, Child2], Intersection[Child1, Child2]))
-static_assert(is_assignable_to(Intersection[Child1, Child2], Intersection[Child2, Child1]))
-static_assert(is_assignable_to(Grandchild, Intersection[Child1, Child2]))
-
-static_assert(not is_assignable_to(Parent, Intersection[Parent, Unrelated]))
-static_assert(not is_assignable_to(int, Intersection[int, Not[Literal[1]]]))
-static_assert(not is_assignable_to(int, Not[int]))
-static_assert(not is_assignable_to(int, Not[Literal[1]]))
-
-static_assert(not is_assignable_to(Intersection[Any, Parent], Unrelated))
-
-# TODO: The following assertions should not fail (see https://github.com/astral-sh/ruff/issues/14899)
-# error: [static-assert-error]
-static_assert(is_assignable_to(Intersection[Any, int], int))
-
-# error: [static-assert-error]
-static_assert(is_assignable_to(Intersection[Unrelated, Any], Intersection[Unrelated, Any]))
-# error: [static-assert-error]
-static_assert(is_assignable_to(Intersection[Unrelated, Any], Intersection[Unrelated, Not[Any]]))
-# error: [static-assert-error]
-static_assert(is_assignable_to(Intersection[Unrelated, Any], Not[tuple[Unrelated, Any]]))
-```
-
-## General properties
-
-See also: our property tests in `property_tests.rs`.
-
-### Everything is assignable to `object`
-
-`object` is Python's top type; the set of all possible objects at runtime:
-
-```py
-from knot_extensions import static_assert, is_assignable_to, Unknown
-from typing import Literal, Any
-
-static_assert(is_assignable_to(str, object))
-static_assert(is_assignable_to(Literal[1], object))
-static_assert(is_assignable_to(object, object))
-static_assert(is_assignable_to(type, object))
-static_assert(is_assignable_to(Any, object))
-static_assert(is_assignable_to(Unknown, object))
-static_assert(is_assignable_to(type[object], object))
-static_assert(is_assignable_to(type[str], object))
-static_assert(is_assignable_to(type[Any], object))
-```
-
-### Every type is assignable to `Any` / `Unknown`
-
-`Any` and `Unknown` are gradual types. They could materialize to any given type at runtime, and so
-any type is assignable to them:
-
-```py
-from knot_extensions import static_assert, is_assignable_to, Unknown
-from typing import Literal, Any
-
-static_assert(is_assignable_to(str, Any))
-static_assert(is_assignable_to(Literal[1], Any))
-static_assert(is_assignable_to(object, Any))
-static_assert(is_assignable_to(type, Any))
-static_assert(is_assignable_to(Any, Any))
-static_assert(is_assignable_to(Unknown, Any))
-static_assert(is_assignable_to(type[object], Any))
-static_assert(is_assignable_to(type[str], Any))
-static_assert(is_assignable_to(type[Any], Any))
-
-static_assert(is_assignable_to(str, Unknown))
-static_assert(is_assignable_to(Literal[1], Unknown))
-static_assert(is_assignable_to(object, Unknown))
-static_assert(is_assignable_to(type, Unknown))
-static_assert(is_assignable_to(Any, Unknown))
-static_assert(is_assignable_to(Unknown, Unknown))
-static_assert(is_assignable_to(type[object], Unknown))
-static_assert(is_assignable_to(type[str], Unknown))
-static_assert(is_assignable_to(type[Any], Unknown))
-```
-
-### `Never` is assignable to every type
-
-`Never` is Python's bottom type: the empty set, a type with no inhabitants. It is therefore
-assignable to any arbitrary type.
-
-```py
-from knot_extensions import static_assert, is_assignable_to, Unknown
-from typing_extensions import Never, Any
-
-static_assert(is_assignable_to(Never, str))
-static_assert(is_assignable_to(Never, Literal[1]))
-static_assert(is_assignable_to(Never, object))
-static_assert(is_assignable_to(Never, type))
-static_assert(is_assignable_to(Never, Any))
-static_assert(is_assignable_to(Never, Unknown))
-static_assert(is_assignable_to(Never, type[object]))
-static_assert(is_assignable_to(Never, type[str]))
-static_assert(is_assignable_to(Never, type[Any]))
-```
-
-[typing documentation]: https://typing.readthedocs.io/en/latest/spec/concepts.html#the-assignable-to-or-consistent-subtyping-relation

crates/red_knot_python_semantic/resources/mdtest/type_properties/tuples_containing_never.md

@@ -1,33 +0,0 @@
-# Tuples containing `Never`
-
-A heterogeneous `tuple[…]` type that contains `Never` as a type argument simplifies to `Never`. One
-way to think about this is the following: in order to construct a tuple, you need to have an object
-of every element type. But since there is no object of type `Never`, you cannot construct the tuple.
-Such a tuple type is therefore uninhabited and equivalent to `Never`.
-
-In the language of algebraic data types, a tuple type is a product type and `Never` acts like the
-zero element in multiplication, similar to how a Cartesian product with the empty set is the empty
-set.
-
-```py
-from knot_extensions import static_assert, is_equivalent_to
-from typing_extensions import Never, NoReturn
-
-static_assert(is_equivalent_to(Never, tuple[Never]))
-static_assert(is_equivalent_to(Never, tuple[Never, int]))
-static_assert(is_equivalent_to(Never, tuple[int, Never]))
-static_assert(is_equivalent_to(Never, tuple[int, Never, str]))
-static_assert(is_equivalent_to(Never, tuple[int, tuple[str, Never]]))
-static_assert(is_equivalent_to(Never, tuple[tuple[str, Never], int]))
-
-# The empty tuple is *not* equivalent to Never!
-static_assert(not is_equivalent_to(Never, tuple[()]))
-
-# NoReturn is just a different spelling of Never, so the same is true for NoReturn
-static_assert(is_equivalent_to(NoReturn, tuple[NoReturn]))
-static_assert(is_equivalent_to(NoReturn, tuple[NoReturn, int]))
-static_assert(is_equivalent_to(NoReturn, tuple[int, NoReturn]))
-static_assert(is_equivalent_to(NoReturn, tuple[int, NoReturn, str]))
-static_assert(is_equivalent_to(NoReturn, tuple[int, tuple[str, NoReturn]]))
-static_assert(is_equivalent_to(NoReturn, tuple[tuple[str, NoReturn], int]))
-```

crates/red_knot_python_semantic/resources/mdtest/unary/custom.md

@@ -34,10 +34,6 @@ reveal_type(~No())  # revealed: Unknown
 
 ## Classes
 
-Dunder methods defined in a class are available to instances of that class, but not to the class
-itself. (For these operators to work on the class itself, they would have to be defined on the
-class's type, i.e. `type`.)
-
 ```py
 class Yes:
     def __pos__(self) -> bool:

crates/red_knot_python_semantic/resources/mdtest/union_types.md

@@ -1,143 +0,0 @@
-# Union types
-
-This test suite covers certain basic properties and simplification strategies for union types.
-
-## Basic unions
-
-```py
-from typing import Literal
-
-def _(u1: int | str, u2: Literal[0] | Literal[1]) -> None:
-    reveal_type(u1)  # revealed: int | str
-    reveal_type(u2)  # revealed: Literal[0, 1]
-```
-
-## Duplicate elements are collapsed
-
-```py
-def _(u1: int | int | str, u2: int | str | int) -> None:
-    reveal_type(u1)  # revealed: int | str
-    reveal_type(u2)  # revealed: int | str
-```
-
-## `Never` is removed
-
-`Never` is an empty set, a type with no inhabitants. Its presence in a union is always redundant,
-and so we eagerly simplify it away. `NoReturn` is equivalent to `Never`.
-
-```py
-from typing_extensions import Never, NoReturn
-
-def never(u1: int | Never, u2: int | Never | str) -> None:
-    reveal_type(u1)  # revealed: int
-    reveal_type(u2)  # revealed:  int | str
-
-def noreturn(u1: int | NoReturn, u2: int | NoReturn | str) -> None:
-    reveal_type(u1)  # revealed: int
-    reveal_type(u2)  # revealed:  int | str
-```
-
-## Flattening of nested unions
-
-```py
-from typing import Literal
-
-def _(
-    u1: (int | str) | bytes,
-    u2: int | (str | bytes),
-    u3: int | (str | (bytes | complex)),
-) -> None:
-    reveal_type(u1)  # revealed: int | str | bytes
-    reveal_type(u2)  # revealed: int | str | bytes
-    reveal_type(u3)  # revealed: int | str | bytes | complex
-```
-
-## Simplification using subtyping
-
-The type `S | T` can be simplified to `T` if `S` is a subtype of `T`:
-
-```py
-from typing_extensions import Literal, LiteralString
-
-def _(
-    u1: str | LiteralString, u2: LiteralString | str, u3: Literal["a"] | str | LiteralString, u4: str | bytes | LiteralString
-) -> None:
-    reveal_type(u1)  # revealed: str
-    reveal_type(u2)  # revealed: str
-    reveal_type(u3)  # revealed: str
-    reveal_type(u4)  # revealed: str | bytes
-```
-
-## Boolean literals
-
-The union `Literal[True] | Literal[False]` is exactly equivalent to `bool`:
-
-```py
-from typing import Literal
-
-def _(
-    u1: Literal[True, False],
-    u2: bool | Literal[True],
-    u3: Literal[True] | bool,
-    u4: Literal[True] | Literal[True, 17],
-    u5: Literal[True, False, True, 17],
-) -> None:
-    reveal_type(u1)  # revealed: bool
-    reveal_type(u2)  # revealed: bool
-    reveal_type(u3)  # revealed: bool
-    reveal_type(u4)  # revealed: Literal[True, 17]
-    reveal_type(u5)  # revealed: bool | Literal[17]
-```
-
-## Do not erase `Unknown`
-
-```py
-from knot_extensions import Unknown
-
-def _(u1: Unknown | str, u2: str | Unknown) -> None:
-    reveal_type(u1)  # revealed: Unknown | str
-    reveal_type(u2)  # revealed: str | Unknown
-```
-
-## Collapse multiple `Unknown`s
-
-Since `Unknown` is a gradual type, it is not a subtype of anything, but multiple `Unknown`s in a
-union are still redundant:
-
-```py
-from knot_extensions import Unknown
-
-def _(u1: Unknown | Unknown | str, u2: Unknown | str | Unknown, u3: str | Unknown | Unknown) -> None:
-    reveal_type(u1)  # revealed: Unknown | str
-    reveal_type(u2)  # revealed: Unknown | str
-    reveal_type(u3)  # revealed: str | Unknown
-```
-
-## Subsume multiple elements
-
-Simplifications still apply when `Unknown` is present.
-
-```py
-from knot_extensions import Unknown
-
-def _(u1: str | Unknown | int | object):
-    reveal_type(u1)  # revealed: Unknown | object
-```
-
-## Union of intersections
-
-We can simplify unions of intersections:
-
-```py
-from knot_extensions import Intersection, Not
-
-class P: ...
-class Q: ...
-
-def _(
-    i1: Intersection[P, Q] | Intersection[P, Q],
-    i2: Intersection[P, Q] | Intersection[Q, P],
-) -> None:
-    reveal_type(i1)  # revealed: P & Q
-    reveal_type(i2)  # revealed: P & Q
-```

crates/red_knot_python_semantic/resources/mdtest/unpacking.md

@@ -426,8 +426,8 @@ def _(flag: bool):
         value = ("a", "b")
 
     a, b = value
-    reveal_type(a)  # revealed: Literal[1, "a"]
-    reveal_type(b)  # revealed: Literal[2, "b"]
+    reveal_type(a)  # revealed: Literal[1] | Literal["a"]
+    reveal_type(b)  # revealed: Literal[2] | Literal["b"]
 ```
 
 ### Typing literal
@@ -528,8 +528,8 @@ for a, b in ((1, 2), (3, 4)):
 
 ```py
 for a, b in ((1, 2), ("a", "b")):
-    reveal_type(a)  # revealed: Literal[1, "a"]
-    reveal_type(b)  # revealed: Literal[2, "b"]
+    reveal_type(a)  # revealed: Literal[1] | Literal["a"]
+    reveal_type(b)  # revealed: Literal[2] | Literal["b"]
 ```
 
 ### Mixed literals values (2)

crates/red_knot_python_semantic/src/module_resolver/module.rs

@@ -109,7 +109,6 @@ pub enum KnownModule {
     #[allow(dead_code)]
     Abc, // currently only used in tests
     Collections,
-    KnotExtensions,
 }
 
 impl KnownModule {
@@ -123,7 +122,6 @@ impl KnownModule {
             Self::Sys => "sys",
             Self::Abc => "abc",
             Self::Collections => "collections",
-            Self::KnotExtensions => "knot_extensions",
         }
     }
 
@@ -149,7 +147,6 @@ impl KnownModule {
             "sys" => Some(Self::Sys),
             "abc" => Some(Self::Abc),
             "collections" => Some(Self::Collections),
-            "knot_extensions" => Some(Self::KnotExtensions),
             _ => None,
         }
     }
@@ -157,8 +154,4 @@ impl KnownModule {
     pub const fn is_typing(self) -> bool {
         matches!(self, Self::Typing)
     }
-
-    pub const fn is_knot_extensions(self) -> bool {
-        matches!(self, Self::KnotExtensions)
-    }
 }

crates/red_knot_python_semantic/src/semantic_index/builder.rs

@@ -404,17 +404,6 @@ impl<'db> SemanticIndexBuilder<'db> {
         pattern: &ast::Pattern,
         guard: Option<&ast::Expr>,
     ) -> Constraint<'db> {
-        // This is called for the top-level pattern of each match arm. We need to create a
-        // standalone expression for each arm of a match statement, since they can introduce
-        // constraints on the match subject. (Or more accurately, for the match arm's pattern,
-        // since its the pattern that introduces any constraints, not the body.) Ideally, that
-        // standalone expression would wrap the match arm's pattern as a whole. But a standalone
-        // expression can currently only wrap an ast::Expr, which patterns are not. So, we need to
-        // choose an Expr that can “stand in” for the pattern, which we can wrap in a standalone
-        // expression.
-        //
-        // See the comment in TypeInferenceBuilder::infer_match_pattern for more details.
-
         let guard = guard.map(|guard| self.add_standalone_expression(guard));
 
         let kind = match pattern {
@@ -425,10 +414,6 @@ impl<'db> SemanticIndexBuilder<'db> {
             ast::Pattern::MatchSingleton(singleton) => {
                 PatternConstraintKind::Singleton(singleton.value, guard)
             }
-            ast::Pattern::MatchClass(pattern) => {
-                let cls = self.add_standalone_expression(&pattern.cls);
-                PatternConstraintKind::Class(cls, guard)
-            }
             _ => PatternConstraintKind::Unsupported,
         };
 
@@ -893,11 +878,12 @@ where
             }
             ast::Stmt::If(node) => {
                 self.visit_expr(&node.test);
-                let mut no_branch_taken = self.flow_snapshot();
-                let mut last_constraint = self.record_expression_constraint(&node.test);
+                let pre_if = self.flow_snapshot();
+                let constraint = self.record_expression_constraint(&node.test);
+                let mut constraints = vec![constraint];
                 self.visit_body(&node.body);
 
-                let visibility_constraint_id = self.record_visibility_constraint(last_constraint);
+                let visibility_constraint_id = self.record_visibility_constraint(constraint);
                 let mut vis_constraints = vec![visibility_constraint_id];
 
                 let mut post_clauses: Vec<FlowSnapshot> = vec![];
@@ -921,27 +907,26 @@ where
                     // the state that we merge the other snapshots into
                     post_clauses.push(self.flow_snapshot());
                     // we can only take an elif/else branch if none of the previous ones were
-                    // taken
-                    self.flow_restore(no_branch_taken.clone());
-                    self.record_negated_constraint(last_constraint);
+                    // taken, so the block entry state is always `pre_if`
+                    self.flow_restore(pre_if.clone());
+                    for constraint in &constraints {
+                        self.record_negated_constraint(*constraint);
+                    }
 
                     let elif_constraint = if let Some(elif_test) = clause_test {
                         self.visit_expr(elif_test);
-                        // A test expression is evaluated whether the branch is taken or not
-                        no_branch_taken = self.flow_snapshot();
                         let constraint = self.record_expression_constraint(elif_test);
+                        constraints.push(constraint);
                         Some(constraint)
                     } else {
                         None
                     };
-
                     self.visit_body(clause_body);
 
                     for id in &vis_constraints {
                         self.record_negated_visibility_constraint(*id);
                     }
                     if let Some(elif_constraint) = elif_constraint {
-                        last_constraint = elif_constraint;
                         let id = self.record_visibility_constraint(elif_constraint);
                         vis_constraints.push(id);
                     }
@@ -951,7 +936,7 @@ where
                     self.flow_merge(post_clause_state);
                 }
 
-                self.simplify_visibility_constraints(no_branch_taken);
+                self.simplify_visibility_constraints(pre_if);
             }
             ast::Stmt::While(ast::StmtWhile {
                 test,
@@ -1104,35 +1089,37 @@ where
                 cases,
                 range: _,
             }) => {
-                debug_assert_eq!(self.current_match_case, None);
-
                 let subject_expr = self.add_standalone_expression(subject);
                 self.visit_expr(subject);
-                if cases.is_empty() {
+
+                let after_subject = self.flow_snapshot();
+                let Some((first, remaining)) = cases.split_first() else {
                     return;
                 };
 
-                let after_subject = self.flow_snapshot();
-                let mut vis_constraints = vec![];
-                let mut post_case_snapshots = vec![];
-                for (i, case) in cases.iter().enumerate() {
-                    if i != 0 {
-                        post_case_snapshots.push(self.flow_snapshot());
-                        self.flow_restore(after_subject.clone());
-                    }
+                let first_constraint_id = self.add_pattern_constraint(
+                    subject_expr,
+                    &first.pattern,
+                    first.guard.as_deref(),
+                );
 
-                    self.current_match_case = Some(CurrentMatchCase::new(&case.pattern));
-                    self.visit_pattern(&case.pattern);
-                    self.current_match_case = None;
+                self.visit_match_case(first);
+
+                let first_vis_constraint_id =
+                    self.record_visibility_constraint(first_constraint_id);
+                let mut vis_constraints = vec![first_vis_constraint_id];
+
+                let mut post_case_snapshots = vec![];
+                for case in remaining {
+                    post_case_snapshots.push(self.flow_snapshot());
+                    self.flow_restore(after_subject.clone());
                     let constraint_id = self.add_pattern_constraint(
                         subject_expr,
                         &case.pattern,
                         case.guard.as_deref(),
                     );
-                    if let Some(expr) = &case.guard {
-                        self.visit_expr(expr);
-                    }
-                    self.visit_body(&case.body);
+                    self.visit_match_case(case);
+
                     for id in &vis_constraints {
                         self.record_negated_visibility_constraint(*id);
                     }
@@ -1551,6 +1538,18 @@ where
         }
     }
 
+    fn visit_match_case(&mut self, match_case: &'ast ast::MatchCase) {
+        debug_assert!(self.current_match_case.is_none());
+        self.current_match_case = Some(CurrentMatchCase::new(&match_case.pattern));
+        self.visit_pattern(&match_case.pattern);
+        self.current_match_case = None;
+
+        if let Some(expr) = &match_case.guard {
+            self.visit_expr(expr);
+        }
+        self.visit_body(&match_case.body);
+    }
+
     fn visit_pattern(&mut self, pattern: &'ast ast::Pattern) {
         if let ast::Pattern::MatchStar(ast::PatternMatchStar {
             name: Some(name),
@@ -1637,7 +1636,6 @@ impl<'a> From<&'a ast::ExprNamed> for CurrentAssignment<'a> {
     }
 }
 
-#[derive(Debug, PartialEq)]
 struct CurrentMatchCase<'a> {
     /// The pattern that's part of the current match case.
     pattern: &'a ast::Pattern,

crates/red_knot_python_semantic/src/semantic_index/constraint.rs

@@ -22,7 +22,6 @@ pub(crate) enum ConstraintNode<'db> {
 pub(crate) enum PatternConstraintKind<'db> {
     Singleton(Singleton, Option<Expression<'db>>),
     Value(Expression<'db>, Option<Expression<'db>>),
-    Class(Expression<'db>, Option<Expression<'db>>),
     Unsupported,
 }
 

crates/red_knot_python_semantic/src/semantic_index/definition.rs

@@ -74,11 +74,6 @@ impl<'db> Definition<'db> {
             Some(KnownModule::Typing | KnownModule::TypingExtensions)
         )
     }
-
-    pub(crate) fn is_knot_extensions_definition(self, db: &'db dyn Db) -> bool {
-        file_to_module(db, self.file(db))
-            .is_some_and(|module| module.is_known(KnownModule::KnotExtensions))
-    }
 }
 
 #[derive(Copy, Clone, Debug)]

crates/red_knot_python_semantic/src/types/builder.rs

@@ -321,15 +321,7 @@ impl<'db> InnerIntersectionBuilder<'db> {
                     self.add_positive(db, *neg);
                 }
             }
-            Type::Never => {
-                // Adding ~Never to an intersection is a no-op.
-            }
-            Type::Instance(instance) if instance.class.is_known(db, KnownClass::Object) => {
-                // Adding ~object to an intersection results in Never.
-                *self = Self::default();
-                self.positive.insert(Type::Never);
-            }
-            ty @ Type::Dynamic(_) => {
+            ty @ (Type::Any | Type::Unknown | Type::Todo(_)) => {
                 // Adding any of these types to the negative side of an intersection
                 // is equivalent to adding it to the positive side. We do this to
                 // simplify the representation.
@@ -394,34 +386,18 @@ impl<'db> InnerIntersectionBuilder<'db> {
 
