Remove mdtest Diagnostic trait, support tests with syntax errors

.editorconfig

@@ -17,7 +17,4 @@ indent_size = 4
 trim_trailing_whitespace = false
 
 [*.md]
-max_line_length = 100
-
-[*.toml]
-indent_size = 4
+max_line_length = 100

.github/workflows/ci.yaml

@@ -16,7 +16,7 @@ env:
   CARGO_TERM_COLOR: always
   RUSTUP_MAX_RETRIES: 10
   PACKAGE_NAME: ruff
-  PYTHON_VERSION: "3.12"
+  PYTHON_VERSION: "3.11"
 
 jobs:
   determine_changes:
@@ -115,7 +115,7 @@ jobs:
 
   cargo-test-linux:
     name: "cargo test (linux)"
-    runs-on: depot-ubuntu-22.04-16
+    runs-on: ubuntu-latest
     needs: determine_changes
     if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
@@ -157,36 +157,9 @@ jobs:
           name: ruff
           path: target/debug/ruff
 
-  cargo-test-linux-release:
-    name: "cargo test (linux, release)"
-    runs-on: depot-ubuntu-22.04-16
-    needs: determine_changes
-    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
-    timeout-minutes: 20
-    steps:
-      - uses: actions/checkout@v4
-      - name: "Install Rust toolchain"
-        run: rustup show
-      - name: "Install mold"
-        uses: rui314/setup-mold@v1
-      - name: "Install cargo nextest"
-        uses: taiki-e/install-action@v2
-        with:
-          tool: cargo-nextest
-      - name: "Install cargo insta"
-        uses: taiki-e/install-action@v2
-        with:
-          tool: cargo-insta
-      - uses: Swatinem/rust-cache@v2
-      - name: "Run tests"
-        shell: bash
-        env:
-          NEXTEST_PROFILE: "ci"
-        run: cargo insta test --release --all-features --unreferenced reject --test-runner nextest
-
   cargo-test-windows:
     name: "cargo test (windows)"
-    runs-on: windows-latest-xlarge
+    runs-on: windows-latest
     needs: determine_changes
     if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
@@ -224,8 +197,6 @@ jobs:
           cache: "npm"
           cache-dependency-path: playground/package-lock.json
       - uses: jetli/wasm-pack-action@v0.4.0
-        with:
-          version: v0.13.1
       - uses: Swatinem/rust-cache@v2
       - name: "Test ruff_wasm"
         run: |
@@ -239,7 +210,8 @@ jobs:
   cargo-build-release:
     name: "cargo build (release)"
     runs-on: macos-latest
-    if: ${{ github.ref == 'refs/heads/main' }}
+    needs: determine_changes
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
@@ -283,11 +255,11 @@ jobs:
           NEXTEST_PROFILE: "ci"
         run: cargo +${{ steps.msrv.outputs.value }} insta test --all-features --unreferenced reject --test-runner nextest
 
-  cargo-fuzz-build:
-    name: "cargo fuzz build"
+  cargo-fuzz:
+    name: "cargo fuzz"
     runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ github.ref == 'refs/heads/main' }}
+    if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v4
@@ -306,7 +278,7 @@ jobs:
       - run: cargo fuzz build -s none
 
   fuzz-parser:
-    name: "fuzz parser"
+    name: "Fuzz the parser"
     runs-on: ubuntu-latest
     needs:
       - cargo-test-linux
@@ -335,7 +307,7 @@ jobs:
           # Make executable, since artifact download doesn't preserve this
           chmod +x ${{ steps.download-cached-binary.outputs.download-path }}/ruff
 
-          python scripts/fuzz-parser/fuzz.py --bin ruff 0-500 --test-executable ${{ steps.download-cached-binary.outputs.download-path }}/ruff
+          python scripts/fuzz-parser/fuzz.py 0-500 --test-executable ${{ steps.download-cached-binary.outputs.download-path }}/ruff
 
   scripts:
     name: "test scripts"
@@ -359,7 +331,7 @@ jobs:
 
   ecosystem:
     name: "ecosystem"
-    runs-on: depot-ubuntu-latest-8
+    runs-on: ubuntu-latest
     needs:
       - cargo-test-linux
       - determine_changes
@@ -589,12 +561,12 @@ jobs:
         run: rustup show
       - name: "Cache rust"
         uses: Swatinem/rust-cache@v2
-      - name: "Run checks"
+      - name: "Formatter progress"
         run: scripts/formatter_ecosystem_checks.sh
       - name: "Github step summary"
-        run: cat target/formatter-ecosystem/stats.txt > $GITHUB_STEP_SUMMARY
+        run: cat target/progress_projects_stats.txt > $GITHUB_STEP_SUMMARY
       - name: "Remove checkouts from cache"
-        run: rm -r target/formatter-ecosystem
+        run: rm -r target/progress_projects
 
   check-ruff-lsp:
     name: "test ruff-lsp"

.github/workflows/daily_fuzz.yaml

@@ -49,7 +49,7 @@ jobs:
         # but this is outweighed by the fact that a release build takes *much* longer to compile in CI
         run: cargo build --locked
       - name: Fuzz
-        run: python scripts/fuzz-parser/fuzz.py --bin ruff $(shuf -i 0-9999999999999999999 -n 1000) --test-executable target/debug/ruff
+        run: python scripts/fuzz-parser/fuzz.py $(shuf -i 0-9999999999999999999 -n 1000) --test-executable target/debug/ruff
 
   create-issue-on-failure:
     name: Create an issue if the daily fuzz surfaced any bugs

.github/workflows/publish-playground.yml

@@ -47,7 +47,7 @@ jobs:
         working-directory: playground
       - name: "Deploy to Cloudflare Pages"
         if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        uses: cloudflare/wrangler-action@v3.12.1
+        uses: cloudflare/wrangler-action@v3.11.0
         with:
           apiToken: ${{ secrets.CF_API_TOKEN }}
           accountId: ${{ secrets.CF_ACCOUNT_ID }}

.github/workflows/release.yml

@@ -1,4 +1,4 @@
-# This file was autogenerated by dist: https://opensource.axo.dev/cargo-dist/
+# This file was autogenerated by cargo-dist: https://opensource.axo.dev/cargo-dist/
 #
 # Copyright 2022-2024, axodotdev
 # SPDX-License-Identifier: MIT or Apache-2.0
@@ -6,7 +6,7 @@
 # CI that:
 #
 # * checks for a Git Tag that looks like a release
-# * builds artifacts with dist (archives, installers, hashes)
+# * builds artifacts with cargo-dist (archives, installers, hashes)
 # * uploads those artifacts to temporary workflow zip
 # * on success, uploads the artifacts to a GitHub Release
 #
@@ -24,10 +24,10 @@ permissions:
 # must be a Cargo-style SemVer Version (must have at least major.minor.patch).
 #
 # If PACKAGE_NAME is specified, then the announcement will be for that
-# package (erroring out if it doesn't have the given version or isn't dist-able).
+# package (erroring out if it doesn't have the given version or isn't cargo-dist-able).
 #
 # If PACKAGE_NAME isn't specified, then the announcement will be for all
-# (dist-able) packages in the workspace with that version (this mode is
+# (cargo-dist-able) packages in the workspace with that version (this mode is
 # intended for workspaces with only one dist-able package, or with all dist-able
 # packages versioned/released in lockstep).
 #
@@ -48,7 +48,7 @@ on:
         type: string
 
 jobs:
-  # Run 'dist plan' (or host) to determine what tasks we need to do
+  # Run 'cargo dist plan' (or host) to determine what tasks we need to do
   plan:
     runs-on: "ubuntu-20.04"
     outputs:
@@ -62,16 +62,16 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-      - name: Install dist
+      - name: Install cargo-dist
         # we specify bash to get pipefail; it guards against the `curl` command
         # failing. otherwise `sh` won't catch that `curl` returned non-0
         shell: bash
-        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/axodotdev/cargo-dist/releases/download/v0.25.2-prerelease.3/cargo-dist-installer.sh | sh"
-      - name: Cache dist
+        run: "curl --proto '=https' --tlsv1.2 -LsSf https://github.com/axodotdev/cargo-dist/releases/download/v0.22.1/cargo-dist-installer.sh | sh"
+      - name: Cache cargo-dist
         uses: actions/upload-artifact@v4
         with:
           name: cargo-dist-cache
-          path: ~/.cargo/bin/dist
+          path: ~/.cargo/bin/cargo-dist
       # sure would be cool if github gave us proper conditionals...
       # so here's a doubly-nested ternary-via-truthiness to try to provide the best possible
       # functionality based on whether this is a pull_request, and whether it's from a fork.
@@ -79,8 +79,8 @@ jobs:
       # but also really annoying to build CI around when it needs secrets to work right.)
       - id: plan
         run: |
-          dist ${{ (inputs.tag && inputs.tag != 'dry-run' && format('host --steps=create --tag={0}', inputs.tag)) || 'plan' }} --output-format=json > plan-dist-manifest.json
-          echo "dist ran successfully"
+          cargo dist ${{ (inputs.tag && inputs.tag != 'dry-run' && format('host --steps=create --tag={0}', inputs.tag)) || 'plan' }} --output-format=json > plan-dist-manifest.json
+          echo "cargo dist ran successfully"
           cat plan-dist-manifest.json
           echo "manifest=$(jq -c "." plan-dist-manifest.json)" >> "$GITHUB_OUTPUT"
       - name: "Upload dist-manifest.json"
@@ -124,12 +124,12 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-      - name: Install cached dist
+      - name: Install cached cargo-dist
         uses: actions/download-artifact@v4
         with:
           name: cargo-dist-cache
           path: ~/.cargo/bin/
-      - run: chmod +x ~/.cargo/bin/dist
+      - run: chmod +x ~/.cargo/bin/cargo-dist
       # Get all the local artifacts for the global tasks to use (for e.g. checksums)
       - name: Fetch local artifacts
         uses: actions/download-artifact@v4
@@ -140,8 +140,8 @@ jobs:
       - id: cargo-dist
         shell: bash
         run: |
-          dist build ${{ needs.plan.outputs.tag-flag }} --output-format=json "--artifacts=global" > dist-manifest.json
-          echo "dist ran successfully"
+          cargo dist build ${{ needs.plan.outputs.tag-flag }} --output-format=json "--artifacts=global" > dist-manifest.json
+          echo "cargo dist ran successfully"
 
           # Parse out what we just built and upload it to scratch storage
           echo "paths<<EOF" >> "$GITHUB_OUTPUT"
@@ -174,12 +174,12 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-      - name: Install cached dist
+      - name: Install cached cargo-dist
         uses: actions/download-artifact@v4
         with:
           name: cargo-dist-cache
           path: ~/.cargo/bin/
-      - run: chmod +x ~/.cargo/bin/dist
+      - run: chmod +x ~/.cargo/bin/cargo-dist
       # Fetch artifacts from scratch-storage
       - name: Fetch artifacts
         uses: actions/download-artifact@v4
@@ -191,7 +191,7 @@ jobs:
       - id: host
         shell: bash
         run: |
-          dist host ${{ needs.plan.outputs.tag-flag }} --steps=upload --steps=release --output-format=json > dist-manifest.json
+          cargo dist host ${{ needs.plan.outputs.tag-flag }} --steps=upload --steps=release --output-format=json > dist-manifest.json
           echo "artifacts uploaded and released successfully"
           cat dist-manifest.json
           echo "manifest=$(jq -c "." dist-manifest.json)" >> "$GITHUB_OUTPUT"

.pre-commit-config.yaml

@@ -17,7 +17,7 @@ exclude: |
 
 repos:
   - repo: https://github.com/abravalheri/validate-pyproject
-    rev: v0.23
+    rev: v0.22
     hooks:
       - id: validate-pyproject
 
@@ -53,13 +53,13 @@ repos:
         files: '^crates/.*/resources/mdtest/.*\.md'
         exclude: |
           (?x)^(
-            .*?invalid(_.+)*_syntax\.md
+            .*?invalid(_.+)_syntax.md
           )$
         additional_dependencies:
           - black==24.10.0
 
   - repo: https://github.com/crate-ci/typos
-    rev: v1.27.3
+    rev: v1.27.0
     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: v0.7.4
+    rev: v0.7.2
     hooks:
       - id: ruff-format
       - id: ruff

BREAKING_CHANGES.md

@@ -1,30 +1,5 @@
 # Breaking Changes
 
-## 0.8.0
-
-- **Default to Python 3.9**
-
-    Ruff now defaults to Python 3.9 instead of 3.8 if no explicit Python version is configured using [`ruff.target-version`](https://docs.astral.sh/ruff/settings/#target-version) or [`project.requires-python`](https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#python-requires) ([#13896](https://github.com/astral-sh/ruff/pull/13896))
-
-- **Changed location of `pydoclint` diagnostics**
-
-    [`pydoclint`](https://docs.astral.sh/ruff/rules/#pydoclint-doc) diagnostics now point to the first-line of the problematic docstring. Previously, this was not the case.
-
-    If you've opted into these preview rules but have them suppressed using
-    [`noqa`](https://docs.astral.sh/ruff/linter/#error-suppression) comments in
-    some places, this change may mean that you need to move the `noqa` suppression
-    comments. Most users should be unaffected by this change.
-
-- **Use XDG (i.e. `~/.local/bin`) instead of the Cargo home directory in the standalone installer**
-
-    Previously, Ruff's installer used `$CARGO_HOME` or `~/.cargo/bin` for its target install directory. Now, Ruff will be installed into `$XDG_BIN_HOME`, `$XDG_DATA_HOME/../bin`, or `~/.local/bin` (in that order).
-
-    This change is only relevant to users of the standalone Ruff installer (using the shell or PowerShell script). If you installed Ruff using uv or pip, you should be unaffected.
-
-- **Changes to the line width calculation**
-
-    Ruff now uses a new version of the [unicode-width](https://github.com/unicode-rs/unicode-width) Rust crate to calculate the line width. In very rare cases, this may lead to lines containing Unicode characters being reformatted, or being considered too long when they were not before ([`E501`](https://docs.astral.sh/ruff/rules/line-too-long/)).
-
 ## 0.7.0
 
 - The pytest rules `PT001` and `PT023` now default to omitting the decorator parentheses when there are no arguments

CHANGELOG.md

@@ -1,190 +1,5 @@
 # Changelog
 
-## 0.8.0
-
-Check out the [blog post](https://astral.sh/blog/ruff-v0.8.0) for a migration guide and overview of the changes!
-
-### Breaking changes
-
-See also, the "Remapped rules" section which may result in disabled rules.
-
-- **Default to Python 3.9**
-
-    Ruff now defaults to Python 3.9 instead of 3.8 if no explicit Python version is configured using [`ruff.target-version`](https://docs.astral.sh/ruff/settings/#target-version) or [`project.requires-python`](https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#python-requires) ([#13896](https://github.com/astral-sh/ruff/pull/13896))
-
-- **Changed location of `pydoclint` diagnostics**
-
-    [`pydoclint`](https://docs.astral.sh/ruff/rules/#pydoclint-doc) diagnostics now point to the first-line of the problematic docstring. Previously, this was not the case.
-
-    If you've opted into these preview rules but have them suppressed using
-    [`noqa`](https://docs.astral.sh/ruff/linter/#error-suppression) comments in
-    some places, this change may mean that you need to move the `noqa` suppression
-    comments. Most users should be unaffected by this change.
-
-- **Use XDG (i.e. `~/.local/bin`) instead of the Cargo home directory in the standalone installer**
-
-    Previously, Ruff's installer used `$CARGO_HOME` or `~/.cargo/bin` for its target install directory. Now, Ruff will be installed into `$XDG_BIN_HOME`, `$XDG_DATA_HOME/../bin`, or `~/.local/bin` (in that order).
-
-    This change is only relevant to users of the standalone Ruff installer (using the shell or PowerShell script). If you installed Ruff using uv or pip, you should be unaffected.
-
-- **Changes to the line width calculation**
-
-    Ruff now uses a new version of the [unicode-width](https://github.com/unicode-rs/unicode-width) Rust crate to calculate the line width. In very rare cases, this may lead to lines containing Unicode characters being reformatted, or being considered too long when they were not before ([`E501`](https://docs.astral.sh/ruff/rules/line-too-long/)).
-
-### Removed Rules
-
-The following deprecated rules have been removed:
-
-- [`missing-type-self`](https://docs.astral.sh/ruff/rules/missing-type-self/) (`ANN101`)
-- [`missing-type-cls`](https://docs.astral.sh/ruff/rules/missing-type-cls/) (`ANN102`)
-- [`syntax-error`](https://docs.astral.sh/ruff/rules/syntax-error/) (`E999`)
-- [`pytest-missing-fixture-name-underscore`](https://docs.astral.sh/ruff/rules/pytest-missing-fixture-name-underscore/) (`PT004`)
-- [`pytest-incorrect-fixture-name-underscore`](https://docs.astral.sh/ruff/rules/pytest-incorrect-fixture-name-underscore/) (`PT005`)
-- [`unpacked-list-comprehension`](https://docs.astral.sh/ruff/rules/unpacked-list-comprehension/) (`UP027`)
-
-### Remapped rules
-
-The following rules have been remapped to new rule codes:
-
-- [`flake8-type-checking`](https://docs.astral.sh/ruff/rules/#flake8-type-checking-tc): `TCH` to `TC`
-
-### Stabilization
-
-The following rules have been stabilized and are no longer in preview:
-
-- [`builtin-import-shadowing`](https://docs.astral.sh/ruff/rules/builtin-import-shadowing/) (`A004`)
-- [`mutable-contextvar-default`](https://docs.astral.sh/ruff/rules/mutable-contextvar-default/) (`B039`)
-- [`fast-api-redundant-response-model`](https://docs.astral.sh/ruff/rules/fast-api-redundant-response-model/) (`FAST001`)
-- [`fast-api-non-annotated-dependency`](https://docs.astral.sh/ruff/rules/fast-api-non-annotated-dependency/) (`FAST002`)
-- [`dict-index-missing-items`](https://docs.astral.sh/ruff/rules/dict-index-missing-items/) (`PLC0206`)
-- [`pep484-style-positional-only-parameter`](https://docs.astral.sh/ruff/rules/pep484-style-positional-only-parameter/) (`PYI063`)
-- [`redundant-final-literal`](https://docs.astral.sh/ruff/rules/redundant-final-literal/) (`PYI064`)
-- [`bad-version-info-order`](https://docs.astral.sh/ruff/rules/bad-version-info-order/) (`PYI066`)
-- [`parenthesize-chained-operators`](https://docs.astral.sh/ruff/rules/parenthesize-chained-operators/) (`RUF021`)
-- [`unsorted-dunder-all`](https://docs.astral.sh/ruff/rules/unsorted-dunder-all/) (`RUF022`)
-- [`unsorted-dunder-slots`](https://docs.astral.sh/ruff/rules/unsorted-dunder-slots/) (`RUF023`)
-- [`assert-with-print-message`](https://docs.astral.sh/ruff/rules/assert-with-print-message/) (`RUF030`)
-- [`unnecessary-default-type-args`](https://docs.astral.sh/ruff/rules/unnecessary-default-type-args/) (`UP043`)
-
-The following behaviors have been stabilized:
-
-- [`ambiguous-variable-name`](https://docs.astral.sh/ruff/rules/ambiguous-variable-name/) (`E741`): Violations in stub files are now ignored. Stub authors typically don't control variable names.
-- [`printf-string-formatting`](https://docs.astral.sh/ruff/rules/printf-string-formatting/) (`UP031`): Report all `printf`-like usages even if no autofix is available
-
-The following fixes have been stabilized:
-
-- [`zip-instead-of-pairwise`](https://docs.astral.sh/ruff/rules/zip-instead-of-pairwise/) (`RUF007`)
-
-### Preview features
-
-- \[`flake8-datetimez`\] Exempt `min.time()` and `max.time()` (`DTZ901`) ([#14394](https://github.com/astral-sh/ruff/pull/14394))
-- \[`flake8-pie`\] Mark fix as unsafe if the following statement is a string literal (`PIE790`) ([#14393](https://github.com/astral-sh/ruff/pull/14393))
-- \[`flake8-pyi`\] New rule `redundant-none-literal` (`PYI061`) ([#14316](https://github.com/astral-sh/ruff/pull/14316))
-- \[`flake8-pyi`\] Add autofix for `redundant-numeric-union` (`PYI041`) ([#14273](https://github.com/astral-sh/ruff/pull/14273))
-- \[`ruff`\] New rule `map-int-version-parsing` (`RUF048`) ([#14373](https://github.com/astral-sh/ruff/pull/14373))
-- \[`ruff`\] New rule `redundant-bool-literal` (`RUF038`) ([#14319](https://github.com/astral-sh/ruff/pull/14319))
-- \[`ruff`\] New rule `unraw-re-pattern` (`RUF039`) ([#14446](https://github.com/astral-sh/ruff/pull/14446))
-- \[`pycodestyle`\] Exempt `pytest.importorskip()` calls (`E402`) ([#14474](https://github.com/astral-sh/ruff/pull/14474))
-- \[`pylint`\] Autofix suggests using sets when possible (`PLR1714`) ([#14372](https://github.com/astral-sh/ruff/pull/14372))
-
-### Rule changes
-
-- [`invalid-pyproject-toml`](https://docs.astral.sh/ruff/rules/invalid-pyproject-toml/) (`RUF200`): Updated to reflect the provisionally accepted [PEP 639](https://peps.python.org/pep-0639/).
-- \[`flake8-pyi`\] Avoid panic in unfixable case (`PYI041`) ([#14402](https://github.com/astral-sh/ruff/pull/14402))
-- \[`flake8-type-checking`\] Correctly handle quotes in subscript expression when generating an autofix ([#14371](https://github.com/astral-sh/ruff/pull/14371))
-- \[`pylint`\] Suggest correct autofix for `__contains__` (`PLC2801`) ([#14424](https://github.com/astral-sh/ruff/pull/14424))
-
-### Configuration
-
-- Ruff now emits a warning instead of an error when a configuration [`ignore`](https://docs.astral.sh/ruff/settings/#lint_ignore)s a rule that has been removed ([#14435](https://github.com/astral-sh/ruff/pull/14435))
-- Ruff now validates that `lint.flake8-import-conventions.aliases` only uses valid module names and aliases ([#14477](https://github.com/astral-sh/ruff/pull/14477))
-
-## 0.7.4
-
-### Preview features
-
-- \[`flake8-datetimez`\] Detect usages of `datetime.max`/`datetime.min` (`DTZ901`) ([#14288](https://github.com/astral-sh/ruff/pull/14288))
-- \[`flake8-logging`\] Implement `root-logger-calls` (`LOG015`) ([#14302](https://github.com/astral-sh/ruff/pull/14302))
-- \[`flake8-no-pep420`\] Detect empty implicit namespace packages (`INP001`) ([#14236](https://github.com/astral-sh/ruff/pull/14236))
-- \[`flake8-pyi`\] Add "replace with `Self`" fix (`PYI019`) ([#14238](https://github.com/astral-sh/ruff/pull/14238))
-- \[`perflint`\] Implement quick-fix for `manual-list-comprehension` (`PERF401`) ([#13919](https://github.com/astral-sh/ruff/pull/13919))
-- \[`pylint`\] Implement `shallow-copy-environ` (`W1507`) ([#14241](https://github.com/astral-sh/ruff/pull/14241))
-- \[`ruff`\] Implement `none-not-at-end-of-union` (`RUF036`) ([#14314](https://github.com/astral-sh/ruff/pull/14314))
-- \[`ruff`\] Implementation `unsafe-markup-call` from `flake8-markupsafe` plugin (`RUF035`) ([#14224](https://github.com/astral-sh/ruff/pull/14224))
-- \[`ruff`\] Report problems for `attrs` dataclasses (`RUF008`, `RUF009`) ([#14327](https://github.com/astral-sh/ruff/pull/14327))
-
-### Rule changes
-
-- \[`flake8-boolean-trap`\] Exclude dunder methods that define operators (`FBT001`) ([#14203](https://github.com/astral-sh/ruff/pull/14203))
-- \[`flake8-pyi`\] Add "replace with `Self`" fix (`PYI034`) ([#14217](https://github.com/astral-sh/ruff/pull/14217))
-- \[`flake8-pyi`\] Always autofix `duplicate-union-members` (`PYI016`) ([#14270](https://github.com/astral-sh/ruff/pull/14270))
-- \[`flake8-pyi`\] Improve autofix for nested and mixed type unions for `unnecessary-type-union` (`PYI055`) ([#14272](https://github.com/astral-sh/ruff/pull/14272))
-- \[`flake8-pyi`\] Mark fix as unsafe when type annotation contains comments for `duplicate-literal-member` (`PYI062`) ([#14268](https://github.com/astral-sh/ruff/pull/14268))
-
-### Server
-
-- Use the current working directory to resolve settings from `ruff.configuration` ([#14352](https://github.com/astral-sh/ruff/pull/14352))
-
-### Bug fixes
-
-- Avoid conflicts between `PLC014` (`useless-import-alias`) and `I002` (`missing-required-import`) by considering `lint.isort.required-imports` for `PLC014` ([#14287](https://github.com/astral-sh/ruff/pull/14287))
-- \[`flake8-type-checking`\] Skip quoting annotation if it becomes invalid syntax (`TCH001`)
-- \[`flake8-pyi`\] Avoid using `typing.Self` in stub files pre-Python 3.11 (`PYI034`) ([#14230](https://github.com/astral-sh/ruff/pull/14230))
-- \[`flake8-pytest-style`\] Flag `pytest.raises` call with keyword argument `expected_exception` (`PT011`) ([#14298](https://github.com/astral-sh/ruff/pull/14298))
-- \[`flake8-simplify`\] Infer "unknown" truthiness for literal iterables whose items are all unpacks (`SIM222`) ([#14263](https://github.com/astral-sh/ruff/pull/14263))
-- \[`flake8-type-checking`\] Fix false positives for `typing.Annotated` (`TCH001`) ([#14311](https://github.com/astral-sh/ruff/pull/14311))
-- \[`pylint`\] Allow `await` at the top-level scope of a notebook (`PLE1142`) ([#14225](https://github.com/astral-sh/ruff/pull/14225))
-- \[`pylint`\] Fix miscellaneous issues in `await-outside-async` detection (`PLE1142`) ([#14218](https://github.com/astral-sh/ruff/pull/14218))
-- \[`pyupgrade`\] Avoid applying PEP 646 rewrites in invalid contexts (`UP044`) ([#14234](https://github.com/astral-sh/ruff/pull/14234))
-- \[`pyupgrade`\] Detect permutations in redundant open modes (`UP015`) ([#14255](https://github.com/astral-sh/ruff/pull/14255))
-- \[`refurb`\] Avoid triggering `hardcoded-string-charset` for reordered sets (`FURB156`) ([#14233](https://github.com/astral-sh/ruff/pull/14233))
-- \[`refurb`\] Further special cases added to `verbose-decimal-constructor` (`FURB157`) ([#14216](https://github.com/astral-sh/ruff/pull/14216))
-- \[`refurb`\] Use `UserString` instead of non-existent `UserStr` (`FURB189`) ([#14209](https://github.com/astral-sh/ruff/pull/14209))
-- \[`ruff`\] Avoid treating lowercase letters as `# noqa` codes (`RUF100`) ([#14229](https://github.com/astral-sh/ruff/pull/14229))
-- \[`ruff`\] Do not report when `Optional` has no type arguments (`RUF013`) ([#14181](https://github.com/astral-sh/ruff/pull/14181))
-
-### Documentation
-
-- Add "Notebook behavior" section for `F704`, `PLE1142` ([#14266](https://github.com/astral-sh/ruff/pull/14266))
-- Document comment policy around fix safety ([#14300](https://github.com/astral-sh/ruff/pull/14300))
-
-## 0.7.3
-
-### Preview features
-
-- Formatter: Disallow single-line implicit concatenated strings ([#13928](https://github.com/astral-sh/ruff/pull/13928))
-- \[`flake8-pyi`\] Include all Python file types for `PYI006` and `PYI066` ([#14059](https://github.com/astral-sh/ruff/pull/14059))
-- \[`flake8-simplify`\] Implement `split-of-static-string` (`SIM905`) ([#14008](https://github.com/astral-sh/ruff/pull/14008))
-- \[`refurb`\] Implement `subclass-builtin` (`FURB189`) ([#14105](https://github.com/astral-sh/ruff/pull/14105))
-- \[`ruff`\] Improve diagnostic messages and docs (`RUF031`, `RUF032`, `RUF034`) ([#14068](https://github.com/astral-sh/ruff/pull/14068))
-
-### Rule changes
-
-- Detect items that hash to same value in duplicate sets (`B033`, `PLC0208`) ([#14064](https://github.com/astral-sh/ruff/pull/14064))
-- \[`eradicate`\] Better detection of IntelliJ language injection comments (`ERA001`) ([#14094](https://github.com/astral-sh/ruff/pull/14094))
-- \[`flake8-pyi`\] Add autofix for `docstring-in-stub` (`PYI021`) ([#14150](https://github.com/astral-sh/ruff/pull/14150))
-- \[`flake8-pyi`\] Update `duplicate-literal-member` (`PYI062`) to alawys provide an autofix ([#14188](https://github.com/astral-sh/ruff/pull/14188))
-- \[`pyflakes`\] Detect items that hash to same value in duplicate dictionaries (`F601`) ([#14065](https://github.com/astral-sh/ruff/pull/14065))
-- \[`ruff`\] Fix false positive for decorators (`RUF028`) ([#14061](https://github.com/astral-sh/ruff/pull/14061))
-
-### Bug fixes
-
-- Avoid parsing joint rule codes as distinct codes in `# noqa` ([#12809](https://github.com/astral-sh/ruff/pull/12809))
-- \[`eradicate`\] ignore `# language=` in commented-out-code rule (ERA001) ([#14069](https://github.com/astral-sh/ruff/pull/14069))
-- \[`flake8-bugbear`\] - do not run `mutable-argument-default` on stubs (`B006`) ([#14058](https://github.com/astral-sh/ruff/pull/14058))
-- \[`flake8-builtins`\] Skip lambda expressions in `builtin-argument-shadowing (A002)` ([#14144](https://github.com/astral-sh/ruff/pull/14144))
-- \[`flake8-comprehension`\] Also remove trailing comma while fixing `C409` and `C419` ([#14097](https://github.com/astral-sh/ruff/pull/14097))
-- \[`flake8-simplify`\] Allow `open` without context manager in `return` statement (`SIM115`) ([#14066](https://github.com/astral-sh/ruff/pull/14066))
-- \[`pylint`\] Respect hash-equivalent literals in `iteration-over-set` (`PLC0208`) ([#14063](https://github.com/astral-sh/ruff/pull/14063))
-- \[`pylint`\] Update known dunder methods for Python 3.13 (`PLW3201`) ([#14146](https://github.com/astral-sh/ruff/pull/14146))
-- \[`pyupgrade`\] - ignore kwarg unpacking for `UP044` ([#14053](https://github.com/astral-sh/ruff/pull/14053))
-- \[`refurb`\] Parse more exotic decimal strings in `verbose-decimal-constructor` (`FURB157`) ([#14098](https://github.com/astral-sh/ruff/pull/14098))
-
-### Documentation
-
-- Add links to missing related options within rule documentations ([#13971](https://github.com/astral-sh/ruff/pull/13971))
-- Add rule short code to mkdocs tags to allow searching via rule codes ([#14040](https://github.com/astral-sh/ruff/pull/14040))
-
 ## 0.7.2
 
 ### Preview features
@@ -1077,7 +892,7 @@ The following deprecated CLI commands have been removed:
 ### Preview features
 
 - \[`flake8-bugbear`\] Implement `return-in-generator` (`B901`) ([#11644](https://github.com/astral-sh/ruff/pull/11644))
-- \[`flake8-pyi`\] Implement `pep484-style-positional-only-parameter` (`PYI063`) ([#11699](https://github.com/astral-sh/ruff/pull/11699))
+- \[`flake8-pyi`\] Implement `PYI063` ([#11699](https://github.com/astral-sh/ruff/pull/11699))
 - \[`pygrep_hooks`\] Check blanket ignores via file-level pragmas (`PGH004`) ([#11540](https://github.com/astral-sh/ruff/pull/11540))
 
 ### Rule changes

Cargo.toml

@@ -65,8 +65,7 @@ compact_str = "0.8.0"
 criterion = { version = "0.5.1", default-features = false }
 crossbeam = { version = "0.8.4" }
 dashmap = { version = "6.0.1" }
-dir-test = { version = "0.4.0" }
-dunce = { version = "1.0.5" }
+dir-test = { version = "0.3.0" }
 drop_bomb = { version = "0.1.5" }
 env_logger = { version = "0.11.0" }
 etcetera = { version = "0.8.0" }
@@ -82,7 +81,7 @@ hashbrown = { version = "0.15.0", default-features = false, features = [
 ignore = { version = "0.4.22" }
 imara-diff = { version = "0.1.5" }
 imperative = { version = "1.0.4" }
-indexmap = { version = "2.6.0" }
+indexmap = {version = "2.6.0" }
 indicatif = { version = "0.17.8" }
 indoc = { version = "2.0.4" }
 insta = { version = "1.35.1" }
@@ -111,7 +110,7 @@ pathdiff = { version = "0.2.1" }
 pep440_rs = { version = "0.7.1" }
 pretty_assertions = "1.3.0"
 proc-macro2 = { version = "1.0.79" }
-pyproject-toml = { version = "0.13.4" }
+pyproject-toml = { version = "0.9.0" }
 quick-junit = { version = "0.5.0" }
 quote = { version = "1.0.23" }
 rand = { version = "0.8.5" }
@@ -137,7 +136,7 @@ strum_macros = { version = "0.26.0" }
 syn = { version = "2.0.55" }
 tempfile = { version = "3.9.0" }
 test-case = { version = "3.3.1" }
-thiserror = { version = "2.0.0" }
+thiserror = { version = "1.0.58" }
 tikv-jemallocator = { version = "0.6.0" }
 toml = { version = "0.8.11" }
 tracing = { version = "0.1.40" }
@@ -151,7 +150,7 @@ tracing-tree = { version = "0.4.0" }
 typed-arena = { version = "2.0.2" }
 unic-ucd-category = { version = "0.9" }
 unicode-ident = { version = "1.0.12" }
-unicode-width = { version = "0.2.0" }
+unicode-width = { version = "0.1.11" }
 unicode_names2 = { version = "1.2.2" }
 unicode-normalization = { version = "0.1.23" }
 ureq = { version = "2.9.6" }
@@ -248,10 +247,10 @@ debug = 1
 [profile.dist]
 inherits = "release"
 
-# Config for 'dist'
+# Config for 'cargo dist'
 [workspace.metadata.dist]
-# The preferred dist version to use in CI (Cargo.toml SemVer syntax)
-cargo-dist-version = "0.25.2-prerelease.3"
+# The preferred cargo-dist version to use in CI (Cargo.toml SemVer syntax)
+cargo-dist-version = "0.22.1"
 # CI backends to support
 ci = "github"
 # The installers to generate for each app
@@ -282,13 +281,13 @@ targets = [
 ]
 # Whether to auto-include files like READMEs, LICENSEs, and CHANGELOGs (default true)
 auto-includes = false
-# Whether dist should create a Github Release or use an existing draft
+# Whether cargo-dist should create a GitHub Release or use an existing draft
 create-release = true
 # Which actions to run on pull requests
 pr-run-mode = "skip"
 # Whether CI should trigger releases with dispatches instead of tag pushes
 dispatch-releases = true
-# Which phase dist should use to create the GitHub release
+# Which phase cargo-dist should use to create the GitHub release
 github-release = "announce"
 # Whether CI should include auto-generated code to build local artifacts
 build-local-artifacts = false
@@ -297,10 +296,14 @@ local-artifacts-jobs = ["./build-binaries", "./build-docker"]
 # Publish jobs to run in CI
 publish-jobs = ["./publish-pypi", "./publish-wasm"]
 # Post-announce jobs to run in CI
-post-announce-jobs = ["./notify-dependents", "./publish-docs", "./publish-playground"]
+post-announce-jobs = [
+    "./notify-dependents",
+    "./publish-docs",
+    "./publish-playground",
+]
 # Custom permissions for GitHub Jobs
 github-custom-job-permissions = { "build-docker" = { packages = "write", contents = "read" }, "publish-wasm" = { contents = "read", id-token = "write", packages = "write" } }
 # Whether to install an updater program
 install-updater = false
 # Path that installers should place binaries in
-install-path = ["$XDG_BIN_HOME/", "$XDG_DATA_HOME/../bin", "~/.local/bin"]
+install-path = "CARGO_HOME"

README.md

@@ -136,8 +136,8 @@ 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/0.8.0/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.8.0/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.7.2/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.7.2/install.ps1 | iex"
 ```
 
 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -170,7 +170,7 @@ 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: v0.8.0
+  rev: v0.7.2
   hooks:
     # Run the linter.
     - id: ruff
@@ -238,8 +238,8 @@ exclude = [
 line-length = 88
 indent-width = 4
 
-# Assume Python 3.9
-target-version = "py39"
+# Assume Python 3.8
+target-version = "py38"
 
 [lint]
 # Enable Pyflakes (`F`) and a subset of the pycodestyle (`E`)  codes by default.

_typos.toml

@@ -1,11 +1,6 @@
 [files]
 # https://github.com/crate-ci/typos/issues/868
-extend-exclude = [
-  "crates/red_knot_vendored/vendor/**/*",
-  "**/resources/**/*",
-  "**/snapshots/**/*",
-  "crates/red_knot_workspace/src/workspace/pyproject/package_name.rs"
-]
+extend-exclude = ["crates/red_knot_vendored/vendor/**/*", "**/resources/**/*", "**/snapshots/**/*"]
 
 [default.extend-words]
 "arange" = "arange"  # e.g. `numpy.arange`

crates/red_knot/Cargo.toml

@@ -34,7 +34,6 @@ tracing-tree = { workspace = true }
 [dev-dependencies]
 filetime = { workspace = true }
 tempfile = { workspace = true }
-ruff_db = { workspace = true, features = ["testing"] }
 
 [lints]
 workspace = true

crates/red_knot/src/main.rs

@@ -5,6 +5,9 @@ use anyhow::{anyhow, Context};
 use clap::Parser;
 use colored::Colorize;
 use crossbeam::channel as crossbeam_channel;
+use ruff_db::diagnostic::CompileDiagnostic;
+use salsa::plumbing::ZalsaDatabase;
+
 use red_knot_python_semantic::SitePackages;
 use red_knot_server::run_server;
 use red_knot_workspace::db::RootDatabase;
@@ -12,9 +15,7 @@ use red_knot_workspace::watch;
 use red_knot_workspace::watch::WorkspaceWatcher;
 use red_knot_workspace::workspace::settings::Configuration;
 use red_knot_workspace::workspace::WorkspaceMetadata;
-use ruff_db::diagnostic::Diagnostic;
 use ruff_db::system::{OsSystem, System, SystemPath, SystemPathBuf};
-use salsa::plumbing::ZalsaDatabase;
 use target_version::TargetVersion;
 
 use crate::logging::{setup_tracing, Verbosity};
@@ -183,10 +184,10 @@ fn run() -> anyhow::Result<ExitStatus> {
 
     let system = OsSystem::new(cwd.clone());
     let cli_configuration = args.to_configuration(&cwd);
-    let workspace_metadata = WorkspaceMetadata::discover(
+    let workspace_metadata = WorkspaceMetadata::from_path(
         system.current_directory(),
         &system,
-        Some(&cli_configuration),
+        Some(cli_configuration.clone()),
     )?;
 
     // TODO: Use the `program_settings` to compute the key for the database's persistent
@@ -380,7 +381,7 @@ impl MainLoopCancellationToken {
 enum MainLoopMessage {
     CheckWorkspace,
     CheckCompleted {
-        result: Vec<Box<dyn Diagnostic>>,
+        result: Vec<CompileDiagnostic>,
         revision: u64,
     },
     ApplyChanges(Vec<watch::ChangeEvent>),

crates/red_knot/src/target_version.rs

@@ -4,8 +4,8 @@
 #[derive(Copy, Clone, Hash, Debug, PartialEq, Eq, PartialOrd, Ord, Default, clap::ValueEnum)]
 pub enum TargetVersion {
     Py37,
-    Py38,
     #[default]
+    Py38,
     Py39,
     Py310,
     Py311,
@@ -46,17 +46,3 @@ impl From<TargetVersion> for red_knot_python_semantic::PythonVersion {
         }
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use crate::target_version::TargetVersion;
-    use red_knot_python_semantic::PythonVersion;
-
-    #[test]
-    fn same_default_as_python_version() {
-        assert_eq!(
-            PythonVersion::from(TargetVersion::default()),
-            PythonVersion::default()
-        );
-    }
-}

crates/red_knot/tests/file_watching.rs

@@ -4,8 +4,9 @@ use std::io::Write;
 use std::time::Duration;
 
 use anyhow::{anyhow, Context};
+
 use red_knot_python_semantic::{resolve_module, ModuleName, Program, PythonVersion, SitePackages};
-use red_knot_workspace::db::{Db, RootDatabase};
+use red_knot_workspace::db::RootDatabase;
 use red_knot_workspace::watch;
 use red_knot_workspace::watch::{directory_watcher, WorkspaceWatcher};
 use red_knot_workspace::workspace::settings::{Configuration, SearchPathConfiguration};
@@ -13,7 +14,6 @@ use red_knot_workspace::workspace::WorkspaceMetadata;
 use ruff_db::files::{system_path_to_file, File, FileError};
 use ruff_db::source::source_text;
 use ruff_db::system::{OsSystem, SystemPath, SystemPathBuf};
-use ruff_db::testing::{setup_logging, setup_logging_with_filter};
 use ruff_db::Upcast;
 
 struct TestCase {
@@ -46,8 +46,6 @@ impl TestCase {
     }
 
     fn try_stop_watch(&mut self, timeout: Duration) -> Option<Vec<watch::ChangeEvent>> {
-        tracing::debug!("Try stopping watch with timeout {:?}", timeout);
-
         let watcher = self
             .watcher
             .take()
@@ -57,11 +55,8 @@ impl TestCase {
             .changes_receiver
             .recv_timeout(timeout)
             .unwrap_or_default();
-
         watcher.flush();
-        tracing::debug!("Flushed file watcher");
         watcher.stop();
-        tracing::debug!("Stopping file watcher");
 
         for event in &self.changes_receiver {
             all_events.extend(event);
@@ -74,6 +69,7 @@ impl TestCase {
         Some(all_events)
     }
 
+    #[cfg(unix)]
     fn take_watch_changes(&self) -> Vec<watch::ChangeEvent> {
         self.try_take_watch_changes(Duration::from_secs(10))
             .expect("Expected watch changes but observed none")
@@ -114,8 +110,8 @@ impl TestCase {
     ) -> anyhow::Result<()> {
         let program = Program::get(self.db());
 
-        let new_settings = configuration.to_settings(self.db.workspace().root(&self.db));
-        self.configuration.search_paths = configuration;
+        self.configuration.search_paths = configuration.clone();
+        let new_settings = configuration.into_settings(self.db.workspace().root(&self.db));
 
         program.update_search_paths(&mut self.db, &new_settings)?;
 
@@ -208,9 +204,7 @@ where
             .as_utf8_path()
             .canonicalize_utf8()
             .with_context(|| "Failed to canonicalize root path.")?,
-    )
-    .simplified()
-    .to_path_buf();
+    );
 
     let workspace_path = root_path.join("workspace");
 
@@ -247,7 +241,8 @@ where
         search_paths,
     };
 
-    let workspace = WorkspaceMetadata::discover(&workspace_path, &system, Some(&configuration))?;
+    let workspace =
+        WorkspaceMetadata::from_path(&workspace_path, &system, Some(configuration.clone()))?;
 
     let db = RootDatabase::new(workspace, system)?;
 
@@ -604,8 +599,6 @@ fn directory_moved_to_trash() -> anyhow::Result<()> {
 
 #[test]
 fn directory_renamed() -> anyhow::Result<()> {
-    let _tracing = setup_logging_with_filter("file_watching=TRACE,red_knot=TRACE");
-
     let mut case = setup([
         ("bar.py", "import sub.a"),
         ("sub/__init__.py", ""),
@@ -646,10 +639,6 @@ fn directory_renamed() -> anyhow::Result<()> {
 
     let changes = case.stop_watch();
 
-    for event in &changes {
-        tracing::debug!("Event: {:?}", event);
-    }
-
     case.apply_changes(changes);
 
     // `import sub.a` should no longer resolve
@@ -1322,138 +1311,3 @@ mod unix {
         Ok(())
     }
 }
-
-#[test]
-fn nested_packages_delete_root() -> anyhow::Result<()> {
-    let mut case = setup(|root: &SystemPath, workspace_root: &SystemPath| {
-        std::fs::write(
-            workspace_root.join("pyproject.toml").as_std_path(),
-            r#"
-            [project]
-            name = "inner"
-            "#,
-        )?;
-
-        std::fs::write(
-            root.join("pyproject.toml").as_std_path(),
-            r#"
-            [project]
-            name = "outer"
-            "#,
-        )?;
-
-        Ok(())
-    })?;
-
-    assert_eq!(
-        case.db().workspace().root(case.db()),
-        &*case.workspace_path("")
-    );
-
-    std::fs::remove_file(case.workspace_path("pyproject.toml").as_std_path())?;
-
-    let changes = case.stop_watch();
-
-    case.apply_changes(changes);
-
-    // It should now pick up the outer workspace.
-    assert_eq!(case.db().workspace().root(case.db()), case.root_path());
-
-    Ok(())
-}
-
-#[test]
-fn added_package() -> anyhow::Result<()> {
-    let _ = setup_logging();
-    let mut case = setup([
-        (
-            "pyproject.toml",
-            r#"
-            [project]
-            name = "inner"
-
-            [tool.knot.workspace]
-            members = ["packages/*"]
-            "#,
-        ),
-        (
-            "packages/a/pyproject.toml",
-            r#"
-            [project]
-            name = "a"
-            "#,
-        ),
-    ])?;
-
-    assert_eq!(case.db().workspace().packages(case.db()).len(), 2);
-
-    std::fs::create_dir(case.workspace_path("packages/b").as_std_path())
-        .context("failed to create folder for package 'b'")?;
-
-    // It seems that the file watcher won't pick up on file changes shortly after the folder
-    // was created... I suspect this is because most file watchers don't support recursive
-    // file watching. Instead, file-watching libraries manually implement recursive file watching
-    // by setting a watcher for each directory. But doing this obviously "lags" behind.
-    case.take_watch_changes();
-
-    std::fs::write(
-        case.workspace_path("packages/b/pyproject.toml")
-            .as_std_path(),
-        r#"
-            [project]
-            name = "b"
-            "#,
-    )
-    .context("failed to write pyproject.toml for package b")?;
-
-    let changes = case.stop_watch();
-
-    case.apply_changes(changes);
-
-    assert_eq!(case.db().workspace().packages(case.db()).len(), 3);
-
-    Ok(())
-}
-
-#[test]
-fn removed_package() -> anyhow::Result<()> {
-    let mut case = setup([
-        (
-            "pyproject.toml",
-            r#"
-            [project]
-            name = "inner"
-
-            [tool.knot.workspace]
-            members = ["packages/*"]
-            "#,
-        ),
-        (
-            "packages/a/pyproject.toml",
-            r#"
-            [project]
-            name = "a"
-            "#,
-        ),
-        (
-            "packages/b/pyproject.toml",
-            r#"
-            [project]
-            name = "b"
-            "#,
-        ),
-    ])?;
-
-    assert_eq!(case.db().workspace().packages(case.db()).len(), 3);
-
-    std::fs::remove_dir_all(case.workspace_path("packages/b").as_std_path())
-        .context("failed to remove package 'b'")?;
-
-    let changes = case.stop_watch();
-
-    case.apply_changes(changes);
-
-    assert_eq!(case.db().workspace().packages(case.db()).len(), 2);
-
-    Ok(())
-}

crates/red_knot_python_semantic/Cargo.toml

@@ -13,8 +13,7 @@ license = { workspace = true }
 [dependencies]
 ruff_db = { workspace = true }
 ruff_index = { workspace = true }
-ruff_python_ast = { workspace = true }
-ruff_python_parser = { workspace = true }
+ruff_python_ast = { workspace = true, features = ["salsa"] }
 ruff_python_stdlib = { workspace = true }
 ruff_source_file = { workspace = true }
 ruff_text_size = { workspace = true }
@@ -33,7 +32,6 @@ thiserror = { workspace = true }
 tracing = { workspace = true }
 rustc-hash = { workspace = true }
 hashbrown = { workspace = true }
-serde = { workspace = true, optional = true }
 smallvec = { workspace = true }
 static_assertions = { workspace = true }
 test-case = { workspace = true }

crates/red_knot_python_semantic/resources/mdtest/annotations/never.md

@@ -1,62 +0,0 @@
-# NoReturn & Never
-
-`NoReturn` is used to annotate the return type for functions that never return. `Never` is the
-bottom type, representing the empty set of Python objects. These two annotations can be used
-interchangeably.
-
-## Function Return Type Annotation
-
-```py
-from typing import NoReturn
-
-def stop() -> NoReturn:
-    raise RuntimeError("no way")
-
-# revealed: Never
-reveal_type(stop())
-```
-
-## Assignment
-
-```py
-from typing import NoReturn, Never, Any
-
-# error: [invalid-type-parameter] "Type `typing.Never` expected no type parameter"
-x: Never[int]
-a1: NoReturn
-# TODO: Test `Never` is only available in python >= 3.11
-a2: Never
-b1: Any
-b2: int
-
-def f():
-    # revealed: Never
-    reveal_type(a1)
-    # revealed: Never
-    reveal_type(a2)
-
-    # Never is assignable to all types.
-    v1: int = a1
-    v2: str = a1
-    # Other types are not assignable to Never except for Never (and Any).
-    v3: Never = b1
-    v4: Never = a2
-    v5: Any = b2
-    # error: [invalid-assignment] "Object of type `Literal[1]` is not assignable to `Never`"
-    v6: Never = 1
-```
-
-## Typing Extensions
-
-```py
-from typing_extensions import NoReturn, Never
-
-x: NoReturn
-y: Never
-
-def f():
-    # revealed: Never
-    reveal_type(x)
-    # revealed: Never
-    reveal_type(y)
-```

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

@@ -1,47 +0,0 @@
-# Optional
-
-## Annotation
-
-`typing.Optional` is equivalent to using the type with a None in a Union.
-
-```py
-from typing import Optional
-
-a: Optional[int]
-a1: Optional[bool]
-a2: Optional[Optional[bool]]
-a3: Optional[None]
-
-def f():
-    # revealed: int | None
-    reveal_type(a)
-    # revealed: bool | None
-    reveal_type(a1)
-    # revealed: bool | None
-    reveal_type(a2)
-    # revealed: None
-    reveal_type(a3)
-```
-
-## Assignment
-
-```py
-from typing import Optional
-
-a: Optional[int] = 1
-a = None
-# error: [invalid-assignment] "Object of type `Literal[""]` is not assignable to `int | None`"
-a = ""
-```
-
-## Typing Extensions
-
-```py
-from typing_extensions import Optional
-
-a: Optional[int]
-
-def f():
-    # revealed: int | None
-    reveal_type(a)
-```

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

@@ -9,10 +9,10 @@ Ts = TypeVarTuple("Ts")
 
 def append_int(*args: *Ts) -> tuple[*Ts, int]:
     # TODO: should show some representation of the variadic generic type
-    reveal_type(args)  # revealed: @Todo(function parameter type)
+    reveal_type(args)  # revealed: @Todo
 
     return (*args, 1)
 
 # TODO should be tuple[Literal[True], Literal["a"], int]
-reveal_type(append_int(True, "a"))  # revealed: @Todo(full tuple[...] support)
+reveal_type(append_int(True, "a"))  # revealed: @Todo
 ```

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

@@ -1,218 +0,0 @@
-# String annotations
-
-## Simple
-
-```py
-def f() -> "int":
-    return 1
-
-reveal_type(f())  # revealed: int
-```
-
-## Nested
-
-```py
-def f() -> "'int'":
-    return 1
-
-reveal_type(f())  # revealed: int
-```
-
-## Type expression
-
-```py
-def f1() -> "int | str":
-    return 1
-
-def f2() -> "tuple[int, str]":
-    return 1
-
-reveal_type(f1())  # revealed: int | str
-reveal_type(f2())  # revealed: tuple[int, str]
-```
-
-## Partial
-
-```py
-def f() -> tuple[int, "str"]:
-    return 1
-
-reveal_type(f())  # revealed: tuple[int, str]
-```
-
-## Deferred
-
-```py
-def f() -> "Foo":
-    return Foo()
-
-class Foo:
-    pass
-
-reveal_type(f())  # revealed: Foo
-```
-
-## Deferred (undefined)
-
-```py
-# error: [unresolved-reference]
-def f() -> "Foo":
-    pass
-
-reveal_type(f())  # revealed: Unknown
-```
-
-## Partial deferred
-
-```py
-def f() -> int | "Foo":
-    return 1
-
-class Foo:
-    pass
-
-reveal_type(f())  # revealed: int | Foo
-```
-
-## `typing.Literal`
-
-```py
-from typing import Literal
-
-def f1() -> Literal["Foo", "Bar"]:
-    return "Foo"
-
-def f2() -> 'Literal["Foo", "Bar"]':
-    return "Foo"
-
-class Foo:
-    pass
-
-reveal_type(f1())  # revealed: Literal["Foo", "Bar"]
-reveal_type(f2())  # revealed: Literal["Foo", "Bar"]
-```
-
-## Various string kinds
-
-```py
-# error: [annotation-raw-string] "Type expressions cannot use raw string literal"
-def f1() -> r"int":
-    return 1
-
-# error: [annotation-f-string] "Type expressions cannot use f-strings"
-def f2() -> f"int":
-    return 1
-
-# error: [annotation-byte-string] "Type expressions cannot use bytes literal"
-def f3() -> b"int":
-    return 1
-
-def f4() -> "int":
-    return 1
-
-# error: [annotation-implicit-concat] "Type expressions cannot span multiple string literals"
-def f5() -> "in" "t":
-    return 1
-
-# error: [annotation-escape-character] "Type expressions cannot contain escape characters"
-def f6() -> "\N{LATIN SMALL LETTER I}nt":
-    return 1
-
-# error: [annotation-escape-character] "Type expressions cannot contain escape characters"
-def f7() -> "\x69nt":
-    return 1
-
-def f8() -> """int""":
-    return 1
-
-def f9() -> "b'int'":
-    return 1
-
-reveal_type(f1())  # revealed: Unknown
-reveal_type(f2())  # revealed: Unknown
-reveal_type(f3())  # revealed: Unknown
-reveal_type(f4())  # revealed: int
-reveal_type(f5())  # revealed: Unknown
-reveal_type(f6())  # revealed: Unknown
-reveal_type(f7())  # revealed: Unknown
-reveal_type(f8())  # revealed: int
-reveal_type(f9())  # revealed: Unknown
-```
-
-## Various string kinds in `typing.Literal`
-
-```py
-from typing import Literal
-
-def f() -> Literal["a", r"b", b"c", "d" "e", "\N{LATIN SMALL LETTER F}", "\x67", """h"""]:
-    return "normal"
-
-reveal_type(f())  # revealed: Literal["a", "b", "de", "f", "g", "h"] | Literal[b"c"]
-```
-
-## Class variables
-
-```py
-MyType = int
-
-class Aliases:
-    MyType = str
-
-    forward: "MyType"
-    not_forward: MyType
-
-reveal_type(Aliases.forward)  # revealed: str
-reveal_type(Aliases.not_forward)  # revealed: str
-```
-
-## Annotated assignment
-
-```py
-a: "int" = 1
-b: "'int'" = 1
-c: "Foo"
-# error: [invalid-assignment] "Object of type `Literal[1]` is not assignable to `Foo`"
-d: "Foo" = 1
-
-class Foo:
-    pass
-
-c = Foo()
-
-reveal_type(a)  # revealed: Literal[1]
-reveal_type(b)  # revealed: Literal[1]
-reveal_type(c)  # revealed: Foo
-reveal_type(d)  # revealed: Foo
-```
-
-## Parameter
-
-TODO: Add tests once parameter inference is supported
-
-## Invalid expressions
-
-The expressions in these string annotations aren't valid expressions in this context but we
-shouldn't panic.
-
-```py
-a: "1 or 2"
-b: "(x := 1)"
-c: "1 + 2"
-d: "lambda x: x"
-e: "x if True else y"
-f: "{'a': 1, 'b': 2}"
-g: "{1, 2}"
-h: "[i for i in range(5)]"
-i: "{i for i in range(5)}"
-j: "{i: i for i in range(5)}"
-k: "(i for i in range(5))"
-l: "await 1"
-# error: [forward-annotation-syntax-error]
-m: "yield 1"
-# error: [forward-annotation-syntax-error]
-n: "yield from 1"
-o: "1 < 2"
-p: "call()"
-r: "[1, 2]"
-s: "(1, 2)"
-```