 #[cfg(test)]
 mod tests {
-    use super::{IntersectionBuilder, Type, UnionBuilder, UnionType};
+    use super::{IntersectionBuilder, IntersectionType, Type, UnionType};
 
-    use crate::db::tests::setup_db;
-    use crate::types::{KnownClass, Truthiness};
+    use crate::db::tests::{setup_db, TestDb};
+    use crate::types::{global_symbol, todo_type, KnownClass, Truthiness, UnionBuilder};
 
+    use ruff_db::files::system_path_to_file;
+    use ruff_db::system::DbWithTestSystem;
     use test_case::test_case;
 
     #[test]
-    fn build_union_no_elements() {
+    fn build_union() {
         let db = setup_db();
-
-        let empty_union = UnionBuilder::new(&db).build();
-        assert_eq!(empty_union, Type::Never);
-    }
-
-    #[test]
-    fn build_union_single_element() {
-        let db = setup_db();
-
-        let t0 = Type::IntLiteral(0);
-        let union = UnionType::from_elements(&db, [t0]);
-        assert_eq!(union, t0);
-    }
-
-    #[test]
-    fn build_union_two_elements() {
-        let db = setup_db();
-
         let t0 = Type::IntLiteral(0);
         let t1 = Type::IntLiteral(1);
         let union = UnionType::from_elements(&db, [t0, t1]).expect_union();
@@ -429,12 +405,605 @@ mod tests {
         assert_eq!(union.elements(&db), &[t0, t1]);
     }
 
+    #[test]
+    fn build_union_single() {
+        let db = setup_db();
+        let t0 = Type::IntLiteral(0);
+        let ty = UnionType::from_elements(&db, [t0]);
+        assert_eq!(ty, t0);
+    }
+
+    #[test]
+    fn build_union_empty() {
+        let db = setup_db();
+        let ty = UnionBuilder::new(&db).build();
+        assert_eq!(ty, Type::Never);
+    }
+
+    #[test]
+    fn build_union_never() {
+        let db = setup_db();
+        let t0 = Type::IntLiteral(0);
+        let ty = UnionType::from_elements(&db, [t0, Type::Never]);
+        assert_eq!(ty, t0);
+    }
+
+    #[test]
+    fn build_union_bool() {
+        let db = setup_db();
+        let bool_instance_ty = KnownClass::Bool.to_instance(&db);
+
+        let t0 = Type::BooleanLiteral(true);
+        let t1 = Type::BooleanLiteral(true);
+        let t2 = Type::BooleanLiteral(false);
+        let t3 = Type::IntLiteral(17);
+
+        let union = UnionType::from_elements(&db, [t0, t1, t3]).expect_union();
+        assert_eq!(union.elements(&db), &[t0, t3]);
+
+        let union = UnionType::from_elements(&db, [t0, t1, t2, t3]).expect_union();
+        assert_eq!(union.elements(&db), &[bool_instance_ty, t3]);
+
+        let result_ty = UnionType::from_elements(&db, [bool_instance_ty, t0]);
+        assert_eq!(result_ty, bool_instance_ty);
+
+        let result_ty = UnionType::from_elements(&db, [t0, bool_instance_ty]);
+        assert_eq!(result_ty, bool_instance_ty);
+    }
+
+    #[test]
+    fn build_union_flatten() {
+        let db = setup_db();
+        let t0 = Type::IntLiteral(0);
+        let t1 = Type::IntLiteral(1);
+        let t2 = Type::IntLiteral(2);
+        let u1 = UnionType::from_elements(&db, [t0, t1]);
+        let union = UnionType::from_elements(&db, [u1, t2]).expect_union();
+
+        assert_eq!(union.elements(&db), &[t0, t1, t2]);
+    }
+
+    #[test]
+    fn build_union_simplify_subtype() {
+        let db = setup_db();
+        let t0 = KnownClass::Str.to_instance(&db);
+        let t1 = Type::LiteralString;
+        let u0 = UnionType::from_elements(&db, [t0, t1]);
+        let u1 = UnionType::from_elements(&db, [t1, t0]);
+
+        assert_eq!(u0, t0);
+        assert_eq!(u1, t0);
+    }
+
+    #[test]
+    fn build_union_no_simplify_unknown() {
+        let db = setup_db();
+        let t0 = KnownClass::Str.to_instance(&db);
+        let t1 = Type::Unknown;
+        let u0 = UnionType::from_elements(&db, [t0, t1]);
+        let u1 = UnionType::from_elements(&db, [t1, t0]);
+
+        assert_eq!(u0.expect_union().elements(&db), &[t0, t1]);
+        assert_eq!(u1.expect_union().elements(&db), &[t1, t0]);
+    }
+
+    #[test]
+    fn build_union_simplify_multiple_unknown() {
+        let db = setup_db();
+        let t0 = KnownClass::Str.to_instance(&db);
+        let t1 = Type::Unknown;
+
+        let u = UnionType::from_elements(&db, [t0, t1, t1]);
+
+        assert_eq!(u.expect_union().elements(&db), &[t0, t1]);
+    }
+
+    #[test]
+    fn build_union_subsume_multiple() {
+        let db = setup_db();
+        let str_ty = KnownClass::Str.to_instance(&db);
+        let int_ty = KnownClass::Int.to_instance(&db);
+        let object_ty = KnownClass::Object.to_instance(&db);
+        let unknown_ty = Type::Unknown;
+
+        let u0 = UnionType::from_elements(&db, [str_ty, unknown_ty, int_ty, object_ty]);
+
+        assert_eq!(u0.expect_union().elements(&db), &[unknown_ty, object_ty]);
+    }
+
+    impl<'db> IntersectionType<'db> {
+        fn pos_vec(self, db: &'db TestDb) -> Vec<Type<'db>> {
+            self.positive(db).into_iter().copied().collect()
+        }
+
+        fn neg_vec(self, db: &'db TestDb) -> Vec<Type<'db>> {
+            self.negative(db).into_iter().copied().collect()
+        }
+    }
+
+    #[test]
+    fn build_intersection() {
+        let db = setup_db();
+        let t0 = Type::IntLiteral(0);
+        let ta = Type::Any;
+        let intersection = IntersectionBuilder::new(&db)
+            .add_positive(ta)
+            .add_negative(t0)
+            .build()
+            .expect_intersection();
+
+        assert_eq!(intersection.pos_vec(&db), &[ta]);
+        assert_eq!(intersection.neg_vec(&db), &[t0]);
+    }
+
     #[test]
     fn build_intersection_empty_intersection_equals_object() {
         let db = setup_db();
 
-        let intersection = IntersectionBuilder::new(&db).build();
-        assert_eq!(intersection, KnownClass::Object.to_instance(&db));
+        let ty = IntersectionBuilder::new(&db).build();
+
+        assert_eq!(ty, KnownClass::Object.to_instance(&db));
+    }
+
+    #[test]
+    fn build_intersection_flatten_positive() {
+        let db = setup_db();
+        let ta = Type::Any;
+        let t1 = Type::IntLiteral(1);
+        let t2 = Type::IntLiteral(2);
+        let i0 = IntersectionBuilder::new(&db)
+            .add_positive(ta)
+            .add_negative(t1)
+            .build();
+        let intersection = IntersectionBuilder::new(&db)
+            .add_positive(t2)
+            .add_positive(i0)
+            .build()
+            .expect_intersection();
+
+        assert_eq!(intersection.pos_vec(&db), &[t2, ta]);
+        assert_eq!(intersection.neg_vec(&db), &[]);
+    }
+
+    #[test]
+    fn build_intersection_flatten_negative() {
+        let db = setup_db();
+        let ta = Type::Any;
+        let t1 = Type::IntLiteral(1);
+        let t2 = KnownClass::Int.to_instance(&db);
+        // i0 = Any & ~Literal[1]
+        let i0 = IntersectionBuilder::new(&db)
+            .add_positive(ta)
+            .add_negative(t1)
+            .build();
+        // ta_not_i0 = int & ~(Any & ~Literal[1])
+        // -> int & (~Any  | Literal[1])
+        // (~Any is equivalent to Any)
+        // -> (int & Any) | (int & Literal[1])
+        // -> (int & Any) | Literal[1]
+        let ta_not_i0 = IntersectionBuilder::new(&db)
+            .add_positive(t2)
+            .add_negative(i0)
+            .build();
+
+        assert_eq!(ta_not_i0.display(&db).to_string(), "int & Any | Literal[1]");
+    }
+
+    #[test]
+    fn build_intersection_simplify_negative_any() {
+        let db = setup_db();
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(Type::Any)
+            .build();
+        assert_eq!(ty, Type::Any);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::Never)
+            .add_negative(Type::Any)
+            .build();
+        assert_eq!(ty, Type::Never);
+    }
+
+    #[test]
+    fn build_intersection_simplify_multiple_unknown() {
+        let db = setup_db();
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::Unknown)
+            .add_positive(Type::Unknown)
+            .build();
+        assert_eq!(ty, Type::Unknown);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::Unknown)
+            .add_negative(Type::Unknown)
+            .build();
+        assert_eq!(ty, Type::Unknown);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(Type::Unknown)
+            .add_negative(Type::Unknown)
+            .build();
+        assert_eq!(ty, Type::Unknown);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::Unknown)
+            .add_positive(Type::IntLiteral(0))
+            .add_negative(Type::Unknown)
+            .build();
+        assert_eq!(
+            ty,
+            IntersectionBuilder::new(&db)
+                .add_positive(Type::Unknown)
+                .add_positive(Type::IntLiteral(0))
+                .build()
+        );
+    }
+
+    #[test]
+    fn intersection_distributes_over_union() {
+        let db = setup_db();
+        let t0 = Type::IntLiteral(0);
+        let t1 = Type::IntLiteral(1);
+        let ta = Type::Any;
+        let u0 = UnionType::from_elements(&db, [t0, t1]);
+
+        let union = IntersectionBuilder::new(&db)
+            .add_positive(ta)
+            .add_positive(u0)
+            .build()
+            .expect_union();
+        let [Type::Intersection(i0), Type::Intersection(i1)] = union.elements(&db)[..] else {
+            panic!("expected a union of two intersections");
+        };
+        assert_eq!(i0.pos_vec(&db), &[ta, t0]);
+        assert_eq!(i1.pos_vec(&db), &[ta, t1]);
+    }
+
+    #[test]
+    fn intersection_negation_distributes_over_union() {
+        let mut db = setup_db();
+        db.write_dedented(
+            "/src/module.py",
+            r#"
+            class A: ...
+            class B: ...
+            "#,
+        )
+        .unwrap();
+        let module = ruff_db::files::system_path_to_file(&db, "/src/module.py").unwrap();
+
+        let a = global_symbol(&db, module, "A")
+            .expect_type()
+            .to_instance(&db);
+        let b = global_symbol(&db, module, "B")
+            .expect_type()
+            .to_instance(&db);
+
+        // intersection: A & B
+        let intersection = IntersectionBuilder::new(&db)
+            .add_positive(a)
+            .add_positive(b)
+            .build()
+            .expect_intersection();
+        assert_eq!(intersection.pos_vec(&db), &[a, b]);
+        assert_eq!(intersection.neg_vec(&db), &[]);
+
+        // ~intersection => ~A | ~B
+        let negated_intersection = IntersectionBuilder::new(&db)
+            .add_negative(Type::Intersection(intersection))
+            .build()
+            .expect_union();
+
+        // should have as elements ~A and ~B
+        let not_a = a.negate(&db);
+        let not_b = b.negate(&db);
+        assert_eq!(negated_intersection.elements(&db), &[not_a, not_b]);
+    }
+
+    #[test]
+    fn mixed_intersection_negation_distributes_over_union() {
+        let mut db = setup_db();
+        db.write_dedented(
+            "/src/module.py",
+            r#"
+            class A: ...
+            class B: ...
+            "#,
+        )
+        .unwrap();
+        let module = ruff_db::files::system_path_to_file(&db, "/src/module.py").unwrap();
+
+        let a = global_symbol(&db, module, "A")
+            .expect_type()
+            .to_instance(&db);
+        let b = global_symbol(&db, module, "B")
+            .expect_type()
+            .to_instance(&db);
+        let int = KnownClass::Int.to_instance(&db);
+
+        // a_not_b: A & ~B
+        let a_not_b = IntersectionBuilder::new(&db)
+            .add_positive(a)
+            .add_negative(b)
+            .build()
+            .expect_intersection();
+        assert_eq!(a_not_b.pos_vec(&db), &[a]);
+        assert_eq!(a_not_b.neg_vec(&db), &[b]);
+
+        // let's build
+        //         int & ~(A & ~B)
+        //       = int & ~(A & ~B)
+        //       = int & (~A | B)
+        //       = (int & ~A) | (int & B)
+        let t = IntersectionBuilder::new(&db)
+            .add_positive(int)
+            .add_negative(Type::Intersection(a_not_b))
+            .build();
+        assert_eq!(t.display(&db).to_string(), "int & ~A | int & B");
+    }
+
+    #[test]
+    fn build_intersection_self_negation() {
+        let db = setup_db();
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::none(&db))
+            .add_negative(Type::none(&db))
+            .build();
+
+        assert_eq!(ty, Type::Never);
+    }
+
+    #[test]
+    fn build_intersection_simplify_negative_never() {
+        let db = setup_db();
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::none(&db))
+            .add_negative(Type::Never)
+            .build();
+
+        assert_eq!(ty, Type::none(&db));
+    }
+
+    #[test]
+    fn build_intersection_simplify_positive_never() {
+        let db = setup_db();
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::none(&db))
+            .add_positive(Type::Never)
+            .build();
+
+        assert_eq!(ty, Type::Never);
+    }
+
+    #[test]
+    fn build_intersection_simplify_negative_none() {
+        let db = setup_db();
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(Type::none(&db))
+            .add_positive(Type::IntLiteral(1))
+            .build();
+        assert_eq!(ty, Type::IntLiteral(1));
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::IntLiteral(1))
+            .add_negative(Type::none(&db))
+            .build();
+        assert_eq!(ty, Type::IntLiteral(1));
+    }
+
+    #[test]
+    fn build_negative_union_de_morgan() {
+        let db = setup_db();
+
+        let union = UnionBuilder::new(&db)
+            .add(Type::IntLiteral(1))
+            .add(Type::IntLiteral(2))
+            .build();
+        assert_eq!(union.display(&db).to_string(), "Literal[1, 2]");
+
+        let ty = IntersectionBuilder::new(&db).add_negative(union).build();
+
+        let expected = IntersectionBuilder::new(&db)
+            .add_negative(Type::IntLiteral(1))
+            .add_negative(Type::IntLiteral(2))
+            .build();
+
+        assert_eq!(ty.display(&db).to_string(), "~Literal[1] & ~Literal[2]");
+        assert_eq!(ty, expected);
+    }
+
+    #[test]
+    fn build_intersection_simplify_positive_type_and_positive_subtype() {
+        let db = setup_db();
+
+        let t = KnownClass::Str.to_instance(&db);
+        let s = Type::LiteralString;
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(t)
+            .add_positive(s)
+            .build();
+        assert_eq!(ty, s);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(s)
+            .add_positive(t)
+            .build();
+        assert_eq!(ty, s);
+
+        let literal = Type::string_literal(&db, "a");
+        let expected = IntersectionBuilder::new(&db)
+            .add_positive(s)
+            .add_negative(literal)
+            .build();
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(t)
+            .add_negative(literal)
+            .add_positive(s)
+            .build();
+        assert_eq!(ty, expected);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(s)
+            .add_negative(literal)
+            .add_positive(t)
+            .build();
+        assert_eq!(ty, expected);
+    }
+
+    #[test]
+    fn build_intersection_simplify_negative_type_and_negative_subtype() {
+        let db = setup_db();
+
+        let t = KnownClass::Str.to_instance(&db);
+        let s = Type::LiteralString;
+
+        let expected = IntersectionBuilder::new(&db).add_negative(t).build();
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(t)
+            .add_negative(s)
+            .build();
+        assert_eq!(ty, expected);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(s)
+            .add_negative(t)
+            .build();
+        assert_eq!(ty, expected);
+
+        let object = KnownClass::Object.to_instance(&db);
+        let expected = IntersectionBuilder::new(&db)
+            .add_negative(t)
+            .add_positive(object)
+            .build();
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(t)
+            .add_positive(object)
+            .add_negative(s)
+            .build();
+        assert_eq!(ty, expected);
+    }
+
+    #[test]
+    fn build_intersection_simplify_negative_type_and_multiple_negative_subtypes() {
+        let db = setup_db();
+
+        let s1 = Type::IntLiteral(1);
+        let s2 = Type::IntLiteral(2);
+        let t = KnownClass::Int.to_instance(&db);
+
+        let expected = IntersectionBuilder::new(&db).add_negative(t).build();
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(s1)
+            .add_negative(s2)
+            .add_negative(t)
+            .build();
+        assert_eq!(ty, expected);
+    }
+
+    #[test]
+    fn build_intersection_simplify_negative_type_and_positive_subtype() {
+        let db = setup_db();
+
+        let t = KnownClass::Str.to_instance(&db);
+        let s = Type::LiteralString;
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(t)
+            .add_positive(s)
+            .build();
+        assert_eq!(ty, Type::Never);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(s)
+            .add_negative(t)
+            .build();
+        assert_eq!(ty, Type::Never);
+
+        // This should also work in the presence of additional contributions:
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(KnownClass::Object.to_instance(&db))
+            .add_negative(t)
+            .add_positive(s)
+            .build();
+        assert_eq!(ty, Type::Never);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(s)
+            .add_negative(Type::string_literal(&db, "a"))
+            .add_negative(t)
+            .build();
+        assert_eq!(ty, Type::Never);
+    }
+
+    #[test]
+    fn build_intersection_simplify_disjoint_positive_types() {
+        let db = setup_db();
+
+        let t1 = Type::IntLiteral(1);
+        let t2 = Type::none(&db);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(t1)
+            .add_positive(t2)
+            .build();
+        assert_eq!(ty, Type::Never);
+
+        // If there are any negative contributions, they should
+        // be removed too.
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(KnownClass::Str.to_instance(&db))
+            .add_negative(Type::LiteralString)
+            .add_positive(t2)
+            .build();
+        assert_eq!(ty, Type::Never);
+    }
+
+    #[test]
+    fn build_intersection_simplify_disjoint_positive_and_negative_types() {
+        let db = setup_db();
+
+        let t_p = KnownClass::Int.to_instance(&db);
+        let t_n = Type::string_literal(&db, "t_n");
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(t_p)
+            .add_negative(t_n)
+            .build();
+        assert_eq!(ty, t_p);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(t_n)
+            .add_positive(t_p)
+            .build();
+        assert_eq!(ty, t_p);
+
+        let int_literal = Type::IntLiteral(1);
+        let expected = IntersectionBuilder::new(&db)
+            .add_positive(t_p)
+            .add_negative(int_literal)
+            .build();
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(t_p)
+            .add_negative(int_literal)
+            .add_negative(t_n)
+            .build();
+        assert_eq!(ty, expected);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(t_n)
+            .add_negative(int_literal)
+            .add_positive(t_p)
+            .build();
+        assert_eq!(ty, expected);
     }
 
     #[test_case(Type::BooleanLiteral(true))]
@@ -479,4 +1048,85 @@ mod tests {
             .build();
         assert_eq!(ty, Type::BooleanLiteral(!bool_value));
     }
+
+    #[test_case(Type::Any)]
+    #[test_case(Type::Unknown)]
+    #[test_case(todo_type!())]
+    fn build_intersection_t_and_negative_t_does_not_simplify(ty: Type) {
+        let db = setup_db();
+
+        let result = IntersectionBuilder::new(&db)
+            .add_positive(ty)
+            .add_negative(ty)
+            .build();
+        assert_eq!(result, ty);
+
+        let result = IntersectionBuilder::new(&db)
+            .add_negative(ty)
+            .add_positive(ty)
+            .build();
+        assert_eq!(result, ty);
+    }
+
+    #[test]
+    fn build_intersection_of_two_unions_simplify() {
+        let mut db = setup_db();
+        db.write_dedented(
+            "/src/module.py",
+            "
+            class A: ...
+            class B: ...
+            a = A()
+            b = B()
+        ",
+        )
+        .unwrap();
+
+        let file = system_path_to_file(&db, "src/module.py").expect("file to exist");
+
+        let a = global_symbol(&db, file, "a").expect_type();
+        let b = global_symbol(&db, file, "b").expect_type();
+        let union = UnionBuilder::new(&db).add(a).add(b).build();
+        assert_eq!(union.display(&db).to_string(), "A | B");
+        let reversed_union = UnionBuilder::new(&db).add(b).add(a).build();
+        assert_eq!(reversed_union.display(&db).to_string(), "B | A");
+        let intersection = IntersectionBuilder::new(&db)
+            .add_positive(union)
+            .add_positive(reversed_union)
+            .build();
+        assert_eq!(intersection.display(&db).to_string(), "B | A");
+    }
+
+    #[test]
+    fn build_union_of_two_intersections_simplify() {
+        let mut db = setup_db();
+        db.write_dedented(
+            "/src/module.py",
+            "
+            class A: ...
+            class B: ...
+            a = A()
+            b = B()
+        ",
+        )
+        .unwrap();
+
+        let file = system_path_to_file(&db, "src/module.py").expect("file to exist");
+
+        let a = global_symbol(&db, file, "a").expect_type();
+        let b = global_symbol(&db, file, "b").expect_type();
+        let intersection = IntersectionBuilder::new(&db)
+            .add_positive(a)
+            .add_positive(b)
+            .build();
+        let reversed_intersection = IntersectionBuilder::new(&db)
+            .add_positive(b)
+            .add_positive(a)
+            .build();
+        let union = UnionBuilder::new(&db)
+            .add(intersection)
+            .add(reversed_intersection)
+            .build();
+        assert_eq!(union.display(&db).to_string(), "A & B");
+    }
 }

crates/red_knot_python_semantic/src/types/call.rs

@@ -1,32 +1,17 @@
 use super::context::InferContext;
-use super::diagnostic::{CALL_NON_CALLABLE, TYPE_ASSERTION_FAILURE};
-use super::{Severity, Signature, Type, TypeArrayDisplay, UnionBuilder};
-use crate::types::diagnostic::STATIC_ASSERT_ERROR;
+use super::diagnostic::CALL_NON_CALLABLE;
+use super::{Severity, Type, TypeArrayDisplay, UnionBuilder};
 use crate::Db;
 use ruff_db::diagnostic::DiagnosticId;
 use ruff_python_ast as ast;
 