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

@@ -0,0 +1,9 @@
+# String annotations
+
+```py
+def f() -> "int":
+    return 1
+
+# TODO: We do not support string annotations, but we should not panic if we encounter them
+reveal_type(f())  # revealed: @Todo
+```

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

@@ -1,61 +0,0 @@
-# Union
-
-## Annotation
-
-`typing.Union` can be used to construct union types same as `|` operator.
-
-```py
-from typing import Union
-
-a: Union[int, str]
-a1: Union[int, bool]
-a2: Union[int, Union[float, str]]
-a3: Union[int, None]
-a4: Union[Union[float, str]]
-a5: Union[int]
-a6: Union[()]
-
-def f():
-    # revealed: int | str
-    reveal_type(a)
-    # Since bool is a subtype of int we simplify to int here. But we do allow assigning boolean values (see below).
-    # revealed: int
-    reveal_type(a1)
-    # revealed: int | float | str
-    reveal_type(a2)
-    # revealed: int | None
-    reveal_type(a3)
-    # revealed: float | str
-    reveal_type(a4)
-    # revealed: int
-    reveal_type(a5)
-    # revealed: Never
-    reveal_type(a6)
-```
-
-## Assignment
-
-```py
-from typing import Union
-
-a: Union[int, str]
-a = 1
-a = ""
-a1: Union[int, bool]
-a1 = 1
-a1 = True
-# error: [invalid-assignment] "Object of type `Literal[b""]` is not assignable to `int | str`"
-a = b""
-```
-
-## Typing Extensions
-
-```py
-from typing_extensions import Union
-
-a: Union[int, str]
-
-def f():
-    # revealed: int | str
-    reveal_type(a)
-```

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

@@ -51,12 +51,12 @@ reveal_type(c)  # revealed: tuple[str, int]
 reveal_type(d)  # revealed: tuple[tuple[str, str], tuple[int, int]]
 
 # TODO: homogenous tuples, PEP-646 tuples
-reveal_type(e)  # revealed: @Todo(full tuple[...] support)
-reveal_type(f)  # revealed: @Todo(full tuple[...] support)
-reveal_type(g)  # revealed: @Todo(full tuple[...] support)
+reveal_type(e)  # revealed: @Todo
+reveal_type(f)  # revealed: @Todo
+reveal_type(g)  # revealed: @Todo
 
 # TODO: support more kinds of type expressions in annotations
-reveal_type(h)  # revealed: @Todo(full tuple[...] support)
+reveal_type(h)  # revealed: @Todo
 
 reveal_type(i)  # revealed: tuple[str | int, str | int]
 reveal_type(j)  # revealed: tuple[str | int]
@@ -110,29 +110,3 @@ c: builtins.tuple[builtins.tuple[builtins.int, builtins.int], builtins.int] = ((
 # error: [invalid-assignment] "Object of type `Literal["foo"]` is not assignable to `tuple[tuple[int, int], int]`"
 c: builtins.tuple[builtins.tuple[builtins.int, builtins.int], builtins.int] = "foo"
 ```
-
-## Future annotations are deferred
-
-```py
-from __future__ import annotations
-
-x: Foo
-
-class Foo:
-    pass
-
-x = Foo()
-reveal_type(x)  # revealed: Foo
-```
-
-## Annotations in stub files are deferred
-
-```pyi path=main.pyi
-x: Foo
-
-class Foo:
-    pass
-
-x = Foo()
-reveal_type(x)  # revealed: Foo
-```

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

@@ -35,7 +35,6 @@ class C:
     if flag:
         x = 2
 
-# error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C]` is possibly unbound"
 reveal_type(C.x)  # revealed: Literal[2]
 reveal_type(C.y)  # revealed: Literal[1]
 ```

crates/red_knot_python_semantic/resources/mdtest/attributes.md

@@ -9,21 +9,14 @@ def bool_instance() -> bool:
 flag = bool_instance()
 
 if flag:
-    class C1:
+    class C:
         x = 1
 
 else:
-    class C1:
+    class C:
         x = 2
 
-class C2:
-    if flag:
-        x = 3
-    else:
-        x = 4
-
-reveal_type(C1.x)  # revealed: Literal[1, 2]
-reveal_type(C2.x)  # revealed: Literal[3, 4]
+reveal_type(C.x)  # revealed: Literal[1, 2]
 ```
 
 ## Inherited attributes
@@ -60,77 +53,3 @@ reveal_type(A.__mro__)
 # `E` is earlier in the MRO than `F`, so we should use the type of `E.X`
 reveal_type(A.X)  # revealed: Literal[42]
 ```
-
-## Unions with possibly unbound paths
-
-### Definite boundness within a class
-
-In this example, the `x` attribute is not defined in the `C2` element of the union:
-
-```py
-def bool_instance() -> bool:
-    return True
-
-class C1:
-    x = 1
-
-class C2: ...
-
-class C3:
-    x = 3
-
-flag1 = bool_instance()
-flag2 = bool_instance()
-
-C = C1 if flag1 else C2 if flag2 else C3
-
-# error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
-reveal_type(C.x)  # revealed: Literal[1, 3]
-```
-
-### Possibly-unbound within a class
-
-We raise the same diagnostic if the attribute is possibly-unbound in at least one element of the
-union:
-
-```py
-def bool_instance() -> bool:
-    return True
-
-class C1:
-    x = 1
-
-class C2:
-    if bool_instance():
-        x = 2
-
-class C3:
-    x = 3
-
-flag1 = bool_instance()
-flag2 = bool_instance()
-
-C = C1 if flag1 else C2 if flag2 else C3
-
-# error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
-reveal_type(C.x)  # revealed: Literal[1, 2, 3]
-```
-
-## Unions with all paths unbound
-
-If the symbol is unbound in all elements of the union, we detect that:
-
-```py
-def bool_instance() -> bool:
-    return True
-
-class C1: ...
-class C2: ...
-
-flag = bool_instance()
-
-C = C1 if flag else C2
-
-# error: [unresolved-attribute] "Type `Literal[C1, C2]` has no attribute `x`"
-reveal_type(C.x)  # revealed: Unknown
-```

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

@@ -317,7 +317,7 @@ reveal_type(1 + A())  # revealed: int
 reveal_type(A() + "foo")  # revealed: A
 # TODO should be `A` since `str.__add__` doesn't support `A` instances
 # TODO overloads
-reveal_type("foo" + A())  # revealed: @Todo(return type)
+reveal_type("foo" + A())  # revealed: @Todo
 
 reveal_type(A() + b"foo")  # revealed: A
 # TODO should be `A` since `bytes.__add__` doesn't support `A` instances
@@ -325,7 +325,7 @@ reveal_type(b"foo" + A())  # revealed: bytes
 
 reveal_type(A() + ())  # revealed: A
 # TODO this should be `A`, since `tuple.__add__` doesn't support `A` instances
-reveal_type(() + A())  # revealed: @Todo(return type)
+reveal_type(() + A())  # revealed: @Todo
 
 literal_string_instance = "foo" * 1_000_000_000
 # the test is not testing what it's meant to be testing if this isn't a `LiteralString`:
@@ -334,7 +334,7 @@ reveal_type(literal_string_instance)  # revealed: LiteralString
 reveal_type(A() + literal_string_instance)  # revealed: A
 # TODO should be `A` since `str.__add__` doesn't support `A` instances
 # TODO overloads
-reveal_type(literal_string_instance + A())  # revealed: @Todo(return type)
+reveal_type(literal_string_instance + A())  # revealed: @Todo
 ```
 
 ## Operations involving instances of classes inheriting from `Any`

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

@@ -18,58 +18,3 @@ class Unit: ...
 b = Unit()(3.0)  # error: "Object of type `Unit` is not callable"
 reveal_type(b)  # revealed: Unknown
 ```
-
-## Possibly unbound `__call__` method
-
-```py
-def flag() -> bool: ...
-
-class PossiblyNotCallable:
-    if flag():
-        def __call__(self) -> int: ...
-
-a = PossiblyNotCallable()
-result = a()  # error: "Object of type `PossiblyNotCallable` is not callable (possibly unbound `__call__` method)"
-reveal_type(result)  # revealed: int
-```
-
-## Possibly unbound callable
-
-```py
-def flag() -> bool: ...
-
-if flag():
-    class PossiblyUnbound:
-        def __call__(self) -> int: ...
-
-# error: [possibly-unresolved-reference]
-a = PossiblyUnbound()
-reveal_type(a())  # revealed: int
-```
-
-## Non-callable `__call__`
-
-```py
-class NonCallable:
-    __call__ = 1
-
-a = NonCallable()
-# error: "Object of type `NonCallable` is not callable"
-reveal_type(a())  # revealed: Unknown
-```
-
-## Possibly non-callable `__call__`
-
-```py
-def flag() -> bool: ...
-
-class NonCallable:
-    if flag():
-        __call__ = 1
-    else:
-        def __call__(self) -> int: ...
-
-a = NonCallable()
-# error: "Object of type `Literal[1] | Literal[__call__]` is not callable (due to union element `Literal[1]`)"
-reveal_type(a())  # revealed: Unknown | int
-```

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

@@ -16,16 +16,7 @@ async def get_int_async() -> int:
     return 42
 
 # TODO: we don't yet support `types.CoroutineType`, should be generic `Coroutine[Any, Any, int]`
-reveal_type(get_int_async())  # revealed: @Todo(generic types.CoroutineType)
-```
-
-## Generic
-
-```py
-def get_int[T]() -> int:
-    return 42
-
-reveal_type(get_int())  # revealed: int
+reveal_type(get_int_async())  # revealed: @Todo
 ```
 
 ## Decorated
@@ -36,8 +27,6 @@ from typing import Callable
 def foo() -> int:
     return 42
 
-# TODO: This should be resolved once we understand `Callable` annotations
-# error: [annotation-with-invalid-expression]
 def decorator(func) -> Callable[[], int]:
     return foo
 
@@ -46,7 +35,7 @@ def bar() -> str:
     return "bar"
 
 # TODO: should reveal `int`, as the decorator replaces `bar` with `foo`
-reveal_type(bar())  # revealed: @Todo(return type)
+reveal_type(bar())  # revealed: @Todo
 ```
 
 ## Invalid callable
@@ -55,16 +44,3 @@ reveal_type(bar())  # revealed: @Todo(return type)
 nonsense = 123
 x = nonsense()  # error: "Object of type `Literal[123]` is not callable"
 ```
-
-## Potentially unbound function
-
-```py
-def flag() -> bool: ...
-
-if flag():
-    def foo() -> int:
-        return 42
-
-# error: [possibly-unresolved-reference]
-reveal_type(foo())  # revealed: int
-```

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

@@ -1,155 +0,0 @@
-# Comparison: Intersections
-
-## Positive contributions
-
-If we have an intersection type `A & B` and we get a definitive true/false answer for one of the
-types, we can infer that the result for the intersection type is also true/false:
-
-```py
-class Base: ...
-
-class Child1(Base):
-    def __eq__(self, other) -> Literal[True]:
-        return True
-
-class Child2(Base): ...
-
-def get_base() -> Base: ...
-
-x = get_base()
-c1 = Child1()
-
-# Create an intersection type through narrowing:
-if isinstance(x, Child1):
-    if isinstance(x, Child2):
-        reveal_type(x)  # revealed: Child1 & Child2
-
-        reveal_type(x == 1)  # revealed: Literal[True]
-
-        # Other comparison operators fall back to the base type:
-        reveal_type(x > 1)  # revealed: bool
-        reveal_type(x is c1)  # revealed: bool
-```
-
-## Negative contributions
-
-Negative contributions to the intersection type only allow simplifications in a few special cases
-(equality and identity comparisons).
-
-### Equality comparisons
-
-#### Literal strings
-
-```py
-x = "x" * 1_000_000_000
-y = "y" * 1_000_000_000
-reveal_type(x)  # revealed: LiteralString
-
-if x != "abc":
-    reveal_type(x)  # revealed: LiteralString & ~Literal["abc"]
-
-    reveal_type(x == "abc")  # revealed: Literal[False]
-    reveal_type("abc" == x)  # revealed: Literal[False]
-    reveal_type(x == "something else")  # revealed: bool
-    reveal_type("something else" == x)  # revealed: bool
-
-    reveal_type(x != "abc")  # revealed: Literal[True]
-    reveal_type("abc" != x)  # revealed: Literal[True]
-    reveal_type(x != "something else")  # revealed: bool
-    reveal_type("something else" != x)  # revealed: bool
-
-    reveal_type(x == y)  # revealed: bool
-    reveal_type(y == x)  # revealed: bool
-    reveal_type(x != y)  # revealed: bool
-    reveal_type(y != x)  # revealed: bool
-
-    reveal_type(x >= "abc")  # revealed: bool
-    reveal_type("abc" >= x)  # revealed: bool
-
-    reveal_type(x in "abc")  # revealed: bool
-    reveal_type("abc" in x)  # revealed: bool
-```
-
-#### Integers
-
-```py
-def get_int() -> int: ...
-
-x = get_int()
-
-if x != 1:
-    reveal_type(x)  # revealed: int & ~Literal[1]
-
-    reveal_type(x != 1)  # revealed: Literal[True]
-    reveal_type(x != 2)  # revealed: bool
-
-    reveal_type(x == 1)  # revealed: Literal[False]
-    reveal_type(x == 2)  # revealed: bool
-```
-
-### Identity comparisons
-
-```py
-class A: ...
-
-def get_object() -> object: ...
-
-o = object()
-
-a = A()
-n = None
-
-if o is not None:
-    reveal_type(o)  # revealed: object & ~None
-
-    reveal_type(o is n)  # revealed: Literal[False]
-    reveal_type(o is not n)  # revealed: Literal[True]
-```
-
-## Diagnostics
-
-### Unsupported operators for positive contributions
-
-Raise an error if any of the positive contributions to the intersection type are unsupported for the
-given operator:
-
-```py
-class Container:
-    def __contains__(self, x) -> bool: ...
-
-class NonContainer: ...
-
-def get_object() -> object: ...
-
-x = get_object()
-
-if isinstance(x, Container):
-    if isinstance(x, NonContainer):
-        reveal_type(x)  # revealed: Container & NonContainer
-
-        # error: [unsupported-operator] "Operator `in` is not supported for types `int` and `NonContainer`"
-        reveal_type(2 in x)  # revealed: bool
-```
-
-### Unsupported operators for negative contributions
-
-Do *not* raise an error if any of the negative contributions to the intersection type are
-unsupported for the given operator:
-
-```py
-class Container:
-    def __contains__(self, x) -> bool: ...
-
-class NonContainer: ...
-
-def get_object() -> object: ...
-
-x = get_object()
-
-if isinstance(x, Container):
-    if not isinstance(x, NonContainer):
-        reveal_type(x)  # revealed: Container & ~NonContainer
-
-        # No error here!
-        reveal_type(2 in x)  # revealed: bool
-```

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

@@ -58,9 +58,7 @@ reveal_type(c >= d)  # revealed: Literal[True]
 #### Results with Ambiguity
 
 ```py
-def bool_instance() -> bool:
-    return True
-
+def bool_instance() -> bool: ...
 def int_instance() -> int:
     return 42
 
@@ -136,158 +134,23 @@ reveal_type(c >= c)  # revealed: Literal[True]
 
 #### Non Boolean Rich Comparisons
 
-Rich comparison methods defined in a class affect tuple comparisons as well. Proper type inference
-should be possible even in cases where these methods return non-boolean types.
-
-Note: Tuples use lexicographic comparisons. If the `==` result for all paired elements in the tuple
-is True, the comparison then considers the tuple’s length. Regardless of the return type of the
-dunder methods, the final result can still be a boolean value.
-
-(+cpython: For tuples, `==` and `!=` always produce boolean results, regardless of the return type
-of the dunder methods.)
-
 ```py
-from __future__ import annotations
-
 class A:
-    def __eq__(self, o: object) -> str:
-        return "hello"
-
-    def __ne__(self, o: object) -> bytes:
-        return b"world"
-
-    def __lt__(self, o: A) -> float:
-        return 3.14
-
-    def __le__(self, o: A) -> complex:
-        return complex(0.5, -0.5)
-
-    def __gt__(self, o: A) -> tuple:
-        return (1, 2, 3)
-
-    def __ge__(self, o: A) -> list:
-        return [1, 2, 3]
+    def __eq__(self, o) -> str: ...
+    def __ne__(self, o) -> int: ...
+    def __lt__(self, o) -> float: ...
+    def __le__(self, o) -> object: ...
+    def __gt__(self, o) -> tuple: ...
+    def __ge__(self, o) -> list: ...
 
 a = (A(), A())
 
-reveal_type(a == a)  # revealed: bool
-reveal_type(a != a)  # revealed: bool
-reveal_type(a < a)  # revealed: float | Literal[False]
-reveal_type(a <= a)  # revealed: complex | Literal[True]
-reveal_type(a > a)  # revealed: tuple | Literal[False]
-reveal_type(a >= a)  # revealed: list | Literal[True]
-
-# If lexicographic comparison is finished before comparing A()
-b = ("1_foo", A())
-c = ("2_bar", A())
-
-reveal_type(b == c)  # revealed: Literal[False]
-reveal_type(b != c)  # revealed: Literal[True]
-reveal_type(b < c)  # revealed: Literal[True]
-reveal_type(b <= c)  # revealed: Literal[True]
-reveal_type(b > c)  # revealed: Literal[False]
-reveal_type(b >= c)  # revealed: Literal[False]
-
-class B:
-    def __lt__(self, o: B) -> set:
-        return set()
-
-reveal_type((A(), B()) < (A(), B()))  # revealed: float | set | Literal[False]
-```
-
-#### Special Handling of Eq and NotEq in Lexicographic Comparisons
-
-> Example: `(int_instance(), "foo") == (int_instance(), "bar")`
-
-`Eq` and `NotEq` have unique behavior compared to other operators in lexicographic comparisons.
-Specifically, for `Eq`, if any non-equal pair exists within the tuples being compared, we can
-immediately conclude that the tuples are not equal. Conversely, for `NotEq`, if any non-equal pair
-exists, we can determine that the tuples are unequal.
-
-In contrast, with operators like `<` and `>`, the comparison must consider each pair of elements
-sequentially, and the final outcome might remain ambiguous until all pairs are compared.
-
-```py
-def str_instance() -> str:
-    return "hello"
-
-def int_instance() -> int:
-    return 42
-
-reveal_type("foo" == "bar")  # revealed: Literal[False]
-reveal_type(("foo",) == ("bar",))  # revealed: Literal[False]
-reveal_type((4, "foo") == (4, "bar"))  # revealed: Literal[False]
-reveal_type((int_instance(), "foo") == (int_instance(), "bar"))  # revealed: Literal[False]
-
-a = (str_instance(), int_instance(), "foo")
-
 reveal_type(a == a)  # revealed: bool
 reveal_type(a != a)  # revealed: bool
 reveal_type(a < a)  # revealed: bool
 reveal_type(a <= a)  # revealed: bool
 reveal_type(a > a)  # revealed: bool
 reveal_type(a >= a)  # revealed: bool
-
-b = (str_instance(), int_instance(), "bar")
-
-reveal_type(a == b)  # revealed: Literal[False]
-reveal_type(a != b)  # revealed: Literal[True]
-reveal_type(a < b)  # revealed: bool
-reveal_type(a <= b)  # revealed: bool
-reveal_type(a > b)  # revealed: bool
-reveal_type(a >= b)  # revealed: bool
-
-c = (str_instance(), int_instance(), "foo", "different_length")
-reveal_type(a == c)  # revealed: Literal[False]
-reveal_type(a != c)  # revealed: Literal[True]
-reveal_type(a < c)  # revealed: bool
-reveal_type(a <= c)  # revealed: bool
-reveal_type(a > c)  # revealed: bool
-reveal_type(a >= c)  # revealed: bool
-```
-
-#### Error Propagation
-
-Errors occurring within a tuple comparison should propagate outward. However, if the tuple
-comparison can clearly conclude before encountering an error, the error should not be raised.
-
-```py
-def int_instance() -> int:
-    return 42
-
-def str_instance() -> str:
-    return "hello"
-
-class A: ...
-
-# error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`"
-A() < A()
-# error: [unsupported-operator] "Operator `<=` is not supported for types `A` and `A`"
-A() <= A()
-# error: [unsupported-operator] "Operator `>` is not supported for types `A` and `A`"
-A() > A()
-# error: [unsupported-operator] "Operator `>=` is not supported for types `A` and `A`"
-A() >= A()
-
-a = (0, int_instance(), A())
-
-# error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
-reveal_type(a < a)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `<=` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
-reveal_type(a <= a)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
-reveal_type(a > a)  # revealed: Unknown
-# error: [unsupported-operator] "Operator `>=` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
-reveal_type(a >= a)  # revealed: Unknown
-
-# Comparison between `a` and `b` should only involve the first elements, `Literal[0]` and `Literal[99999]`,
-# and should terminate immediately.
-b = (99999, int_instance(), A())
-
-reveal_type(a < b)  # revealed: Literal[True]
-reveal_type(a <= b)  # revealed: Literal[True]
-reveal_type(a > b)  # revealed: Literal[False]
-reveal_type(a >= b)  # revealed: Literal[False]
 ```
 
 ### Membership Test Comparisons

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

@@ -4,8 +4,6 @@
 def bool_instance() -> bool:
     return True
 
-class A: ...
-
 a = 1 in 7  # error: "Operator `in` is not supported for types `Literal[1]` and `Literal[7]`"
 reveal_type(a)  # revealed: bool
 
@@ -35,8 +33,4 @@ reveal_type(e)  # revealed: bool
 f = (1, 2) < (1, "hello")
 # TODO: should be Unknown, once operand type check is implemented
 reveal_type(f)  # revealed: bool
-
-# error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`, in comparing `tuple[bool, A]` with `tuple[bool, A]`"
-g = (bool_instance(), A()) < (bool_instance(), A())
-reveal_type(g)  # revealed: Unknown
 ```

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

@@ -41,20 +41,21 @@ except EXCEPTIONS as f:
 ## Dynamic exception types
 
 ```py
+# TODO: we should not emit these `call-possibly-unbound-method` errors for `tuple.__class_getitem__`
 def foo(
     x: type[AttributeError],
-    y: tuple[type[OSError], type[RuntimeError]],
-    z: tuple[type[BaseException], ...],
+    y: tuple[type[OSError], type[RuntimeError]],  # error: [call-possibly-unbound-method]
+    z: tuple[type[BaseException], ...],  # error: [call-possibly-unbound-method]
 ):
     try:
         help()
     except x as e:
         # TODO: should be `AttributeError`
-        reveal_type(e)  # revealed: @Todo(exception type)
+        reveal_type(e)  # revealed: @Todo
     except y as f:
         # TODO: should be `OSError | RuntimeError`
-        reveal_type(f)  # revealed: @Todo(exception type)
+        reveal_type(f)  # revealed: @Todo
     except z as g:
         # TODO: should be `BaseException`
-        reveal_type(g)  # revealed: @Todo(exception type)
+        reveal_type(g)  # revealed: @Todo
 ```

crates/red_knot_python_semantic/resources/mdtest/exception/invalid_exception_syntax.md

@@ -9,5 +9,4 @@ try:
     print
 except as e:  # error: [invalid-syntax]
     reveal_type(e)  # revealed: Unknown
-
 ```

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

@@ -1,28 +0,0 @@
-# Attribute access
-
-## Boundness
-
-```py
-def flag() -> bool: ...
-
-class A:
-    always_bound = 1
-
-    if flag():
-        union = 1
-    else:
-        union = "abc"
-
-    if flag():
-        possibly_unbound = "abc"
-
-reveal_type(A.always_bound)  # revealed: Literal[1]
-
-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"]
-
-# error: [unresolved-attribute] "Type `Literal[A]` has no attribute `non_existent`"
-reveal_type(A.non_existent)  # revealed: Unknown
-```

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

@@ -22,22 +22,3 @@ reveal_type(1 if None else 2)  # revealed: Literal[2]
 reveal_type(1 if "" else 2)  # revealed: Literal[2]
 reveal_type(1 if 0 else 2)  # revealed: Literal[2]
 ```
-
-## Leaked Narrowing Constraint
-
-(issue #14588)
-
-The test inside an if expression should not affect code outside of the expression.
-
-```py
-def bool_instance() -> bool:
-    return True
-
-x: Literal[42, "hello"] = 42 if bool_instance() else "hello"
-
-reveal_type(x)  # revealed: Literal[42] | Literal["hello"]
-
-_ = ... if isinstance(x, str) else ...
-
-reveal_type(x)  # revealed: Literal[42] | Literal["hello"]
-```

crates/red_knot_python_semantic/resources/mdtest/generics.md

@@ -6,9 +6,13 @@ Basic PEP 695 generics
 
 ```py
 class MyBox[T]:
+    # TODO: `T` is defined here
+    # error: [unresolved-reference] "Name `T` used when not defined"
     data: T
     box_model_number = 695
 
+    # TODO: `T` is defined here
+    # error: [unresolved-reference] "Name `T` used when not defined"
     def __init__(self, data: T):
         self.data = data
 
@@ -18,7 +22,7 @@ box: MyBox[int] = MyBox(5)
 wrong_innards: MyBox[int] = MyBox("five")
 
 # TODO reveal int
-reveal_type(box.data)  # revealed: @Todo(instance attributes)
+reveal_type(box.data)  # revealed: @Todo
 
 reveal_type(MyBox.box_model_number)  # revealed: Literal[695]
 ```
@@ -27,19 +31,24 @@ reveal_type(MyBox.box_model_number)  # revealed: Literal[695]
 
 ```py
 class MyBox[T]:
+    # TODO: `T` is defined here
+    # error: [unresolved-reference] "Name `T` used when not defined"
     data: T
 
+    # TODO: `T` is defined here
+    # error: [unresolved-reference] "Name `T` used when not defined"
     def __init__(self, data: T):
         self.data = data
 
-# TODO not error on the subscripting
+# TODO not error on the subscripting or the use of type param
+# error: [unresolved-reference] "Name `T` used when not defined"
 # error: [non-subscriptable]
 class MySecureBox[T](MyBox[T]): ...
 
 secure_box: MySecureBox[int] = MySecureBox(5)
 reveal_type(secure_box)  # revealed: MySecureBox
 # TODO reveal int
-reveal_type(secure_box.data)  # revealed: @Todo(instance attributes)
+reveal_type(secure_box.data)  # revealed: @Todo
 ```
 
 ## Cyclical class definition
@@ -57,23 +66,3 @@ class S[T](Seq[S]): ...  # error: [non-subscriptable]
 
 reveal_type(S)  # revealed: Literal[S]
 ```
-
-## Type params
-
-A PEP695 type variable defines a value of type `typing.TypeVar`.
-
-```py
-def f[T]():
-    reveal_type(T)  # revealed: T
-    reveal_type(T.__name__)  # revealed: Literal["T"]
-```
-
-## Minimum two constraints
-
-A typevar with less than two constraints emits a diagnostic:
-
-```py
-# error: [invalid-typevar-constraints] "TypeVar must have at least two constrained types"
-def f[T: (int,)]():
-    pass
-```

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

@@ -21,7 +21,6 @@ reveal_type(y)
 ```
 
 ```py
-# error: [possibly-unbound-import] "Member `y` of module `maybe_unbound` is possibly unbound"
 from maybe_unbound import x, y
 
 reveal_type(x)  # revealed: Literal[3]
@@ -51,7 +50,6 @@ reveal_type(y)
 Importing an annotated name prefers the declared type over the inferred type:
 
 ```py
-# error: [possibly-unbound-import] "Member `y` of module `maybe_unbound_annotated` is possibly unbound"
 from maybe_unbound_annotated import x, y
 
 reveal_type(x)  # revealed: Literal[3]

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

@@ -51,8 +51,6 @@ invalid1: Literal[3 + 4]
 invalid2: Literal[4 + 3j]
 # error: [invalid-literal-parameter]
 invalid3: Literal[(3, 4)]
-
-hello = "hello"
 invalid4: Literal[
     1 + 2,  # error: [invalid-literal-parameter]
     "foo",
@@ -75,11 +73,10 @@ Literal: _SpecialForm
 ```py
 from other import Literal
 