-mod arguments;
-mod bind;
-
-pub(super) use arguments::{Argument, CallArguments};
-pub(super) use bind::{bind_call, CallBinding};
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub(super) enum StaticAssertionErrorKind<'db> {
-    ArgumentIsFalse,
-    ArgumentIsFalsy(Type<'db>),
-    ArgumentTruthinessIsAmbiguous(Type<'db>),
-    CustomError(&'db str),
-}
-
 #[derive(Debug, Clone, PartialEq, Eq)]
 pub(super) enum CallOutcome<'db> {
     Callable {
-        binding: CallBinding<'db>,
+        return_ty: Type<'db>,
     },
     RevealType {
-        binding: CallBinding<'db>,
+        return_ty: Type<'db>,
         revealed_ty: Type<'db>,
     },
     NotCallable {
@@ -40,20 +25,12 @@ pub(super) enum CallOutcome<'db> {
         called_ty: Type<'db>,
         call_outcome: Box<CallOutcome<'db>>,
     },
-    StaticAssertionError {
-        binding: CallBinding<'db>,
-        error_kind: StaticAssertionErrorKind<'db>,
-    },
-    AssertType {
-        binding: CallBinding<'db>,
-        asserted_ty: Type<'db>,
-    },
 }
 
 impl<'db> CallOutcome<'db> {
     /// Create a new `CallOutcome::Callable` with given return type.
-    pub(super) fn callable(binding: CallBinding<'db>) -> CallOutcome<'db> {
-        CallOutcome::Callable { binding }
+    pub(super) fn callable(return_ty: Type<'db>) -> CallOutcome<'db> {
+        CallOutcome::Callable { return_ty }
     }
 
     /// Create a new `CallOutcome::NotCallable` with given not-callable type.
@@ -62,9 +39,9 @@ impl<'db> CallOutcome<'db> {
     }
 
     /// Create a new `CallOutcome::RevealType` with given revealed and return types.
-    pub(super) fn revealed(binding: CallBinding<'db>, revealed_ty: Type<'db>) -> CallOutcome<'db> {
+    pub(super) fn revealed(return_ty: Type<'db>, revealed_ty: Type<'db>) -> CallOutcome<'db> {
         CallOutcome::RevealType {
-            binding,
+            return_ty,
             revealed_ty,
         }
     }
@@ -80,22 +57,14 @@ impl<'db> CallOutcome<'db> {
         }
     }
 
-    /// Create a new `CallOutcome::AssertType` with given revealed and return types.
-    pub(super) fn asserted(binding: CallBinding<'db>, asserted_ty: Type<'db>) -> CallOutcome<'db> {
-        CallOutcome::AssertType {
-            binding,
-            asserted_ty,
-        }
-    }
-
     /// Get the return type of the call, or `None` if not callable.
     pub(super) fn return_ty(&self, db: &'db dyn Db) -> Option<Type<'db>> {
         match self {
-            Self::Callable { binding } => Some(binding.return_ty()),
+            Self::Callable { return_ty } => Some(*return_ty),
             Self::RevealType {
-                binding,
+                return_ty,
                 revealed_ty: _,
-            } => Some(binding.return_ty()),
+            } => Some(*return_ty),
             Self::NotCallable { not_callable_ty: _ } => None,
             Self::Union {
                 outcomes,
@@ -109,16 +78,11 @@ impl<'db> CallOutcome<'db> {
                     match (acc, ty) {
                         (None, None) => None,
                         (None, Some(ty)) => Some(UnionBuilder::new(db).add(ty)),
-                        (Some(builder), ty) => Some(builder.add(ty.unwrap_or(Type::unknown()))),
+                        (Some(builder), ty) => Some(builder.add(ty.unwrap_or(Type::Unknown))),
                     }
                 })
                 .map(UnionBuilder::build),
             Self::PossiblyUnboundDunderCall { call_outcome, .. } => call_outcome.return_ty(db),
-            Self::StaticAssertionError { .. } => Some(Type::none(db)),
-            Self::AssertType {
-                binding,
-                asserted_ty: _,
-            } => Some(binding.return_ty()),
         }
     }
 
@@ -199,30 +163,23 @@ impl<'db> CallOutcome<'db> {
         context: &InferContext<'db>,
         node: ast::AnyNodeRef,
     ) -> Result<Type<'db>, NotCallableError<'db>> {
-        // TODO should this method emit diagnostics directly, or just return results that allow the
-        // caller to decide about emitting diagnostics? Currently it emits binding diagnostics, but
-        // only non-callable diagnostics in the union case, which is inconsistent.
         match self {
-            Self::Callable { binding } => {
-                binding.report_diagnostics(context, node);
-                Ok(binding.return_ty())
-            }
+            Self::Callable { return_ty } => Ok(*return_ty),
             Self::RevealType {
-                binding,
+                return_ty,
                 revealed_ty,
             } => {
-                binding.report_diagnostics(context, node);
                 context.report_diagnostic(
                     node,
                     DiagnosticId::RevealedType,
                     Severity::Info,
                     format_args!("Revealed type is `{}`", revealed_ty.display(context.db())),
                 );
-                Ok(binding.return_ty())
+                Ok(*return_ty)
             }
             Self::NotCallable { not_callable_ty } => Err(NotCallableError::Type {
                 not_callable_ty: *not_callable_ty,
-                return_ty: Type::unknown(),
+                return_ty: Type::Unknown,
             }),
             Self::PossiblyUnboundDunderCall {
                 called_ty,
@@ -231,7 +188,7 @@ impl<'db> CallOutcome<'db> {
                 callable_ty: *called_ty,
                 return_ty: call_outcome
                     .return_ty(context.db())
-                    .unwrap_or(Type::unknown()),
+                    .unwrap_or(Type::Unknown),
             }),
             Self::Union {
                 outcomes,
@@ -244,14 +201,14 @@ impl<'db> CallOutcome<'db> {
                     let return_ty = match outcome {
                         Self::NotCallable { not_callable_ty } => {
                             not_callable.push(*not_callable_ty);
-                            Type::unknown()
+                            Type::Unknown
                         }
                         Self::RevealType {
-                            binding,
+                            return_ty,
                             revealed_ty: _,
                         } => {
                             if revealed {
-                                binding.return_ty()
+                                *return_ty
                             } else {
                                 revealed = true;
                                 outcome.unwrap_with_diagnostic(context, node)
@@ -280,73 +237,6 @@ impl<'db> CallOutcome<'db> {
                     }),
                 }
             }
-            CallOutcome::StaticAssertionError {
-                binding,
-                error_kind,
-            } => {
-                binding.report_diagnostics(context, node);
-
-                match error_kind {
-                    StaticAssertionErrorKind::ArgumentIsFalse => {
-                        context.report_lint(
-                            &STATIC_ASSERT_ERROR,
-                            node,
-                            format_args!("Static assertion error: argument evaluates to `False`"),
-                        );
-                    }
-                    StaticAssertionErrorKind::ArgumentIsFalsy(parameter_ty) => {
-                        context.report_lint(
-                            &STATIC_ASSERT_ERROR,
-                            node,
-                            format_args!(
-                                "Static assertion error: argument of type `{parameter_ty}` is statically known to be falsy",
-                                parameter_ty=parameter_ty.display(context.db())
-                            ),
-                        );
-                    }
-                    StaticAssertionErrorKind::ArgumentTruthinessIsAmbiguous(parameter_ty) => {
-                        context.report_lint(
-                            &STATIC_ASSERT_ERROR,
-                            node,
-                            format_args!(
-                                "Static assertion error: argument of type `{parameter_ty}` has an ambiguous static truthiness",
-                                parameter_ty=parameter_ty.display(context.db())
-                            ),
-                        );
-                    }
-                    StaticAssertionErrorKind::CustomError(message) => {
-                        context.report_lint(
-                            &STATIC_ASSERT_ERROR,
-                            node,
-                            format_args!("Static assertion error: {message}"),
-                        );
-                    }
-                }
-
-                Ok(Type::unknown())
-            }
-            CallOutcome::AssertType {
-                binding,
-                asserted_ty,
-            } => {
-                let [actual_ty, _asserted] = binding.parameter_tys() else {
-                    return Ok(binding.return_ty());
-                };
-
-                if !actual_ty.is_gradual_equivalent_to(context.db(), *asserted_ty) {
-                    context.report_lint(
-                        &TYPE_ASSERTION_FAILURE,
-                        node,
-                        format_args!(
-                            "Actual type `{}` is not the same as asserted type `{}`",
-                            actual_ty.display(context.db()),
-                            asserted_ty.display(context.db()),
-                        ),
-                    );
-                }
-
-                Ok(binding.return_ty())
-            }
         }
     }
 }

crates/red_knot_python_semantic/src/types/call/arguments.rs

@@ -1,73 +0,0 @@
-use super::Type;
-
-/// Typed arguments for a single call, in source order.
-#[derive(Clone, Debug, Default)]
-pub(crate) struct CallArguments<'a, 'db>(Vec<Argument<'a, 'db>>);
-
-impl<'a, 'db> CallArguments<'a, 'db> {
-    /// Create a [`CallArguments`] from an iterator over non-variadic positional argument types.
-    pub(crate) fn positional(positional_tys: impl IntoIterator<Item = Type<'db>>) -> Self {
-        positional_tys
-            .into_iter()
-            .map(Argument::Positional)
-            .collect()
-    }
-
-    /// Prepend an extra positional argument.
-    pub(crate) fn with_self(&self, self_ty: Type<'db>) -> Self {
-        let mut arguments = Vec::with_capacity(self.0.len() + 1);
-        arguments.push(Argument::Synthetic(self_ty));
-        arguments.extend_from_slice(&self.0);
-        Self(arguments)
-    }
-
-    pub(crate) fn iter(&self) -> impl Iterator<Item = &Argument<'a, 'db>> {
-        self.0.iter()
-    }
-
-    // TODO this should be eliminated in favor of [`bind_call`]
-    pub(crate) fn first_argument(&self) -> Option<Type<'db>> {
-        self.0.first().map(Argument::ty)
-    }
-}
-
-impl<'db, 'a, 'b> IntoIterator for &'b CallArguments<'a, 'db> {
-    type Item = &'b Argument<'a, 'db>;
-    type IntoIter = std::slice::Iter<'b, Argument<'a, 'db>>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.0.iter()
-    }
-}
-
-impl<'a, 'db> FromIterator<Argument<'a, 'db>> for CallArguments<'a, 'db> {
-    fn from_iter<T: IntoIterator<Item = Argument<'a, 'db>>>(iter: T) -> Self {
-        Self(iter.into_iter().collect())
-    }
-}
-
-#[derive(Clone, Debug)]
-pub(crate) enum Argument<'a, 'db> {
-    /// The synthetic `self` or `cls` argument, which doesn't appear explicitly at the call site.
-    Synthetic(Type<'db>),
-    /// A positional argument.
-    Positional(Type<'db>),
-    /// A starred positional argument (e.g. `*args`).
-    Variadic(Type<'db>),
-    /// A keyword argument (e.g. `a=1`).
-    Keyword { name: &'a str, ty: Type<'db> },
-    /// The double-starred keywords argument (e.g. `**kwargs`).
-    Keywords(Type<'db>),
-}
-
-impl<'db> Argument<'_, 'db> {
-    fn ty(&self) -> Type<'db> {
-        match self {
-            Self::Synthetic(ty) => *ty,
-            Self::Positional(ty) => *ty,
-            Self::Variadic(ty) => *ty,
-            Self::Keyword { name: _, ty } => *ty,
-            Self::Keywords(ty) => *ty,
-        }
-    }
-}

crates/red_knot_python_semantic/src/types/call/bind.rs

@@ -1,411 +0,0 @@
-use super::{Argument, CallArguments, InferContext, Signature, Type};
-use crate::db::Db;
-use crate::types::diagnostic::{
-    INVALID_ARGUMENT_TYPE, MISSING_ARGUMENT, PARAMETER_ALREADY_ASSIGNED,
-    TOO_MANY_POSITIONAL_ARGUMENTS, UNKNOWN_ARGUMENT,
-};
-use crate::types::signatures::Parameter;
-use crate::types::UnionType;
-use ruff_python_ast as ast;
-
-/// Bind a [`CallArguments`] against a callable [`Signature`].
-///
-/// The returned [`CallBinding`] provides the return type of the call, the bound types for all
-/// parameters, and any errors resulting from binding the call.
-pub(crate) fn bind_call<'db>(
-    db: &'db dyn Db,
-    arguments: &CallArguments<'_, 'db>,
-    signature: &Signature<'db>,
-    callable_ty: Option<Type<'db>>,
-) -> CallBinding<'db> {
-    let parameters = signature.parameters();
-    // The type assigned to each parameter at this call site.
-    let mut parameter_tys = vec![None; parameters.len()];
-    let mut errors = vec![];
-    let mut next_positional = 0;
-    let mut first_excess_positional = None;
-    let mut num_synthetic_args = 0;
-    let get_argument_index = |argument_index: usize, num_synthetic_args: usize| {
-        if argument_index >= num_synthetic_args {
-            // Adjust the argument index to skip synthetic args, which don't appear at the call
-            // site and thus won't be in the Call node arguments list.
-            Some(argument_index - num_synthetic_args)
-        } else {
-            // we are erroring on a synthetic argument, we'll just emit the diagnostic on the
-            // entire Call node, since there's no argument node for this argument at the call site
-            None
-        }
-    };
-    for (argument_index, argument) in arguments.iter().enumerate() {
-        let (index, parameter, argument_ty, positional) = match argument {
-            Argument::Positional(ty) | Argument::Synthetic(ty) => {
-                if matches!(argument, Argument::Synthetic(_)) {
-                    num_synthetic_args += 1;
-                }
-                let Some((index, parameter)) = parameters
-                    .get_positional(next_positional)
-                    .map(|param| (next_positional, param))
-                    .or_else(|| parameters.variadic())
-                else {
-                    first_excess_positional.get_or_insert(argument_index);
-                    next_positional += 1;
-                    continue;
-                };
-                next_positional += 1;
-                (index, parameter, ty, !parameter.is_variadic())
-            }
-            Argument::Keyword { name, ty } => {
-                let Some((index, parameter)) = parameters
-                    .keyword_by_name(name)
-                    .or_else(|| parameters.keyword_variadic())
-                else {
-                    errors.push(CallBindingError::UnknownArgument {
-                        argument_name: ast::name::Name::new(name),
-                        argument_index: get_argument_index(argument_index, num_synthetic_args),
-                    });
-                    continue;
-                };
-                (index, parameter, ty, false)
-            }
-
-            Argument::Variadic(_) | Argument::Keywords(_) => {
-                // TODO
-                continue;
-            }
-        };
-        if let Some(expected_ty) = parameter.annotated_ty() {
-            if !argument_ty.is_assignable_to(db, expected_ty) {
-                errors.push(CallBindingError::InvalidArgumentType {
-                    parameter: ParameterContext::new(parameter, index, positional),
-                    argument_index: get_argument_index(argument_index, num_synthetic_args),
-                    expected_ty,
-                    provided_ty: *argument_ty,
-                });
-            }
-        }
-        if let Some(existing) = parameter_tys[index].replace(*argument_ty) {
-            if parameter.is_variadic() {
-                let union = UnionType::from_elements(db, [existing, *argument_ty]);
-                parameter_tys[index].replace(union);
-            } else {
-                errors.push(CallBindingError::ParameterAlreadyAssigned {
-                    argument_index: get_argument_index(argument_index, num_synthetic_args),
-                    parameter: ParameterContext::new(parameter, index, positional),
-                });
-            }
-        }
-    }
-    if let Some(first_excess_argument_index) = first_excess_positional {
-        errors.push(CallBindingError::TooManyPositionalArguments {
-            first_excess_argument_index: get_argument_index(
-                first_excess_argument_index,
-                num_synthetic_args,
-            ),
-            expected_positional_count: parameters.positional().count(),
-            provided_positional_count: next_positional,
-        });
-    }
-    let mut missing = vec![];
-    for (index, bound_ty) in parameter_tys.iter().enumerate() {
-        if bound_ty.is_none() {
-            let param = &parameters[index];
-            if param.is_variadic() || param.is_keyword_variadic() || param.default_ty().is_some() {
-                // variadic/keywords and defaulted arguments are not required
-                continue;
-            }
-            missing.push(ParameterContext::new(param, index, false));
-        }
-    }
-
-    if !missing.is_empty() {
-        errors.push(CallBindingError::MissingArguments {
-            parameters: ParameterContexts(missing),
-        });
-    }
-
-    CallBinding {
-        callable_ty,
-        return_ty: signature.return_ty.unwrap_or(Type::unknown()),
-        parameter_tys: parameter_tys
-            .into_iter()
-            .map(|opt_ty| opt_ty.unwrap_or(Type::unknown()))
-            .collect(),
-        errors,
-    }
-}
-
-#[derive(Debug, Clone, PartialEq, Eq)]
-pub(crate) struct CallBinding<'db> {
-    /// Type of the callable object (function, class...)
-    callable_ty: Option<Type<'db>>,
-
-    /// Return type of the call.
-    return_ty: Type<'db>,
-
-    /// Bound types for parameters, in parameter source order.
-    parameter_tys: Box<[Type<'db>]>,
-
-    /// Call binding errors, if any.
-    errors: Vec<CallBindingError<'db>>,
-}
-
-impl<'db> CallBinding<'db> {
-    // TODO remove this constructor and construct always from `bind_call`
-    pub(crate) fn from_return_ty(return_ty: Type<'db>) -> Self {
-        Self {
-            callable_ty: None,
-            return_ty,
-            parameter_tys: Box::default(),
-            errors: vec![],
-        }
-    }
-
-    pub(crate) fn set_return_ty(&mut self, return_ty: Type<'db>) {
-        self.return_ty = return_ty;
-    }
-
-    pub(crate) fn return_ty(&self) -> Type<'db> {
-        self.return_ty
-    }
-
-    pub(crate) fn parameter_tys(&self) -> &[Type<'db>] {
-        &self.parameter_tys
-    }
-
-    pub(crate) fn one_parameter_ty(&self) -> Option<Type<'db>> {
-        match self.parameter_tys() {
-            [ty] => Some(*ty),
-            _ => None,
-        }
-    }
-
-    pub(crate) fn two_parameter_tys(&self) -> Option<(Type<'db>, Type<'db>)> {
-        match self.parameter_tys() {
-            [first, second] => Some((*first, *second)),
-            _ => None,
-        }
-    }
-
-    fn callable_name(&self, db: &'db dyn Db) -> Option<&str> {
-        match self.callable_ty {
-            Some(Type::FunctionLiteral(function)) => Some(function.name(db)),
-            Some(Type::ClassLiteral(class_type)) => Some(class_type.class.name(db)),
-            _ => None,
-        }
-    }
-
-    pub(super) fn report_diagnostics(&self, context: &InferContext<'db>, node: ast::AnyNodeRef) {
-        let callable_name = self.callable_name(context.db());
-        for error in &self.errors {
-            error.report_diagnostic(context, node, callable_name);
-        }
-    }
-}
-
-/// Information needed to emit a diagnostic regarding a parameter.
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) struct ParameterContext {
-    name: Option<ast::name::Name>,
-    index: usize,
-
-    /// Was the argument for this parameter passed positionally, and matched to a non-variadic
-    /// positional parameter? (If so, we will provide the index in the diagnostic, not just the
-    /// name.)
-    positional: bool,
-}
-
-impl ParameterContext {
-    fn new(parameter: &Parameter, index: usize, positional: bool) -> Self {
-        Self {
-            name: parameter.display_name(),
-            index,
-            positional,
-        }
-    }
-}
-
-impl std::fmt::Display for ParameterContext {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        if let Some(name) = &self.name {
-            if self.positional {
-                write!(f, "{} (`{name}`)", self.index + 1)
-            } else {
-                write!(f, "`{name}`")
-            }
-        } else {
-            write!(f, "{}", self.index + 1)
-        }
-    }
-}
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) struct ParameterContexts(Vec<ParameterContext>);
-
-impl std::fmt::Display for ParameterContexts {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        let mut iter = self.0.iter();
-        if let Some(first) = iter.next() {
-            write!(f, "{first}")?;
-            for param in iter {
-                f.write_str(", ")?;
-                write!(f, "{param}")?;
-            }
-        }
-        Ok(())
-    }
-}
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) enum CallBindingError<'db> {
-    /// The type of an argument is not assignable to the annotated type of its corresponding
-    /// parameter.
-    InvalidArgumentType {
-        parameter: ParameterContext,
-        argument_index: Option<usize>,
-        expected_ty: Type<'db>,
-        provided_ty: Type<'db>,
-    },
-    /// One or more required parameters (that is, with no default) is not supplied by any argument.
-    MissingArguments { parameters: ParameterContexts },
-    /// A call argument can't be matched to any parameter.
-    UnknownArgument {
-        argument_name: ast::name::Name,
-        argument_index: Option<usize>,
-    },
-    /// More positional arguments are provided in the call than can be handled by the signature.
-    TooManyPositionalArguments {
-        first_excess_argument_index: Option<usize>,
-        expected_positional_count: usize,
-        provided_positional_count: usize,
-    },
-    /// Multiple arguments were provided for a single parameter.
-    ParameterAlreadyAssigned {
-        argument_index: Option<usize>,
-        parameter: ParameterContext,
-    },
-}
-
-impl<'db> CallBindingError<'db> {
-    pub(super) fn report_diagnostic(
-        &self,
-        context: &InferContext<'db>,
-        node: ast::AnyNodeRef,
-        callable_name: Option<&str>,
-    ) {
-        match self {
-            Self::InvalidArgumentType {
-                parameter,
-                argument_index,
-                expected_ty,
-                provided_ty,
-            } => {
-                let provided_ty_display = provided_ty.display(context.db());
-                let expected_ty_display = expected_ty.display(context.db());
-                context.report_lint(
-                    &INVALID_ARGUMENT_TYPE,
-                    Self::get_node(node, *argument_index),
-                    format_args!(
-                        "Object of type `{provided_ty_display}` cannot be assigned to \
-                        parameter {parameter}{}; expected type `{expected_ty_display}`",
-                        if let Some(callable_name) = callable_name {
-                            format!(" of function `{callable_name}`")
-                        } else {
-                            String::new()
-                        }
-                    ),
-                );
-            }
-
-            Self::TooManyPositionalArguments {
-                first_excess_argument_index,
-                expected_positional_count,
-                provided_positional_count,
-            } => {
-                context.report_lint(
-                    &TOO_MANY_POSITIONAL_ARGUMENTS,
-                    Self::get_node(node, *first_excess_argument_index),
-                    format_args!(
-                        "Too many positional arguments{}: expected \
-                        {expected_positional_count}, got {provided_positional_count}",
-                        if let Some(callable_name) = callable_name {
-                            format!(" to function `{callable_name}`")
-                        } else {
-                            String::new()
-                        }
-                    ),
-                );
-            }
-
-            Self::MissingArguments { parameters } => {
-                let s = if parameters.0.len() == 1 { "" } else { "s" };
-                context.report_lint(
-                    &MISSING_ARGUMENT,
-                    node,
-                    format_args!(
-                        "No argument{s} provided for required parameter{s} {parameters}{}",
-                        if let Some(callable_name) = callable_name {
-                            format!(" of function `{callable_name}`")
-                        } else {
-                            String::new()
-                        }
-                    ),
-                );
-            }
-
-            Self::UnknownArgument {
-                argument_name,
-                argument_index,
-            } => {
-                context.report_lint(
-                    &UNKNOWN_ARGUMENT,
-                    Self::get_node(node, *argument_index),
-                    format_args!(
-                        "Argument `{argument_name}` does not match any known parameter{}",
-                        if let Some(callable_name) = callable_name {
-                            format!(" of function `{callable_name}`")
-                        } else {
-                            String::new()
-                        }
-                    ),
-                );
-            }
-
-            Self::ParameterAlreadyAssigned {
-                argument_index,
-                parameter,
-            } => {
-                context.report_lint(
-                    &PARAMETER_ALREADY_ASSIGNED,
-                    Self::get_node(node, *argument_index),
-                    format_args!(
-                        "Multiple values provided for parameter {parameter}{}",
-                        if let Some(callable_name) = callable_name {
-                            format!(" of function `{callable_name}`")
-                        } else {
-                            String::new()
-                        }
-                    ),
-                );
-            }
-        }
-    }
-
-    fn get_node(node: ast::AnyNodeRef, argument_index: Option<usize>) -> ast::AnyNodeRef {
-        // If we have a Call node and an argument index, report the diagnostic on the correct
-        // argument node; otherwise, report it on the entire provided node.
-        match (node, argument_index) {
-            (ast::AnyNodeRef::ExprCall(call_node), Some(argument_index)) => {
-                match call_node
-                    .arguments
-                    .arguments_source_order()
-                    .nth(argument_index)
-                    .expect("argument index should not be out of range")
-                {
-                    ast::ArgOrKeyword::Arg(expr) => expr.into(),
-                    ast::ArgOrKeyword::Keyword(keyword) => keyword.into(),
-                }
-            }
-            _ => node,
-        }
-    }
-}

crates/red_knot_python_semantic/src/types/class_base.rs

@@ -1,5 +1,5 @@
 use crate::types::{
-    todo_type, Class, ClassLiteralType, DynamicType, KnownClass, KnownInstanceType, Type,
+    todo_type, Class, ClassLiteralType, KnownClass, KnownInstanceType, TodoType, Type,
 };
 use crate::Db;
 use itertools::Either;
@@ -8,29 +8,16 @@ use itertools::Either;
 ///
 /// This is much more limited than the [`Type`] enum:
 /// all types that would be invalid to have as a class base are
-/// transformed into [`ClassBase::unknown`]
+/// transformed into [`ClassBase::Unknown`]
 #[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, salsa::Update)]
 pub enum ClassBase<'db> {
-    Dynamic(DynamicType),
+    Any,
+    Unknown,
+    Todo(TodoType),
     Class(Class<'db>),
 }
 
 impl<'db> ClassBase<'db> {
-    pub const fn any() -> Self {
-        Self::Dynamic(DynamicType::Any)
-    }
-
-    pub const fn unknown() -> Self {
-        Self::Dynamic(DynamicType::Unknown)
-    }
-
-    pub const fn is_dynamic(self) -> bool {
-        match self {
-            ClassBase::Dynamic(_) => true,
-            ClassBase::Class(_) => false,
-        }
-    }
-
     pub fn display(self, db: &'db dyn Db) -> impl std::fmt::Display + 'db {
         struct Display<'db> {
             base: ClassBase<'db>,
@@ -40,7 +27,9 @@ impl<'db> ClassBase<'db> {
         impl std::fmt::Display for Display<'_> {
             fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
                 match self.base {
-                    ClassBase::Dynamic(dynamic) => dynamic.fmt(f),
+                    ClassBase::Any => f.write_str("Any"),
+                    ClassBase::Todo(todo) => todo.fmt(f),
+                    ClassBase::Unknown => f.write_str("Unknown"),
                     ClassBase::Class(class) => write!(f, "<class '{}'>", class.name(self.db)),
                 }
             }
@@ -54,7 +43,7 @@ impl<'db> ClassBase<'db> {
         KnownClass::Object
             .to_class_literal(db)
             .into_class_literal()
-            .map_or(Self::unknown(), |ClassLiteralType { class }| {
+            .map_or(Self::Unknown, |ClassLiteralType { class }| {
                 Self::Class(class)
             })
     }
@@ -64,7 +53,9 @@ impl<'db> ClassBase<'db> {
     /// Return `None` if `ty` is not an acceptable type for a class base.
     pub(super) fn try_from_ty(db: &'db dyn Db, ty: Type<'db>) -> Option<Self> {
         match ty {
-            Type::Dynamic(dynamic) => Some(Self::Dynamic(dynamic)),
+            Type::Any => Some(Self::Any),
+            Type::Unknown => Some(Self::Unknown),
+            Type::Todo(todo) => Some(Self::Todo(todo)),
             Type::ClassLiteral(ClassLiteralType { class }) => Some(Self::Class(class)),
             Type::Union(_) => None, // TODO -- forces consideration of multiple possible MROs?
             Type::Intersection(_) => None, // TODO -- probably incorrect?
@@ -102,12 +93,8 @@ impl<'db> ClassBase<'db> {
                 | KnownInstanceType::Required
                 | KnownInstanceType::TypeAlias
                 | KnownInstanceType::ReadOnly
-                | KnownInstanceType::Optional
-                | KnownInstanceType::Not
-                | KnownInstanceType::Intersection
-                | KnownInstanceType::TypeOf => None,
-                KnownInstanceType::Unknown => Some(Self::unknown()),
-                KnownInstanceType::Any => Some(Self::any()),
+                | KnownInstanceType::Optional => None,
+                KnownInstanceType::Any => Some(Self::Any),
                 // TODO: Classes inheriting from `typing.Type` et al. also have `Generic` in their MRO
                 KnownInstanceType::Dict => {
                     Self::try_from_ty(db, KnownClass::Dict.to_class_literal(db))
@@ -152,7 +139,7 @@ impl<'db> ClassBase<'db> {
     pub(super) fn into_class(self) -> Option<Class<'db>> {
         match self {
             Self::Class(class) => Some(class),
-            Self::Dynamic(_) => None,
+            _ => None,
         }
     }
 
@@ -162,7 +149,13 @@ impl<'db> ClassBase<'db> {
         db: &'db dyn Db,
     ) -> Either<impl Iterator<Item = ClassBase<'db>>, impl Iterator<Item = ClassBase<'db>>> {
         match self {
-            ClassBase::Dynamic(_) => Either::Left([self, ClassBase::object(db)].into_iter()),
+            ClassBase::Any => Either::Left([ClassBase::Any, ClassBase::object(db)].into_iter()),
+            ClassBase::Unknown => {
+                Either::Left([ClassBase::Unknown, ClassBase::object(db)].into_iter())
+            }
+            ClassBase::Todo(todo) => {
+                Either::Left([ClassBase::Todo(todo), ClassBase::object(db)].into_iter())
+            }
             ClassBase::Class(class) => Either::Right(class.iter_mro(db)),
         }
     }
@@ -177,7 +170,9 @@ impl<'db> From<Class<'db>> for ClassBase<'db> {
 impl<'db> From<ClassBase<'db>> for Type<'db> {
     fn from(value: ClassBase<'db>) -> Self {
         match value {
-            ClassBase::Dynamic(dynamic) => Type::Dynamic(dynamic),
+            ClassBase::Any => Type::Any,
+            ClassBase::Todo(todo) => Type::Todo(todo),
+            ClassBase::Unknown => Type::Unknown,
             ClassBase::Class(class) => Type::class_literal(class),
         }
     }

crates/red_knot_python_semantic/src/types/context.rs

@@ -162,11 +162,6 @@ impl<'db> InferContext<'db> {
         }
     }
 
-    /// Are we currently inferring types in a stub file?
-    pub(crate) fn in_stub(&self) -> bool {
-        self.file.is_stub(self.db().upcast())
-    }
-
     #[must_use]
     pub(crate) fn finish(mut self) -> TypeCheckDiagnostics {
         self.bomb.defuse();

crates/red_knot_python_semantic/src/types/diagnostic.rs

@@ -30,35 +30,27 @@ pub(crate) fn register_lints(registry: &mut LintRegistryBuilder) {
     registry.register_lint(&INCOMPATIBLE_SLOTS);
     registry.register_lint(&INCONSISTENT_MRO);
     registry.register_lint(&INDEX_OUT_OF_BOUNDS);
-    registry.register_lint(&INVALID_ARGUMENT_TYPE);
     registry.register_lint(&INVALID_ASSIGNMENT);
     registry.register_lint(&INVALID_BASE);
     registry.register_lint(&INVALID_CONTEXT_MANAGER);
     registry.register_lint(&INVALID_DECLARATION);
     registry.register_lint(&INVALID_EXCEPTION_CAUGHT);
-    registry.register_lint(&INVALID_METACLASS);
     registry.register_lint(&INVALID_PARAMETER_DEFAULT);
     registry.register_lint(&INVALID_RAISE);
     registry.register_lint(&INVALID_TYPE_FORM);
     registry.register_lint(&INVALID_TYPE_VARIABLE_CONSTRAINTS);
-    registry.register_lint(&MISSING_ARGUMENT);
     registry.register_lint(&NON_SUBSCRIPTABLE);
     registry.register_lint(&NOT_ITERABLE);
-    registry.register_lint(&PARAMETER_ALREADY_ASSIGNED);
     registry.register_lint(&POSSIBLY_UNBOUND_ATTRIBUTE);
     registry.register_lint(&POSSIBLY_UNBOUND_IMPORT);
     registry.register_lint(&POSSIBLY_UNRESOLVED_REFERENCE);
     registry.register_lint(&SUBCLASS_OF_FINAL_CLASS);
-    registry.register_lint(&TYPE_ASSERTION_FAILURE);
-    registry.register_lint(&TOO_MANY_POSITIONAL_ARGUMENTS);
     registry.register_lint(&UNDEFINED_REVEAL);
-    registry.register_lint(&UNKNOWN_ARGUMENT);
     registry.register_lint(&UNRESOLVED_ATTRIBUTE);
     registry.register_lint(&UNRESOLVED_IMPORT);
     registry.register_lint(&UNRESOLVED_REFERENCE);
     registry.register_lint(&UNSUPPORTED_OPERATOR);
     registry.register_lint(&ZERO_STEPSIZE_IN_SLICE);
-    registry.register_lint(&STATIC_ASSERT_ERROR);
 
     // String annotations
     registry.register_lint(&BYTE_STRING_TYPE_ANNOTATION);
@@ -234,27 +226,6 @@ declare_lint! {
     }
 }
 
-declare_lint! {
-    /// ## What it does
-    /// Detects call arguments whose type is not assignable to the corresponding typed parameter.
-    ///
-    /// ## Why is this bad?
-    /// Passing an argument of a type the function (or callable object) does not accept violates
-    /// the expectations of the function author and may cause unexpected runtime errors within the
-    /// body of the function.
-    ///
-    /// ## Examples
-    /// ```python
-    /// def func(x: int): ...
-    /// func("foo")  # error: [invalid-argument-type]
-    /// ```
-    pub(crate) static INVALID_ARGUMENT_TYPE = {
-        summary: "detects call arguments whose type is not assignable to the corresponding typed parameter",
-        status: LintStatus::preview("1.0.0"),
-        default_level: Level::Error,
-    }
-}
-
 declare_lint! {
     /// TODO #14889
     pub(crate) static INVALID_ASSIGNMENT = {
@@ -292,7 +263,6 @@ declare_lint! {
 }
 
 declare_lint! {
-    /// ## What it does
     /// Checks for exception handlers that catch non-exception classes.
     ///
     /// ## Why is this bad?
@@ -327,33 +297,6 @@ declare_lint! {
     }
 }
 
-declare_lint! {
-    /// ## What it does
-    /// Checks for arguments to `metaclass=` that are invalid.
-    ///
-    /// ## Why is this bad?
-    /// Python allows arbitrary expressions to be used as the argument to `metaclass=`.
-    /// These expressions, however, need to be callable and accept the same arguments
-    /// as `type.__new__`.
-    ///
-    /// ## Example
-    ///
-    /// ```python
-    /// def f(): ...
-    ///
-    /// # TypeError: f() takes 0 positional arguments but 3 were given
-    /// class B(metaclass=f): ...
-    /// ```
-    ///
-    /// ## References
-    /// - [Python documentation: Metaclasses](https://docs.python.org/3/reference/datamodel.html#metaclasses)
-    pub(crate) static INVALID_METACLASS = {
-        summary: "detects invalid `metaclass=` arguments",
-        status: LintStatus::preview("1.0.0"),
-        default_level: Level::Error,
-    }
-}
-
 declare_lint! {
     /// ## What it does
     /// Checks for default values that can't be assigned to the parameter's annotated type.
@@ -432,25 +375,6 @@ declare_lint! {
     }
 }
 
-declare_lint! {
-    /// ## What it does
-    /// Checks for missing required arguments in a call.
-    ///
-    /// ## Why is this bad?
-    /// Failing to provide a required argument will raise a `TypeError` at runtime.
-    ///
-    /// ## Examples
-    /// ```python
-    /// def func(x: int): ...
-    /// func()  # TypeError: func() missing 1 required positional argument: 'x'
-    /// ```
-    pub(crate) static MISSING_ARGUMENT = {
-        summary: "detects missing required arguments in a call",
-        status: LintStatus::preview("1.0.0"),
-        default_level: Level::Error,
-    }
-}
-
 declare_lint! {
     /// ## What it does
     /// Checks for subscripting objects that do not support subscripting.
@@ -489,27 +413,6 @@ declare_lint! {
     }
 }
 
-declare_lint! {
-    /// ## What it does
-    /// Checks for calls which provide more than one argument for a single parameter.
-    ///
-    /// ## Why is this bad?
-    /// Providing multiple values for a single parameter will raise a `TypeError` at runtime.
-    ///
-    /// ## Examples
-    ///
-    /// ```python
-    /// def f(x: int) -> int: ...
-    ///
-    /// f(1, x=2)  # Error raised here
-    /// ```
-    pub(crate) static PARAMETER_ALREADY_ASSIGNED = {
-        summary: "detects multiple arguments for the same parameter",
-        status: LintStatus::preview("1.0.0"),
-        default_level: Level::Error,
-    }
-}
-
 declare_lint! {
     /// ## What it does
     /// Checks for possibly unbound attributes.
@@ -576,49 +479,6 @@ declare_lint! {
     }
 }
 
-declare_lint! {
-    /// ## What it does
-    /// Checks for `assert_type()` calls where the actual type
-    /// is not the same as the asserted type.
-    ///
-    /// ## Why is this bad?
-    /// `assert_type()` allows confirming the inferred type of a certain value.
-    ///
-    /// ## Example
-    ///
-    /// ```python
-    /// def _(x: int):
-    ///     assert_type(x, int)  # fine
-    ///     assert_type(x, str)  # error: Actual type does not match asserted type
-    /// ```
-    pub(crate) static TYPE_ASSERTION_FAILURE = {
-        summary: "detects failed type assertions",
-        status: LintStatus::preview("1.0.0"),
-        default_level: Level::Error,
-    }
-}
-
-declare_lint! {
-    /// ## What it does
-    /// Checks for calls that pass more positional arguments than the callable can accept.
-    ///
-    /// ## Why is this bad?
-    /// Passing too many positional arguments will raise `TypeError` at runtime.
-    ///
-    /// ## Example
-    ///
-    /// ```python
-    /// def f(): ...
-    ///
-    /// f("foo")  # Error raised here
-    /// ```
-    pub(crate) static TOO_MANY_POSITIONAL_ARGUMENTS = {
-        summary: "detects calls passing too many positional arguments",
-        status: LintStatus::preview("1.0.0"),
-        default_level: Level::Error,
-    }
-}
-
 declare_lint! {
     /// ## What it does
     /// Checks for calls to `reveal_type` without importing it.
@@ -635,27 +495,6 @@ declare_lint! {
     }
 }
 
-declare_lint! {
-    /// ## What it does
-    /// Checks for keyword arguments in calls that don't match any parameter of the callable.
-    ///
-    /// ## Why is this bad?
-    /// Providing an unknown keyword argument will raise `TypeError` at runtime.
-    ///
-    /// ## Example
-    ///
-    /// ```python
-    /// def f(x: int) -> int: ...
-    ///
-    /// f(x=1, y=2)  # Error raised here
-    /// ```
-    pub(crate) static UNKNOWN_ARGUMENT = {
-        summary: "detects unknown keyword arguments in calls",
-        status: LintStatus::preview("1.0.0"),
-        default_level: Level::Error,
-    }
-}
-
 declare_lint! {
     /// ## What it does
     /// Checks for unresolved attributes.
@@ -731,25 +570,6 @@ declare_lint! {
     }
 }
 
-declare_lint! {
-    /// ## What it does
-    /// Makes sure that the argument of `static_assert` is statically known to be true.
-    ///
-    /// ## Examples
-    /// ```python
-    /// from knot_extensions import static_assert
-    ///
-    /// static_assert(1 + 1 == 3)  # error: evaluates to `False`
-    ///
-    /// static_assert(int(2.0 * 3.0) == 6)  # error: does not have a statically known truthiness
-    /// ```
-    pub(crate) static STATIC_ASSERT_ERROR = {
-        summary: "Failed static assertion",
-        status: LintStatus::preview("1.0.0"),
-        default_level: Level::Error,
-    }
-}
-
 #[derive(Debug, Eq, PartialEq, Clone)]
 pub struct TypeCheckDiagnostic {
     pub(crate) id: DiagnosticId,

crates/red_knot_python_semantic/src/types/display.rs

@@ -8,8 +8,8 @@ use ruff_python_literal::escape::AsciiEscape;
 
 use crate::types::class_base::ClassBase;
 use crate::types::{
-    ClassLiteralType, InstanceType, IntersectionType, KnownClass, StringLiteralType, Type,
-    UnionType,
+    ClassLiteralType, InstanceType, IntersectionType, KnownClass, StringLiteralType,
+    SubclassOfType, Type, UnionType,
 };
 use crate::Db;
 use rustc_hash::FxHashMap;
@@ -65,8 +65,9 @@ struct DisplayRepresentation<'db> {
 impl Display for DisplayRepresentation<'_> {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         match self.ty {
-            Type::Dynamic(dynamic) => dynamic.fmt(f),
+            Type::Any => f.write_str("Any"),
             Type::Never => f.write_str("Never"),
+            Type::Unknown => f.write_str("Unknown"),
             Type::Instance(InstanceType { class }) => {
                 let representation = match class.known(self.db) {
                     Some(KnownClass::NoneType) => "None",
@@ -75,17 +76,24 @@ impl Display for DisplayRepresentation<'_> {
                 };
                 f.write_str(representation)
             }
+            // `[Type::Todo]`'s display should be explicit that is not a valid display of
+            // any other type
+            Type::Todo(todo) => write!(f, "@Todo{todo}"),
             Type::ModuleLiteral(module) => {
                 write!(f, "<module '{}'>", module.module(self.db).name())
             }
             // TODO functions and classes should display using a fully qualified name
             Type::ClassLiteral(ClassLiteralType { class }) => f.write_str(class.name(self.db)),
-            Type::SubclassOf(subclass_of_ty) => match subclass_of_ty.subclass_of() {
+            Type::SubclassOf(SubclassOfType {
+                base: ClassBase::Class(class),
+            }) => {
                 // Only show the bare class name here; ClassBase::display would render this as
                 // type[<class 'Foo'>] instead of type[Foo].
-                ClassBase::Class(class) => write!(f, "type[{}]", class.name(self.db)),
-                ClassBase::Dynamic(dynamic) => write!(f, "type[{dynamic}]"),
-            },
+                write!(f, "type[{}]", class.name(self.db))
+            }
+            Type::SubclassOf(SubclassOfType { base }) => {
+                write!(f, "type[{}]", base.display(self.db))
+            }
             Type::KnownInstance(known_instance) => f.write_str(known_instance.repr(self.db)),
             Type::FunctionLiteral(function) => f.write_str(function.name(self.db)),
             Type::Union(union) => union.display(self.db).fmt(f),
@@ -169,9 +177,12 @@ impl Display for DisplayUnionType<'_> {
 
         for element in elements {
             if let Ok(kind) = CondensedDisplayTypeKind::try_from(*element) {
-                let Some(condensed_kind) = grouped_condensed_kinds.remove(&kind) else {
+                let Some(mut condensed_kind) = grouped_condensed_kinds.remove(&kind) else {
                     continue;
                 };
+                if kind == CondensedDisplayTypeKind::Int {
+                    condensed_kind.sort_unstable_by_key(|ty| ty.expect_int_literal());
+                }
                 join.entry(&DisplayLiteralGroup {
                     literals: condensed_kind,
                     db: self.db,
@@ -212,12 +223,17 @@ impl Display for DisplayLiteralGroup<'_> {
 