-# error: [annotation-with-invalid-expression]
 a1: Literal[26]
 
 def f():
-    reveal_type(a1)  # revealed: @Todo(generics)
+    reveal_type(a1)  # revealed: @Todo
 ```
 
 ## Detecting typing_extensions.Literal

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

@@ -18,7 +18,7 @@ async def foo():
         pass
 
     # TODO: should reveal `Unknown` because `__aiter__` is not defined
-    # revealed: @Todo(async iterables/iterators)
+    # revealed: @Todo
     # error: [possibly-unresolved-reference]
     reveal_type(x)
 ```
@@ -40,6 +40,6 @@ async def foo():
         pass
 
     # error: [possibly-unresolved-reference]
-    # revealed: @Todo(async iterables/iterators)
+    # revealed: @Todo
     reveal_type(x)
 ```

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

@@ -238,7 +238,7 @@ class Test:
 def coinflip() -> bool:
     return True
 
-# error: [not-iterable] "Object of type `Test | Literal[42]` is not iterable because its `__iter__` method is possibly unbound"
+# TODO: we should emit a diagnostic here (it might not be iterable)
 for x in Test() if coinflip() else 42:
     reveal_type(x)  # revealed: int
 ```

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

@@ -52,29 +52,3 @@ else:
 reveal_type(x)  # revealed: Literal[2, 3]
 reveal_type(y)  # revealed: Literal[1, 2, 4]
 ```
-
-## Nested while loops
-
-```py
-def flag() -> bool:
-    return True
-
-x = 1
-
-while flag():
-    x = 2
-
-    while flag():
-        x = 3
-        if flag():
-            break
-    else:
-        x = 4
-
-    if flag():
-        break
-else:
-    x = 5
-
-reveal_type(x)  # revealed: Literal[3, 4, 5]
-```

crates/red_knot_python_semantic/resources/mdtest/metaclass.md

@@ -1,196 +0,0 @@
-## Default
-
-```py
-class M(type): ...
-
-reveal_type(M.__class__)  # revealed: Literal[type]
-```
-
-## `object`
-
-```py
-reveal_type(object.__class__)  # revealed: Literal[type]
-```
-
-## `type`
-
-```py
-reveal_type(type.__class__)  # revealed: Literal[type]
-```
-
-## Basic
-
-```py
-class M(type): ...
-class B(metaclass=M): ...
-
-reveal_type(B.__class__)  # revealed: Literal[M]
-```
-
-## Invalid metaclass
-
-A class which doesn't inherit `type` (and/or doesn't implement a custom `__new__` accepting the same
-arguments as `type.__new__`) isn't a valid metaclass.
-
-```py
-class M: ...
-class A(metaclass=M): ...
-
-# TODO: emit a diagnostic for the invalid metaclass
-reveal_type(A.__class__)  # revealed: Literal[M]
-```
-
-## Linear inheritance
-
-If a class is a subclass of a class with a custom metaclass, then the subclass will also have that
-metaclass.
-
-```py
-class M(type): ...
-class A(metaclass=M): ...
-class B(A): ...
-
-reveal_type(B.__class__)  # revealed: Literal[M]
-```
-
-## Conflict (1)
-
-The metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its
-bases. ("Strict subclass" is a synonym for "proper subclass"; a non-strict subclass can be a
-subclass or the class itself.)
-
-```py
-class M1(type): ...
-class M2(type): ...
-class A(metaclass=M1): ...
-class B(metaclass=M2): ...
-
-# error: [conflicting-metaclass] "The metaclass of a derived class (`C`) must be a subclass of the metaclasses of all its bases, but `M1` (metaclass of base class `A`) and `M2` (metaclass of base class `B`) have no subclass relationship"
-class C(A, B): ...
-
-reveal_type(C.__class__)  # revealed: Unknown
-```
-
-## Conflict (2)
-
-The metaclass of a derived class must be a (non-strict) subclass of the metaclasses of all its
-bases. ("Strict subclass" is a synonym for "proper subclass"; a non-strict subclass can be a
-subclass or the class itself.)
-
-```py
-class M1(type): ...
-class M2(type): ...
-class A(metaclass=M1): ...
-
-# error: [conflicting-metaclass] "The metaclass of a derived class (`B`) must be a subclass of the metaclasses of all its bases, but `M2` (metaclass of `B`) and `M1` (metaclass of base class `A`) have no subclass relationship"
-class B(A, metaclass=M2): ...
-
-reveal_type(B.__class__)  # revealed: Unknown
-```
-
-## Common metaclass
-
-A class has two explicit bases, both of which have the same metaclass.
-
-```py
-class M(type): ...
-class A(metaclass=M): ...
-class B(metaclass=M): ...
-class C(A, B): ...
-
-reveal_type(C.__class__)  # revealed: Literal[M]
-```
-
-## Metaclass metaclass
-
-A class has an explicit base with a custom metaclass. That metaclass itself has a custom metaclass.
-
-```py
-class M1(type): ...
-class M2(type, metaclass=M1): ...
-class M3(M2): ...
-class A(metaclass=M3): ...
-class B(A): ...
-
-reveal_type(A.__class__)  # revealed: Literal[M3]
-```
-
-## Diamond inheritance
-
-```py
-class M(type): ...
-class M1(M): ...
-class M2(M): ...
-class M12(M1, M2): ...
-class A(metaclass=M1): ...
-class B(metaclass=M2): ...
-class C(metaclass=M12): ...
-
-# error: [conflicting-metaclass] "The metaclass of a derived class (`D`) must be a subclass of the metaclasses of all its bases, but `M1` (metaclass of base class `A`) and `M2` (metaclass of base class `B`) have no subclass relationship"
-class D(A, B, C): ...
-
-reveal_type(D.__class__)  # revealed: Unknown
-```
-
-## Unknown
-
-```py
-from nonexistent_module import UnknownClass  # error: [unresolved-import]
-
-class C(UnknownClass): ...
-
-# TODO: should be `type[type] & Unknown`
-reveal_type(C.__class__)  # revealed: Literal[type]
-
-class M(type): ...
-class A(metaclass=M): ...
-class B(A, UnknownClass): ...
-
-# TODO: should be `type[M] & Unknown`
-reveal_type(B.__class__)  # revealed: Literal[M]
-```
-
-## Duplicate
-
-```py
-class M(type): ...
-class A(metaclass=M): ...
-class B(A, A): ...  # error: [duplicate-base] "Duplicate base class `A`"
-
-reveal_type(B.__class__)  # revealed: Literal[M]
-```
-
-## Non-class
-
-When a class has an explicit `metaclass` that is not a class, but is a callable that accepts
-`type.__new__` arguments, we should return the meta type of its return type.
-
-```py
-def f(*args, **kwargs) -> int: ...
-
-class A(metaclass=f): ...
-
-# TODO should be `type[int]`
-reveal_type(A.__class__)  # revealed: @Todo(metaclass not a class)
-```
-
-## Cyclic
-
-Retrieving the metaclass of a cyclically defined class should not cause an infinite loop.
-
-```py path=a.pyi
-class A(B): ...  # error: [cyclic-class-def]
-class B(C): ...  # error: [cyclic-class-def]
-class C(A): ...  # error: [cyclic-class-def]
-
-reveal_type(A.__class__)  # revealed: Unknown
-```
-
-## PEP 695 generic
-
-```py
-class M(type): ...
-class A[T: str](metaclass=M): ...
-
-reveal_type(A.__class__)  # revealed: Literal[M]
-```

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

@@ -1,247 +0,0 @@
-# Narrowing for `issubclass` checks
-
-Narrowing for `issubclass(class, classinfo)` expressions.
-
-## `classinfo` is a single type
-
-### Basic example
-
-```py
-def flag() -> bool: ...
-
-t = int if flag() else str
-
-if issubclass(t, bytes):
-    reveal_type(t)  # revealed: Never
-
-if issubclass(t, object):
-    reveal_type(t)  # revealed: Literal[int, str]
-
-if issubclass(t, int):
-    reveal_type(t)  # revealed: Literal[int]
-else:
-    reveal_type(t)  # revealed: Literal[str]
-
-if issubclass(t, str):
-    reveal_type(t)  # revealed: Literal[str]
-    if issubclass(t, int):
-        reveal_type(t)  # revealed: Never
-```
-
-### Proper narrowing in `elif` and `else` branches
-
-```py
-def flag() -> bool: ...
-
-t = int if flag() else str if flag() else bytes
-
-if issubclass(t, int):
-    reveal_type(t)  # revealed: Literal[int]
-else:
-    reveal_type(t)  # revealed: Literal[str, bytes]
-
-if issubclass(t, int):
-    reveal_type(t)  # revealed: Literal[int]
-elif issubclass(t, str):
-    reveal_type(t)  # revealed: Literal[str]
-else:
-    reveal_type(t)  # revealed: Literal[bytes]
-```
-
-### Multiple derived classes
-
-```py
-class Base: ...
-class Derived1(Base): ...
-class Derived2(Base): ...
-class Unrelated: ...
-
-def flag() -> bool: ...
-
-t1 = Derived1 if flag() else Derived2
-
-if issubclass(t1, Base):
-    reveal_type(t1)  # revealed: Literal[Derived1, Derived2]
-
-if issubclass(t1, Derived1):
-    reveal_type(t1)  # revealed: Literal[Derived1]
-else:
-    reveal_type(t1)  # revealed: Literal[Derived2]
-
-t2 = Derived1 if flag() else Base
-
-if issubclass(t2, Base):
-    reveal_type(t2)  # revealed: Literal[Derived1, Base]
-
-t3 = Derived1 if flag() else Unrelated
-
-if issubclass(t3, Base):
-    reveal_type(t3)  # revealed: Literal[Derived1]
-else:
-    reveal_type(t3)  # revealed: Literal[Unrelated]
-```
-
-### Narrowing for non-literals
-
-```py
-class A: ...
-class B: ...
-
-def get_class() -> type[object]: ...
-
-t = get_class()
-
-if issubclass(t, A):
-    reveal_type(t)  # revealed: type[A]
-    if issubclass(t, B):
-        reveal_type(t)  # revealed: type[A] & type[B]
-else:
-    reveal_type(t)  # revealed: type[object] & ~type[A]
-```
-
-### Handling of `None`
-
-```py
-# TODO: this error should ideally go away once we (1) understand `sys.version_info` branches,
-# and (2) set the target Python version for this test to 3.10.
-# error: [possibly-unbound-import] "Member `NoneType` of module `types` is possibly unbound"
-from types import NoneType
-
-def flag() -> bool: ...
-
-t = int if flag() else NoneType
-
-if issubclass(t, NoneType):
-    reveal_type(t)  # revealed: Literal[NoneType]
-
-if issubclass(t, type(None)):
-    # TODO: this should be just `Literal[NoneType]`
-    reveal_type(t)  # revealed: Literal[int, NoneType]
-```
-
-## `classinfo` contains multiple types
-
-### (Nested) tuples of types
-
-```py
-class Unrelated: ...
-
-def flag() -> bool: ...
-
-t = int if flag() else str if flag() else bytes
-
-if issubclass(t, (int, (Unrelated, (bytes,)))):
-    reveal_type(t)  # revealed: Literal[int, bytes]
-else:
-    reveal_type(t)  # revealed: Literal[str]
-```
-
-## Special cases
-
-### Emit a diagnostic if the first argument is of wrong type
-
-#### Too wide
-
-`type[object]` is a subtype of `object`, but not every `object` can be passed as the first argument
-to `issubclass`:
-
-```py
-class A: ...
-
-def get_object() -> object: ...
-
-t = get_object()
-
-# TODO: we should emit a diagnostic here
-if issubclass(t, A):
-    reveal_type(t)  # revealed: type[A]
-```
-
-#### Wrong
-
-`Literal[1]` and `type` are entirely disjoint, so the inferred type of `Literal[1] & type[int]` is
-eagerly simplified to `Never` as a result of the type narrowing in the `if issubclass(t, int)`
-branch:
-
-```py
-t = 1
-
-# TODO: we should emit a diagnostic here
-if issubclass(t, int):
-    reveal_type(t)  # revealed: Never
-```
-
-### Do not use custom `issubclass` for narrowing
-
-```py
-def issubclass(c, ci):
-    return True
-
-def flag() -> bool: ...
-
-t = int if flag() else str
-if issubclass(t, int):
-    reveal_type(t)  # revealed: Literal[int, str]
-```
-
-### Do support narrowing if `issubclass` is aliased
-
-```py
-issubclass_alias = issubclass
-
-def flag() -> bool: ...
-
-t = int if flag() else str
-if issubclass_alias(t, int):
-    reveal_type(t)  # revealed: Literal[int]
-```
-
-### Do support narrowing if `issubclass` is imported
-
-```py
-from builtins import issubclass as imported_issubclass
-
-def flag() -> bool: ...
-
-t = int if flag() else str
-if imported_issubclass(t, int):
-    reveal_type(t)  # revealed: Literal[int]
-```
-
-### Do not narrow if second argument is not a proper `classinfo` argument
-
-```py
-from typing import Any
-
-def flag() -> bool: ...
-
-t = int if flag() else str
-
-# TODO: this should cause us to emit a diagnostic during
-# type checking
-if issubclass(t, "str"):
-    reveal_type(t)  # revealed: Literal[int, str]
-
-# TODO: this should cause us to emit a diagnostic during
-# type checking
-if issubclass(t, (bytes, "str")):
-    reveal_type(t)  # revealed: Literal[int, str]
-
-# TODO: this should cause us to emit a diagnostic during
-# type checking
-if issubclass(t, Any):
-    reveal_type(t)  # revealed: Literal[int, str]
-```
-
-### Do not narrow if there are keyword arguments
-
-```py
-def flag() -> bool: ...
-
-t = int if flag() else str
-
-# 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]
-```

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

@@ -1,152 +0,0 @@
-# Narrowing for checks involving `type(x)`
-
-## `type(x) is C`
-
-```py
-class A: ...
-class B: ...
-
-def get_a_or_b() -> A | B:
-    return A()
-
-x = get_a_or_b()
-
-if type(x) is A:
-    reveal_type(x)  # revealed: A
-else:
-    # It would be wrong to infer `B` here. The type
-    # of `x` could be a subclass of `A`, so we need
-    # to infer the full union type:
-    reveal_type(x)  # revealed: A | B
-```
-
-## `type(x) is not C`
-
-```py
-class A: ...
-class B: ...
-
-def get_a_or_b() -> A | B:
-    return A()
-
-x = get_a_or_b()
-
-if type(x) is not A:
-    # Same reasoning as above: no narrowing should occur here.
-    reveal_type(x)  # revealed: A | B
-else:
-    reveal_type(x)  # revealed: A
-```
-
-## `type(x) == C`, `type(x) != C`
-
-No narrowing can occur for equality comparisons, since there might be a custom `__eq__`
-implementation on the metaclass.
-
-TODO: Narrowing might be possible in some cases where the classes themselves are `@final` or their
-metaclass is `@final`.
-
-```py
-class IsEqualToEverything(type):
-    def __eq__(cls, other):
-        return True
-
-class A(metaclass=IsEqualToEverything): ...
-class B(metaclass=IsEqualToEverything): ...
-
-def get_a_or_b() -> A | B:
-    return B()
-
-x = get_a_or_b()
-
-if type(x) == A:
-    reveal_type(x)  # revealed: A | B
-
-if type(x) != A:
-    reveal_type(x)  # revealed: A | B
-```
-
-## No narrowing for custom `type` callable
-
-```py
-class A: ...
-class B: ...
-
-def type(x):
-    return int
-
-def get_a_or_b() -> A | B:
-    return A()
-
-x = get_a_or_b()
-
-if type(x) is A:
-    reveal_type(x)  # revealed: A | B
-else:
-    reveal_type(x)  # revealed: A | B
-```
-
-## No narrowing for multiple arguments
-
-No narrowing should occur if `type` is used to dynamically create a class:
-
-```py
-def get_str_or_int() -> str | int:
-    return "test"
-
-x = get_str_or_int()
-
-if type(x, (), {}) is str:
-    reveal_type(x)  # revealed: str | int
-else:
-    reveal_type(x)  # revealed: str | int
-```
-
-## No narrowing for keyword arguments
-
-`type` can't be used with a keyword argument:
-
-```py
-def get_str_or_int() -> str | int:
-    return "test"
-
-x = get_str_or_int()
-
-# TODO: we could issue a diagnostic here
-if type(object=x) is str:
-    reveal_type(x)  # revealed: str | int
-```
-
-## Narrowing if `type` is aliased
-
-```py
-class A: ...
-class B: ...
-
-alias_for_type = type
-
-def get_a_or_b() -> A | B:
-    return A()
-
-x = get_a_or_b()
-
-if alias_for_type(x) is A:
-    reveal_type(x)  # revealed: A
-```
-
-## Limitations
-
-```py
-class Base: ...
-class Derived(Base): ...
-
-def get_base() -> Base:
-    return Base()
-
-x = get_base()
-
-if type(x) is Base:
-    # Ideally, this could be narrower, but there is now way to
-    # express a constraint like `Base & ~ProperSubtypeOf[Base]`.
-    reveal_type(x)  # revealed: Base
-```

crates/red_knot_python_semantic/resources/mdtest/regression/14334_diagnostics_in_wrong_file.md

@@ -1,13 +0,0 @@
-# Regression test for #14334
-
-Regression test for [this issue](https://github.com/astral-sh/ruff/issues/14334).
-
-```py path=base.py
-# error: [invalid-base]
-class Base(2): ...
-```
-
-```py path=a.py
-# No error here
-from base import Base
-```

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

@@ -17,7 +17,8 @@ reveal_type(__doc__)  # revealed: str | None
 # (needs support for `*` imports)
 reveal_type(__spec__)  # revealed: Unknown | None
 
-reveal_type(__path__)  # revealed: @Todo(generics)
+# TODO: generics
+reveal_type(__path__)  # revealed: @Todo
 
 class X:
     reveal_type(__name__)  # revealed: str
@@ -59,11 +60,12 @@ reveal_type(typing.__init__)  # revealed: Literal[__init__]
 # These come from `builtins.object`, not `types.ModuleType`:
 reveal_type(typing.__eq__)  # revealed: Literal[__eq__]
 
-reveal_type(typing.__class__)  # revealed: Literal[type]
+# TODO: understand properties
+reveal_type(typing.__class__)  # revealed: Literal[__class__]
 
 # TODO: needs support for attribute access on instances, properties and generics;
 # should be `dict[str, Any]`
-reveal_type(typing.__dict__)  # revealed: @Todo(instance attributes)
+reveal_type(typing.__dict__)  # revealed: @Todo
 ```
 
 Typeshed includes a fake `__getattr__` method in the stub for `types.ModuleType` to help out with
@@ -73,7 +75,6 @@ we're dealing with:
 ```py path=__getattr__.py
 import typing
 
-# error: [unresolved-attribute]
 reveal_type(typing.__getattr__)  # revealed: Unknown
 ```
 
@@ -95,8 +96,8 @@ from foo import __dict__ as foo_dict
 
 # TODO: needs support for attribute access on instances, properties, and generics;
 # should be `dict[str, Any]` for both of these:
-reveal_type(foo.__dict__)  # revealed: @Todo(instance attributes)
-reveal_type(foo_dict)  # revealed: @Todo(instance attributes)
+reveal_type(foo.__dict__)  # revealed: @Todo
+reveal_type(foo_dict)  # revealed: @Todo
 ```
 
 ## Conditionally global or `ModuleType` attribute

crates/red_knot_python_semantic/resources/mdtest/subscript/bytes.md

@@ -27,7 +27,7 @@ def int_instance() -> int:
 
 a = b"abcde"[int_instance()]
 # TODO: Support overloads... Should be `bytes`
-reveal_type(a)  # revealed: @Todo(return type)
+reveal_type(a)  # revealed: @Todo
 ```
 
 ## Slices
@@ -47,11 +47,11 @@ def int_instance() -> int: ...
 
 byte_slice1 = b[int_instance() : int_instance()]
 # TODO: Support overloads... Should be `bytes`
-reveal_type(byte_slice1)  # revealed: @Todo(return type)
+reveal_type(byte_slice1)  # revealed: @Todo
 
 def bytes_instance() -> bytes: ...
 
 byte_slice2 = bytes_instance()[0:5]
 # TODO: Support overloads... Should be `bytes`
-reveal_type(byte_slice2)  # revealed: @Todo(return type)
+reveal_type(byte_slice2)  # revealed: @Todo
 ```

crates/red_knot_python_semantic/resources/mdtest/subscript/lists.md

@@ -12,13 +12,13 @@ x = [1, 2, 3]
 reveal_type(x)  # revealed: list
 
 # TODO reveal int
-reveal_type(x[0])  # revealed: @Todo(return type)
+reveal_type(x[0])  # revealed: @Todo
 
 # TODO reveal list
-reveal_type(x[0:1])  # revealed: @Todo(return type)
+reveal_type(x[0:1])  # revealed: @Todo
 
 # TODO error
-reveal_type(x["a"])  # revealed: @Todo(return type)
+reveal_type(x["a"])  # revealed: @Todo
 ```
 
 ## Assignments within list assignment

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

@@ -23,7 +23,7 @@ def int_instance() -> int: ...
 
 a = "abcde"[int_instance()]
 # TODO: Support overloads... Should be `str`
-reveal_type(a)  # revealed: @Todo(return type)
+reveal_type(a)  # revealed: @Todo
 ```
 
 ## Slices
@@ -78,13 +78,13 @@ def int_instance() -> int: ...
 
 substring1 = s[int_instance() : int_instance()]
 # TODO: Support overloads... Should be `LiteralString`
-reveal_type(substring1)  # revealed: @Todo(return type)
+reveal_type(substring1)  # revealed: @Todo
 
 def str_instance() -> str: ...
 
 substring2 = str_instance()[0:5]
 # TODO: Support overloads... Should be `str`
-reveal_type(substring2)  # revealed: @Todo(return type)
+reveal_type(substring2)  # revealed: @Todo
 ```
 
 ## Unsupported slice types

crates/red_knot_python_semantic/resources/mdtest/subscript/tuple.md

@@ -71,5 +71,5 @@ def int_instance() -> int: ...
 
 tuple_slice = t[int_instance() : int_instance()]
 # TODO: Support overloads... Should be `tuple[Literal[1, 'a', b"b"] | None, ...]`
-reveal_type(tuple_slice)  # revealed: @Todo(return type)
+reveal_type(tuple_slice)  # revealed: @Todo
 ```

crates/red_knot_python_semantic/resources/mdtest/sys_version_info.md

@@ -1,138 +0,0 @@
-# `sys.version_info`
-
-## The type of `sys.version_info`
-
-The type of `sys.version_info` is `sys._version_info`, at least according to typeshed's stubs (which
-we treat as the single source of truth for the standard library). This is quite a complicated type
-in typeshed, so there are many things we don't fully understand about the type yet; this is the
-source of several TODOs in this test file. Many of these TODOs should be naturally fixed as we
-implement more type-system features in the future.
-
-```py
-import sys
-
-reveal_type(sys.version_info)  # revealed: _version_info
-```
-
-## Literal types from comparisons
-
-Comparing `sys.version_info` with a 2-element tuple of literal integers always produces a `Literal`
-type:
-
-```py
-import sys
-
-reveal_type(sys.version_info >= (3, 9))  # revealed: Literal[True]
-reveal_type((3, 9) <= sys.version_info)  # revealed: Literal[True]
-
-reveal_type(sys.version_info > (3, 9))  # revealed: Literal[True]
-reveal_type((3, 9) < sys.version_info)  # revealed: Literal[True]
-
-reveal_type(sys.version_info < (3, 9))  # revealed: Literal[False]
-reveal_type((3, 9) > sys.version_info)  # revealed: Literal[False]
-
-reveal_type(sys.version_info <= (3, 9))  # revealed: Literal[False]
-reveal_type((3, 9) >= sys.version_info)  # revealed: Literal[False]
-
-reveal_type(sys.version_info == (3, 9))  # revealed: Literal[False]
-reveal_type((3, 9) == sys.version_info)  # revealed: Literal[False]
-
-reveal_type(sys.version_info != (3, 9))  # revealed: Literal[True]
-reveal_type((3, 9) != sys.version_info)  # revealed: Literal[True]
-```
-
-## Non-literal types from comparisons
-
-Comparing `sys.version_info` with tuples of other lengths will sometimes produce `Literal` types,
-sometimes not:
-
-```py
-import sys
-
-reveal_type(sys.version_info >= (3, 9, 1))  # revealed: bool
-reveal_type(sys.version_info >= (3, 9, 1, "final", 0))  # revealed: bool
-
-# TODO: While this won't fail at runtime, the user has probably made a mistake
-# if they're comparing a tuple of length >5 with `sys.version_info`
-# (`sys.version_info` is a tuple of length 5). It might be worth
-# emitting a lint diagnostic of some kind warning them about the probable error?
-reveal_type(sys.version_info >= (3, 9, 1, "final", 0, 5))  # revealed: bool
-
-reveal_type(sys.version_info == (3, 8, 1, "finallllll", 0))  # revealed: Literal[False]
-```
-
-## Imports and aliases
-
-Comparisons with `sys.version_info` still produce literal types, even if the symbol is aliased to
-another name:
-
-```py
-from sys import version_info
-from sys import version_info as foo
-
-reveal_type(version_info >= (3, 9))  # revealed: Literal[True]
-reveal_type(foo >= (3, 9))  # revealed: Literal[True]
-
-bar = version_info
-reveal_type(bar >= (3, 9))  # revealed: Literal[True]
-```
-
-## Non-stdlib modules named `sys`
-
-Only comparisons with the symbol `version_info` from the `sys` module produce literal types:
-
-```py path=package/__init__.py
-```
-
-```py path=package/sys.py
-version_info: tuple[int, int] = (4, 2)
-```
-
-```py path=package/script.py
-from .sys import version_info
-
-reveal_type(version_info >= (3, 9))  # revealed: bool
-```
-
-## Accessing fields by name
-
-The fields of `sys.version_info` can be accessed by name:
-
-```py path=a.py
-import sys
-
-reveal_type(sys.version_info.major >= 3)  # revealed: Literal[True]
-reveal_type(sys.version_info.minor >= 9)  # revealed: Literal[True]
-reveal_type(sys.version_info.minor >= 10)  # revealed: Literal[False]
-```
-
-But the `micro`, `releaselevel` and `serial` fields are inferred as `@Todo` until we support
-properties on instance types:
-
-```py path=b.py
-import sys
-
-reveal_type(sys.version_info.micro)  # revealed: @Todo(instance attributes)
-reveal_type(sys.version_info.releaselevel)  # revealed: @Todo(instance attributes)
-reveal_type(sys.version_info.serial)  # revealed: @Todo(instance attributes)
-```
-
-## Accessing fields by index/slice
-
-The fields of `sys.version_info` can be accessed by index or by slice:
-
-```py
-import sys
-
-reveal_type(sys.version_info[0] < 3)  # revealed: Literal[False]
-reveal_type(sys.version_info[1] > 9)  # revealed: Literal[False]
-
-# revealed: tuple[Literal[3], Literal[9], int, Literal["alpha", "beta", "candidate", "final"], int]
-reveal_type(sys.version_info[:5])
-
-reveal_type(sys.version_info[:2] >= (3, 9))  # revealed: Literal[True]
-reveal_type(sys.version_info[0:2] >= (3, 10))  # revealed: Literal[False]
-reveal_type(sys.version_info[:3] >= (3, 10, 1))  # revealed: Literal[False]
-reveal_type(sys.version_info[3] == "final")  # revealed: bool
-reveal_type(sys.version_info[3] == "finalllllll")  # revealed: Literal[False]
-```

crates/red_knot_python_semantic/resources/mdtest/type_alias.md

@@ -1,71 +0,0 @@
-# Type aliases
-
-## Basic
-
-```py
-type IntOrStr = int | str
-
-reveal_type(IntOrStr)  # revealed: typing.TypeAliasType
-reveal_type(IntOrStr.__name__)  # revealed: Literal["IntOrStr"]
-
-x: IntOrStr = 1
-
-reveal_type(x)  # revealed: Literal[1]
-
-def f() -> None:
-    reveal_type(x)  # revealed: int | str
-```
-
-## `__value__` attribute
-
-```py
-type IntOrStr = int | str
-
-# TODO: This should either fall back to the specified type from typeshed,
-# which is `Any`, or be the actual type of the runtime value expression
-# `int | str`, i.e. `types.UnionType`.
-reveal_type(IntOrStr.__value__)  # revealed: @Todo(instance attributes)
-```
-
-## Invalid assignment
-
-```py
-type OptionalInt = int | None
-
-# error: [invalid-assignment]
-x: OptionalInt = "1"
-```
-
-## Type aliases in type aliases
-
-```py
-type IntOrStr = int | str
-type IntOrStrOrBytes = IntOrStr | bytes
-
-x: IntOrStrOrBytes = 1
-
-def f() -> None:
-    reveal_type(x)  # revealed: int | str | bytes
-```
-
-## Aliased type aliases
-
-```py
-type IntOrStr = int | str
-MyIntOrStr = IntOrStr
-
-x: MyIntOrStr = 1
-
-# error: [invalid-assignment]
-y: MyIntOrStr = None
-```
-
-## Generic type aliases
-
-```py
-type ListOrSet[T] = list[T] | set[T]
-
-# TODO: Should be `tuple[typing.TypeVar | typing.ParamSpec | typing.TypeVarTuple, ...]`,
-# as specified in the `typeshed` stubs.
-reveal_type(ListOrSet.__type_params__)  # revealed: @Todo(instance attributes)
-```

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

@@ -1,6 +1,4 @@
-# Invert, UAdd, USub
-
-## Instance
+# Unary Operations
 