 /// Enumeration of literal types that are displayed in a "condensed way" inside `Literal` slices.
 ///
-/// For example, `Literal[1] | Literal[2] | Literal["s"]` is displayed as `"Literal[1, 2, "s"]"`.
+/// For example, `Literal[1] | Literal[2]` is displayed as `"Literal[1, 2]"`.
+/// Not all `Literal` types are displayed using `Literal` slices
+/// (e.g. it would be inappropriate to display `LiteralString`
+/// as `Literal[LiteralString]`).
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
 enum CondensedDisplayTypeKind {
     Class,
     Function,
-    LiteralExpression,
+    Int,
+    String,
+    Bytes,
 }
 
 impl TryFrom<Type<'_>> for CondensedDisplayTypeKind {
@@ -227,10 +243,9 @@ impl TryFrom<Type<'_>> for CondensedDisplayTypeKind {
         match value {
             Type::ClassLiteral(_) => Ok(Self::Class),
             Type::FunctionLiteral(_) => Ok(Self::Function),
-            Type::IntLiteral(_)
-            | Type::StringLiteral(_)
-            | Type::BytesLiteral(_)
-            | Type::BooleanLiteral(_) => Ok(Self::LiteralExpression),
+            Type::IntLiteral(_) => Ok(Self::Int),
+            Type::StringLiteral(_) => Ok(Self::String),
+            Type::BytesLiteral(_) => Ok(Self::Bytes),
             _ => Err(()),
         }
     }
@@ -357,8 +372,64 @@ impl Display for DisplayStringLiteralType<'_> {
 
 #[cfg(test)]
 mod tests {
+    use ruff_db::files::system_path_to_file;
+    use ruff_db::system::DbWithTestSystem;
+
     use crate::db::tests::setup_db;
-    use crate::types::{SliceLiteralType, StringLiteralType, Type};
+    use crate::types::{global_symbol, SliceLiteralType, StringLiteralType, Type, UnionType};
+
+    #[test]
+    fn test_condense_literal_display_by_type() -> anyhow::Result<()> {
+        let mut db = setup_db();
+
+        db.write_dedented(
+            "src/main.py",
+            "
+            def foo(x: int) -> int:
+                return x + 1
+
+            def bar(s: str) -> str:
+                return s
+
+            class A: ...
+            class B: ...
+            ",
+        )?;
+        let mod_file = system_path_to_file(&db, "src/main.py").expect("file to exist");
+
+        let union_elements = &[
+            Type::Unknown,
+            Type::IntLiteral(-1),
+            global_symbol(&db, mod_file, "A").expect_type(),
+            Type::string_literal(&db, "A"),
+            Type::bytes_literal(&db, &[0u8]),
+            Type::bytes_literal(&db, &[7u8]),
+            Type::IntLiteral(0),
+            Type::IntLiteral(1),
+            Type::string_literal(&db, "B"),
+            global_symbol(&db, mod_file, "foo").expect_type(),
+            global_symbol(&db, mod_file, "bar").expect_type(),
+            global_symbol(&db, mod_file, "B").expect_type(),
+            Type::BooleanLiteral(true),
+            Type::none(&db),
+        ];
+        let union = UnionType::from_elements(&db, union_elements).expect_union();
+        let display = format!("{}", union.display(&db));
+        assert_eq!(
+            display,
+            concat!(
+                "Unknown | ",
+                "Literal[-1, 0, 1] | ",
+                "Literal[A, B] | ",
+                "Literal[\"A\", \"B\"] | ",
+                "Literal[b\"\\x00\", b\"\\x07\"] | ",
+                "Literal[foo, bar] | ",
+                "Literal[True] | ",
+                "None"
+            )
+        );
+        Ok(())
+    }
 
     #[test]
     fn test_slice_literal_display() {

crates/red_knot_python_semantic/src/types/mro.rs

@@ -34,7 +34,7 @@ impl<'db> Mro<'db> {
     pub(super) fn from_error(db: &'db dyn Db, class: Class<'db>) -> Self {
         Self::from([
             ClassBase::Class(class),
-            ClassBase::unknown(),
+            ClassBase::Unknown,
             ClassBase::object(db),
         ])
     }

crates/red_knot_python_semantic/src/types/narrow.rs

@@ -7,8 +7,8 @@ use crate::semantic_index::expression::Expression;
 use crate::semantic_index::symbol::{ScopeId, ScopedSymbolId, SymbolTable};
 use crate::semantic_index::symbol_table;
 use crate::types::{
-    infer_expression_types, ClassLiteralType, IntersectionBuilder, KnownClass, KnownFunction,
-    SubclassOfType, Truthiness, Type, UnionBuilder,
+    infer_expression_types, ClassLiteralType, IntersectionBuilder, KnownClass,
+    KnownConstraintFunction, KnownFunction, Truthiness, Type, UnionBuilder,
 };
 use crate::Db;
 use itertools::Itertools;
@@ -83,39 +83,28 @@ fn all_negative_narrowing_constraints_for_expression<'db>(
     NarrowingConstraintsBuilder::new(db, ConstraintNode::Expression(expression), false).finish()
 }
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
-pub enum KnownConstraintFunction {
-    /// `builtins.isinstance`
-    IsInstance,
-    /// `builtins.issubclass`
-    IsSubclass,
-}
-
-impl KnownConstraintFunction {
-    /// Generate a constraint from the type of a `classinfo` argument to `isinstance` or `issubclass`.
-    ///
-    /// The `classinfo` argument can be a class literal, a tuple of (tuples of) class literals. PEP 604
-    /// union types are not yet supported. Returns `None` if the `classinfo` argument has a wrong type.
-    fn generate_constraint<'db>(self, db: &'db dyn Db, classinfo: Type<'db>) -> Option<Type<'db>> {
-        let constraint_fn = |class| match self {
-            KnownConstraintFunction::IsInstance => Type::instance(class),
-            KnownConstraintFunction::IsSubclass => SubclassOfType::from(db, class),
-        };
-
-        match classinfo {
-            Type::Tuple(tuple) => {
-                let mut builder = UnionBuilder::new(db);
-                for element in tuple.elements(db) {
-                    builder = builder.add(self.generate_constraint(db, *element)?);
-                }
-                Some(builder.build())
+/// Generate a constraint from the type of a `classinfo` argument to `isinstance` or `issubclass`.
+///
+/// The `classinfo` argument can be a class literal, a tuple of (tuples of) class literals. PEP 604
+/// union types are not yet supported. Returns `None` if the `classinfo` argument has a wrong type.
+fn generate_classinfo_constraint<'db, F>(
+    db: &'db dyn Db,
+    classinfo: &Type<'db>,
+    to_constraint: F,
+) -> Option<Type<'db>>
+where
+    F: Fn(ClassLiteralType<'db>) -> Type<'db> + Copy,
+{
+    match classinfo {
+        Type::Tuple(tuple) => {
+            let mut builder = UnionBuilder::new(db);
+            for element in tuple.elements(db) {
+                builder = builder.add(generate_classinfo_constraint(db, element, to_constraint)?);
             }
-            Type::ClassLiteral(ClassLiteralType { class }) => Some(constraint_fn(class)),
-            Type::SubclassOf(subclass_of_ty) => {
-                subclass_of_ty.subclass_of().into_class().map(constraint_fn)
-            }
-            _ => None,
+            Some(builder.build())
         }
+        Type::ClassLiteral(class_literal_type) => Some(to_constraint(*class_literal_type)),
+        _ => None,
     }
 }
 
@@ -233,9 +222,6 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
             PatternConstraintKind::Singleton(singleton, _guard) => {
                 self.evaluate_match_pattern_singleton(*subject, *singleton)
             }
-            PatternConstraintKind::Class(cls, _guard) => {
-                self.evaluate_match_pattern_class(*subject, *cls)
-            }
             // TODO: support more pattern kinds
             PatternConstraintKind::Value(..) | PatternConstraintKind::Unsupported => None,
         }
@@ -443,13 +429,24 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
                 let class_info_ty =
                     inference.expression_ty(class_info.scoped_expression_id(self.db, scope));
 
-                function
-                    .generate_constraint(self.db, class_info_ty)
-                    .map(|constraint| {
+                let to_constraint = match function {
+                    KnownConstraintFunction::IsInstance => {
+                        |class_literal: ClassLiteralType<'db>| Type::instance(class_literal.class)
+                    }
+                    KnownConstraintFunction::IsSubclass => {
+                        |class_literal: ClassLiteralType<'db>| {
+                            Type::subclass_of(class_literal.class)
+                        }
+                    }
+                };
+
+                generate_classinfo_constraint(self.db, &class_info_ty, to_constraint).map(
+                    |constraint| {
                         let mut constraints = NarrowingConstraints::default();
                         constraints.insert(symbol, constraint.negate_if(self.db, !is_positive));
                         constraints
-                    })
+                    },
+                )
             }
             // for the expression `bool(E)`, we further narrow the type based on `E`
             Type::ClassLiteral(class_type)
@@ -489,27 +486,6 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
         }
     }
 
-    fn evaluate_match_pattern_class(
-        &mut self,
-        subject: Expression<'db>,
-        cls: Expression<'db>,
-    ) -> Option<NarrowingConstraints<'db>> {
-        if let Some(ast::ExprName { id, .. }) = subject.node_ref(self.db).as_name_expr() {
-            // SAFETY: we should always have a symbol for every Name node.
-            let symbol = self.symbols().symbol_id_by_name(id).unwrap();
-            let scope = self.scope();
-            let inference = infer_expression_types(self.db, cls);
-            let ty = inference
-                .expression_ty(cls.node_ref(self.db).scoped_expression_id(self.db, scope))
-                .to_instance(self.db);
-            let mut constraints = NarrowingConstraints::default();
-            constraints.insert(symbol, ty);
-            Some(constraints)
-        } else {
-            None
-        }
-    }
-
     fn evaluate_bool_op(
         &mut self,
         expr_bool_op: &ExprBoolOp,

crates/red_knot_python_semantic/src/types/property_tests.rs

@@ -123,61 +123,14 @@ impl Arbitrary for Ty {
     }
 
     fn shrink(&self) -> Box<dyn Iterator<Item = Self>> {
+        // This is incredibly naive. We can do much better here by
+        // trying various subsets of the elements in unions, tuples,
+        // and intersections. For now, we only try to shrink by
+        // reducing unions/tuples/intersections to a single element.
         match self.clone() {
-            Ty::Union(types) => Box::new(types.shrink().filter_map(|elts| match elts.len() {
-                0 => None,
-                1 => Some(elts.into_iter().next().unwrap()),
-                _ => Some(Ty::Union(elts)),
-            })),
-            Ty::Tuple(types) => Box::new(types.shrink().filter_map(|elts| match elts.len() {
-                0 => None,
-                1 => Some(elts.into_iter().next().unwrap()),
-                _ => Some(Ty::Tuple(elts)),
-            })),
-            Ty::Intersection { pos, neg } => {
-                // Shrinking on intersections is not exhaustive!
-                //
-                // We try to shrink the positive side or the negative side,
-                // but we aren't shrinking both at the same time.
-                //
-                // This should remove positive or negative constraints but
-                // won't shrink (A & B & ~C & ~D) to (A & ~C) in one shrink
-                // iteration.
-                //
-                // Instead, it hopes that (A & B & ~C) or (A & ~C & ~D) fails
-                // so that shrinking can happen there.
-                let pos_orig = pos.clone();
-                let neg_orig = neg.clone();
-                Box::new(
-                    // we shrink negative constraints first, as
-                    // intersections with only negative constraints are
-                    // more confusing
-                    neg.shrink()
-                        .map(move |shrunk_neg| Ty::Intersection {
-                            pos: pos_orig.clone(),
-                            neg: shrunk_neg,
-                        })
-                        .chain(pos.shrink().map(move |shrunk_pos| Ty::Intersection {
-                            pos: shrunk_pos,
-                            neg: neg_orig.clone(),
-                        }))
-                        .filter_map(|ty| {
-                            if let Ty::Intersection { pos, neg } = &ty {
-                                match (pos.len(), neg.len()) {
-                                    // an empty intersection does not mean
-                                    // anything
-                                    (0, 0) => None,
-                                    // a single positive element should be
-                                    // unwrapped
-                                    (1, 0) => Some(pos[0].clone()),
-                                    _ => Some(ty),
-                                }
-                            } else {
-                                unreachable!()
-                            }
-                        }),
-                )
-            }
+            Ty::Union(types) => Box::new(types.into_iter()),
+            Ty::Tuple(types) => Box::new(types.into_iter()),
+            Ty::Intersection { pos, neg } => Box::new(pos.into_iter().chain(neg)),
             _ => Box::new(std::iter::empty()),
         }
     }
@@ -220,8 +173,6 @@ macro_rules! type_property_test {
 }
 
 mod stable {
-    use crate::types::{KnownClass, Type};
-
     // `T` is equivalent to itself.
     type_property_test!(
         equivalent_to_is_reflexive, db,
@@ -258,6 +209,12 @@ mod stable {
         forall types s, t. s.is_subtype_of(db, t) => !s.is_disjoint_from(db, t) || s.is_never()
     );
 
+    // `T` can be assigned to itself.
+    type_property_test!(
+        assignable_to_is_reflexive, db,
+        forall types t. t.is_assignable_to(db, t)
+    );
+
     // `S <: T` implies that `S` can be assigned to `T`.
     type_property_test!(
         subtype_of_implies_assignable_to, db,
@@ -281,30 +238,6 @@ mod stable {
         non_fully_static_types_do_not_participate_in_subtyping, db,
         forall types s, t. !s.is_fully_static(db) => !s.is_subtype_of(db, t) && !t.is_subtype_of(db, s)
     );
-
-    // All types should be assignable to `object`
-    type_property_test!(
-        all_types_assignable_to_object, db,
-        forall types t. t.is_assignable_to(db, KnownClass::Object.to_instance(db))
-    );
-
-    // And for fully static types, they should also be subtypes of `object`
-    type_property_test!(
-        all_fully_static_types_subtype_of_object, db,
-        forall types t. t.is_fully_static(db) => t.is_subtype_of(db, KnownClass::Object.to_instance(db))
-    );
-
-    // Never should be assignable to every type
-    type_property_test!(
-        never_assignable_to_every_type, db,
-        forall types t. Type::Never.is_assignable_to(db, t)
-    );
-
-    // And it should be a subtype of all fully static types
-    type_property_test!(
-        never_subtype_of_every_fully_static_type, db,
-        forall types t. t.is_fully_static(db) => Type::Never.is_subtype_of(db, t)
-    );
 }
 
 /// This module contains property tests that currently lead to many false positives.
@@ -315,32 +248,6 @@ mod stable {
 /// tests to the `stable` section. In the meantime, it can still be useful to run these
 /// tests (using [`types::property_tests::flaky`]), to see if there are any new obvious bugs.
 mod flaky {
-    use crate::{
-        db::tests::TestDb,
-        types::{IntersectionBuilder, Type},
-    };
-
-    // Currently fails due to https://github.com/astral-sh/ruff/issues/14899
-    // `T` can be assigned to itself.
-    type_property_test!(
-        assignable_to_is_reflexive, db,
-        forall types t. t.is_assignable_to(db, t)
-    );
-
-    // Currently fails due to https://github.com/astral-sh/ruff/issues/14899
-    // An intersection of two types should be assignable to both of them
-    fn intersection<'db>(db: &'db TestDb, s: Type<'db>, t: Type<'db>) -> Type<'db> {
-        IntersectionBuilder::new(db)
-            .add_positive(s)
-            .add_positive(t)
-            .build()
-    }
-
-    type_property_test!(
-        intersection_assignable_to_both, db,
-        forall types s, t. intersection(db, s, t).is_assignable_to(db, s) && intersection(db, s, t).is_assignable_to(db, t)
-    );
-
     // `S <: T` and `T <: S` implies that `S` is equivalent to `T`.
     type_property_test!(
         subtype_of_is_antisymmetric, db,

crates/red_knot_python_semantic/src/types/signatures.rs

@@ -1,3 +1,4 @@
+#![allow(dead_code)]
 use super::{definition_expression_ty, Type};
 use crate::Db;
 use crate::{semantic_index::definition::Definition, types::todo_type};
@@ -6,18 +7,10 @@ use ruff_python_ast::{self as ast, name::Name};
 /// A typed callable signature.
 #[derive(Clone, Debug, PartialEq, Eq)]
 pub(crate) struct Signature<'db> {
-    /// Parameters, in source order.
-    ///
-    /// The ordering of parameters in a valid signature must be: first positional-only parameters,
-    /// then positional-or-keyword, then optionally the variadic parameter, then keyword-only
-    /// parameters, and last, optionally the variadic keywords parameter. Parameters with defaults
-    /// must come after parameters without defaults.
-    ///
-    /// We may get invalid signatures, though, and need to handle them without panicking.
     parameters: Parameters<'db>,
 
-    /// Annotated return type, if any.
-    pub(crate) return_ty: Option<Type<'db>>,
+    /// Annotated return type (Unknown if no annotation.)
+    pub(crate) return_ty: Type<'db>,
 }
 
 impl<'db> Signature<'db> {
@@ -25,7 +18,7 @@ impl<'db> Signature<'db> {
     pub(crate) fn todo() -> Self {
         Self {
             parameters: Parameters::todo(),
-            return_ty: Some(todo_type!("return type")),
+            return_ty: todo_type!("return type"),
         }
     }
 
@@ -35,13 +28,17 @@ impl<'db> Signature<'db> {
         definition: Definition<'db>,
         function_node: &'db ast::StmtFunctionDef,
     ) -> Self {
-        let return_ty = function_node.returns.as_ref().map(|returns| {
-            if function_node.is_async {
-                todo_type!("generic types.CoroutineType")
-            } else {
-                definition_expression_ty(db, definition, returns.as_ref())
-            }
-        });
+        let return_ty = function_node
+            .returns
+            .as_ref()
+            .map(|returns| {
+                if function_node.is_async {
+                    todo_type!("generic types.CoroutineType")
+                } else {
+                    definition_expression_ty(db, definition, returns.as_ref())
+                }
+            })
+            .unwrap_or(Type::Unknown);
 
         Self {
             parameters: Parameters::from_parameters(
@@ -52,32 +49,45 @@ impl<'db> Signature<'db> {
             return_ty,
         }
     }
-
-    /// Return the parameters in this signature.
-    pub(crate) fn parameters(&self) -> &Parameters<'db> {
-        &self.parameters
-    }
 }
 