 ```py
 from typing import Literal

crates/red_knot_python_semantic/resources/mdtest/unary/not.md

@@ -10,6 +10,8 @@ reveal_type(not not None)  # revealed: Literal[False]
 ## Function
 
 ```py
+from typing import reveal_type
+
 def f():
     return 1
 
@@ -113,101 +115,3 @@ reveal_type(not ())  # revealed: Literal[True]
 reveal_type(not ("hello",))  # revealed: Literal[False]
 reveal_type(not (1, "hello"))  # revealed: Literal[False]
 ```
-
-## Instance
-
-Not operator is inferred based on
-<https://docs.python.org/3/library/stdtypes.html#truth-value-testing>. An instance is True or False
-if the `__bool__` method says so.
-
-At runtime, the `__len__` method is a fallback for `__bool__`, but we can't make use of that. If we
-have a class that defines `__len__` but not `__bool__`, it is possible that any subclass could add a
-`__bool__` method that would invalidate whatever conclusion we drew from `__len__`. So instances of
-classes without a `__bool__` method, with or without `__len__`, must be inferred as unknown
-truthiness.
-
-```py
-class AlwaysTrue:
-    def __bool__(self) -> Literal[True]:
-        return True
-
-# revealed: Literal[False]
-reveal_type(not AlwaysTrue())
-
-class AlwaysFalse:
-    def __bool__(self) -> Literal[False]:
-        return False
-
-# revealed: Literal[True]
-reveal_type(not AlwaysFalse())
-
-# We don't get into a cycle if someone sets their `__bool__` method to the `bool` builtin:
-class BoolIsBool:
-    __bool__ = bool
-
-# revealed: bool
-reveal_type(not BoolIsBool())
-
-# At runtime, no `__bool__` and no `__len__` means truthy, but we can't rely on that, because
-# a subclass could add a `__bool__` method.
-class NoBoolMethod: ...
-
-# revealed: bool
-reveal_type(not NoBoolMethod())
-
-# And we can't rely on `__len__` for the same reason: a subclass could add `__bool__`.
-class LenZero:
-    def __len__(self) -> Literal[0]:
-        return 0
-
-# revealed: bool
-reveal_type(not LenZero())
-
-class LenNonZero:
-    def __len__(self) -> Literal[1]:
-        return 1
-
-# revealed: bool
-reveal_type(not LenNonZero())
-
-class WithBothLenAndBool1:
-    def __bool__(self) -> Literal[False]:
-        return False
-
-    def __len__(self) -> Literal[2]:
-        return 2
-
-# revealed: Literal[True]
-reveal_type(not WithBothLenAndBool1())
-
-class WithBothLenAndBool2:
-    def __bool__(self) -> Literal[True]:
-        return True
-
-    def __len__(self) -> Literal[0]:
-        return 0
-
-# revealed: Literal[False]
-reveal_type(not WithBothLenAndBool2())
-
-# TODO: raise diagnostic when __bool__ method is not valid: [unsupported-operator] "Method __bool__ for type `MethodBoolInvalid` should return `bool`, returned type `int`"
-# https://docs.python.org/3/reference/datamodel.html#object.__bool__
-class MethodBoolInvalid:
-    def __bool__(self) -> int:
-        return 0
-
-# revealed: bool
-reveal_type(not MethodBoolInvalid())
-
-# Don't trust a possibly-unbound `__bool__` method:
-def get_flag() -> bool:
-    return True
-
-class PossiblyUnboundBool:
-    if get_flag():
-        def __bool__(self) -> Literal[False]:
-            return False
-
-# revealed: bool
-reveal_type(not PossiblyUnboundBool())
-```

crates/red_knot_python_semantic/resources/mdtest/unpacking.md

@@ -84,7 +84,7 @@ reveal_type(b)  # revealed: Literal[2]
 [a, *b, c, d] = (1, 2)
 reveal_type(a)  # revealed: Literal[1]
 # TODO: Should be list[Any] once support for assigning to starred expression is added
-reveal_type(b)  # revealed: @Todo(starred unpacking)
+reveal_type(b)  # revealed: @Todo
 reveal_type(c)  # revealed: Literal[2]
 reveal_type(d)  # revealed: Unknown
 ```
@@ -95,7 +95,7 @@ reveal_type(d)  # revealed: Unknown
 [a, *b, c] = (1, 2)
 reveal_type(a)  # revealed: Literal[1]
 # TODO: Should be list[Any] once support for assigning to starred expression is added
-reveal_type(b)  # revealed: @Todo(starred unpacking)
+reveal_type(b)  # revealed: @Todo
 reveal_type(c)  # revealed: Literal[2]
 ```
 
@@ -105,7 +105,7 @@ reveal_type(c)  # revealed: Literal[2]
 [a, *b, c] = (1, 2, 3)
 reveal_type(a)  # revealed: Literal[1]
 # TODO: Should be list[int] once support for assigning to starred expression is added
-reveal_type(b)  # revealed: @Todo(starred unpacking)
+reveal_type(b)  # revealed: @Todo
 reveal_type(c)  # revealed: Literal[3]
 ```
 
@@ -115,7 +115,7 @@ reveal_type(c)  # revealed: Literal[3]
 [a, *b, c, d] = (1, 2, 3, 4, 5, 6)
 reveal_type(a)  # revealed: Literal[1]
 # TODO: Should be list[int] once support for assigning to starred expression is added
-reveal_type(b)  # revealed: @Todo(starred unpacking)
+reveal_type(b)  # revealed: @Todo
 reveal_type(c)  # revealed: Literal[5]
 reveal_type(d)  # revealed: Literal[6]
 ```
@@ -127,7 +127,7 @@ reveal_type(d)  # revealed: Literal[6]
 reveal_type(a)  # revealed: Literal[1]
 reveal_type(b)  # revealed: Literal[2]
 # TODO: Should be list[int] once support for assigning to starred expression is added
-reveal_type(c)  # revealed: @Todo(starred unpacking)
+reveal_type(c)  # revealed: @Todo
 ```
 
 ### Starred expression (6)
@@ -138,7 +138,7 @@ reveal_type(c)  # revealed: @Todo(starred unpacking)
 reveal_type(a)  # revealed: Literal[1]
 reveal_type(b)  # revealed: Unknown
 reveal_type(c)  # revealed: Unknown
-reveal_type(d)  # revealed: @Todo(starred unpacking)
+reveal_type(d)  # revealed: @Todo
 reveal_type(e)  # revealed: Unknown
 reveal_type(f)  # revealed: Unknown
 ```
@@ -222,7 +222,7 @@ reveal_type(b)  # revealed: LiteralString
 (a, *b, c, d) = "ab"
 reveal_type(a)  # revealed: LiteralString
 # TODO: Should be list[LiteralString] once support for assigning to starred expression is added
-reveal_type(b)  # revealed: @Todo(starred unpacking)
+reveal_type(b)  # revealed: @Todo
 reveal_type(c)  # revealed: LiteralString
 reveal_type(d)  # revealed: Unknown
 ```
@@ -233,7 +233,7 @@ reveal_type(d)  # revealed: Unknown
 (a, *b, c) = "ab"
 reveal_type(a)  # revealed: LiteralString
 # TODO: Should be list[Any] once support for assigning to starred expression is added
-reveal_type(b)  # revealed: @Todo(starred unpacking)
+reveal_type(b)  # revealed: @Todo
 reveal_type(c)  # revealed: LiteralString
 ```
 
@@ -243,7 +243,7 @@ reveal_type(c)  # revealed: LiteralString
 (a, *b, c) = "abc"
 reveal_type(a)  # revealed: LiteralString
 # TODO: Should be list[LiteralString] once support for assigning to starred expression is added
-reveal_type(b)  # revealed: @Todo(starred unpacking)
+reveal_type(b)  # revealed: @Todo
 reveal_type(c)  # revealed: LiteralString
 ```
 
@@ -253,7 +253,7 @@ reveal_type(c)  # revealed: LiteralString
 (a, *b, c, d) = "abcdef"
 reveal_type(a)  # revealed: LiteralString
 # TODO: Should be list[LiteralString] once support for assigning to starred expression is added
-reveal_type(b)  # revealed: @Todo(starred unpacking)
+reveal_type(b)  # revealed: @Todo
 reveal_type(c)  # revealed: LiteralString
 reveal_type(d)  # revealed: LiteralString
 ```
@@ -265,5 +265,5 @@ reveal_type(d)  # revealed: LiteralString
 reveal_type(a)  # revealed: LiteralString
 reveal_type(b)  # revealed: LiteralString
 # TODO: Should be list[int] once support for assigning to starred expression is added
-reveal_type(c)  # revealed: @Todo(starred unpacking)
+reveal_type(c)  # revealed: @Todo
 ```

crates/red_knot_python_semantic/resources/mdtest/with/async_with.md

@@ -17,5 +17,5 @@ class Manager:
 
 async def test():
     async with Manager() as f:
-        reveal_type(f)  # revealed: @Todo(async with statement)
+        reveal_type(f)  # revealed: @Todo
 ```

crates/red_knot_python_semantic/src/module_resolver/typeshed.rs

@@ -459,11 +459,11 @@ foo: 3.8-   # trailing comment
 ";
         let parsed_versions = TypeshedVersions::from_str(VERSIONS).unwrap();
         assert_eq!(parsed_versions.len(), 3);
-        assert_snapshot!(parsed_versions.to_string(), @r"
+        assert_snapshot!(parsed_versions.to_string(), @r###"
         bar: 2.7-3.10
         bar.baz: 3.1-3.9
         foo: 3.8-
-        "
+        "###
         );
     }
 

crates/red_knot_python_semantic/src/node_key.rs

@@ -1,14 +1,14 @@
-use ruff_python_ast::AnyNodeRef;
+use ruff_python_ast::{AnyNodeRef, NodeKind};
+use ruff_text_size::{Ranged, TextRange};
 
 /// Compact key for a node for use in a hash map.
 ///
-/// Stores the memory address of the node, because using the range and the kind
-/// of the node is not enough to uniquely identify them in ASTs resulting from
-/// invalid syntax. For example, parsing the input `for` results in a `StmtFor`
-/// AST node where both the `target` and the `iter` field are `ExprName` nodes
-/// with the same (empty) range `3..3`.
+/// Compares two nodes by their kind and text range.
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
-pub(super) struct NodeKey(usize);
+pub(super) struct NodeKey {
+    kind: NodeKind,
+    range: TextRange,
+}
 
 impl NodeKey {
     pub(super) fn from_node<'a, N>(node: N) -> Self
@@ -16,6 +16,9 @@ impl NodeKey {
         N: Into<AnyNodeRef<'a>>,
     {
         let node = node.into();
-        NodeKey(node.as_ptr().as_ptr() as usize)
+        NodeKey {
+            kind: node.kind(),
+            range: node.range(),
+        }
     }
 }

crates/red_knot_python_semantic/src/program.rs

@@ -54,7 +54,6 @@ impl Program {
 }
 
 #[derive(Clone, Debug, Eq, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Serialize))]
 pub struct ProgramSettings {
     pub target_version: PythonVersion,
     pub search_paths: SearchPathSettings,
@@ -62,7 +61,6 @@ pub struct ProgramSettings {
 
 /// Configures the search paths for module resolution.
 #[derive(Eq, PartialEq, Debug, Clone)]
-#[cfg_attr(feature = "serde", derive(serde::Serialize))]
 pub struct SearchPathSettings {
     /// List of user-provided paths that should take first priority in the module resolution.
     /// Examples in other type checkers are mypy's MYPYPATH environment variable,
@@ -93,7 +91,6 @@ impl SearchPathSettings {
 }
 
 #[derive(Debug, Clone, Eq, PartialEq)]
-#[cfg_attr(feature = "serde", derive(serde::Serialize))]
 pub enum SitePackages {
     Derived {
         venv_path: SystemPathBuf,

crates/red_knot_python_semantic/src/python_version.rs

@@ -5,7 +5,6 @@ use std::fmt;
 /// Unlike the `TargetVersion` enums in the CLI crates,
 /// this does not necessarily represent a Python version that we actually support.
 #[derive(Debug, Clone, Copy, Eq, PartialEq, Ord, PartialOrd, Hash)]
-#[cfg_attr(feature = "serde", derive(serde::Serialize))]
 pub struct PythonVersion {
     pub major: u8,
     pub minor: u8,
@@ -39,7 +38,7 @@ impl PythonVersion {
 
 impl Default for PythonVersion {
     fn default() -> Self {
-        Self::PY39
+        Self::PY38
     }
 }
 

crates/red_knot_python_semantic/src/semantic_index/ast_ids.rs

@@ -49,50 +49,64 @@ fn ast_ids<'db>(db: &'db dyn Db, scope: ScopeId) -> &'db AstIds {
     semantic_index(db, scope.file(db)).ast_ids(scope.file_scope_id(db))
 }
 
+pub trait HasScopedUseId {
+    /// The type of the ID uniquely identifying the use.
+    type Id: Copy;
+
+    /// Returns the ID that uniquely identifies the use in `scope`.
+    fn scoped_use_id(&self, db: &dyn Db, scope: ScopeId) -> Self::Id;
+}
+
 /// Uniquely identifies a use of a name in a [`crate::semantic_index::symbol::FileScopeId`].
 #[newtype_index]
 pub struct ScopedUseId;
 
-pub trait HasScopedUseId {
-    /// Returns the ID that uniquely identifies the use in `scope`.
-    fn scoped_use_id(&self, db: &dyn Db, scope: ScopeId) -> ScopedUseId;
-}
-
 impl HasScopedUseId for ast::ExprName {
-    fn scoped_use_id(&self, db: &dyn Db, scope: ScopeId) -> ScopedUseId {
+    type Id = ScopedUseId;
+
+    fn scoped_use_id(&self, db: &dyn Db, scope: ScopeId) -> Self::Id {
         let expression_ref = ExpressionRef::from(self);
         expression_ref.scoped_use_id(db, scope)
     }
 }
 
 impl HasScopedUseId for ast::ExpressionRef<'_> {
-    fn scoped_use_id(&self, db: &dyn Db, scope: ScopeId) -> ScopedUseId {
+    type Id = ScopedUseId;
+
+    fn scoped_use_id(&self, db: &dyn Db, scope: ScopeId) -> Self::Id {
         let ast_ids = ast_ids(db, scope);
         ast_ids.use_id(*self)
     }
 }
 
+pub trait HasScopedAstId {
+    /// The type of the ID uniquely identifying the node.
+    type Id: Copy;
+
+    /// Returns the ID that uniquely identifies the node in `scope`.
+    fn scoped_ast_id(&self, db: &dyn Db, scope: ScopeId) -> Self::Id;
+}
+
+impl<T: HasScopedAstId> HasScopedAstId for Box<T> {
+    type Id = <T as HasScopedAstId>::Id;
+
+    fn scoped_ast_id(&self, db: &dyn Db, scope: ScopeId) -> Self::Id {
+        self.as_ref().scoped_ast_id(db, scope)
+    }
+}
+
 /// Uniquely identifies an [`ast::Expr`] in a [`crate::semantic_index::symbol::FileScopeId`].
 #[newtype_index]
 pub struct ScopedExpressionId;
 
-pub trait HasScopedExpressionId {
-    /// Returns the ID that uniquely identifies the node in `scope`.
-    fn scoped_expression_id(&self, db: &dyn Db, scope: ScopeId) -> ScopedExpressionId;
-}
-
-impl<T: HasScopedExpressionId> HasScopedExpressionId for Box<T> {
-    fn scoped_expression_id(&self, db: &dyn Db, scope: ScopeId) -> ScopedExpressionId {
-        self.as_ref().scoped_expression_id(db, scope)
-    }
-}
-
 macro_rules! impl_has_scoped_expression_id {
     ($ty: ty) => {
-        impl HasScopedExpressionId for $ty {
-            fn scoped_expression_id(&self, db: &dyn Db, scope: ScopeId) -> ScopedExpressionId {
+        impl HasScopedAstId for $ty {
+            type Id = ScopedExpressionId;
+
+            fn scoped_ast_id(&self, db: &dyn Db, scope: ScopeId) -> Self::Id {
                 let expression_ref = ExpressionRef::from(self);
-                expression_ref.scoped_expression_id(db, scope)
+                expression_ref.scoped_ast_id(db, scope)
             }
         }
     };
@@ -132,20 +146,29 @@ impl_has_scoped_expression_id!(ast::ExprSlice);
 impl_has_scoped_expression_id!(ast::ExprIpyEscapeCommand);
 impl_has_scoped_expression_id!(ast::Expr);
 
-impl HasScopedExpressionId for ast::ExpressionRef<'_> {
-    fn scoped_expression_id(&self, db: &dyn Db, scope: ScopeId) -> ScopedExpressionId {
+impl HasScopedAstId for ast::ExpressionRef<'_> {
+    type Id = ScopedExpressionId;
+
+    fn scoped_ast_id(&self, db: &dyn Db, scope: ScopeId) -> Self::Id {
         let ast_ids = ast_ids(db, scope);
         ast_ids.expression_id(*self)
     }
 }
 
-#[derive(Debug, Default)]
+#[derive(Debug)]
 pub(super) struct AstIdsBuilder {
     expressions_map: FxHashMap<ExpressionNodeKey, ScopedExpressionId>,
     uses_map: FxHashMap<ExpressionNodeKey, ScopedUseId>,
 }
 
 impl AstIdsBuilder {
+    pub(super) fn new() -> Self {
+        Self {
+            expressions_map: FxHashMap::default(),
+            uses_map: FxHashMap::default(),
+        }
+    }
+
     /// Adds `expr` to the expression ids map and returns its id.
     pub(super) fn record_expression(&mut self, expr: &ast::Expr) -> ScopedExpressionId {
         let expression_id = self.expressions_map.len().into();

crates/red_knot_python_semantic/src/semantic_index/builder.rs

@@ -36,25 +36,12 @@ use super::definition::{
 
 mod except_handlers;
 
-/// Are we in a state where a `break` statement is allowed?
-#[derive(Clone, Copy, Debug)]
-enum LoopState {
-    InLoop,
-    NotInLoop,
-}
-
-impl LoopState {
-    fn is_inside(self) -> bool {
-        matches!(self, LoopState::InLoop)
-    }
-}
-
 pub(super) struct SemanticIndexBuilder<'db> {
     // Builder state
     db: &'db dyn Db,
     file: File,
     module: &'db ParsedModule,
-    scope_stack: Vec<(FileScopeId, LoopState)>,
+    scope_stack: Vec<FileScopeId>,
     /// The assignments we're currently visiting, with
     /// the most recent visit at the end of the Vec
     current_assignments: Vec<CurrentAssignment<'db>>,
@@ -116,24 +103,9 @@ impl<'db> SemanticIndexBuilder<'db> {
         *self
             .scope_stack
             .last()
-            .map(|(scope, _)| scope)
             .expect("Always to have a root scope")
     }
 
-    fn loop_state(&self) -> LoopState {
-        self.scope_stack
-            .last()
-            .expect("Always to have a root scope")
-            .1
-    }
-
-    fn set_inside_loop(&mut self, state: LoopState) {
-        self.scope_stack
-            .last_mut()
-            .expect("Always to have a root scope")
-            .1 = state;
-    }
-
     fn push_scope(&mut self, node: NodeWithScopeRef) {
         let parent = self.current_scope();
         self.push_scope_with_parent(node, Some(parent));
@@ -152,23 +124,22 @@ impl<'db> SemanticIndexBuilder<'db> {
         self.try_node_context_stack_manager.enter_nested_scope();
 
         let file_scope_id = self.scopes.push(scope);
-        self.symbol_tables.push(SymbolTableBuilder::default());
-        self.use_def_maps.push(UseDefMapBuilder::default());
-        let ast_id_scope = self.ast_ids.push(AstIdsBuilder::default());
+        self.symbol_tables.push(SymbolTableBuilder::new());
+        self.use_def_maps.push(UseDefMapBuilder::new());
+        let ast_id_scope = self.ast_ids.push(AstIdsBuilder::new());
 
         let scope_id = ScopeId::new(self.db, self.file, file_scope_id, countme::Count::default());
 
         self.scope_ids_by_scope.push(scope_id);
-        let previous = self.scopes_by_node.insert(node.node_key(), file_scope_id);
-        debug_assert_eq!(previous, None);
+        self.scopes_by_node.insert(node.node_key(), file_scope_id);
 
         debug_assert_eq!(ast_id_scope, file_scope_id);
 
-        self.scope_stack.push((file_scope_id, LoopState::NotInLoop));
+        self.scope_stack.push(file_scope_id);
     }
 
     fn pop_scope(&mut self) -> FileScopeId {
-        let (id, _) = self.scope_stack.pop().expect("Root scope to be present");
+        let id = self.scope_stack.pop().expect("Root scope to be present");
         let children_end = self.scopes.next_index();
         let scope = &mut self.scopes[id];
         scope.descendents = scope.descendents.start..children_end;
@@ -310,12 +281,8 @@ impl<'db> SemanticIndexBuilder<'db> {
         debug_assert!(popped_assignment.is_some());
     }
 
-    fn current_assignment(&self) -> Option<CurrentAssignment<'db>> {
-        self.current_assignments.last().copied()
-    }
-
-    fn current_assignment_mut(&mut self) -> Option<&mut CurrentAssignment<'db>> {
-        self.current_assignments.last_mut()
+    fn current_assignment(&self) -> Option<&CurrentAssignment<'db>> {
+        self.current_assignments.last()
     }
 
     fn add_pattern_constraint(
@@ -402,11 +369,6 @@ impl<'db> SemanticIndexBuilder<'db> {
                 if let Some(default) = default {
                     self.visit_expr(default);
                 }
-                match type_param {
-                    ast::TypeParam::TypeVar(node) => self.add_definition(symbol, node),
-                    ast::TypeParam::ParamSpec(node) => self.add_definition(symbol, node),
-                    ast::TypeParam::TypeVarTuple(node) => self.add_definition(symbol, node),
-                };
             }
         }
 
@@ -618,27 +580,6 @@ where
                     },
                 );
             }
-            ast::Stmt::TypeAlias(type_alias) => {
-                let symbol = self.add_symbol(
-                    type_alias
-                        .name
-                        .as_name_expr()
-                        .map(|name| name.id.clone())
-                        .unwrap_or("<unknown>".into()),
-                );
-                self.add_definition(symbol, type_alias);
-                self.visit_expr(&type_alias.name);
-
-                self.with_type_params(
-                    NodeWithScopeRef::TypeAliasTypeParameters(type_alias),
-                    type_alias.type_params.as_ref(),
-                    |builder| {
-                        builder.push_scope(NodeWithScopeRef::TypeAlias(type_alias));
-                        builder.visit_expr(&type_alias.value);
-                        builder.pop_scope()
-                    },
-                );
-            }
             ast::Stmt::Import(node) => {
                 for alias in &node.names {
                     let symbol_name = if let Some(asname) = &alias.asname {
@@ -686,7 +627,6 @@ where
                         ast::Expr::List(_) | ast::Expr::Tuple(_) => {
                             Some(CurrentAssignment::Assign {
                                 node,
-                                first: true,
                                 unpack: Some(Unpack::new(
                                     self.db,
                                     self.file,
@@ -700,11 +640,9 @@ where
                                 )),
                             })
                         }
-                        ast::Expr::Name(_) => Some(CurrentAssignment::Assign {
-                            node,
-                            unpack: None,
-                            first: false,
-                        }),
+                        ast::Expr::Name(_) => {
+                            Some(CurrentAssignment::Assign { node, unpack: None })
+                        }
                         _ => None,
                     };
 
@@ -726,18 +664,9 @@ where
                 if let Some(value) = &node.value {
                     self.visit_expr(value);
                 }
-
-                // See https://docs.python.org/3/library/ast.html#ast.AnnAssign
-                if matches!(
-                    *node.target,
-                    ast::Expr::Attribute(_) | ast::Expr::Subscript(_) | ast::Expr::Name(_)
-                ) {
-                    self.push_assignment(node.into());
-                    self.visit_expr(&node.target);
-                    self.pop_assignment();
-                } else {
-                    self.visit_expr(&node.target);
-                }
+                self.push_assignment(node.into());
+                self.visit_expr(&node.target);
+                self.pop_assignment();
             }
             ast::Stmt::AugAssign(
                 aug_assign @ ast::StmtAugAssign {
@@ -749,18 +678,9 @@ where
             ) => {
                 debug_assert_eq!(&self.current_assignments, &[]);
                 self.visit_expr(value);
-
-                // See https://docs.python.org/3/library/ast.html#ast.AugAssign
-                if matches!(
-                    **target,
-                    ast::Expr::Attribute(_) | ast::Expr::Subscript(_) | ast::Expr::Name(_)
-                ) {
-                    self.push_assignment(aug_assign.into());
-                    self.visit_expr(target);
-                    self.pop_assignment();
-                } else {
-                    self.visit_expr(target);
-                }
+                self.push_assignment(aug_assign.into());
+                self.visit_expr(target);
+                self.pop_assignment();
             }
             ast::Stmt::If(node) => {
                 self.visit_expr(&node.test);
@@ -813,10 +733,7 @@ where
 
                 // TODO: definitions created inside the body should be fully visible
                 // to other statements/expressions inside the body --Alex/Carl
-                let outer_loop_state = self.loop_state();
-                self.set_inside_loop(LoopState::InLoop);
                 self.visit_body(body);
-                self.set_inside_loop(outer_loop_state);
 
                 // Get the break states from the body of this loop, and restore the saved outer
                 // ones.
@@ -855,9 +772,7 @@ where
                 self.visit_body(body);
             }
             ast::Stmt::Break(_) => {
-                if self.loop_state().is_inside() {
-                    self.loop_break_states.push(self.flow_snapshot());
-                }
+                self.loop_break_states.push(self.flow_snapshot());
             }
 
             ast::Stmt::For(
@@ -884,10 +799,7 @@ where
                 // TODO: Definitions created by loop variables
                 // (and definitions created inside the body)
                 // are fully visible to other statements/expressions inside the body --Alex/Carl
-                let outer_loop_state = self.loop_state();
-                self.set_inside_loop(LoopState::InLoop);
                 self.visit_body(body);
-                self.set_inside_loop(outer_loop_state);
 
                 let break_states =
                     std::mem::replace(&mut self.loop_break_states, saved_break_states);
@@ -1075,19 +987,14 @@ where
                 }
 
                 if is_definition {
-                    match self.current_assignment() {
-                        Some(CurrentAssignment::Assign {
-                            node,
-                            first,
-                            unpack,
-                        }) => {
+                    match self.current_assignment().copied() {
+                        Some(CurrentAssignment::Assign { node, unpack }) => {
                             self.add_definition(
                                 symbol,
                                 AssignmentDefinitionNodeRef {
                                     unpack,
                                     value: &node.value,
                                     name: name_node,
-                                    first,
                                 },
                             );
                         }
@@ -1138,25 +1045,14 @@ where
                     }
                 }
 
-                if let Some(CurrentAssignment::Assign { first, .. }) = self.current_assignment_mut()
-                {
-                    *first = false;
-                }
-
                 walk_expr(self, expr);
             }
             ast::Expr::Named(node) => {
                 // TODO walrus in comprehensions is implicitly nonlocal
                 self.visit_expr(&node.value);
-
-                // See https://peps.python.org/pep-0572/#differences-between-assignment-expressions-and-assignment-statements
-                if node.target.is_name_expr() {
-                    self.push_assignment(node.into());
-                    self.visit_expr(&node.target);
-                    self.pop_assignment();
-                } else {
-                    self.visit_expr(&node.target);
-                }
+                self.push_assignment(node.into());
+                self.visit_expr(&node.target);
+                self.pop_assignment();
             }
             ast::Expr::Lambda(lambda) => {
                 if let Some(parameters) = &lambda.parameters {
@@ -1189,8 +1085,8 @@ where
                 // AST inspection, so we can't simplify here, need to record test expression for
                 // later checking)
                 self.visit_expr(test);
-                let pre_if = self.flow_snapshot();
                 let constraint = self.record_expression_constraint(test);
+                let pre_if = self.flow_snapshot();
                 self.visit_expr(body);
                 let post_body = self.flow_snapshot();
                 self.flow_restore(pre_if);
@@ -1349,7 +1245,6 @@ where
 enum CurrentAssignment<'a> {
     Assign {
         node: &'a ast::StmtAssign,
-        first: bool,
         unpack: Option<Unpack<'a>>,
     },
     AnnAssign(&'a ast::StmtAnnAssign),

crates/red_knot_python_semantic/src/semantic_index/definition.rs

@@ -83,7 +83,6 @@ pub(crate) enum DefinitionNodeRef<'a> {
     For(ForStmtDefinitionNodeRef<'a>),
     Function(&'a ast::StmtFunctionDef),
     Class(&'a ast::StmtClassDef),
-    TypeAlias(&'a ast::StmtTypeAlias),
     NamedExpression(&'a ast::ExprNamed),
     Assignment(AssignmentDefinitionNodeRef<'a>),
     AnnotatedAssignment(&'a ast::StmtAnnAssign),
@@ -93,9 +92,6 @@ pub(crate) enum DefinitionNodeRef<'a> {
     WithItem(WithItemDefinitionNodeRef<'a>),
     MatchPattern(MatchPatternDefinitionNodeRef<'a>),
     ExceptHandler(ExceptHandlerDefinitionNodeRef<'a>),
-    TypeVar(&'a ast::TypeParamTypeVar),
-    ParamSpec(&'a ast::TypeParamParamSpec),
-    TypeVarTuple(&'a ast::TypeParamTypeVarTuple),
 }
 
 impl<'a> From<&'a ast::StmtFunctionDef> for DefinitionNodeRef<'a> {
@@ -110,12 +106,6 @@ impl<'a> From<&'a ast::StmtClassDef> for DefinitionNodeRef<'a> {
     }
 }
 
-impl<'a> From<&'a ast::StmtTypeAlias> for DefinitionNodeRef<'a> {
-    fn from(node: &'a ast::StmtTypeAlias) -> Self {
-        Self::TypeAlias(node)
-    }
-}
-
 impl<'a> From<&'a ast::ExprNamed> for DefinitionNodeRef<'a> {
     fn from(node: &'a ast::ExprNamed) -> Self {
         Self::NamedExpression(node)
@@ -140,24 +130,6 @@ impl<'a> From<&'a ast::Alias> for DefinitionNodeRef<'a> {
     }
 }
 
-impl<'a> From<&'a ast::TypeParamTypeVar> for DefinitionNodeRef<'a> {
-    fn from(value: &'a ast::TypeParamTypeVar) -> Self {
-        Self::TypeVar(value)
-    }
-}
-
-impl<'a> From<&'a ast::TypeParamParamSpec> for DefinitionNodeRef<'a> {
-    fn from(value: &'a ast::TypeParamParamSpec) -> Self {
-        Self::ParamSpec(value)
-    }
-}
-
-impl<'a> From<&'a ast::TypeParamTypeVarTuple> for DefinitionNodeRef<'a> {
-    fn from(value: &'a ast::TypeParamTypeVarTuple) -> Self {
-        Self::TypeVarTuple(value)
-    }
-}
-
 impl<'a> From<ImportFromDefinitionNodeRef<'a>> for DefinitionNodeRef<'a> {
     fn from(node_ref: ImportFromDefinitionNodeRef<'a>) -> Self {
         Self::ImportFrom(node_ref)
@@ -211,7 +183,6 @@ pub(crate) struct AssignmentDefinitionNodeRef<'a> {
     pub(crate) unpack: Option<Unpack<'a>>,
     pub(crate) value: &'a ast::Expr,
     pub(crate) name: &'a ast::ExprName,
-    pub(crate) first: bool,
 }
 
 #[derive(Copy, Clone, Debug)]
@@ -272,9 +243,6 @@ impl<'db> DefinitionNodeRef<'db> {
             DefinitionNodeRef::Class(class) => {
                 DefinitionKind::Class(AstNodeRef::new(parsed, class))
             }
-            DefinitionNodeRef::TypeAlias(type_alias) => {
-                DefinitionKind::TypeAlias(AstNodeRef::new(parsed, type_alias))
-            }
             DefinitionNodeRef::NamedExpression(named) => {
                 DefinitionKind::NamedExpression(AstNodeRef::new(parsed, named))
             }
@@ -282,12 +250,10 @@ impl<'db> DefinitionNodeRef<'db> {
                 unpack,
                 value,
                 name,
-                first,
             }) => DefinitionKind::Assignment(AssignmentDefinitionKind {
                 target: TargetKind::from(unpack),
                 value: AstNodeRef::new(parsed.clone(), value),
                 name: AstNodeRef::new(parsed, name),
-                first,
             }),
             DefinitionNodeRef::AnnotatedAssignment(assign) => {
                 DefinitionKind::AnnotatedAssignment(AstNodeRef::new(parsed, assign))
@@ -348,15 +314,6 @@ impl<'db> DefinitionNodeRef<'db> {
                 handler: AstNodeRef::new(parsed, handler),
                 is_star,
             }),
-            DefinitionNodeRef::TypeVar(node) => {
-                DefinitionKind::TypeVar(AstNodeRef::new(parsed, node))
-            }
-            DefinitionNodeRef::ParamSpec(node) => {
-                DefinitionKind::ParamSpec(AstNodeRef::new(parsed, node))
-            }
-            DefinitionNodeRef::TypeVarTuple(node) => {
-                DefinitionKind::TypeVarTuple(AstNodeRef::new(parsed, node))
-            }
         }
     }
 
@@ -368,13 +325,11 @@ impl<'db> DefinitionNodeRef<'db> {
             }
             Self::Function(node) => node.into(),
             Self::Class(node) => node.into(),
-            Self::TypeAlias(node) => node.into(),
             Self::NamedExpression(node) => node.into(),
             Self::Assignment(AssignmentDefinitionNodeRef {
                 value: _,
                 unpack: _,
                 name,
-                first: _,
             }) => name.into(),
             Self::AnnotatedAssignment(node) => node.into(),
             Self::AugmentedAssignment(node) => node.into(),
@@ -397,9 +352,6 @@ impl<'db> DefinitionNodeRef<'db> {
                 identifier.into()
             }
             Self::ExceptHandler(ExceptHandlerDefinitionNodeRef { handler, .. }) => handler.into(),
-            Self::TypeVar(node) => node.into(),
-            Self::ParamSpec(node) => node.into(),
-            Self::TypeVarTuple(node) => node.into(),
         }
     }
 }
@@ -445,7 +397,6 @@ pub enum DefinitionKind<'db> {
     ImportFrom(ImportFromDefinitionKind),
     Function(AstNodeRef<ast::StmtFunctionDef>),
     Class(AstNodeRef<ast::StmtClassDef>),
-    TypeAlias(AstNodeRef<ast::StmtTypeAlias>),
     NamedExpression(AstNodeRef<ast::ExprNamed>),
     Assignment(AssignmentDefinitionKind<'db>),
     AnnotatedAssignment(AstNodeRef<ast::StmtAnnAssign>),
@@ -457,9 +408,6 @@ pub enum DefinitionKind<'db> {
     WithItem(WithItemDefinitionKind),
     MatchPattern(MatchPatternDefinitionKind),
     ExceptHandler(ExceptHandlerDefinitionKind),
-    TypeVar(AstNodeRef<ast::TypeParamTypeVar>),
-    ParamSpec(AstNodeRef<ast::TypeParamParamSpec>),
-    TypeVarTuple(AstNodeRef<ast::TypeParamTypeVarTuple>),
 }
 
 impl DefinitionKind<'_> {
@@ -468,12 +416,8 @@ impl DefinitionKind<'_> {
             // functions, classes, and imports always bind, and we consider them declarations
             DefinitionKind::Function(_)
             | DefinitionKind::Class(_)
-            | DefinitionKind::TypeAlias(_)
             | DefinitionKind::Import(_)
-            | DefinitionKind::ImportFrom(_)
-            | DefinitionKind::TypeVar(_)
-            | DefinitionKind::ParamSpec(_)
-            | DefinitionKind::TypeVarTuple(_) => DefinitionCategory::DeclarationAndBinding,
+            | DefinitionKind::ImportFrom(_) => DefinitionCategory::DeclarationAndBinding,
             // a parameter always binds a value, but is only a declaration if annotated
             DefinitionKind::Parameter(parameter) => {
                 if parameter.annotation.is_some() {
@@ -591,11 +535,10 @@ pub struct AssignmentDefinitionKind<'db> {
     target: TargetKind<'db>,
     value: AstNodeRef<ast::Expr>,
     name: AstNodeRef<ast::ExprName>,
-    first: bool,
 }
 
-impl<'db> AssignmentDefinitionKind<'db> {
-    pub(crate) fn target(&self) -> TargetKind<'db> {
+impl AssignmentDefinitionKind<'_> {
+    pub(crate) fn target(&self) -> TargetKind {
         self.target
     }
 
@@ -606,10 +549,6 @@ impl<'db> AssignmentDefinitionKind<'db> {
     pub(crate) fn name(&self) -> &ast::ExprName {
         self.name.node()
     }
-
-    pub(crate) fn is_first(&self) -> bool {
-        self.first
-    }
 }
 
 #[derive(Clone, Debug)]
@@ -695,12 +634,6 @@ impl From<&ast::StmtClassDef> for DefinitionNodeKey {
     }
 }
 
-impl From<&ast::StmtTypeAlias> for DefinitionNodeKey {
-    fn from(node: &ast::StmtTypeAlias) -> Self {
-        Self(NodeKey::from_node(node))
-    }
-}
-
 impl From<&ast::ExprName> for DefinitionNodeKey {
     fn from(node: &ast::ExprName) -> Self {
         Self(NodeKey::from_node(node))
@@ -754,21 +687,3 @@ impl From<&ast::ExceptHandlerExceptHandler> for DefinitionNodeKey {
         Self(NodeKey::from_node(handler))
     }
 }
-
-impl From<&ast::TypeParamTypeVar> for DefinitionNodeKey {
-    fn from(value: &ast::TypeParamTypeVar) -> Self {
-        Self(NodeKey::from_node(value))
-    }
-}
-
-impl From<&ast::TypeParamParamSpec> for DefinitionNodeKey {
-    fn from(value: &ast::TypeParamParamSpec) -> Self {
-        Self(NodeKey::from_node(value))
-    }
-}
-
-impl From<&ast::TypeParamTypeVarTuple> for DefinitionNodeKey {
-    fn from(value: &ast::TypeParamTypeVarTuple) -> Self {
-        Self(NodeKey::from_node(value))
-    }
-}

crates/red_knot_python_semantic/src/semantic_index/symbol.rs

@@ -116,11 +116,14 @@ impl<'db> ScopeId<'db> {
         // Type parameter scopes behave like function scopes in terms of name resolution; CPython
         // symbol table also uses the term "function-like" for these scopes.
         matches!(
-            self.node(db).scope_kind(),
-            ScopeKind::Annotation
-                | ScopeKind::Function
-                | ScopeKind::TypeAlias
-                | ScopeKind::Comprehension
+            self.node(db),
+            NodeWithScopeKind::ClassTypeParameters(_)
+                | NodeWithScopeKind::FunctionTypeParameters(_)
+                | NodeWithScopeKind::Function(_)
+                | NodeWithScopeKind::ListComprehension(_)
+                | NodeWithScopeKind::SetComprehension(_)
+                | NodeWithScopeKind::DictComprehension(_)
+                | NodeWithScopeKind::GeneratorExpression(_)
         )
     }
 
@@ -141,12 +144,6 @@ impl<'db> ScopeId<'db> {
             }
             NodeWithScopeKind::Function(function)
             | NodeWithScopeKind::FunctionTypeParameters(function) => function.name.as_str(),
-            NodeWithScopeKind::TypeAlias(type_alias)
-            | NodeWithScopeKind::TypeAliasTypeParameters(type_alias) => type_alias
-                .name
-                .as_name_expr()
-                .map(|name| name.id.as_str())
-                .unwrap_or("<type alias>"),
             NodeWithScopeKind::Lambda(_) => "<lambda>",
             NodeWithScopeKind::ListComprehension(_) => "<listcomp>",
             NodeWithScopeKind::SetComprehension(_) => "<setcomp>",
@@ -204,7 +201,6 @@ pub enum ScopeKind {
     Class,
     Function,
     Comprehension,
-    TypeAlias,
 }
 
 impl ScopeKind {
@@ -214,7 +210,7 @@ impl ScopeKind {
 }
 
 /// Symbol table for a specific [`Scope`].
-#[derive(Debug, Default)]
+#[derive(Debug)]
 pub struct SymbolTable {
     /// The symbols in this scope.
     symbols: IndexVec<ScopedSymbolId, Symbol>,
@@ -224,6 +220,13 @@ pub struct SymbolTable {
 }
 
 impl SymbolTable {
+    fn new() -> Self {
+        Self {
+            symbols: IndexVec::new(),
+            symbols_by_name: SymbolMap::default(),
+        }
+    }
+
     fn shrink_to_fit(&mut self) {
         self.symbols.shrink_to_fit();
     }
@@ -275,12 +278,18 @@ impl PartialEq for SymbolTable {
 
 impl Eq for SymbolTable {}
 
-#[derive(Debug, Default)]
+#[derive(Debug)]
 pub(super) struct SymbolTableBuilder {
     table: SymbolTable,
 }
 
 impl SymbolTableBuilder {
+    pub(super) fn new() -> Self {
+        Self {
+            table: SymbolTable::new(),
+        }
+    }
+
     pub(super) fn add_symbol(&mut self, name: Name) -> (ScopedSymbolId, bool) {
         let hash = SymbolTable::hash_name(&name);
         let entry = self
@@ -330,8 +339,6 @@ pub(crate) enum NodeWithScopeRef<'a> {
     Lambda(&'a ast::ExprLambda),
     FunctionTypeParameters(&'a ast::StmtFunctionDef),
     ClassTypeParameters(&'a ast::StmtClassDef),
-    TypeAlias(&'a ast::StmtTypeAlias),
-    TypeAliasTypeParameters(&'a ast::StmtTypeAlias),
     ListComprehension(&'a ast::ExprListComp),
     SetComprehension(&'a ast::ExprSetComp),
     DictComprehension(&'a ast::ExprDictComp),
@@ -353,12 +360,6 @@ impl NodeWithScopeRef<'_> {
             NodeWithScopeRef::Function(function) => {
                 NodeWithScopeKind::Function(AstNodeRef::new(module, function))
             }
-            NodeWithScopeRef::TypeAlias(type_alias) => {
-                NodeWithScopeKind::TypeAlias(AstNodeRef::new(module, type_alias))
-            }
-            NodeWithScopeRef::TypeAliasTypeParameters(type_alias) => {
-                NodeWithScopeKind::TypeAliasTypeParameters(AstNodeRef::new(module, type_alias))
-            }
             NodeWithScopeRef::Lambda(lambda) => {
                 NodeWithScopeKind::Lambda(AstNodeRef::new(module, lambda))
             }
@@ -399,12 +400,6 @@ impl NodeWithScopeRef<'_> {
             NodeWithScopeRef::ClassTypeParameters(class) => {
                 NodeWithScopeKey::ClassTypeParameters(NodeKey::from_node(class))
             }
-            NodeWithScopeRef::TypeAlias(type_alias) => {
-                NodeWithScopeKey::TypeAlias(NodeKey::from_node(type_alias))
-            }
-            NodeWithScopeRef::TypeAliasTypeParameters(type_alias) => {
-                NodeWithScopeKey::TypeAliasTypeParameters(NodeKey::from_node(type_alias))
-            }
             NodeWithScopeRef::ListComprehension(comprehension) => {
                 NodeWithScopeKey::ListComprehension(NodeKey::from_node(comprehension))
             }
@@ -429,8 +424,6 @@ pub enum NodeWithScopeKind {
     ClassTypeParameters(AstNodeRef<ast::StmtClassDef>),
     Function(AstNodeRef<ast::StmtFunctionDef>),
     FunctionTypeParameters(AstNodeRef<ast::StmtFunctionDef>),
-    TypeAliasTypeParameters(AstNodeRef<ast::StmtTypeAlias>),
-    TypeAlias(AstNodeRef<ast::StmtTypeAlias>),
     Lambda(AstNodeRef<ast::ExprLambda>),
     ListComprehension(AstNodeRef<ast::ExprListComp>),
     SetComprehension(AstNodeRef<ast::ExprSetComp>),
@@ -443,11 +436,9 @@ impl NodeWithScopeKind {
         match self {
             Self::Module => ScopeKind::Module,
             Self::Class(_) => ScopeKind::Class,
-            Self::Function(_) | Self::Lambda(_) => ScopeKind::Function,
-            Self::FunctionTypeParameters(_)
-            | Self::ClassTypeParameters(_)
-            | Self::TypeAliasTypeParameters(_) => ScopeKind::Annotation,
-            Self::TypeAlias(_) => ScopeKind::TypeAlias,
+            Self::Function(_) => ScopeKind::Function,
+            Self::Lambda(_) => ScopeKind::Function,
+            Self::FunctionTypeParameters(_) | Self::ClassTypeParameters(_) => ScopeKind::Annotation,
             Self::ListComprehension(_)
             | Self::SetComprehension(_)
             | Self::DictComprehension(_)
@@ -468,13 +459,6 @@ impl NodeWithScopeKind {
             _ => panic!("expected function"),
         }
     }
-
-    pub fn expect_type_alias(&self) -> &ast::StmtTypeAlias {
-        match self {
-            Self::TypeAlias(type_alias) => type_alias.node(),
-            _ => panic!("expected type alias"),
-        }
-    }
 }
 
 #[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
@@ -484,8 +468,6 @@ pub(crate) enum NodeWithScopeKey {
     ClassTypeParameters(NodeKey),
     Function(NodeKey),
     FunctionTypeParameters(NodeKey),
-    TypeAlias(NodeKey),
-    TypeAliasTypeParameters(NodeKey),
     Lambda(NodeKey),
     ListComprehension(NodeKey),
     SetComprehension(NodeKey),

crates/red_knot_python_semantic/src/semantic_index/use_def.rs

@@ -277,7 +277,7 @@ impl<'db> UseDefMap<'db> {
 
     pub(crate) fn use_boundness(&self, use_id: ScopedUseId) -> Boundness {
         if self.bindings_by_use[use_id].may_be_unbound() {
-            Boundness::PossiblyUnbound
+            Boundness::MayBeUnbound
         } else {
             Boundness::Bound
         }
@@ -292,7 +292,7 @@ impl<'db> UseDefMap<'db> {
 
     pub(crate) fn public_boundness(&self, symbol: ScopedSymbolId) -> Boundness {
         if self.public_symbols[symbol].may_be_unbound() {
-            Boundness::PossiblyUnbound
+            Boundness::MayBeUnbound
         } else {
             Boundness::Bound
         }
@@ -459,6 +459,10 @@ pub(super) struct UseDefMapBuilder<'db> {
 }
 
 impl<'db> UseDefMapBuilder<'db> {
+    pub(super) fn new() -> Self {
+        Self::default()
+    }
+
     pub(super) fn add_symbol(&mut self, symbol: ScopedSymbolId) {
         let new_symbol = self.symbol_states.push(SymbolState::undefined());
         debug_assert_eq!(symbol, new_symbol);

crates/red_knot_python_semantic/src/semantic_model.rs

@@ -6,7 +6,7 @@ use ruff_source_file::LineIndex;
 
 use crate::module_name::ModuleName;
 use crate::module_resolver::{resolve_module, Module};
-use crate::semantic_index::ast_ids::HasScopedExpressionId;
+use crate::semantic_index::ast_ids::HasScopedAstId;
 use crate::semantic_index::semantic_index;
 use crate::types::{binding_ty, infer_scope_types, Type};
 use crate::Db;
@@ -54,7 +54,7 @@ impl HasTy for ast::ExpressionRef<'_> {
         let file_scope = index.expression_scope_id(*self);
         let scope = file_scope.to_scope_id(model.db, model.file);
 
-        let expression_id = self.scoped_expression_id(model.db, scope);
+        let expression_id = self.scoped_ast_id(model.db, scope);
         infer_scope_types(model.db, scope).expression_ty(expression_id)
     }
 }

crates/red_knot_python_semantic/src/site_packages.rs

@@ -732,20 +732,7 @@ mod tests {
         let system = TestSystem::default();
         assert!(matches!(
             VirtualEnvironment::new("/.venv", &system),
-            Err(SitePackagesDiscoveryError::VenvDirCanonicalizationError(..))
-        ));
-    }
-
-    #[test]
-    fn reject_venv_that_is_not_a_directory() {
-        let system = TestSystem::default();
-        system
-            .memory_file_system()
-            .write_file("/.venv", "")
-            .unwrap();
-        assert!(matches!(
-            VirtualEnvironment::new("/.venv", &system),
-            Err(SitePackagesDiscoveryError::VenvDirIsNotADirectory(..))
+            Err(SitePackagesDiscoveryError::VenvDirIsNotADirectory(_))
         ));
     }
 

crates/red_knot_python_semantic/src/stdlib.rs

@@ -8,38 +8,32 @@ use crate::Db;
 
 /// Enumeration of various core stdlib modules, for which we have dedicated Salsa queries.
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
-pub(crate) enum CoreStdlibModule {
+enum CoreStdlibModule {
     Builtins,
     Types,
     Typeshed,
     TypingExtensions,
     Typing,
-    Sys,
 }
 
 impl CoreStdlibModule {
-    pub(crate) const fn as_str(self) -> &'static str {
-        match self {
+    fn name(self) -> ModuleName {
+        let module_name = match self {
             Self::Builtins => "builtins",
             Self::Types => "types",
             Self::Typing => "typing",
             Self::Typeshed => "_typeshed",
             Self::TypingExtensions => "typing_extensions",
-            Self::Sys => "sys",
-        }
-    }
-
-    pub(crate) fn name(self) -> ModuleName {
-        let self_as_str = self.as_str();
-        ModuleName::new_static(self_as_str)
-            .unwrap_or_else(|| panic!("{self_as_str} should be a valid module name!"))
+        };
+        ModuleName::new_static(module_name)
+            .unwrap_or_else(|| panic!("{module_name} should be a valid module name!"))
     }
 }
 
 /// Lookup the type of `symbol` in a given core module
 ///
 /// Returns `Symbol::Unbound` if the given core module cannot be resolved for some reason
-pub(crate) fn core_module_symbol<'db>(
+fn core_module_symbol<'db>(
     db: &'db dyn Db,
     core_module: CoreStdlibModule,
     symbol: &str,
@@ -57,14 +51,29 @@ pub(crate) fn builtins_symbol<'db>(db: &'db dyn Db, symbol: &str) -> Symbol<'db>
     core_module_symbol(db, CoreStdlibModule::Builtins, symbol)
 }
 
+/// Lookup the type of `symbol` in the `types` module namespace.
+///
+/// Returns `Symbol::Unbound` if the `types` module isn't available for some reason.
+#[inline]
+pub(crate) fn types_symbol<'db>(db: &'db dyn Db, symbol: &str) -> Symbol<'db> {
+    core_module_symbol(db, CoreStdlibModule::Types, symbol)
+}
+
 /// Lookup the type of `symbol` in the `typing` module namespace.
 ///
 /// Returns `Symbol::Unbound` if the `typing` module isn't available for some reason.
 #[inline]
-#[cfg(test)]
+#[allow(dead_code)] // currently only used in tests
 pub(crate) fn typing_symbol<'db>(db: &'db dyn Db, symbol: &str) -> Symbol<'db> {
     core_module_symbol(db, CoreStdlibModule::Typing, symbol)
 }
+/// Lookup the type of `symbol` in the `_typeshed` module namespace.
+///
+/// Returns `Symbol::Unbound` if the `_typeshed` module isn't available for some reason.
+#[inline]
+pub(crate) fn typeshed_symbol<'db>(db: &'db dyn Db, symbol: &str) -> Symbol<'db> {
+    core_module_symbol(db, CoreStdlibModule::Typeshed, symbol)
+}
 
 /// Lookup the type of `symbol` in the `typing_extensions` module namespace.
 ///

crates/red_knot_python_semantic/src/symbol.rs

@@ -3,19 +3,10 @@ use crate::{
     Db,
 };
 
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq)]
 pub(crate) enum Boundness {
     Bound,
-    PossiblyUnbound,
-}
-
-impl Boundness {
-    pub(crate) fn or(self, other: Boundness) -> Boundness {
-        match (self, other) {
-            (Boundness::Bound, _) | (_, Boundness::Bound) => Boundness::Bound,
-            (Boundness::PossiblyUnbound, Boundness::PossiblyUnbound) => Boundness::PossiblyUnbound,
-        }
-    }
+    MayBeUnbound,
 }
 
 /// The result of a symbol lookup, which can either be a (possibly unbound) type
@@ -26,14 +17,14 @@ impl Boundness {
 /// bound = 1
 ///
 /// if flag:
-///     possibly_unbound = 2
+///     maybe_unbound = 2
 /// ```
 ///
 /// If we look up symbols in this scope, we would get the following results:
 /// ```rs
-/// bound:             Symbol::Type(Type::IntLiteral(1), Boundness::Bound),
-/// possibly_unbound:  Symbol::Type(Type::IntLiteral(2), Boundness::PossiblyUnbound),
-/// non_existent:      Symbol::Unbound,
+/// bound:          Symbol::Type(Type::IntLiteral(1), Boundness::Bound),
+/// maybe_unbound:  Symbol::Type(Type::IntLiteral(2), Boundness::MayBeUnbound),
+/// non_existent:   Symbol::Unbound,
 /// ```
 #[derive(Debug, Clone, PartialEq)]
 pub(crate) enum Symbol<'db> {
@@ -46,18 +37,25 @@ impl<'db> Symbol<'db> {
         matches!(self, Symbol::Unbound)
     }
 
-    pub(crate) fn possibly_unbound(&self) -> bool {
+    pub(crate) fn may_be_unbound(&self) -> bool {
         match self {
-            Symbol::Type(_, Boundness::PossiblyUnbound) | Symbol::Unbound => true,
+            Symbol::Type(_, Boundness::MayBeUnbound) | Symbol::Unbound => true,
             Symbol::Type(_, Boundness::Bound) => false,
         }
     }
 