-// TODO: use SmallVec here once invariance bug is fixed
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) struct Parameters<'db>(Vec<Parameter<'db>>);
+/// The parameters portion of a typed signature.
+///
+/// The ordering of parameters is always as given in this struct: first positional-only parameters,
+/// then positional-or-keyword, then optionally the variadic parameter, then keyword-only
+/// parameters, and last, optionally the variadic keywords parameter.
+#[derive(Clone, Debug, Default, PartialEq, Eq)]
+pub(super) struct Parameters<'db> {
+    /// Parameters which may only be filled by positional arguments.
+    positional_only: Box<[ParameterWithDefault<'db>]>,
+
+    /// Parameters which may be filled by positional or keyword arguments.
+    positional_or_keyword: Box<[ParameterWithDefault<'db>]>,
+
+    /// The `*args` variadic parameter, if any.
+    variadic: Option<Parameter<'db>>,
+
+    /// Parameters which may only be filled by keyword arguments.
+    keyword_only: Box<[ParameterWithDefault<'db>]>,
+
+    /// The `**kwargs` variadic keywords parameter, if any.
+    keywords: Option<Parameter<'db>>,
+}
 
 impl<'db> Parameters<'db> {
     /// Return todo parameters: (*args: Todo, **kwargs: Todo)
     fn todo() -> Self {
-        Self(vec![
-            Parameter {
+        Self {
+            variadic: Some(Parameter {
                 name: Some(Name::new_static("args")),
-                annotated_ty: Some(todo_type!("todo signature *args")),
-                kind: ParameterKind::Variadic,
-            },
-            Parameter {
+                annotated_ty: todo_type!(),
+            }),
+            keywords: Some(Parameter {
                 name: Some(Name::new_static("kwargs")),
-                annotated_ty: Some(todo_type!("todo signature **kwargs")),
-                kind: ParameterKind::KeywordVariadic,
-            },
-        ])
+                annotated_ty: todo_type!(),
+            }),
+            ..Default::default()
+        }
     }
 
     fn from_parameters(
@@ -93,238 +103,94 @@ impl<'db> Parameters<'db> {
             kwarg,
             range: _,
         } = parameters;
-        let default_ty = |parameter_with_default: &ast::ParameterWithDefault| {
-            parameter_with_default
-                .default
-                .as_deref()
-                .map(|default| definition_expression_ty(db, definition, default))
-        };
-        let positional_only = posonlyargs.iter().map(|arg| {
-            Parameter::from_node_and_kind(
-                db,
-                definition,
-                &arg.parameter,
-                ParameterKind::PositionalOnly {
-                    default_ty: default_ty(arg),
-                },
-            )
-        });
-        let positional_or_keyword = args.iter().map(|arg| {
-            Parameter::from_node_and_kind(
-                db,
-                definition,
-                &arg.parameter,
-                ParameterKind::PositionalOrKeyword {
-                    default_ty: default_ty(arg),
-                },
-            )
-        });
+        let positional_only = posonlyargs
+            .iter()
+            .map(|arg| ParameterWithDefault::from_node(db, definition, arg))
+            .collect();
+        let positional_or_keyword = args
+            .iter()
+            .map(|arg| ParameterWithDefault::from_node(db, definition, arg))
+            .collect();
         let variadic = vararg
             .as_ref()
-            .map(|arg| Parameter::from_node_and_kind(db, definition, arg, ParameterKind::Variadic));
-        let keyword_only = kwonlyargs.iter().map(|arg| {
-            Parameter::from_node_and_kind(
-                db,
-                definition,
-                &arg.parameter,
-                ParameterKind::KeywordOnly {
-                    default_ty: default_ty(arg),
-                },
-            )
-        });
-        let keywords = kwarg.as_ref().map(|arg| {
-            Parameter::from_node_and_kind(db, definition, arg, ParameterKind::KeywordVariadic)
-        });
-        Self(
-            positional_only
-                .chain(positional_or_keyword)
-                .chain(variadic)
-                .chain(keyword_only)
-                .chain(keywords)
-                .collect(),
-        )
-    }
-
-    pub(crate) fn len(&self) -> usize {
-        self.0.len()
-    }
-
-    pub(crate) fn iter(&self) -> std::slice::Iter<Parameter<'db>> {
-        self.0.iter()
-    }
-
-    /// Iterate initial positional parameters, not including variadic parameter, if any.
-    ///
-    /// For a valid signature, this will be all positional parameters. In an invalid signature,
-    /// there could be non-initial positional parameters; effectively, we just won't consider those
-    /// to be positional, which is fine.
-    pub(crate) fn positional(&self) -> impl Iterator<Item = &Parameter<'db>> {
-        self.iter().take_while(|param| param.is_positional())
-    }
-
-    /// Return parameter at given index, or `None` if index is out-of-range.
-    pub(crate) fn get(&self, index: usize) -> Option<&Parameter<'db>> {
-        self.0.get(index)
-    }
-
-    /// Return positional parameter at given index, or `None` if `index` is out of range.
-    ///
-    /// Does not return variadic parameter.
-    pub(crate) fn get_positional(&self, index: usize) -> Option<&Parameter<'db>> {
-        self.get(index)
-            .and_then(|parameter| parameter.is_positional().then_some(parameter))
-    }
-
-    /// Return the variadic parameter (`*args`), if any, and its index, or `None`.
-    pub(crate) fn variadic(&self) -> Option<(usize, &Parameter<'db>)> {
-        self.iter()
-            .enumerate()
-            .find(|(_, parameter)| parameter.is_variadic())
-    }
-
-    /// Return parameter (with index) for given name, or `None` if no such parameter.
-    ///
-    /// Does not return keywords (`**kwargs`) parameter.
-    ///
-    /// In an invalid signature, there could be multiple parameters with the same name; we will
-    /// just return the first that matches.
-    pub(crate) fn keyword_by_name(&self, name: &str) -> Option<(usize, &Parameter<'db>)> {
-        self.iter()
-            .enumerate()
-            .find(|(_, parameter)| parameter.callable_by_name(name))
-    }
-
-    /// Return the keywords parameter (`**kwargs`), if any, and its index, or `None`.
-    pub(crate) fn keyword_variadic(&self) -> Option<(usize, &Parameter<'db>)> {
-        self.iter()
-            .enumerate()
-            .rfind(|(_, parameter)| parameter.is_keyword_variadic())
-    }
-}
-
-impl<'db, 'a> IntoIterator for &'a Parameters<'db> {
-    type Item = &'a Parameter<'db>;
-    type IntoIter = std::slice::Iter<'a, Parameter<'db>>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.0.iter()
-    }
-}
-
-impl<'db> std::ops::Index<usize> for Parameters<'db> {
-    type Output = Parameter<'db>;
-
-    fn index(&self, index: usize) -> &Self::Output {
-        &self.0[index]
+            .map(|arg| Parameter::from_node(db, definition, arg));
+        let keyword_only = kwonlyargs
+            .iter()
+            .map(|arg| ParameterWithDefault::from_node(db, definition, arg))
+            .collect();
+        let keywords = kwarg
+            .as_ref()
+            .map(|arg| Parameter::from_node(db, definition, arg));
+        Self {
+            positional_only,
+            positional_or_keyword,
+            variadic,
+            keyword_only,
+            keywords,
+        }
     }
 }
 
+/// A single parameter of a typed signature, with optional default value.
 #[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) struct Parameter<'db> {
+pub(super) struct ParameterWithDefault<'db> {
+    parameter: Parameter<'db>,
+
+    /// Type of the default value, if any.
+    default_ty: Option<Type<'db>>,
+}
+
+impl<'db> ParameterWithDefault<'db> {
+    fn from_node(
+        db: &'db dyn Db,
+        definition: Definition<'db>,
+        parameter_with_default: &'db ast::ParameterWithDefault,
+    ) -> Self {
+        Self {
+            default_ty: parameter_with_default
+                .default
+                .as_deref()
+                .map(|default| definition_expression_ty(db, definition, default)),
+            parameter: Parameter::from_node(db, definition, &parameter_with_default.parameter),
+        }
+    }
+}
+
+/// A single parameter of a typed signature.
+#[derive(Clone, Debug, PartialEq, Eq)]
+pub(super) struct Parameter<'db> {
     /// Parameter name.
     ///
     /// It is possible for signatures to be defined in ways that leave positional-only parameters
     /// nameless (e.g. via `Callable` annotations).
     name: Option<Name>,
 
-    /// Annotated type of the parameter.
-    annotated_ty: Option<Type<'db>>,
-
-    kind: ParameterKind<'db>,
+    /// Annotated type of the parameter (Unknown if no annotation.)
+    annotated_ty: Type<'db>,
 }
 
 impl<'db> Parameter<'db> {
-    fn from_node_and_kind(
+    fn from_node(
         db: &'db dyn Db,
         definition: Definition<'db>,
         parameter: &'db ast::Parameter,
-        kind: ParameterKind<'db>,
     ) -> Self {
-        Self {
+        Parameter {
             name: Some(parameter.name.id.clone()),
             annotated_ty: parameter
                 .annotation
                 .as_deref()
-                .map(|annotation| definition_expression_ty(db, definition, annotation)),
-            kind,
+                .map(|annotation| definition_expression_ty(db, definition, annotation))
+                .unwrap_or(Type::Unknown),
         }
     }
-
-    pub(crate) fn is_variadic(&self) -> bool {
-        matches!(self.kind, ParameterKind::Variadic)
-    }
-
-    pub(crate) fn is_keyword_variadic(&self) -> bool {
-        matches!(self.kind, ParameterKind::KeywordVariadic)
-    }
-
-    pub(crate) fn is_positional(&self) -> bool {
-        matches!(
-            self.kind,
-            ParameterKind::PositionalOnly { .. } | ParameterKind::PositionalOrKeyword { .. }
-        )
-    }
-
-    pub(crate) fn callable_by_name(&self, name: &str) -> bool {
-        match self.kind {
-            ParameterKind::PositionalOrKeyword { .. } | ParameterKind::KeywordOnly { .. } => self
-                .name
-                .as_ref()
-                .is_some_and(|param_name| param_name == name),
-            _ => false,
-        }
-    }
-
-    /// Annotated type of the parameter, if annotated.
-    pub(crate) fn annotated_ty(&self) -> Option<Type<'db>> {
-        self.annotated_ty
-    }
-
-    /// Name of the parameter (if it has one).
-    pub(crate) fn name(&self) -> Option<&ast::name::Name> {
-        self.name.as_ref()
-    }
-
-    /// Display name of the parameter, if it has one.
-    pub(crate) fn display_name(&self) -> Option<ast::name::Name> {
-        self.name().map(|name| match self.kind {
-            ParameterKind::Variadic => ast::name::Name::new(format!("*{name}")),
-            ParameterKind::KeywordVariadic => ast::name::Name::new(format!("**{name}")),
-            _ => name.clone(),
-        })
-    }
-
-    /// Default-value type of the parameter, if any.
-    pub(crate) fn default_ty(&self) -> Option<Type<'db>> {
-        match self.kind {
-            ParameterKind::PositionalOnly { default_ty } => default_ty,
-            ParameterKind::PositionalOrKeyword { default_ty } => default_ty,
-            ParameterKind::Variadic => None,
-            ParameterKind::KeywordOnly { default_ty } => default_ty,
-            ParameterKind::KeywordVariadic => None,
-        }
-    }
-}
-
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) enum ParameterKind<'db> {
-    /// Positional-only parameter, e.g. `def f(x, /): ...`
-    PositionalOnly { default_ty: Option<Type<'db>> },
-    /// Positional-or-keyword parameter, e.g. `def f(x): ...`
-    PositionalOrKeyword { default_ty: Option<Type<'db>> },
-    /// Variadic parameter, e.g. `def f(*args): ...`
-    Variadic,
-    /// Keyword-only parameter, e.g. `def f(*, x): ...`
-    KeywordOnly { default_ty: Option<Type<'db>> },
-    /// Variadic keywords parameter, e.g. `def f(**kwargs): ...`
-    KeywordVariadic,
 }
 
 #[cfg(test)]
 mod tests {
     use super::*;
     use crate::db::tests::{setup_db, TestDb};
-    use crate::types::{global_symbol, FunctionType, KnownClass};
+    use crate::types::{global_symbol, FunctionType};
     use ruff_db::system::DbWithTestSystem;
 
     #[track_caller]
@@ -336,8 +202,39 @@ mod tests {
     }
 
     #[track_caller]
-    fn assert_params<'db>(signature: &Signature<'db>, expected: &[Parameter<'db>]) {
-        assert_eq!(signature.parameters.0.as_slice(), expected);
+    fn assert_param_with_default<'db>(
+        db: &'db TestDb,
+        param_with_default: &ParameterWithDefault<'db>,
+        expected_name: &'static str,
+        expected_annotation_ty_display: &'static str,
+        expected_default_ty_display: Option<&'static str>,
+    ) {
+        assert_eq!(
+            param_with_default
+                .default_ty
+                .map(|ty| ty.display(db).to_string()),
+            expected_default_ty_display.map(ToString::to_string)
+        );
+        assert_param(
+            db,
+            &param_with_default.parameter,
+            expected_name,
+            expected_annotation_ty_display,
+        );
+    }
+
+    #[track_caller]
+    fn assert_param<'db>(
+        db: &'db TestDb,
+        param: &Parameter<'db>,
+        expected_name: &'static str,
+        expected_annotation_ty_display: &'static str,
+    ) {
+        assert_eq!(param.name.as_ref().unwrap(), expected_name);
+        assert_eq!(
+            param.annotated_ty.display(db).to_string(),
+            expected_annotation_ty_display
+        );
     }
 
     #[test]
@@ -348,8 +245,13 @@ mod tests {
 
         let sig = func.internal_signature(&db);
 
-        assert!(sig.return_ty.is_none());
-        assert_params(&sig, &[]);
+        assert_eq!(sig.return_ty.display(&db).to_string(), "Unknown");
+        let params = sig.parameters;
+        assert!(params.positional_only.is_empty());
+        assert!(params.positional_or_keyword.is_empty());
+        assert!(params.variadic.is_none());
+        assert!(params.keyword_only.is_empty());
+        assert!(params.keywords.is_none());
     }
 
     #[test]
@@ -369,74 +271,34 @@ mod tests {
 
         let sig = func.internal_signature(&db);
 
-        assert_eq!(sig.return_ty.unwrap().display(&db).to_string(), "bytes");
-        assert_params(
-            &sig,
-            &[
-                Parameter {
-                    name: Some(Name::new_static("a")),
-                    annotated_ty: None,
-                    kind: ParameterKind::PositionalOnly { default_ty: None },
-                },
-                Parameter {
-                    name: Some(Name::new_static("b")),
-                    annotated_ty: Some(KnownClass::Int.to_instance(&db)),
-                    kind: ParameterKind::PositionalOnly { default_ty: None },
-                },
-                Parameter {
-                    name: Some(Name::new_static("c")),
-                    annotated_ty: None,
-                    kind: ParameterKind::PositionalOnly {
-                        default_ty: Some(Type::IntLiteral(1)),
-                    },
-                },
-                Parameter {
-                    name: Some(Name::new_static("d")),
-                    annotated_ty: Some(KnownClass::Int.to_instance(&db)),
-                    kind: ParameterKind::PositionalOnly {
-                        default_ty: Some(Type::IntLiteral(2)),
-                    },
-                },
-                Parameter {
-                    name: Some(Name::new_static("e")),
-                    annotated_ty: None,
-                    kind: ParameterKind::PositionalOrKeyword {
-                        default_ty: Some(Type::IntLiteral(3)),
-                    },
-                },
-                Parameter {
-                    name: Some(Name::new_static("f")),
-                    annotated_ty: Some(Type::IntLiteral(4)),
-                    kind: ParameterKind::PositionalOrKeyword {
-                        default_ty: Some(Type::IntLiteral(4)),
-                    },
-                },
-                Parameter {
-                    name: Some(Name::new_static("args")),
-                    annotated_ty: Some(KnownClass::Object.to_instance(&db)),
-                    kind: ParameterKind::Variadic,
-                },
-                Parameter {
-                    name: Some(Name::new_static("g")),
-                    annotated_ty: None,
-                    kind: ParameterKind::KeywordOnly {
-                        default_ty: Some(Type::IntLiteral(5)),
-                    },
-                },
-                Parameter {
-                    name: Some(Name::new_static("h")),
-                    annotated_ty: Some(Type::IntLiteral(6)),
-                    kind: ParameterKind::KeywordOnly {
-                        default_ty: Some(Type::IntLiteral(6)),
-                    },
-                },
-                Parameter {
-                    name: Some(Name::new_static("kwargs")),
-                    annotated_ty: Some(KnownClass::Str.to_instance(&db)),
-                    kind: ParameterKind::KeywordVariadic,
-                },
-            ],
-        );
+        assert_eq!(sig.return_ty.display(&db).to_string(), "bytes");
+        let params = sig.parameters;
+        let [a, b, c, d] = &params.positional_only[..] else {
+            panic!("expected four positional-only parameters");
+        };
+        let [e, f] = &params.positional_or_keyword[..] else {
+            panic!("expected two positional-or-keyword parameters");
+        };
+        let Some(args) = params.variadic else {
+            panic!("expected a variadic parameter");
+        };
+        let [g, h] = &params.keyword_only[..] else {
+            panic!("expected two keyword-only parameters");
+        };
+        let Some(kwargs) = params.keywords else {
+            panic!("expected a kwargs parameter");
+        };
+
+        assert_param_with_default(&db, a, "a", "Unknown", None);
+        assert_param_with_default(&db, b, "b", "int", None);
+        assert_param_with_default(&db, c, "c", "Unknown", Some("Literal[1]"));
+        assert_param_with_default(&db, d, "d", "int", Some("Literal[2]"));
+        assert_param_with_default(&db, e, "e", "Unknown", Some("Literal[3]"));
+        assert_param_with_default(&db, f, "f", "Literal[4]", Some("Literal[4]"));
+        assert_param_with_default(&db, g, "g", "Unknown", Some("Literal[5]"));
+        assert_param_with_default(&db, h, "h", "Literal[6]", Some("Literal[6]"));
+        assert_param(&db, &args, "args", "object");
+        assert_param(&db, &kwargs, "kwargs", "str");
     }
 
     #[test]
@@ -460,17 +322,11 @@ mod tests {
 
         let sig = func.internal_signature(&db);
 
-        let [Parameter {
-            name: Some(name),
-            annotated_ty,
-            kind: ParameterKind::PositionalOrKeyword { .. },
-        }] = &sig.parameters.0[..]
-        else {
+        let [a] = &sig.parameters.positional_or_keyword[..] else {
             panic!("expected one positional-or-keyword parameter");
         };
-        assert_eq!(name, "a");
         // Parameter resolution not deferred; we should see A not B
-        assert_eq!(annotated_ty.unwrap().display(&db).to_string(), "A");
+        assert_param_with_default(&db, a, "a", "A", None);
     }
 
     #[test]
@@ -494,17 +350,11 @@ mod tests {
 
         let sig = func.internal_signature(&db);
 
-        let [Parameter {
-            name: Some(name),
-            annotated_ty,
-            kind: ParameterKind::PositionalOrKeyword { .. },
-        }] = &sig.parameters.0[..]
-        else {
+        let [a] = &sig.parameters.positional_or_keyword[..] else {
             panic!("expected one positional-or-keyword parameter");
         };
-        assert_eq!(name, "a");
         // Parameter resolution deferred; we should see B
-        assert_eq!(annotated_ty.unwrap().display(&db).to_string(), "B");
+        assert_param_with_default(&db, a, "a", "B", None);
     }
 
     #[test]
@@ -528,23 +378,12 @@ mod tests {
 
         let sig = func.internal_signature(&db);
 
-        let [Parameter {
-            name: Some(a_name),
-            annotated_ty: a_annotated_ty,
-            kind: ParameterKind::PositionalOrKeyword { .. },
-        }, Parameter {
-            name: Some(b_name),
-            annotated_ty: b_annotated_ty,
-            kind: ParameterKind::PositionalOrKeyword { .. },
-        }] = &sig.parameters.0[..]
-        else {
+        let [a, b] = &sig.parameters.positional_or_keyword[..] else {
             panic!("expected two positional-or-keyword parameters");
         };
-        assert_eq!(a_name, "a");
-        assert_eq!(b_name, "b");
         // TODO resolution should not be deferred; we should see A not B
-        assert_eq!(a_annotated_ty.unwrap().display(&db).to_string(), "B");
-        assert_eq!(b_annotated_ty.unwrap().display(&db).to_string(), "T");
+        assert_param_with_default(&db, a, "a", "B", None);
+        assert_param_with_default(&db, b, "b", "T", None);
     }
 
     #[test]
@@ -568,23 +407,12 @@ mod tests {
 
         let sig = func.internal_signature(&db);
 
-        let [Parameter {
-            name: Some(a_name),
-            annotated_ty: a_annotated_ty,
-            kind: ParameterKind::PositionalOrKeyword { .. },
-        }, Parameter {
-            name: Some(b_name),
-            annotated_ty: b_annotated_ty,
-            kind: ParameterKind::PositionalOrKeyword { .. },
-        }] = &sig.parameters.0[..]
-        else {
+        let [a, b] = &sig.parameters.positional_or_keyword[..] else {
             panic!("expected two positional-or-keyword parameters");
         };
-        assert_eq!(a_name, "a");
-        assert_eq!(b_name, "b");
         // Parameter resolution deferred; we should see B
-        assert_eq!(a_annotated_ty.unwrap().display(&db).to_string(), "B");
-        assert_eq!(b_annotated_ty.unwrap().display(&db).to_string(), "T");
+        assert_param_with_default(&db, a, "a", "B", None);
+        assert_param_with_default(&db, b, "b", "T", None);
     }
 