-    /// Returns the type of the symbol, ignoring possible unboundness.
-    ///
-    /// If the symbol is *definitely* unbound, this function will return `None`. Otherwise,
-    /// if there is at least one control-flow path where the symbol is bound, return the type.
-    pub(crate) fn ignore_possibly_unbound(&self) -> Option<Type<'db>> {
+    pub(crate) fn unwrap_or(&self, other: Type<'db>) -> Type<'db> {
+        match self {
+            Symbol::Type(ty, _) => *ty,
+            Symbol::Unbound => other,
+        }
+    }
+
+    pub(crate) fn unwrap_or_unknown(&self) -> Type<'db> {
+        self.unwrap_or(Type::Unknown)
+    }
+
+    pub(crate) fn as_type(&self) -> Option<Type<'db>> {
         match self {
             Symbol::Type(ty, _) => Some(*ty),
             Symbol::Unbound => None,
@@ -67,80 +65,28 @@ impl<'db> Symbol<'db> {
     #[cfg(test)]
     #[track_caller]
     pub(crate) fn expect_type(self) -> Type<'db> {
-        self.ignore_possibly_unbound()
+        self.as_type()
             .expect("Expected a (possibly unbound) type, not an unbound symbol")
     }
 
     #[must_use]
-    pub(crate) fn or_fall_back_to(self, db: &'db dyn Db, fallback: &Symbol<'db>) -> Symbol<'db> {
-        match fallback {
-            Symbol::Type(fallback_ty, fallback_boundness) => match self {
-                Symbol::Type(_, Boundness::Bound) => self,
-                Symbol::Type(ty, boundness @ Boundness::PossiblyUnbound) => Symbol::Type(
-                    UnionType::from_elements(db, [*fallback_ty, ty]),
-                    fallback_boundness.or(boundness),
-                ),
-                Symbol::Unbound => fallback.clone(),
-            },
+    pub(crate) fn replace_unbound_with(
+        self,
+        db: &'db dyn Db,
+        replacement: &Symbol<'db>,
+    ) -> Symbol<'db> {
+        match replacement {
+            Symbol::Type(replacement, _) => Symbol::Type(
+                match self {
+                    Symbol::Type(ty, Boundness::Bound) => ty,
+                    Symbol::Type(ty, Boundness::MayBeUnbound) => {
+                        UnionType::from_elements(db, [*replacement, ty])
+                    }
+                    Symbol::Unbound => *replacement,
+                },
+                Boundness::Bound,
+            ),
             Symbol::Unbound => self,
         }
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::types::tests::setup_db;
-
-    #[test]
-    fn test_symbol_or_fall_back_to() {
-        use Boundness::{Bound, PossiblyUnbound};
-
-        let db = setup_db();
-        let ty1 = Type::IntLiteral(1);
-        let ty2 = Type::IntLiteral(2);
-
-        // Start from an unbound symbol
-        assert_eq!(
-            Symbol::Unbound.or_fall_back_to(&db, &Symbol::Unbound),
-            Symbol::Unbound
-        );
-        assert_eq!(
-            Symbol::Unbound.or_fall_back_to(&db, &Symbol::Type(ty1, PossiblyUnbound)),
-            Symbol::Type(ty1, PossiblyUnbound)
-        );
-        assert_eq!(
-            Symbol::Unbound.or_fall_back_to(&db, &Symbol::Type(ty1, Bound)),
-            Symbol::Type(ty1, Bound)
-        );
-
-        // Start from a possibly unbound symbol
-        assert_eq!(
-            Symbol::Type(ty1, PossiblyUnbound).or_fall_back_to(&db, &Symbol::Unbound),
-            Symbol::Type(ty1, PossiblyUnbound)
-        );
-        assert_eq!(
-            Symbol::Type(ty1, PossiblyUnbound)
-                .or_fall_back_to(&db, &Symbol::Type(ty2, PossiblyUnbound)),
-            Symbol::Type(UnionType::from_elements(&db, [ty2, ty1]), PossiblyUnbound)
-        );
-        assert_eq!(
-            Symbol::Type(ty1, PossiblyUnbound).or_fall_back_to(&db, &Symbol::Type(ty2, Bound)),
-            Symbol::Type(UnionType::from_elements(&db, [ty2, ty1]), Bound)
-        );
-
-        // Start from a definitely bound symbol
-        assert_eq!(
-            Symbol::Type(ty1, Bound).or_fall_back_to(&db, &Symbol::Unbound),
-            Symbol::Type(ty1, Bound)
-        );
-        assert_eq!(
-            Symbol::Type(ty1, Bound).or_fall_back_to(&db, &Symbol::Type(ty2, PossiblyUnbound)),
-            Symbol::Type(ty1, Bound)
-        );
-        assert_eq!(
-            Symbol::Type(ty1, Bound).or_fall_back_to(&db, &Symbol::Type(ty2, Bound)),
-            Symbol::Type(ty1, Bound)
-        );
-    }
-}

crates/red_knot_python_semantic/src/types/builder.rs

@@ -128,7 +128,7 @@ impl<'db> IntersectionBuilder<'db> {
     pub(crate) fn new(db: &'db dyn Db) -> Self {
         Self {
             db,
-            intersections: vec![InnerIntersectionBuilder::default()],
+            intersections: vec![InnerIntersectionBuilder::new()],
         }
     }
 
@@ -231,6 +231,10 @@ struct InnerIntersectionBuilder<'db> {
 }
 
 impl<'db> InnerIntersectionBuilder<'db> {
+    fn new() -> Self {
+        Self::default()
+    }
+
     /// Adds a positive type to this intersection.
     fn add_positive(&mut self, db: &'db dyn Db, new_positive: Type<'db>) {
         if let Type::Intersection(other) = new_positive {
@@ -242,14 +246,14 @@ impl<'db> InnerIntersectionBuilder<'db> {
             }
         } else {
             // ~Literal[True] & bool = Literal[False]
-            if let Type::Instance(InstanceType { class }) = new_positive {
+            if let Type::Instance(InstanceType { class, .. }) = new_positive {
                 if class.is_known(db, KnownClass::Bool) {
                     if let Some(&Type::BooleanLiteral(value)) = self
                         .negative
                         .iter()
                         .find(|element| element.is_boolean_literal())
                     {
-                        *self = Self::default();
+                        *self = Self::new();
                         self.positive.insert(Type::BooleanLiteral(!value));
                         return;
                     }
@@ -268,7 +272,7 @@ impl<'db> InnerIntersectionBuilder<'db> {
                 }
                 // A & B = Never    if A and B are disjoint
                 if new_positive.is_disjoint_from(db, *existing_positive) {
-                    *self = Self::default();
+                    *self = Self::new();
                     self.positive.insert(Type::Never);
                     return;
                 }
@@ -281,7 +285,7 @@ impl<'db> InnerIntersectionBuilder<'db> {
             for (index, existing_negative) in self.negative.iter().enumerate() {
                 // S & ~T = Never    if S <: T
                 if new_positive.is_subtype_of(db, *existing_negative) {
-                    *self = Self::default();
+                    *self = Self::new();
                     self.positive.insert(Type::Never);
                     return;
                 }
@@ -309,11 +313,11 @@ impl<'db> InnerIntersectionBuilder<'db> {
                     self.add_positive(db, *neg);
                 }
             }
-            ty @ (Type::Any | Type::Unknown | Type::Todo(_)) => {
+            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.
-                self.add_positive(db, ty);
+                self.positive.insert(ty);
             }
             // ~Literal[True] & bool = Literal[False]
             Type::BooleanLiteral(bool)
@@ -322,7 +326,7 @@ impl<'db> InnerIntersectionBuilder<'db> {
                     .iter()
                     .any(|pos| *pos == KnownClass::Bool.to_instance(db)) =>
             {
-                *self = Self::default();
+                *self = Self::new();
                 self.positive.insert(Type::BooleanLiteral(!bool));
             }
             _ => {
@@ -344,7 +348,7 @@ impl<'db> InnerIntersectionBuilder<'db> {
                 for existing_positive in &self.positive {
                     // S & ~T = Never    if S <: T
                     if existing_positive.is_subtype_of(db, new_negative) {
-                        *self = Self::default();
+                        *self = Self::new();
                         self.positive.insert(Type::Never);
                         return;
                     }
@@ -379,7 +383,7 @@ mod tests {
     use crate::program::{Program, SearchPathSettings};
     use crate::python_version::PythonVersion;
     use crate::stdlib::typing_symbol;
-    use crate::types::{global_symbol, todo_type, KnownClass, UnionBuilder};
+    use crate::types::{global_symbol, KnownClass, StringLiteralType, UnionBuilder};
     use crate::ProgramSettings;
     use ruff_db::files::system_path_to_file;
     use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
@@ -588,22 +592,6 @@ mod tests {
         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 intersection_distributes_over_union() {
         let db = setup_db();
@@ -771,7 +759,7 @@ mod tests {
             .build();
         assert_eq!(ty, s);
 
-        let literal = Type::string_literal(&db, "a");
+        let literal = Type::StringLiteral(StringLiteralType::new(&db, "a"));
         let expected = IntersectionBuilder::new(&db)
             .add_positive(s)
             .add_negative(literal)
@@ -874,7 +862,7 @@ mod tests {
 
         let ty = IntersectionBuilder::new(&db)
             .add_positive(s)
-            .add_negative(Type::string_literal(&db, "a"))
+            .add_negative(Type::StringLiteral(StringLiteralType::new(&db, "a")))
             .add_negative(t)
             .build();
         assert_eq!(ty, Type::Never);
@@ -908,7 +896,7 @@ mod tests {
         let db = setup_db();
 
         let t_p = KnownClass::Int.to_instance(&db);
-        let t_n = Type::string_literal(&db, "t_n");
+        let t_n = Type::StringLiteral(StringLiteralType::new(&db, "t_n"));
 
         let ty = IntersectionBuilder::new(&db)
             .add_positive(t_p)
@@ -987,7 +975,7 @@ mod tests {
 
     #[test_case(Type::Any)]
     #[test_case(Type::Unknown)]
-    #[test_case(todo_type!())]
+    #[test_case(Type::Todo)]
     fn build_intersection_t_and_negative_t_does_not_simplify(ty: Type) {
         let db = setup_db();
 

crates/red_knot_python_semantic/src/types/diagnostic.rs

@@ -1,15 +1,199 @@
-use crate::types::{ClassLiteralType, Type};
-use crate::Db;
-use ruff_db::diagnostic::{Diagnostic, Severity};
+use ruff_db::diagnostic::{CompileDiagnostic, Diagnostic, Severity};
 use ruff_db::files::File;
 use ruff_python_ast::{self as ast, AnyNodeRef};
 use ruff_text_size::{Ranged, TextRange};
 use std::borrow::Cow;
-use std::fmt::Formatter;
-use std::ops::Deref;
-use std::sync::Arc;
 
-#[derive(Debug, Eq, PartialEq, Clone)]
+use crate::types::{ClassLiteralType, Type};
+use crate::Db;
+
+/// Returns `true` if any diagnostic is enabled for this file.
+pub(crate) fn is_any_diagnostic_enabled(db: &dyn Db, file: File) -> bool {
+    db.is_file_open(file)
+}
+
+pub(crate) fn report_type_diagnostic(
+    db: &dyn Db,
+    file: File,
+    node: AnyNodeRef,
+    rule: &str,
+    message: std::fmt::Arguments,
+) {
+    if !is_any_diagnostic_enabled(db, file) {
+        return;
+    }
+
+    // TODO: Don't emit the diagnostic if:
+    // * The enclosing node contains any syntax errors
+    // * The rule is disabled for this file. We probably want to introduce a new query that
+    //   returns a rule selector for a given file that respects the package's settings,
+    //   any global pragma comments in the file, and any per-file-ignores.
+
+    CompileDiagnostic::report(
+        db.upcast(),
+        TypeCheckDiagnostic {
+            file,
+            rule: rule.to_string(),
+            message: message.to_string(),
+            range: node.range(),
+        },
+    );
+}
+
+/// Emit a diagnostic declaring that the object represented by `node` is not iterable
+pub(super) fn report_not_iterable(
+    db: &dyn Db,
+    file: File,
+    node: AnyNodeRef,
+    not_iterable_ty: Type,
+) {
+    report_type_diagnostic(
+        db,
+        file,
+        node,
+        "not-iterable",
+        format_args!(
+            "Object of type `{}` is not iterable",
+            not_iterable_ty.display(db)
+        ),
+    );
+}
+
+/// Emit a diagnostic declaring that an index is out of bounds for a tuple.
+pub(super) fn report_index_out_of_bounds(
+    db: &dyn Db,
+    file: File,
+    kind: &'static str,
+    node: AnyNodeRef,
+    tuple_ty: Type,
+    length: usize,
+    index: i64,
+) {
+    report_type_diagnostic(
+        db,
+        file,
+        node,
+        "index-out-of-bounds",
+        format_args!(
+            "Index {index} is out of bounds for {kind} `{}` with length {length}",
+            tuple_ty.display(db)
+        ),
+    );
+}
+
+/// Emit a diagnostic declaring that a type does not support subscripting.
+pub(super) fn report_non_subscriptable(
+    db: &dyn Db,
+    file: File,
+    node: AnyNodeRef,
+    non_subscriptable_ty: Type,
+    method: &str,
+) {
+    report_type_diagnostic(
+        db,
+        file,
+        node,
+        "non-subscriptable",
+        format_args!(
+            "Cannot subscript object of type `{}` with no `{method}` method",
+            non_subscriptable_ty.display(db)
+        ),
+    );
+}
+
+pub(super) fn report_unresolved_module<'a>(
+    db: &dyn Db,
+    file: File,
+    import_node: impl Into<AnyNodeRef<'a>>,
+    level: u32,
+    module: Option<&str>,
+) {
+    report_type_diagnostic(
+        db,
+        file,
+        import_node.into(),
+        "unresolved-import",
+        format_args!(
+            "Cannot resolve import `{}{}`",
+            ".".repeat(level as usize),
+            module.unwrap_or_default()
+        ),
+    );
+}
+
+pub(super) fn report_slice_step_size_zero(db: &dyn Db, file: File, node: AnyNodeRef) {
+    report_type_diagnostic(
+        db,
+        file,
+        node,
+        "zero-stepsize-in-slice",
+        format_args!("Slice step size can not be zero"),
+    );
+}
+
+pub(super) fn report_invalid_assignment(
+    db: &dyn Db,
+    file: File,
+    node: AnyNodeRef,
+    declared_ty: Type,
+    assigned_ty: Type,
+) {
+    match declared_ty {
+        Type::ClassLiteral(ClassLiteralType { class }) => {
+            report_type_diagnostic(db, file, node, "invalid-assignment", format_args!(
+                    "Implicit shadowing of class `{}`; annotate to make it explicit if this is intentional",
+                    class.name(db)));
+        }
+        Type::FunctionLiteral(function) => {
+            report_type_diagnostic(db, file, node, "invalid-assignment", format_args!(
+                    "Implicit shadowing of function `{}`; annotate to make it explicit if this is intentional",
+                    function.name(db)));
+        }
+        _ => {
+            report_type_diagnostic(
+                db,
+                file,
+                node,
+                "invalid-assignment",
+                format_args!(
+                    "Object of type `{}` is not assignable to `{}`",
+                    assigned_ty.display(db),
+                    declared_ty.display(db),
+                ),
+            );
+        }
+    }
+}
+
+pub(super) fn report_possibly_unresolved_reference(
+    db: &dyn Db,
+    file: File,
+    expr_name_node: &ast::ExprName,
+) {
+    let ast::ExprName { id, .. } = expr_name_node;
+
+    report_type_diagnostic(
+        db,
+        file,
+        expr_name_node.into(),
+        "possibly-unresolved-reference",
+        format_args!("Name `{id}` used when possibly not defined"),
+    );
+}
+
+pub(super) fn report_unresolved_reference(db: &dyn Db, file: File, expr_name_node: &ast::ExprName) {
+    let ast::ExprName { id, .. } = expr_name_node;
+
+    report_type_diagnostic(
+        db,
+        file,
+        expr_name_node.into(),
+        "unresolved-reference",
+        format_args!("Name `{id}` used when not defined"),
+    );
+}
+
+#[derive(Debug, Eq, PartialEq)]
 pub struct TypeCheckDiagnostic {
     // TODO: Don't use string keys for rules
     pub(super) rule: String,
@@ -23,300 +207,29 @@ impl TypeCheckDiagnostic {
         &self.rule
     }
 
-    pub fn message(&self) -> &str {
-        &self.message
-    }
-
-    pub fn file(&self) -> File {
-        self.file
+    pub fn range(&self) -> TextRange {
+        self.range
     }
 }
 
 impl Diagnostic for TypeCheckDiagnostic {
-    fn rule(&self) -> &str {
-        TypeCheckDiagnostic::rule(self)
-    }
-
-    fn message(&self) -> Cow<str> {
-        TypeCheckDiagnostic::message(self).into()
+    fn message(&self) -> std::borrow::Cow<str> {
+        Cow::Borrowed(&self.message)
     }
 
     fn file(&self) -> File {
-        TypeCheckDiagnostic::file(self)
+        self.file
     }
 
     fn range(&self) -> Option<TextRange> {
-        Some(Ranged::range(self))
+        Some(self.range)
     }
 
     fn severity(&self) -> Severity {
         Severity::Error
     }
-}
 
-impl Ranged for TypeCheckDiagnostic {
-    fn range(&self) -> TextRange {
-        self.range
-    }
-}
-
-/// A collection of type check diagnostics.
-///
-/// The diagnostics are wrapped in an `Arc` because they need to be cloned multiple times
-/// when going from `infer_expression` to `check_file`. We could consider
-/// making [`TypeCheckDiagnostic`] a Salsa struct to have them Arena-allocated (once the Tables refactor is done).
-/// Using Salsa struct does have the downside that it leaks the Salsa dependency into diagnostics and
-/// each Salsa-struct comes with an overhead.
-#[derive(Default, Eq, PartialEq)]
-pub struct TypeCheckDiagnostics {
-    inner: Vec<std::sync::Arc<TypeCheckDiagnostic>>,
-}
-
-impl TypeCheckDiagnostics {
-    pub(super) fn push(&mut self, diagnostic: TypeCheckDiagnostic) {
-        self.inner.push(Arc::new(diagnostic));
-    }
-
-    pub(crate) fn shrink_to_fit(&mut self) {
-        self.inner.shrink_to_fit();
-    }
-}
-
-impl Extend<TypeCheckDiagnostic> for TypeCheckDiagnostics {
-    fn extend<T: IntoIterator<Item = TypeCheckDiagnostic>>(&mut self, iter: T) {
-        self.inner.extend(iter.into_iter().map(std::sync::Arc::new));
-    }
-}
-
-impl Extend<std::sync::Arc<TypeCheckDiagnostic>> for TypeCheckDiagnostics {
-    fn extend<T: IntoIterator<Item = Arc<TypeCheckDiagnostic>>>(&mut self, iter: T) {
-        self.inner.extend(iter);
-    }
-}
-
-impl<'a> Extend<&'a std::sync::Arc<TypeCheckDiagnostic>> for TypeCheckDiagnostics {
-    fn extend<T: IntoIterator<Item = &'a Arc<TypeCheckDiagnostic>>>(&mut self, iter: T) {
-        self.inner
-            .extend(iter.into_iter().map(std::sync::Arc::clone));
-    }
-}
-
-impl std::fmt::Debug for TypeCheckDiagnostics {
-    fn fmt(&self, f: &mut Formatter<'_>) -> std::fmt::Result {
-        self.inner.fmt(f)
-    }
-}
-
-impl Deref for TypeCheckDiagnostics {
-    type Target = [std::sync::Arc<TypeCheckDiagnostic>];
-
-    fn deref(&self) -> &Self::Target {
-        &self.inner
-    }
-}
-
-impl IntoIterator for TypeCheckDiagnostics {
-    type Item = Arc<TypeCheckDiagnostic>;
-    type IntoIter = std::vec::IntoIter<std::sync::Arc<TypeCheckDiagnostic>>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.inner.into_iter()
-    }
-}
-
-impl<'a> IntoIterator for &'a TypeCheckDiagnostics {
-    type Item = &'a Arc<TypeCheckDiagnostic>;
-    type IntoIter = std::slice::Iter<'a, std::sync::Arc<TypeCheckDiagnostic>>;
-
-    fn into_iter(self) -> Self::IntoIter {
-        self.inner.iter()
-    }
-}
-
-pub(super) struct TypeCheckDiagnosticsBuilder<'db> {
-    db: &'db dyn Db,
-    file: File,
-    diagnostics: TypeCheckDiagnostics,
-}
-
-impl<'db> TypeCheckDiagnosticsBuilder<'db> {
-    pub(super) fn new(db: &'db dyn Db, file: File) -> Self {
-        Self {
-            db,
-            file,
-            diagnostics: TypeCheckDiagnostics::default(),
-        }
-    }
-
-    /// Emit a diagnostic declaring that the object represented by `node` is not iterable
-    pub(super) fn add_not_iterable(&mut self, node: AnyNodeRef, not_iterable_ty: Type<'db>) {
-        self.add(
-            node,
-            "not-iterable",
-            format_args!(
-                "Object of type `{}` is not iterable",
-                not_iterable_ty.display(self.db)
-            ),
-        );
-    }
-
-    /// Emit a diagnostic declaring that the object represented by `node` is not iterable
-    /// because its `__iter__` method is possibly unbound.
-    pub(super) fn add_not_iterable_possibly_unbound(
-        &mut self,
-        node: AnyNodeRef,
-        element_ty: Type<'db>,
-    ) {
-        self.add(
-            node,
-            "not-iterable",
-            format_args!(
-                "Object of type `{}` is not iterable because its `__iter__` method is possibly unbound",
-                element_ty.display(self.db)
-            ),
-        );
-    }
-
-    /// Emit a diagnostic declaring that an index is out of bounds for a tuple.
-    pub(super) fn add_index_out_of_bounds(
-        &mut self,
-        kind: &'static str,
-        node: AnyNodeRef,
-        tuple_ty: Type<'db>,
-        length: usize,
-        index: i64,
-    ) {
-        self.add(
-            node,
-            "index-out-of-bounds",
-            format_args!(
-                "Index {index} is out of bounds for {kind} `{}` with length {length}",
-                tuple_ty.display(self.db)
-            ),
-        );
-    }
-
-    /// Emit a diagnostic declaring that a type does not support subscripting.
-    pub(super) fn add_non_subscriptable(
-        &mut self,
-        node: AnyNodeRef,
-        non_subscriptable_ty: Type<'db>,
-        method: &str,
-    ) {
-        self.add(
-            node,
-            "non-subscriptable",
-            format_args!(
-                "Cannot subscript object of type `{}` with no `{method}` method",
-                non_subscriptable_ty.display(self.db)
-            ),
-        );
-    }
-
-    pub(super) fn add_unresolved_module(
-        &mut self,
-        import_node: impl Into<AnyNodeRef<'db>>,
-        level: u32,
-        module: Option<&str>,
-    ) {
-        self.add(
-            import_node.into(),
-            "unresolved-import",
-            format_args!(
-                "Cannot resolve import `{}{}`",
-                ".".repeat(level as usize),
-                module.unwrap_or_default()
-            ),
-        );
-    }
-
-    pub(super) fn add_slice_step_size_zero(&mut self, node: AnyNodeRef) {
-        self.add(
-            node,
-            "zero-stepsize-in-slice",
-            format_args!("Slice step size can not be zero"),
-        );
-    }
-
-    pub(super) fn add_invalid_assignment(
-        &mut self,
-        node: AnyNodeRef,
-        declared_ty: Type<'db>,
-        assigned_ty: Type<'db>,
-    ) {
-        match declared_ty {
-            Type::ClassLiteral(ClassLiteralType { class }) => {
-                self.add(node, "invalid-assignment", format_args!(
-                        "Implicit shadowing of class `{}`; annotate to make it explicit if this is intentional",
-                        class.name(self.db)));
-            }
-            Type::FunctionLiteral(function) => {
-                self.add(node, "invalid-assignment", format_args!(
-                        "Implicit shadowing of function `{}`; annotate to make it explicit if this is intentional",
-                        function.name(self.db)));
-            }
-            _ => {
-                self.add(
-                    node,
-                    "invalid-assignment",
-                    format_args!(
-                        "Object of type `{}` is not assignable to `{}`",
-                        assigned_ty.display(self.db),
-                        declared_ty.display(self.db),
-                    ),
-                );
-            }
-        }
-    }
-
-    pub(super) fn add_possibly_unresolved_reference(&mut self, expr_name_node: &ast::ExprName) {
-        let ast::ExprName { id, .. } = expr_name_node;
-
-        self.add(
-            expr_name_node.into(),
-            "possibly-unresolved-reference",
-            format_args!("Name `{id}` used when possibly not defined"),
-        );
-    }
-
-    pub(super) fn add_unresolved_reference(&mut self, expr_name_node: &ast::ExprName) {
-        let ast::ExprName { id, .. } = expr_name_node;
-
-        self.add(
-            expr_name_node.into(),
-            "unresolved-reference",
-            format_args!("Name `{id}` used when not defined"),
-        );
-    }
-
-    /// Adds a new diagnostic.
-    ///
-    /// The diagnostic does not get added if the rule isn't enabled for this file.
-    pub(super) fn add(&mut self, node: AnyNodeRef, rule: &str, message: std::fmt::Arguments) {
-        if !self.db.is_file_open(self.file) {
-            return;
-        }
-
-        // TODO: Don't emit the diagnostic if:
-        // * The enclosing node contains any syntax errors
-        // * The rule is disabled for this file. We probably want to introduce a new query that
-        //   returns a rule selector for a given file that respects the package's settings,
-        //   any global pragma comments in the file, and any per-file-ignores.
-
-        self.diagnostics.push(TypeCheckDiagnostic {
-            file: self.file,
-            rule: rule.to_string(),
-            message: message.to_string(),
-            range: node.range(),
-        });
-    }
-
-    pub(super) fn extend(&mut self, diagnostics: &TypeCheckDiagnostics) {
-        self.diagnostics.extend(diagnostics);
-    }
-
-    pub(super) fn finish(mut self) -> TypeCheckDiagnostics {
-        self.diagnostics.shrink_to_fit();
-        self.diagnostics
+    fn rule(&self) -> &str {
+        &self.rule
     }
 }

crates/red_knot_python_semantic/src/types/display.rs

@@ -1,15 +1,12 @@
 //! Display implementations for types.
 