     #[test]

crates/red_knot_python_semantic/src/types/subclass_of.rs

@@ -1,89 +0,0 @@
-use super::{ClassBase, ClassLiteralType, Db, KnownClass, Symbol, Type};
-
-/// A type that represents `type[C]`, i.e. the class object `C` and class objects that are subclasses of `C`.
-#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash, salsa::Update)]
-pub struct SubclassOfType<'db> {
-    // Keep this field private, so that the only way of constructing the struct is through the `from` method.
-    subclass_of: ClassBase<'db>,
-}
-
-impl<'db> SubclassOfType<'db> {
-    /// Construct a new [`Type`] instance representing a given class object (or a given dynamic type)
-    /// and all possible subclasses of that class object/dynamic type.
-    ///
-    /// This method does not always return a [`Type::SubclassOf`] variant.
-    /// If the class object is known to be a final class,
-    /// this method will return a [`Type::ClassLiteral`] variant; this is a more precise type.
-    /// If the class object is `builtins.object`, `Type::Instance(<builtins.type>)` will be returned;
-    /// this is no more precise, but it is exactly equivalent to `type[object]`.
-    ///
-    /// The eager normalization here means that we do not need to worry elsewhere about distinguishing
-    /// between `@final` classes and other classes when dealing with [`Type::SubclassOf`] variants.
-    pub(crate) fn from(db: &'db dyn Db, subclass_of: impl Into<ClassBase<'db>>) -> Type<'db> {
-        let subclass_of = subclass_of.into();
-        match subclass_of {
-            ClassBase::Dynamic(_) => Type::SubclassOf(Self { subclass_of }),
-            ClassBase::Class(class) => {
-                if class.is_final(db) {
-                    Type::ClassLiteral(ClassLiteralType { class })
-                } else if class.is_known(db, KnownClass::Object) {
-                    KnownClass::Type.to_instance(db)
-                } else {
-                    Type::SubclassOf(Self { subclass_of })
-                }
-            }
-        }
-    }
-
-    /// Return a [`Type`] instance representing the type `type[Unknown]`.
-    pub(crate) const fn subclass_of_unknown() -> Type<'db> {
-        Type::SubclassOf(SubclassOfType {
-            subclass_of: ClassBase::unknown(),
-        })
-    }
-
-    /// Return a [`Type`] instance representing the type `type[Any]`.
-    pub(crate) const fn subclass_of_any() -> Type<'db> {
-        Type::SubclassOf(SubclassOfType {
-            subclass_of: ClassBase::any(),
-        })
-    }
-
-    /// Return the inner [`ClassBase`] value wrapped by this `SubclassOfType`.
-    pub(crate) const fn subclass_of(self) -> ClassBase<'db> {
-        self.subclass_of
-    }
-
-    pub const fn is_dynamic(self) -> bool {
-        // Unpack `self` so that we're forced to update this method if any more fields are added in the future.
-        let Self { subclass_of } = self;
-        subclass_of.is_dynamic()
-    }
-
-    pub const fn is_fully_static(self) -> bool {
-        !self.is_dynamic()
-    }
-
-    pub(crate) fn member(self, db: &'db dyn Db, name: &str) -> Symbol<'db> {
-        Type::from(self.subclass_of).member(db, name)
-    }
-
-    /// Return `true` if `self` is a subtype of `other`.
-    ///
-    /// This can only return `true` if `self.subclass_of` is a [`ClassBase::Class`] variant;
-    /// only fully static types participate in subtyping.
-    pub(crate) fn is_subtype_of(self, db: &'db dyn Db, other: SubclassOfType<'db>) -> bool {
-        match (self.subclass_of, other.subclass_of) {
-            // Non-fully-static types do not participate in subtyping
-            (ClassBase::Dynamic(_), _) | (_, ClassBase::Dynamic(_)) => false,
-
-            // For example, `type[bool]` describes all possible runtime subclasses of the class `bool`,
-            // and `type[int]` describes all possible runtime subclasses of the class `int`.
-            // The first set is a subset of the second set, because `bool` is itself a subclass of `int`.
-            (ClassBase::Class(self_class), ClassBase::Class(other_class)) => {
-                // N.B. The subclass relation is fully static
-                self_class.is_subclass_of(db, other_class)
-            }
-        }
-    }
-}

crates/red_knot_python_semantic/src/types/unpacker.rs

@@ -45,15 +45,6 @@ impl<'db> Unpacker<'db> {
         let mut value_ty = infer_expression_types(self.db(), value.expression())
             .expression_ty(value.scoped_expression_id(self.db(), self.scope));
 
-        if value.is_assign()
-            && self.context.in_stub()
-            && value
-                .expression()
-                .node_ref(self.db())
-                .is_ellipsis_literal_expr()
-        {
-            value_ty = Type::unknown();
-        }
         if value.is_iterable() {
             // If the value is an iterable, then the type that needs to be unpacked is the iterator
             // type.
@@ -105,7 +96,7 @@ impl<'db> Unpacker<'db> {
                             // with each individual character, instead of just an array of
                             // `LiteralString`, but there would be a cost and it's not clear that
                             // it's worth it.
-                            TupleType::from_elements(
+                            Type::tuple(
                                 self.db(),
                                 std::iter::repeat(Type::LiteralString)
                                     .take(string_literal_ty.python_len(self.db())),
@@ -164,7 +155,7 @@ impl<'db> Unpacker<'db> {
                 for (index, element) in elts.iter().enumerate() {
                     // SAFETY: `target_types` is initialized with the same length as `elts`.
                     let element_ty = match target_types[index].as_slice() {
-                        [] => Type::unknown(),
+                        [] => Type::Unknown,
                         types => UnionType::from_elements(self.db(), types),
                     };
                     self.unpack_inner(element, element_ty);
@@ -241,7 +232,7 @@ impl<'db> Unpacker<'db> {
 
             // Subtract 1 to insert the starred expression type at the correct
             // index.
-            element_types.resize(targets.len() - 1, Type::unknown());
+            element_types.resize(targets.len() - 1, Type::Unknown);
             // TODO: This should be `list[Unknown]`
             element_types.insert(starred_index, todo_type!("starred unpacking"));
 

crates/red_knot_python_semantic/src/unpack.rs

@@ -76,11 +76,6 @@ impl<'db> UnpackValue<'db> {
         matches!(self, UnpackValue::Iterable(_))
     }
 
-    /// Returns `true` if the value is being assigned to a target.
-    pub(crate) const fn is_assign(self) -> bool {
-        matches!(self, UnpackValue::Assign(_))
-    }
-
     /// Returns the underlying [`Expression`] that is being unpacked.
     pub(crate) const fn expression(self) -> Expression<'db> {
         match self {

crates/red_knot_python_semantic/src/visibility_constraints.rs

@@ -329,9 +329,9 @@ impl<'db> VisibilityConstraints<'db> {
                         Truthiness::Ambiguous
                     }
                 }
-                PatternConstraintKind::Singleton(..)
-                | PatternConstraintKind::Class(..)
-                | PatternConstraintKind::Unsupported => Truthiness::Ambiguous,
+                PatternConstraintKind::Singleton(..) | PatternConstraintKind::Unsupported => {
+                    Truthiness::Ambiguous
+                }
             },
         }
     }

crates/red_knot_server/src/lib.rs

@@ -11,10 +11,10 @@ use crate::server::Server;
 mod message;
 
 mod edit;
-mod logging;
 mod server;
 mod session;
 mod system;
+mod trace;
 
 pub(crate) const SERVER_NAME: &str = "red-knot";
 pub(crate) const DIAGNOSTIC_NAME: &str = "Red Knot";

crates/red_knot_server/src/logging.rs

@@ -1,114 +0,0 @@
-//! The logging system for `red_knot server`.
-//!
-//! Log messages are controlled by the `logLevel` setting which defaults to `"info"`. Log messages
-//! are written to `stderr` by default, which should appear in the logs for most LSP clients. A
-//! `logFile` path can also be specified in the settings, and output will be directed there
-//! instead.
-use core::str;
-use serde::Deserialize;
-use std::{path::PathBuf, str::FromStr, sync::Arc};
-use tracing::level_filters::LevelFilter;
-use tracing_subscriber::{
-    fmt::{time::Uptime, writer::BoxMakeWriter},
-    layer::SubscriberExt,
-    Layer,
-};
-
-pub(crate) fn init_logging(log_level: LogLevel, log_file: Option<&std::path::Path>) {
-    let log_file = log_file
-        .map(|path| {
-            // this expands `logFile` so that tildes and environment variables
-            // are replaced with their values, if possible.
-            if let Some(expanded) = shellexpand::full(&path.to_string_lossy())
-                .ok()
-                .and_then(|path| PathBuf::from_str(&path).ok())
-            {
-                expanded
-            } else {
-                path.to_path_buf()
-            }
-        })
-        .and_then(|path| {
-            std::fs::OpenOptions::new()
-                .create(true)
-                .append(true)
-                .open(&path)
-                .map_err(|err| {
-                    #[allow(clippy::print_stderr)]
-                    {
-                        eprintln!(
-                            "Failed to open file at {} for logging: {err}",
-                            path.display()
-                        );
-                    }
-                })
-                .ok()
-        });
-
-    let logger = match log_file {
-        Some(file) => BoxMakeWriter::new(Arc::new(file)),
-        None => BoxMakeWriter::new(std::io::stderr),
-    };
-    let subscriber = tracing_subscriber::Registry::default().with(
-        tracing_subscriber::fmt::layer()
-            .with_timer(Uptime::default())
-            .with_thread_names(true)
-            .with_ansi(false)
-            .with_writer(logger)
-            .with_filter(LogLevelFilter { filter: log_level }),
-    );
-
-    tracing::subscriber::set_global_default(subscriber)
-        .expect("should be able to set global default subscriber");
-}
-
-/// The log level for the server as provided by the client during initialization.
-///
-/// The default log level is `info`.
-#[derive(Clone, Copy, Debug, Deserialize, Default, PartialEq, Eq, PartialOrd, Ord)]
-#[serde(rename_all = "lowercase")]
-pub(crate) enum LogLevel {
-    Error,
-    Warn,
-    #[default]
-    Info,
-    Debug,
-    Trace,
-}
-
-impl LogLevel {
-    fn trace_level(self) -> tracing::Level {
-        match self {
-            Self::Error => tracing::Level::ERROR,
-            Self::Warn => tracing::Level::WARN,
-            Self::Info => tracing::Level::INFO,
-            Self::Debug => tracing::Level::DEBUG,
-            Self::Trace => tracing::Level::TRACE,
-        }
-    }
-}
-
-/// Filters out traces which have a log level lower than the `logLevel` set by the client.
-struct LogLevelFilter {
-    filter: LogLevel,
-}
-
-impl<S> tracing_subscriber::layer::Filter<S> for LogLevelFilter {
-    fn enabled(
-        &self,
-        meta: &tracing::Metadata<'_>,
-        _: &tracing_subscriber::layer::Context<'_, S>,
-    ) -> bool {
-        let filter = if meta.target().starts_with("red_knot") {
-            self.filter.trace_level()
-        } else {
-            tracing::Level::INFO
-        };
-
-        meta.level() <= &filter
-    }
-
-    fn max_level_hint(&self) -> Option<tracing::level_filters::LevelFilter> {
-        Some(LevelFilter::from_level(self.filter.trace_level()))
-    }
-}

crates/red_knot_server/src/server.rs

@@ -51,6 +51,10 @@ impl Server {
             crate::version(),
         )?;
 
+        if let Some(trace) = init_params.trace {
+            crate::trace::set_trace_value(trace);
+        }
+
         crate::message::init_messenger(connection.make_sender());
 
         let AllSettings {
@@ -62,9 +66,14 @@ impl Server {
                 .unwrap_or_else(|| serde_json::Value::Object(serde_json::Map::default())),
         );
 
-        crate::logging::init_logging(
-            global_settings.tracing.log_level.unwrap_or_default(),
+        crate::trace::init_tracing(
+            connection.make_sender(),
+            global_settings
+                .tracing
+                .log_level
+                .unwrap_or(crate::trace::LogLevel::Info),
             global_settings.tracing.log_file.as_deref(),
+            init_params.client_info.as_ref(),
         );
 
         let mut workspace_for_url = |url: Url| {

crates/red_knot_server/src/server/api.rs

@@ -52,6 +52,9 @@ pub(super) fn notification<'a>(notif: server::Notification) -> Task<'a> {
         notification::DidCloseNotebookHandler::METHOD => {
             local_notification_task::<notification::DidCloseNotebookHandler>(notif)
         }
+        notification::SetTraceHandler::METHOD => {
+            local_notification_task::<notification::SetTraceHandler>(notif)
+        }
         method => {
             tracing::warn!("Received notification {method} which does not have a handler.");
             return Task::nothing();

crates/red_knot_server/src/server/api/notifications.rs

@@ -3,9 +3,11 @@ mod did_close;
 mod did_close_notebook;
 mod did_open;
 mod did_open_notebook;
+mod set_trace;
 
 pub(super) use did_change::DidChangeTextDocumentHandler;
 pub(super) use did_close::DidCloseTextDocumentHandler;
 pub(super) use did_close_notebook::DidCloseNotebookHandler;
 pub(super) use did_open::DidOpenTextDocumentHandler;
 pub(super) use did_open_notebook::DidOpenNotebookHandler;
+pub(super) use set_trace::SetTraceHandler;

crates/red_knot_server/src/server/api/notifications/set_trace.rs

@@ -0,0 +1,25 @@
+use lsp_types::notification::SetTrace;
+use lsp_types::SetTraceParams;
+
+use crate::server::api::traits::{NotificationHandler, SyncNotificationHandler};
+use crate::server::client::{Notifier, Requester};
+use crate::server::Result;
+use crate::session::Session;
+
+pub(crate) struct SetTraceHandler;
+
+impl NotificationHandler for SetTraceHandler {
+    type NotificationType = SetTrace;
+}
+
+impl SyncNotificationHandler for SetTraceHandler {
+    fn run(
+        _session: &mut Session,
+        _notifier: Notifier,
+        _requester: &mut Requester,
+        params: SetTraceParams,
+    ) -> Result<()> {
+        crate::trace::set_trace_value(params.value);
+        Ok(())
+    }
+}

crates/red_knot_server/src/session/settings.rs

@@ -24,7 +24,7 @@ pub struct ClientSettings {
 #[cfg_attr(test, derive(PartialEq, Eq))]
 #[serde(rename_all = "camelCase")]
 pub(crate) struct TracingSettings {
-    pub(crate) log_level: Option<crate::logging::LogLevel>,
+    pub(crate) log_level: Option<crate::trace::LogLevel>,
     /// Path to the log file - tildes and environment variables are supported.
     pub(crate) log_file: Option<PathBuf>,
 }

crates/red_knot_server/src/trace.rs

@@ -0,0 +1,221 @@
+//! The tracing system for `ruff server`.
+//!
+//! Traces are controlled by the `logLevel` setting, along with the
+//! trace level set through the LSP. On VS Code, the trace level can
+//! also be set with `ruff.trace.server`. A trace level of `messages` or
+//! `verbose` will enable tracing - otherwise, no traces will be shown.
+//!
+//! `logLevel` can be used to configure the level of tracing that is shown.
+//! By default, `logLevel` is set to `"info"`.
+//!
+//! The server also supports the `RUFF_TRACE` environment variable, which will
+//! override the trace value provided by the LSP client. Use this if there's no good way
+//! to set the trace value through your editor's configuration.
+//!
+//! Tracing will write to `stderr` by default, which should appear in the logs for most LSP clients.
+//! A `logFile` path can also be specified in the settings, and output will be directed there instead.
+use core::str;
+use lsp_server::{Message, Notification};
+use lsp_types::{
+    notification::{LogTrace, Notification as _},
+    ClientInfo, TraceValue,
+};
+use serde::Deserialize;
+use std::{
+    io::{Error as IoError, ErrorKind, Write},
+    path::PathBuf,
+    str::FromStr,
+    sync::{Arc, Mutex, OnceLock},
+};
+use tracing::level_filters::LevelFilter;
+use tracing_subscriber::{
+    fmt::{time::Uptime, writer::BoxMakeWriter, MakeWriter},
+    layer::SubscriberExt,
+    Layer,
+};
+
+use crate::server::ClientSender;
+
+const TRACE_ENV_KEY: &str = "RUFF_TRACE";
+
+static LOGGING_SENDER: OnceLock<ClientSender> = OnceLock::new();
+
+static TRACE_VALUE: Mutex<lsp_types::TraceValue> = Mutex::new(lsp_types::TraceValue::Off);
+
+pub(crate) fn set_trace_value(trace_value: TraceValue) {
+    let mut global_trace_value = TRACE_VALUE
+        .lock()
+        .expect("trace value mutex should be available");
+    *global_trace_value = trace_value;
+}
+
+// A tracing writer that uses LSPs logTrace method.
+struct TraceLogWriter;
+
+impl Write for TraceLogWriter {
+    fn write(&mut self, buf: &[u8]) -> std::io::Result<usize> {
+        let message = str::from_utf8(buf).map_err(|e| IoError::new(ErrorKind::InvalidData, e))?;
+        LOGGING_SENDER
+            .get()
+            .expect("logging sender should be initialized at this point")
+            .send(Message::Notification(Notification {
+                method: LogTrace::METHOD.to_owned(),
+                params: serde_json::json!({
+                    "message": message
+                }),
+            }))
+            .map_err(|e| IoError::new(ErrorKind::Other, e))?;
+        Ok(buf.len())
+    }
+
+    fn flush(&mut self) -> std::io::Result<()> {
+        Ok(())
+    }
+}
+
+impl<'a> MakeWriter<'a> for TraceLogWriter {
+    type Writer = Self;
+
+    fn make_writer(&'a self) -> Self::Writer {
+        Self
+    }
+}
+
+pub(crate) fn init_tracing(
+    sender: ClientSender,
+    log_level: LogLevel,
+    log_file: Option<&std::path::Path>,
+    client: Option<&ClientInfo>,
+) {
+    LOGGING_SENDER
+        .set(sender)
+        .expect("logging sender should only be initialized once");
+
+    let log_file = log_file
+        .map(|path| {
+            // this expands `logFile` so that tildes and environment variables
+            // are replaced with their values, if possible.
+            if let Some(expanded) = shellexpand::full(&path.to_string_lossy())
+                .ok()
+                .and_then(|path| PathBuf::from_str(&path).ok())
+            {
+                expanded
+            } else {
+                path.to_path_buf()
+            }
+        })
+        .and_then(|path| {
+            std::fs::OpenOptions::new()
+                .create(true)
+                .append(true)
+                .open(&path)
+                .map_err(|err| {
+                    #[allow(clippy::print_stderr)]
+                    {
+                        eprintln!(
+                            "Failed to open file at {} for logging: {err}",
+                            path.display()
+                        );
+                    }
+                })
+                .ok()
+        });
+
+    let logger = match log_file {
+        Some(file) => BoxMakeWriter::new(Arc::new(file)),
+        None => {
+            if client.is_some_and(|client| {
+                client.name.starts_with("Zed") || client.name.starts_with("Visual Studio Code")
+            }) {
+                BoxMakeWriter::new(TraceLogWriter)
+            } else {
+                BoxMakeWriter::new(std::io::stderr)
+            }
+        }
+    };
+    let subscriber = tracing_subscriber::Registry::default().with(
+        tracing_subscriber::fmt::layer()
+            .with_timer(Uptime::default())
+            .with_thread_names(true)
+            .with_ansi(false)
+            .with_writer(logger)
+            .with_filter(TraceLevelFilter)
+            .with_filter(LogLevelFilter { filter: log_level }),
+    );
+
+    tracing::subscriber::set_global_default(subscriber)
+        .expect("should be able to set global default subscriber");
+}
+
+#[derive(Clone, Copy, Debug, Deserialize, Default, PartialEq, Eq, PartialOrd, Ord)]
+#[serde(rename_all = "lowercase")]
+pub(crate) enum LogLevel {
+    #[default]
+    Error,
+    Warn,
+    Info,
+    Debug,
+    Trace,
+}
+
+impl LogLevel {
+    fn trace_level(self) -> tracing::Level {
+        match self {
+            Self::Error => tracing::Level::ERROR,
+            Self::Warn => tracing::Level::WARN,
+            Self::Info => tracing::Level::INFO,
+            Self::Debug => tracing::Level::DEBUG,
+            Self::Trace => tracing::Level::TRACE,
+        }
+    }
+}
+
+/// Filters out traces which have a log level lower than the `logLevel` set by the client.
+struct LogLevelFilter {
+    filter: LogLevel,
+}
+
+/// Filters out traces if the trace value set by the client is `off`.
+struct TraceLevelFilter;
+
+impl<S> tracing_subscriber::layer::Filter<S> for LogLevelFilter {
+    fn enabled(
+        &self,
+        meta: &tracing::Metadata<'_>,
+        _: &tracing_subscriber::layer::Context<'_, S>,
+    ) -> bool {
+        let filter = if meta.target().starts_with("ruff") {
+            self.filter.trace_level()
+        } else {
+            tracing::Level::INFO
+        };
+
+        meta.level() <= &filter
+    }
+
+    fn max_level_hint(&self) -> Option<tracing::level_filters::LevelFilter> {
+        Some(LevelFilter::from_level(self.filter.trace_level()))
+    }
+}
+
+impl<S> tracing_subscriber::layer::Filter<S> for TraceLevelFilter {
+    fn enabled(
+        &self,
+        _: &tracing::Metadata<'_>,
+        _: &tracing_subscriber::layer::Context<'_, S>,
+    ) -> bool {
+        trace_value() != lsp_types::TraceValue::Off
+    }
+}
+
+#[inline]
+fn trace_value() -> lsp_types::TraceValue {
+    std::env::var(TRACE_ENV_KEY)
+        .ok()
+        .and_then(|trace| serde_json::from_value(serde_json::Value::String(trace)).ok())
+        .unwrap_or_else(|| {
+            *TRACE_VALUE
+                .lock()
+                .expect("trace value mutex should be available")
+        })
+}

crates/red_knot_test/src/lib.rs

@@ -6,11 +6,10 @@ use red_knot_python_semantic::types::check_types;
 use red_knot_python_semantic::Program;
 use ruff_db::diagnostic::{Diagnostic, ParseDiagnostic};
 use ruff_db::files::{system_path_to_file, File, Files};
-use ruff_db::panic::catch_unwind;
 use ruff_db::parsed::parsed_module;
 use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
 use ruff_db::testing::{setup_logging, setup_logging_with_filter};
-use ruff_source_file::{LineIndex, OneIndexed};
+use ruff_source_file::LineIndex;
 use ruff_text_size::TextSize;
 use salsa::Setter;
 
@@ -137,33 +136,7 @@ fn run_test(db: &mut db::Db, test: &parser::MarkdownTest) -> Result<(), Failures
                 })
                 .collect();
 
-            let type_diagnostics = match catch_unwind(|| check_types(db, test_file.file)) {
-                Ok(type_diagnostics) => type_diagnostics,
-                Err(info) => {
-                    let mut by_line = matcher::FailuresByLine::default();
-                    let mut messages = vec![];
-                    match info.location {
-                        Some(location) => messages.push(format!("panicked at {location}")),
-                        None => messages.push("panicked at unknown location".to_string()),
-                    };
-                    match info.payload {
-                        Some(payload) => messages.push(payload),
-                        // Mimic the default panic hook's rendering of the panic payload if it's
-                        // not a string.
-                        None => messages.push("Box<dyn Any>".to_string()),
-                    };
-                    if let Some(backtrace) = info.backtrace {
-                        if std::env::var("RUST_BACKTRACE").is_ok() {
-                            messages.extend(backtrace.to_string().split('\n').map(String::from));
-                        }
-                    }
-                    by_line.push(OneIndexed::from_zero_indexed(0), messages);
-                    return Some(FileFailures {
-                        backtick_offset: test_file.backtick_offset,
-                        by_line,
-                    });
-                }
-            };
+            let type_diagnostics = check_types(db, test_file.file);
             diagnostics.extend(type_diagnostics.into_iter().map(|diagnostic| {
                 let diagnostic: Box<dyn Diagnostic> = Box::new((*diagnostic).clone());
                 diagnostic

crates/red_knot_test/src/matcher.rs

@@ -27,7 +27,7 @@ impl FailuresByLine {
         })
     }
 
-    pub(super) fn push(&mut self, line_number: OneIndexed, messages: Vec<String>) {
+    fn push(&mut self, line_number: OneIndexed, messages: Vec<String>) {
         let start = self.failures.len();
         self.failures.extend(messages);
         self.lines.push(LineFailures {

crates/red_knot_vendored/build.rs

@@ -6,7 +6,6 @@
 //! in `crates/red_knot_vendored/vendor/typeshed` change.
 
 use std::fs::File;
-use std::io::Write;
 use std::path::Path;
 
 use path_slash::PathExt;
@@ -15,15 +14,13 @@ use zip::write::{FileOptions, ZipWriter};
 use zip::CompressionMethod;
 
 const TYPESHED_SOURCE_DIR: &str = "vendor/typeshed";
-const KNOT_EXTENSIONS_STUBS: &str = "knot_extensions/knot_extensions.pyi";
 const TYPESHED_ZIP_LOCATION: &str = "/zipped_typeshed.zip";
 
-/// Recursively zip the contents of the entire typeshed directory and patch typeshed
-/// on the fly to include the `knot_extensions` module.
+/// Recursively zip the contents of an entire directory.
 ///
 /// This routine is adapted from a recipe at
 /// <https://github.com/zip-rs/zip-old/blob/5d0f198124946b7be4e5969719a7f29f363118cd/examples/write_dir.rs>
-fn write_zipped_typeshed_to(writer: File) -> ZipResult<File> {
+fn zip_dir(directory_path: &str, writer: File) -> ZipResult<File> {
     let mut zip = ZipWriter::new(writer);
 
     // Use deflated compression for WASM builds because compiling `zstd-sys` requires clang
@@ -45,11 +42,11 @@ fn write_zipped_typeshed_to(writer: File) -> ZipResult<File> {
         .compression_method(method)
         .unix_permissions(0o644);
 
-    for entry in walkdir::WalkDir::new(TYPESHED_SOURCE_DIR) {
+    for entry in walkdir::WalkDir::new(directory_path) {
         let dir_entry = entry.unwrap();
         let absolute_path = dir_entry.path();
         let normalized_relative_path = absolute_path
-            .strip_prefix(Path::new(TYPESHED_SOURCE_DIR))
+            .strip_prefix(Path::new(directory_path))
             .unwrap()
             .to_slash()
             .expect("Unexpected non-utf8 typeshed path!");
@@ -58,14 +55,9 @@ fn write_zipped_typeshed_to(writer: File) -> ZipResult<File> {
         // Some unzip tools unzip files with directory paths correctly, some do not!
         if absolute_path.is_file() {
             println!("adding file {absolute_path:?} as {normalized_relative_path:?} ...");
-            zip.start_file(&*normalized_relative_path, options)?;
+            zip.start_file(normalized_relative_path, options)?;
             let mut f = File::open(absolute_path)?;
             std::io::copy(&mut f, &mut zip).unwrap();
-
-            // Patch the VERSIONS file to make `knot_extensions` available
-            if normalized_relative_path == "stdlib/VERSIONS" {
-                writeln!(&mut zip, "knot_extensions: 3.0-")?;
-            }
         } else if !normalized_relative_path.is_empty() {
             // Only if not root! Avoids path spec / warning
             // and mapname conversion failed error on unzip
@@ -73,17 +65,11 @@ fn write_zipped_typeshed_to(writer: File) -> ZipResult<File> {
             zip.add_directory(normalized_relative_path, options)?;
         }
     }
-
-    // Patch typeshed and add the stubs for the `knot_extensions` module
-    println!("adding file {KNOT_EXTENSIONS_STUBS} as stdlib/knot_extensions.pyi ...");
-    zip.start_file("stdlib/knot_extensions.pyi", options)?;
-    let mut f = File::open(KNOT_EXTENSIONS_STUBS)?;
-    std::io::copy(&mut f, &mut zip).unwrap();
-
     zip.finish()
 }
 
 fn main() {
+    println!("cargo::rerun-if-changed={TYPESHED_SOURCE_DIR}");
     assert!(
         Path::new(TYPESHED_SOURCE_DIR).is_dir(),
         "Where is typeshed?"
@@ -98,6 +84,6 @@ fn main() {
     // which can't be done at compile time.)
     let zipped_typeshed_location = format!("{out_dir}{TYPESHED_ZIP_LOCATION}");
 
-    let zipped_typeshed_file = File::create(zipped_typeshed_location).unwrap();
-    write_zipped_typeshed_to(zipped_typeshed_file).unwrap();
+    let zipped_typeshed = File::create(zipped_typeshed_location).unwrap();
+    zip_dir(TYPESHED_SOURCE_DIR, zipped_typeshed).unwrap();
 }

crates/red_knot_vendored/knot_extensions/README.md

@@ -1,3 +0,0 @@
-The `knot_extensions.pyi` file in this directory will be symlinked into
-the `vendor/typeshed/stdlib` directory every time we sync our `typeshed`
-stubs (see `.github/workflows/sync_typeshed.yaml`).

crates/red_knot_vendored/knot_extensions/knot_extensions.pyi

@@ -1,24 +0,0 @@
-from typing import _SpecialForm, Any, LiteralString
-
-# Special operations
-def static_assert(condition: object, msg: LiteralString | None = None) -> None: ...
-
-# Types
-Unknown = object()
-
-# Special forms
-Not: _SpecialForm
-Intersection: _SpecialForm
-TypeOf: _SpecialForm
-
-# Predicates on types
-#
-# Ideally, these would be annotated using `TypeForm`, but that has not been
-# standardized yet (https://peps.python.org/pep-0747).
-def is_equivalent_to(type_a: Any, type_b: Any) -> bool: ...
-def is_subtype_of(type_derived: Any, typ_ebase: Any) -> bool: ...
-def is_assignable_to(type_target: Any, type_source: Any) -> bool: ...
-def is_disjoint_from(type_a: Any, type_b: Any) -> bool: ...
-def is_fully_static(type: Any) -> bool: ...
-def is_singleton(type: Any) -> bool: ...
-def is_single_valued(type: Any) -> bool: ...

crates/red_knot_vendored/vendor/typeshed/source_commit.txt

@@ -1 +1 @@
-2047b820730fdd65d37e6e8efcf29ca9af7ec3e7
+fc11e835108394728930059c8db5b436209bc957

crates/red_knot_vendored/vendor/typeshed/stdlib/_asyncio.pyi

@@ -65,7 +65,7 @@ class Task(Future[_T_co]):  # type: ignore[type-var]  # pyright: ignore[reportIn
             self,
             coro: _TaskCompatibleCoro[_T_co],
             *,
-            loop: AbstractEventLoop | None = None,
+            loop: AbstractEventLoop = ...,
             name: str | None = ...,
             context: Context | None = None,
             eager_start: bool = False,
@@ -75,13 +75,13 @@ class Task(Future[_T_co]):  # type: ignore[type-var]  # pyright: ignore[reportIn
             self,
             coro: _TaskCompatibleCoro[_T_co],
             *,
-            loop: AbstractEventLoop | None = None,
+            loop: AbstractEventLoop = ...,
             name: str | None = ...,
             context: Context | None = None,
         ) -> None: ...
     else:
         def __init__(
-            self, coro: _TaskCompatibleCoro[_T_co], *, loop: AbstractEventLoop | None = None, name: str | None = ...
+            self, coro: _TaskCompatibleCoro[_T_co], *, loop: AbstractEventLoop = ..., name: str | None = ...
         ) -> None: ...
 
     if sys.version_info >= (3, 12):

crates/red_knot_vendored/vendor/typeshed/stdlib/_blake2.pyi

@@ -22,8 +22,8 @@ class blake2b:
     digest_size: int
     name: str
     if sys.version_info >= (3, 9):
-        def __new__(
-            cls,
+        def __init__(
+            self,
             data: ReadableBuffer = b"",
             /,
             *,
@@ -39,10 +39,10 @@ class blake2b:
             inner_size: int = 0,
             last_node: bool = False,
             usedforsecurity: bool = True,
-        ) -> Self: ...
+        ) -> None: ...
     else:
-        def __new__(
-            cls,
+        def __init__(
+            self,
             data: ReadableBuffer = b"",
             /,
             *,
@@ -57,7 +57,7 @@ class blake2b:
             node_depth: int = 0,
             inner_size: int = 0,
             last_node: bool = False,
-        ) -> Self: ...
+        ) -> None: ...
 
     def copy(self) -> Self: ...
     def digest(self) -> bytes: ...
@@ -74,8 +74,8 @@ class blake2s:
     digest_size: int
     name: str
     if sys.version_info >= (3, 9):
-        def __new__(
-            cls,
+        def __init__(
+            self,
             data: ReadableBuffer = b"",
             /,
             *,
@@ -91,10 +91,10 @@ class blake2s:
             inner_size: int = 0,
             last_node: bool = False,
             usedforsecurity: bool = True,
-        ) -> Self: ...
+        ) -> None: ...
     else:
-        def __new__(
-            cls,
+        def __init__(
+            self,
             data: ReadableBuffer = b"",
             /,
             *,
@@ -109,7 +109,7 @@ class blake2s:
             node_depth: int = 0,
             inner_size: int = 0,
             last_node: bool = False,
-        ) -> Self: ...
+        ) -> None: ...
 
     def copy(self) -> Self: ...
     def digest(self) -> bytes: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/_bz2.pyi

@@ -1,15 +1,9 @@
-import sys
 from _typeshed import ReadableBuffer
 from typing import final
-from typing_extensions import Self
 
 @final
 class BZ2Compressor:
-    if sys.version_info >= (3, 12):
-        def __new__(cls, compresslevel: int = 9, /) -> Self: ...
-    else:
-        def __init__(self, compresslevel: int = 9, /) -> None: ...
-
+    def __init__(self, compresslevel: int = 9) -> None: ...
     def compress(self, data: ReadableBuffer, /) -> bytes: ...
     def flush(self) -> bytes: ...
 

crates/red_knot_vendored/vendor/typeshed/stdlib/_collections_abc.pyi

@@ -8,7 +8,6 @@ from typing import (  # noqa: Y022,Y038
     AsyncIterator as AsyncIterator,
     Awaitable as Awaitable,
     Callable as Callable,
-    ClassVar,
     Collection as Collection,
     Container as Container,
     Coroutine as Coroutine,
@@ -75,7 +74,6 @@ _VT_co = TypeVar("_VT_co", covariant=True)  # Value type covariant containers.
 class dict_keys(KeysView[_KT_co], Generic[_KT_co, _VT_co]):  # undocumented
     def __eq__(self, value: object, /) -> bool: ...
     def __reversed__(self) -> Iterator[_KT_co]: ...
-    __hash__: ClassVar[None]  # type: ignore[assignment]
     if sys.version_info >= (3, 13):
         def isdisjoint(self, other: Iterable[_KT_co], /) -> bool: ...
     if sys.version_info >= (3, 10):
@@ -93,7 +91,6 @@ class dict_values(ValuesView[_VT_co], Generic[_KT_co, _VT_co]):  # undocumented
 class dict_items(ItemsView[_KT_co, _VT_co]):  # undocumented
     def __eq__(self, value: object, /) -> bool: ...
     def __reversed__(self) -> Iterator[tuple[_KT_co, _VT_co]]: ...
-    __hash__: ClassVar[None]  # type: ignore[assignment]
     if sys.version_info >= (3, 13):
         def isdisjoint(self, other: Iterable[tuple[_KT_co, _VT_co]], /) -> bool: ...
     if sys.version_info >= (3, 10):

crates/red_knot_vendored/vendor/typeshed/stdlib/_contextvars.pyi

@@ -1,7 +1,7 @@
 import sys
 from collections.abc import Callable, Iterator, Mapping
 from typing import Any, ClassVar, Generic, TypeVar, final, overload
-from typing_extensions import ParamSpec, Self
+from typing_extensions import ParamSpec
 
 if sys.version_info >= (3, 9):
     from types import GenericAlias
@@ -13,9 +13,9 @@ _P = ParamSpec("_P")
 @final
 class ContextVar(Generic[_T]):
     @overload
-    def __new__(cls, name: str) -> Self: ...
+    def __init__(self, name: str) -> None: ...
     @overload
-    def __new__(cls, name: str, *, default: _T) -> Self: ...
+    def __init__(self, name: str, *, default: _T) -> None: ...
     def __hash__(self) -> int: ...
     @property
     def name(self) -> str: ...
@@ -37,7 +37,6 @@ class Token(Generic[_T]):
     @property
     def old_value(self) -> Any: ...  # returns either _T or MISSING, but that's hard to express
     MISSING: ClassVar[object]
-    __hash__: ClassVar[None]  # type: ignore[assignment]
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
 
@@ -56,7 +55,6 @@ class Context(Mapping[ContextVar[Any], Any]):
     def get(self, key: ContextVar[_T], default: _D, /) -> _T | _D: ...
     def run(self, callable: Callable[_P, _T], *args: _P.args, **kwargs: _P.kwargs) -> _T: ...
     def copy(self) -> Context: ...
-    __hash__: ClassVar[None]  # type: ignore[assignment]
     def __getitem__(self, key: ContextVar[_T], /) -> _T: ...
     def __iter__(self) -> Iterator[ContextVar[Any]]: ...
     def __len__(self) -> int: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/_csv.pyi

@@ -32,8 +32,8 @@ class Dialect:
     lineterminator: str
     quoting: _QuotingType
     strict: bool
-    def __new__(
-        cls,
+    def __init__(
+        self,
         dialect: _DialectLike | None = ...,
         delimiter: str = ",",
         doublequote: bool = True,
@@ -43,7 +43,7 @@ class Dialect:
         quoting: _QuotingType = 0,
         skipinitialspace: bool = False,
         strict: bool = False,
-    ) -> Self: ...
+    ) -> None: ...
 
 if sys.version_info >= (3, 10):
     # This class calls itself _csv.reader.
@@ -115,7 +115,7 @@ def reader(
 ) -> _reader: ...
 def register_dialect(
     name: str,
-    dialect: type[Dialect | csv.Dialect] = ...,
+    dialect: type[Dialect] = ...,
     *,
     delimiter: str = ",",
     quotechar: str | None = '"',

crates/red_knot_vendored/vendor/typeshed/stdlib/_ctypes.pyi

@@ -169,18 +169,18 @@ class CFuncPtr(_PointerLike, _CData, metaclass=_PyCFuncPtrType):
     # Abstract attribute that must be defined on subclasses
     _flags_: ClassVar[int]
     @overload
-    def __new__(cls) -> Self: ...
+    def __init__(self) -> None: ...
     @overload
-    def __new__(cls, address: int, /) -> Self: ...
+    def __init__(self, address: int, /) -> None: ...
     @overload
-    def __new__(cls, callable: Callable[..., Any], /) -> Self: ...
+    def __init__(self, callable: Callable[..., Any], /) -> None: ...
     @overload
-    def __new__(cls, func_spec: tuple[str | int, CDLL], paramflags: tuple[_PF, ...] | None = ..., /) -> Self: ...
+    def __init__(self, func_spec: tuple[str | int, CDLL], paramflags: tuple[_PF, ...] | None = ..., /) -> None: ...
     if sys.platform == "win32":
         @overload
-        def __new__(
-            cls, vtbl_index: int, name: str, paramflags: tuple[_PF, ...] | None = ..., iid: _CData | _CDataType | None = ..., /
-        ) -> Self: ...
+        def __init__(
+            self, vtbl_index: int, name: str, paramflags: tuple[_PF, ...] | None = ..., iid: _CData | _CDataType | None = ..., /
+        ) -> None: ...
 
     def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
 

crates/red_knot_vendored/vendor/typeshed/stdlib/_curses.pyi

@@ -1,7 +1,7 @@
 import sys
-from _typeshed import ReadOnlyBuffer, SupportsRead, SupportsWrite
+from _typeshed import ReadOnlyBuffer, SupportsRead
 from curses import _ncurses_version
-from typing import Any, final, overload
+from typing import IO, Any, final, overload
 from typing_extensions import TypeAlias
 
 # NOTE: This module is ordinarily only available on Unix, but the windows-curses
@@ -517,7 +517,7 @@ class window:  # undocumented
     def overwrite(
         self, destwin: window, sminrow: int, smincol: int, dminrow: int, dmincol: int, dmaxrow: int, dmaxcol: int
     ) -> None: ...
-    def putwin(self, file: SupportsWrite[bytes], /) -> None: ...
+    def putwin(self, file: IO[Any], /) -> None: ...
     def redrawln(self, beg: int, num: int, /) -> None: ...
     def redrawwin(self) -> None: ...
     @overload

crates/red_knot_vendored/vendor/typeshed/stdlib/_frozen_importlib.pyi

@@ -5,7 +5,7 @@ import types
 from _typeshed.importlib import LoaderProtocol
 from collections.abc import Mapping, Sequence
 from types import ModuleType
-from typing import Any, ClassVar
+from typing import Any
 
 # Signature of `builtins.__import__` should be kept identical to `importlib.__import__`
 def __import__(
@@ -43,7 +43,6 @@ class ModuleSpec:
     def parent(self) -> str | None: ...
     has_location: bool
     def __eq__(self, other: object) -> bool: ...
-    __hash__: ClassVar[None]  # type: ignore[assignment]
 
 class BuiltinImporter(importlib.abc.MetaPathFinder, importlib.abc.InspectLoader):
     # MetaPathFinder

crates/red_knot_vendored/vendor/typeshed/stdlib/_io.pyi

@@ -112,7 +112,7 @@ class BufferedRandom(BufferedIOBase, _BufferedIOBase, BinaryIO):  # type: ignore
     def truncate(self, pos: int | None = None, /) -> int: ...
 
 class BufferedRWPair(BufferedIOBase, _BufferedIOBase):
-    def __init__(self, reader: RawIOBase, writer: RawIOBase, buffer_size: int = 8192, /) -> None: ...
+    def __init__(self, reader: RawIOBase, writer: RawIOBase, buffer_size: int = 8192) -> None: ...
     def peek(self, size: int = 0, /) -> bytes: ...
 
 class _TextIOBase(_IOBase):

crates/red_knot_vendored/vendor/typeshed/stdlib/_json.pyi

@@ -1,6 +1,5 @@
 from collections.abc import Callable
 from typing import Any, final
-from typing_extensions import Self
 
 @final
 class make_encoder:
@@ -20,8 +19,8 @@ class make_encoder:
     def encoder(self) -> Callable[[str], str]: ...
     @property
     def item_separator(self) -> str: ...
-    def __new__(
-        cls,
+    def __init__(
+        self,
         markers: dict[int, Any] | None,
         default: Callable[[Any], Any],
         encoder: Callable[[str], str],
@@ -31,7 +30,7 @@ class make_encoder:
         sort_keys: bool,
         skipkeys: bool,
         allow_nan: bool,
-    ) -> Self: ...
+    ) -> None: ...
     def __call__(self, obj: object, _current_indent_level: int) -> Any: ...
 
 @final
@@ -43,7 +42,7 @@ class make_scanner:
     parse_float: Any
     strict: bool
     # TODO: 'context' needs the attrs above (ducktype), but not __call__.
-    def __new__(cls, context: make_scanner) -> Self: ...
+    def __init__(self, context: make_scanner) -> None: ...
     def __call__(self, string: str, index: int) -> tuple[Any, int]: ...
 
 def encode_basestring(s: str, /) -> str: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/_lzma.pyi

@@ -1,8 +1,7 @@
-import sys
 from _typeshed import ReadableBuffer
 from collections.abc import Mapping, Sequence
 from typing import Any, Final, final
-from typing_extensions import Self, TypeAlias
+from typing_extensions import TypeAlias
 
 _FilterChain: TypeAlias = Sequence[Mapping[str, Any]]
 
@@ -37,11 +36,7 @@ PRESET_EXTREME: int  # v big number
 
 @final
 class LZMADecompressor:
-    if sys.version_info >= (3, 12):
-        def __new__(cls, format: int | None = ..., memlimit: int | None = ..., filters: _FilterChain | None = ...) -> Self: ...
-    else:
-        def __init__(self, format: int | None = ..., memlimit: int | None = ..., filters: _FilterChain | None = ...) -> None: ...
-
+    def __init__(self, format: int | None = ..., memlimit: int | None = ..., filters: _FilterChain | None = ...) -> None: ...
     def decompress(self, data: ReadableBuffer, max_length: int = -1) -> bytes: ...
     @property
     def check(self) -> int: ...
@@ -54,15 +49,9 @@ class LZMADecompressor:
 
 @final
 class LZMACompressor:
-    if sys.version_info >= (3, 12):
-        def __new__(
-            cls, format: int | None = ..., check: int = ..., preset: int | None = ..., filters: _FilterChain | None = ...
-        ) -> Self: ...
-    else:
-        def __init__(
-            self, format: int | None = ..., check: int = ..., preset: int | None = ..., filters: _FilterChain | None = ...
-        ) -> None: ...
-
+    def __init__(
+        self, format: int | None = ..., check: int = ..., preset: int | None = ..., filters: _FilterChain | None = ...
+    ) -> None: ...
     def compress(self, data: ReadableBuffer, /) -> bytes: ...
     def flush(self) -> bytes: ...