-use std::fmt::{self, Display, Formatter, Write};
+use std::fmt::{self, Display, Formatter};
 
 use ruff_db::display::FormatterJoinExtension;
 use ruff_python_ast::str::Quote;
 use ruff_python_literal::escape::AsciiEscape;
 
-use crate::types::{
-    ClassLiteralType, InstanceType, IntersectionType, KnownClass, StringLiteralType,
-    SubclassOfType, Type, UnionType,
-};
+use crate::types::{ClassLiteralType, InstanceType, IntersectionType, KnownClass, Type, UnionType};
 use crate::Db;
 use rustc_hash::FxHashMap;
 
@@ -67,32 +64,31 @@ impl Display for DisplayRepresentation<'_> {
             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",
-                    Some(KnownClass::NoDefaultType) => "NoDefault",
-                    _ => class.name(self.db),
-                };
-                f.write_str(representation)
+            Type::Instance(InstanceType { class, .. })
+                if class.is_known(self.db, KnownClass::NoneType) =>
+            {
+                f.write_str("None")
             }
             // `[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::Todo => f.write_str("@Todo"),
             Type::ModuleLiteral(file) => {
                 write!(f, "<module '{:?}'>", file.path(self.db))
             }
             // TODO functions and classes should display using a fully qualified name
             Type::ClassLiteral(ClassLiteralType { class }) => f.write_str(class.name(self.db)),
-            Type::SubclassOf(SubclassOfType { class }) => {
-                write!(f, "type[{}]", class.name(self.db))
-            }
-            Type::KnownInstance(known_instance) => f.write_str(known_instance.repr(self.db)),
+            Type::Instance(InstanceType { class, known }) => f.write_str(match known {
+                Some(super::KnownInstance::Literal) => "Literal",
+                _ => class.name(self.db),
+            }),
             Type::FunctionLiteral(function) => f.write_str(function.name(self.db)),
             Type::Union(union) => union.display(self.db).fmt(f),
             Type::Intersection(intersection) => intersection.display(self.db).fmt(f),
             Type::IntLiteral(n) => n.fmt(f),
             Type::BooleanLiteral(boolean) => f.write_str(if boolean { "True" } else { "False" }),
-            Type::StringLiteral(string) => string.display(self.db).fmt(f),
+            Type::StringLiteral(string) => {
+                write!(f, r#""{}""#, string.value(self.db).replace('"', r#"\""#))
+            }
             Type::LiteralString => f.write_str("LiteralString"),
             Type::BytesLiteral(bytes) => {
                 let escape =
@@ -327,40 +323,15 @@ impl<'db> Display for DisplayTypeArray<'_, 'db> {
     }
 }
 
-impl<'db> StringLiteralType<'db> {
-    fn display(&'db self, db: &'db dyn Db) -> DisplayStringLiteralType<'db> {
-        DisplayStringLiteralType { db, ty: self }
-    }
-}
-
-struct DisplayStringLiteralType<'db> {
-    ty: &'db StringLiteralType<'db>,
-    db: &'db dyn Db,
-}
-
-impl Display for DisplayStringLiteralType<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        let value = self.ty.value(self.db);
-        f.write_char('"')?;
-        for ch in value.chars() {
-            match ch {
-                // `escape_debug` will escape even single quotes, which is not necessary for our
-                // use case as we are already using double quotes to wrap the string.
-                '\'' => f.write_char('\'')?,
-                _ => write!(f, "{}", ch.escape_debug())?,
-            }
-        }
-        f.write_char('"')
-    }
-}
-
 #[cfg(test)]
 mod tests {
     use ruff_db::files::system_path_to_file;
     use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
 
     use crate::db::tests::TestDb;
-    use crate::types::{global_symbol, SliceLiteralType, StringLiteralType, Type, UnionType};
+    use crate::types::{
+        global_symbol, BytesLiteralType, SliceLiteralType, StringLiteralType, Type, UnionType,
+    };
     use crate::{Program, ProgramSettings, PythonVersion, SearchPathSettings};
 
     fn setup_db() -> TestDb {
@@ -406,12 +377,12 @@ mod tests {
             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::StringLiteral(StringLiteralType::new(&db, "A")),
+            Type::BytesLiteral(BytesLiteralType::new(&db, [0u8].as_slice())),
+            Type::BytesLiteral(BytesLiteralType::new(&db, [7u8].as_slice())),
             Type::IntLiteral(0),
             Type::IntLiteral(1),
-            Type::string_literal(&db, "B"),
+            Type::StringLiteral(StringLiteralType::new(&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(),
@@ -477,28 +448,4 @@ mod tests {
             "slice[None, None, Literal[2]]"
         );
     }
-
-    #[test]
-    fn string_literal_display() {
-        let db = setup_db();
-
-        assert_eq!(
-            Type::StringLiteral(StringLiteralType::new(&db, r"\n"))
-                .display(&db)
-                .to_string(),
-            r#"Literal["\\n"]"#
-        );
-        assert_eq!(
-            Type::StringLiteral(StringLiteralType::new(&db, "'"))
-                .display(&db)
-                .to_string(),
-            r#"Literal["'"]"#
-        );
-        assert_eq!(
-            Type::StringLiteral(StringLiteralType::new(&db, r#"""#))
-                .display(&db)
-                .to_string(),
-            r#"Literal["\""]"#
-        );
-    }
 }

crates/red_knot_python_semantic/src/types/mro.rs

@@ -1,11 +1,12 @@
 use std::collections::VecDeque;
 use std::ops::Deref;
 
+use indexmap::IndexSet;
 use itertools::Either;
 use rustc_hash::FxHashSet;
 
-use super::{Class, ClassLiteralType, KnownClass, KnownInstanceType, Type};
-use crate::{types::todo_type, Db};
+use super::{Class, ClassLiteralType, KnownClass, Type};
+use crate::Db;
 
 /// The inferred method resolution order of a given class.
 ///
@@ -25,30 +26,22 @@ impl<'db> Mro<'db> {
     /// (We emit a diagnostic warning about the runtime `TypeError` in
     /// [`super::infer::TypeInferenceBuilder::infer_region_scope`].)
     pub(super) fn of_class(db: &'db dyn Db, class: Class<'db>) -> Result<Self, MroError<'db>> {
-        Self::of_class_impl(db, class).map_err(|error_kind| MroError {
-            kind: error_kind,
-            fallback_mro: Self::from_error(db, class),
+        Self::of_class_impl(db, class).map_err(|error_kind| {
+            let fallback_mro = Self::from([
+                ClassBase::Class(class),
+                ClassBase::Unknown,
+                ClassBase::object(db),
+            ]);
+            MroError {
+                kind: error_kind,
+                fallback_mro,
+            }
         })
     }
 
-    pub(super) fn from_error(db: &'db dyn Db, class: Class<'db>) -> Self {
-        Self::from([
-            ClassBase::Class(class),
-            ClassBase::Unknown,
-            ClassBase::object(db),
-        ])
-    }
-
     fn of_class_impl(db: &'db dyn Db, class: Class<'db>) -> Result<Self, MroErrorKind<'db>> {
         let class_bases = class.explicit_bases(db);
 
-        if !class_bases.is_empty() && class.is_cyclically_defined(db) {
-            // We emit errors for cyclically defined classes elsewhere.
-            // It's important that we don't even try to infer the MRO for a cyclically defined class,
-            // or we'll end up in an infinite loop.
-            return Ok(Mro::from_error(db, class));
-        }
-
         match class_bases {
             // `builtins.object` is the special case:
             // the only class in Python that has an MRO with length <2
@@ -84,6 +77,11 @@ impl<'db> Mro<'db> {
                         Err(MroErrorKind::InvalidBases(bases_info))
                     },
                     |single_base| {
+                        if let ClassBase::Class(class_base) = single_base {
+                            if class_is_cyclically_defined(db, class_base) {
+                                return Err(MroErrorKind::CyclicClassDefinition);
+                            }
+                        }
                         let mro = std::iter::once(ClassBase::Class(class))
                             .chain(single_base.mro(db))
                             .collect();
@@ -98,6 +96,10 @@ impl<'db> Mro<'db> {
             // what MRO Python will give this class at runtime
             // (if an MRO is indeed resolvable at all!)
             multiple_bases => {
+                if class_is_cyclically_defined(db, class) {
+                    return Err(MroErrorKind::CyclicClassDefinition);
+                }
+
                 let mut valid_bases = vec![];
                 let mut invalid_bases = vec![];
 
@@ -280,6 +282,13 @@ pub(super) enum MroErrorKind<'db> {
     /// Each index is the index of a node representing an invalid base.
     InvalidBases(Box<[(usize, Type<'db>)]>),
 
+    /// The class inherits from itself!
+    ///
+    /// This is very unlikely to happen in working real-world code,
+    /// but it's important to explicitly account for it.
+    /// If we don't, there's a possibility of an infinite loop and a panic.
+    CyclicClassDefinition,
+
     /// The class has one or more duplicate bases.
     ///
     /// This variant records the indices and [`Class`]es
@@ -340,7 +349,7 @@ impl<'db> ClassBase<'db> {
     /// Return a `ClassBase` representing the class `builtins.object`
     fn object(db: &'db dyn Db) -> Self {
         KnownClass::Object
-            .to_class_literal(db)
+            .to_class(db)
             .into_class_literal()
             .map_or(Self::Unknown, |ClassLiteralType { class }| {
                 Self::Class(class)
@@ -354,7 +363,7 @@ impl<'db> ClassBase<'db> {
         match ty {
             Type::Any => Some(Self::Any),
             Type::Unknown => Some(Self::Unknown),
-            Type::Todo(_) => Some(Self::Todo),
+            Type::Todo => Some(Self::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?
@@ -368,17 +377,7 @@ impl<'db> ClassBase<'db> {
             | Type::LiteralString
             | Type::Tuple(_)
             | Type::SliceLiteral(_)
-            | Type::ModuleLiteral(_)
-            | Type::SubclassOf(_) => None,
-            Type::KnownInstance(known_instance) => match known_instance {
-                KnownInstanceType::TypeVar(_)
-                | KnownInstanceType::TypeAliasType(_)
-                | KnownInstanceType::Literal
-                | KnownInstanceType::Union
-                | KnownInstanceType::NoReturn
-                | KnownInstanceType::Never
-                | KnownInstanceType::Optional => None,
-            },
+            | Type::ModuleLiteral(_) => None,
         }
     }
 
@@ -409,9 +408,9 @@ impl<'db> From<ClassBase<'db>> for Type<'db> {
     fn from(value: ClassBase<'db>) -> Self {
         match value {
             ClassBase::Any => Type::Any,
-            ClassBase::Todo => todo_type!(),
+            ClassBase::Todo => Type::Todo,
             ClassBase::Unknown => Type::Unknown,
-            ClassBase::Class(class) => Type::class_literal(class),
+            ClassBase::Class(class) => Type::ClassLiteral(ClassLiteralType { class }),
         }
     }
 }
@@ -457,3 +456,46 @@ fn c3_merge(mut sequences: Vec<VecDeque<ClassBase>>) -> Option<Mro> {
         }
     }
 }
+
+/// Return `true` if this class appears to be a cyclic definition,
+/// i.e., it inherits either directly or indirectly from itself.
+///
+/// A class definition like this will fail at runtime,
+/// but we must be resilient to it or we could panic.
+fn class_is_cyclically_defined(db: &dyn Db, class: Class) -> bool {
+    fn is_cyclically_defined_recursive<'db>(
+        db: &'db dyn Db,
+        class: Class<'db>,
+        classes_to_watch: &mut IndexSet<Class<'db>>,
+    ) -> bool {
+        if !classes_to_watch.insert(class) {
+            return true;
+        }
+        for explicit_base_class in class
+            .explicit_bases(db)
+            .iter()
+            .copied()
+            .filter_map(Type::into_class_literal)
+            .map(|ClassLiteralType { class }| class)
+        {
+            // Each base must be considered in isolation.
+            // This is due to the fact that if a class uses multiple inheritance,
+            // there could easily be a situation where two bases have the same class in their MROs;
+            // that isn't enough to constitute the class being cyclically defined.
+            let classes_to_watch_len = classes_to_watch.len();
+            if is_cyclically_defined_recursive(db, explicit_base_class, classes_to_watch) {
+                return true;
+            }
+            classes_to_watch.truncate(classes_to_watch_len);
+        }
+        false
+    }
+
+    class
+        .explicit_bases(db)
+        .iter()
+        .copied()
+        .filter_map(Type::into_class_literal)
+        .map(|ClassLiteralType { class }| class)
+        .any(|base_class| is_cyclically_defined_recursive(db, base_class, &mut IndexSet::default()))
+}

crates/red_knot_python_semantic/src/types/narrow.rs

@@ -1,12 +1,12 @@
-use crate::semantic_index::ast_ids::HasScopedExpressionId;
+use crate::semantic_index::ast_ids::HasScopedAstId;
 use crate::semantic_index::constraint::{Constraint, ConstraintNode, PatternConstraint};
 use crate::semantic_index::definition::Definition;
 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,
-    KnownConstraintFunction, KnownFunction, Truthiness, Type, UnionBuilder,
+    infer_expression_types, ClassLiteralType, IntersectionBuilder, KnownClass, KnownFunction,
+    Truthiness, Type, UnionBuilder,
 };
 use crate::Db;
 use itertools::Itertools;
@@ -78,27 +78,24 @@ fn all_negative_narrowing_constraints_for_expression<'db>(
     NarrowingConstraintsBuilder::new(db, ConstraintNode::Expression(expression), false).finish()
 }
 
-/// Generate a constraint from the type of a `classinfo` argument to `isinstance` or `issubclass`.
+/// Generate a constraint from the *type* of the second argument of an `isinstance` call.
 ///
-/// 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>(
+/// Example: for `isinstance(…, str)`, we would infer `Type::ClassLiteral(str)` from the
+/// second argument, but we need to generate a `Type::Instance(str)` constraint that can
+/// be used to narrow down the type of the first argument.
+fn generate_isinstance_constraint<'db>(
     db: &'db dyn Db,
     classinfo: &Type<'db>,
-    to_constraint: F,
-) -> Option<Type<'db>>
-where
-    F: Fn(ClassLiteralType<'db>) -> Type<'db> + Copy,
-{
+) -> Option<Type<'db>> {
     match classinfo {
+        Type::ClassLiteral(ClassLiteralType { class }) => Some(Type::anonymous_instance(*class)),
         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)?);
+                builder = builder.add(generate_isinstance_constraint(db, element)?);
             }
             Some(builder.build())
         }
-        Type::ClassLiteral(class_literal_type) => Some(to_constraint(*class_literal_type)),
         _ => None,
     }
 }
@@ -257,26 +254,17 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
         expression: Expression<'db>,
         is_positive: bool,
     ) -> Option<NarrowingConstraints<'db>> {
-        fn is_narrowing_target_candidate(expr: &ast::Expr) -> bool {
-            matches!(expr, ast::Expr::Name(_) | ast::Expr::Call(_))
-        }
-
         let ast::ExprCompare {
             range: _,
             left,
             ops,
             comparators,
         } = expr_compare;
-
-        // Performance optimization: early return if there are no potential narrowing targets.
-        if !is_narrowing_target_candidate(left)
-            && comparators
-                .iter()
-                .all(|c| !is_narrowing_target_candidate(c))
-        {
+        if !left.is_name_expr() && comparators.iter().all(|c| !c.is_name_expr()) {
+            // If none of the comparators are name expressions,
+            // we have no symbol to narrow down the type of.
             return None;
         }
-
         if !is_positive && comparators.len() > 1 {
             // We can't negate a constraint made by a multi-comparator expression, since we can't
             // know which comparison part is the one being negated.
@@ -292,85 +280,42 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
             .tuple_windows::<(&ruff_python_ast::Expr, &ruff_python_ast::Expr)>();
         let mut constraints = NarrowingConstraints::default();
         for (op, (left, right)) in std::iter::zip(&**ops, comparator_tuples) {
-            let rhs_ty = inference.expression_ty(right.scoped_expression_id(self.db, scope));
+            if let ast::Expr::Name(ast::ExprName {
+                range: _,
+                id,
+                ctx: _,
+            }) = left
+            {
+                // SAFETY: we should always have a symbol for every Name node.
+                let symbol = self.symbols().symbol_id_by_name(id).unwrap();
+                let rhs_ty = inference.expression_ty(right.scoped_ast_id(self.db, scope));
 
-            match left {
-                ast::Expr::Name(ast::ExprName {
-                    range: _,
-                    id,
-                    ctx: _,
-                }) => {
-                    let symbol = self
-                        .symbols()
-                        .symbol_id_by_name(id)
-                        .expect("Should always have a symbol for every Name node");
-
-                    match if is_positive { *op } else { op.negate() } {
-                        ast::CmpOp::IsNot => {
-                            if rhs_ty.is_singleton(self.db) {
-                                let ty = IntersectionBuilder::new(self.db)
-                                    .add_negative(rhs_ty)
-                                    .build();
-                                constraints.insert(symbol, ty);
-                            } else {
-                                // Non-singletons cannot be safely narrowed using `is not`
-                            }
+                match if is_positive { *op } else { op.negate() } {
+                    ast::CmpOp::IsNot => {
+                        if rhs_ty.is_singleton(self.db) {
+                            let ty = IntersectionBuilder::new(self.db)
+                                .add_negative(rhs_ty)
+                                .build();
+                            constraints.insert(symbol, ty);
+                        } else {
+                            // Non-singletons cannot be safely narrowed using `is not`
                         }
-                        ast::CmpOp::Is => {
-                            constraints.insert(symbol, rhs_ty);
-                        }
-                        ast::CmpOp::NotEq => {
-                            if rhs_ty.is_single_valued(self.db) {
-                                let ty = IntersectionBuilder::new(self.db)
-                                    .add_negative(rhs_ty)
-                                    .build();
-                                constraints.insert(symbol, ty);
-                            }
-                        }
-                        _ => {
-                            // TODO other comparison types
+                    }
+                    ast::CmpOp::Is => {
+                        constraints.insert(symbol, rhs_ty);
+                    }
+                    ast::CmpOp::NotEq => {
+                        if rhs_ty.is_single_valued(self.db) {
+                            let ty = IntersectionBuilder::new(self.db)
+                                .add_negative(rhs_ty)
+                                .build();
+                            constraints.insert(symbol, ty);
                         }
                     }
+                    _ => {
+                        // TODO other comparison types
+                    }
                 }
-                ast::Expr::Call(ast::ExprCall {
-                    range: _,
-                    func: callable,
-                    arguments:
-                        ast::Arguments {
-                            args,
-                            keywords,
-                            range: _,
-                        },
-                }) if rhs_ty.is_class_literal() && keywords.is_empty() => {
-                    let [ast::Expr::Name(ast::ExprName { id, .. })] = &**args else {
-                        continue;
-                    };
-
-                    let is_valid_constraint = if is_positive {
-                        op == &ast::CmpOp::Is
-                    } else {
-                        op == &ast::CmpOp::IsNot
-                    };
-
-                    if !is_valid_constraint {
-                        continue;
-                    }
-
-                    let callable_ty =
-                        inference.expression_ty(callable.scoped_expression_id(self.db, scope));
-
-                    if callable_ty
-                        .into_class_literal()
-                        .is_some_and(|c| c.class.is_known(self.db, KnownClass::Type))
-                    {
-                        let symbol = self
-                            .symbols()
-                            .symbol_id_by_name(id)
-                            .expect("Should always have a symbol for every Name node");
-                        constraints.insert(symbol, rhs_ty.to_instance(self.db));
-                    }
-                }
-                _ => {}
             }
         }
         Some(constraints)
@@ -385,49 +330,34 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
         let scope = self.scope();
         let inference = infer_expression_types(self.db, expression);
 
-        // TODO: add support for PEP 604 union types on the right hand side of `isinstance`
-        // and `issubclass`, for example `isinstance(x, str | (int | float))`.
-        match inference
-            .expression_ty(expr_call.func.scoped_expression_id(self.db, scope))
+        if let Some(func_type) = inference
+            .expression_ty(expr_call.func.scoped_ast_id(self.db, scope))
             .into_function_literal()
-            .and_then(|f| f.known(self.db))
-            .and_then(KnownFunction::constraint_function)
         {
-            Some(function) if expr_call.arguments.keywords.is_empty() => {
-                if let [ast::Expr::Name(ast::ExprName { id, .. }), class_info] =
-                    &*expr_call.arguments.args
+            if func_type.is_known(self.db, KnownFunction::IsInstance)
+                && expr_call.arguments.keywords.is_empty()
+            {
+                if let [ast::Expr::Name(ast::ExprName { id, .. }), rhs] = &*expr_call.arguments.args
                 {
                     let symbol = self.symbols().symbol_id_by_name(id).unwrap();
 
-                    let class_info_ty =
-                        inference.expression_ty(class_info.scoped_expression_id(self.db, scope));
+                    let rhs_type = inference.expression_ty(rhs.scoped_ast_id(self.db, scope));
 
-                    let to_constraint = match function {
-                        KnownConstraintFunction::IsInstance => {
-                            |class_literal: ClassLiteralType<'db>| {
-                                Type::instance(class_literal.class)
-                            }
+                    // TODO: add support for PEP 604 union types on the right hand side:
+                    // isinstance(x, str | (int | float))
+                    if let Some(mut constraint) = generate_isinstance_constraint(self.db, &rhs_type)
+                    {
+                        if !is_positive {
+                            constraint = constraint.negate(self.db);
                         }
-                        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
-                        },
-                    )
-                } else {
-                    None
+                        let mut constraints = NarrowingConstraints::default();
+                        constraints.insert(symbol, constraint);
+                        return Some(constraints);
+                    }
                 }
             }
-            _ => None,
         }
+        None
     }
 
     fn evaluate_match_pattern_singleton(
@@ -466,7 +396,7 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
             // filter our arms with statically known truthiness
             .filter(|expr| {
                 inference
-                    .expression_ty(expr.scoped_expression_id(self.db, scope))
+                    .expression_ty(expr.scoped_ast_id(self.db, scope))
                     .bool(self.db)
                     != match expr_bool_op.op {
                         BoolOp::And => Truthiness::AlwaysTrue,

crates/red_knot_python_semantic/src/types/signatures.rs

@@ -1,479 +0,0 @@
-#![allow(dead_code)]
-use super::{definition_expression_ty, Type};
-use crate::Db;
-use crate::{semantic_index::definition::Definition, types::todo_type};
-use ruff_python_ast::{self as ast, name::Name};
-
-/// A typed callable signature.
-#[derive(Clone, Debug, PartialEq, Eq)]
-pub(crate) struct Signature<'db> {
-    parameters: Parameters<'db>,
-
-    /// Annotated return type (Unknown if no annotation.)
-    pub(crate) return_ty: Type<'db>,
-}
-
-impl<'db> Signature<'db> {
-    /// Return a todo signature: (*args: Todo, **kwargs: Todo) -> Todo
-    pub(crate) fn todo() -> Self {
-        Self {
-            parameters: Parameters::todo(),
-            return_ty: todo_type!("return type"),
-        }
-    }
-
-    /// Return a typed signature from a function definition.
-    pub(super) fn from_function(
-        db: &'db dyn 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())
-                }
-            })
-            .unwrap_or(Type::Unknown);
-
-        Self {
-            parameters: Parameters::from_parameters(
-                db,
-                definition,
-                function_node.parameters.as_ref(),
-            ),
-            return_ty,
-        }
-    }
-}
-
-/// 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 {
-            variadic: Some(Parameter {
-                name: Some(Name::new_static("args")),
-                annotated_ty: todo_type!(),
-            }),
-            keywords: Some(Parameter {
-                name: Some(Name::new_static("kwargs")),
-                annotated_ty: todo_type!(),
-            }),
-            ..Default::default()
-        }
-    }
-
-    fn from_parameters(
-        db: &'db dyn Db,
-        definition: Definition<'db>,
-        parameters: &'db ast::Parameters,
-    ) -> Self {
-        let ast::Parameters {
-            posonlyargs,
-            args,
-            vararg,
-            kwonlyargs,
-            kwarg,
-            range: _,
-        } = parameters;
-        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(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(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 (Unknown if no annotation.)
-    annotated_ty: Type<'db>,
-}
-
-impl<'db> Parameter<'db> {
-    fn from_node(
-        db: &'db dyn Db,
-        definition: Definition<'db>,
-        parameter: &'db ast::Parameter,
-    ) -> Self {
-        Parameter {
-            name: Some(parameter.name.id.clone()),
-            annotated_ty: parameter
-                .annotation
-                .as_deref()
-                .map(|annotation| definition_expression_ty(db, definition, annotation))
-                .unwrap_or(Type::Unknown),
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-    use crate::db::tests::TestDb;
-    use crate::program::{Program, SearchPathSettings};
-    use crate::python_version::PythonVersion;
-    use crate::types::{global_symbol, FunctionType};
-    use crate::ProgramSettings;
-    use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
-
-    pub(crate) fn setup_db() -> TestDb {
-        let db = TestDb::new();
-
-        let src_root = SystemPathBuf::from("/src");
-        db.memory_file_system()
-            .create_directory_all(&src_root)
-            .unwrap();
-
-        Program::from_settings(
-            &db,
-            &ProgramSettings {
-                target_version: PythonVersion::default(),
-                search_paths: SearchPathSettings::new(src_root),
-            },
-        )
-        .expect("Valid search path settings");
-
-        db
-    }
-
-    #[track_caller]
-    fn get_function_f<'db>(db: &'db TestDb, file: &'static str) -> FunctionType<'db> {
-        let module = ruff_db::files::system_path_to_file(db, file).unwrap();
-        global_symbol(db, module, "f")
-            .expect_type()
-            .expect_function_literal()
-    }
-
-    #[track_caller]
-    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]
-    fn empty() {
-        let mut db = setup_db();
-        db.write_dedented("/src/a.py", "def f(): ...").unwrap();
-        let func = get_function_f(&db, "/src/a.py");
-
-        let sig = func.internal_signature(&db);
-
-        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]
-    #[allow(clippy::many_single_char_names)]
-    fn full() {
-        let mut db = setup_db();
-        db.write_dedented(
-            "/src/a.py",
-            "
-            def f(a, b: int, c = 1, d: int = 2, /,
-                  e = 3, f: Literal[4] = 4, *args: object,
-                  g = 5, h: Literal[6] = 6, **kwargs: str) -> bytes: ...
-            ",
-        )
-        .unwrap();
-        let func = get_function_f(&db, "/src/a.py");
-
-        let sig = func.internal_signature(&db);
-
-        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]
-    fn not_deferred() {
-        let mut db = setup_db();
-        db.write_dedented(
-            "/src/a.py",
-            "
-            class A: ...
-            class B: ...
-
-            alias = A
-
-            def f(a: alias): ...
-
-            alias = B
-            ",
-        )
-        .unwrap();
-        let func = get_function_f(&db, "/src/a.py");
-
-        let sig = func.internal_signature(&db);
-
-        let [a] = &sig.parameters.positional_or_keyword[..] else {
-            panic!("expected one positional-or-keyword parameter");
-        };
-        // Parameter resolution not deferred; we should see A not B
-        assert_param_with_default(&db, a, "a", "A", None);
-    }
-
-    #[test]
-    fn deferred_in_stub() {
-        let mut db = setup_db();
-        db.write_dedented(
-            "/src/a.pyi",
-            "
-            class A: ...
-            class B: ...
-
-            alias = A
-
-            def f(a: alias): ...
-
-            alias = B
-            ",
-        )
-        .unwrap();
-        let func = get_function_f(&db, "/src/a.pyi");
-
-        let sig = func.internal_signature(&db);
-
-        let [a] = &sig.parameters.positional_or_keyword[..] else {
-            panic!("expected one positional-or-keyword parameter");
-        };
-        // Parameter resolution deferred; we should see B
-        assert_param_with_default(&db, a, "a", "B", None);
-    }
-
-    #[test]
-    fn generic_not_deferred() {
-        let mut db = setup_db();
-        db.write_dedented(
-            "/src/a.py",
-            "
-            class A: ...
-            class B: ...
-
-            alias = A
-
-            def f[T](a: alias, b: T) -> T: ...
-
-            alias = B
-            ",
-        )
-        .unwrap();
-        let func = get_function_f(&db, "/src/a.py");
-
-        let sig = func.internal_signature(&db);
-
-        let [a, b] = &sig.parameters.positional_or_keyword[..] else {
-            panic!("expected two positional-or-keyword parameters");
-        };
-        // TODO resolution should not be deferred; we should see A not B
-        assert_param_with_default(&db, a, "a", "B", None);
-        assert_param_with_default(&db, b, "b", "T", None);
-    }
-
-    #[test]
-    fn generic_deferred_in_stub() {
-        let mut db = setup_db();
-        db.write_dedented(
-            "/src/a.pyi",
-            "
-            class A: ...
-            class B: ...
-
-            alias = A
-
-            def f[T](a: alias, b: T) -> T: ...
-
-            alias = B
-            ",
-        )
-        .unwrap();
-        let func = get_function_f(&db, "/src/a.pyi");
-
-        let sig = func.internal_signature(&db);
-
-        let [a, b] = &sig.parameters.positional_or_keyword[..] else {
-            panic!("expected two positional-or-keyword parameters");
-        };
-        // Parameter resolution deferred; we should see B
-        assert_param_with_default(&db, a, "a", "B", None);
-        assert_param_with_default(&db, b, "b", "T", None);
-    }
-
-    #[test]
-    fn external_signature_no_decorator() {
-        let mut db = setup_db();
-        db.write_dedented(
-            "/src/a.py",
-            "
-            def f(a: int) -> int: ...
-            ",
-        )
-        .unwrap();
-        let func = get_function_f(&db, "/src/a.py");
-
-        let expected_sig = func.internal_signature(&db);
-
-        // With no decorators, internal and external signature are the same
-        assert_eq!(func.signature(&db), &expected_sig);
-    }
-
-    #[test]
-    fn external_signature_decorated() {
-        let mut db = setup_db();
-        db.write_dedented(
-            "/src/a.py",
-            "
-            def deco(func): ...
-
-            @deco
-            def f(a: int) -> int: ...
-            ",
-        )
-        .unwrap();
-        let func = get_function_f(&db, "/src/a.py");
-
-        let expected_sig = Signature::todo();
-
-        // With no decorators, internal and external signature are the same
-        assert_eq!(func.signature(&db), &expected_sig);
-    }
-}

crates/red_knot_python_semantic/src/types/string_annotation.rs

@@ -1,77 +0,0 @@
-use ruff_db::files::File;
-use ruff_db::source::source_text;
-use ruff_python_ast::str::raw_contents;
-use ruff_python_ast::{self as ast, ModExpression, StringFlags};
-use ruff_python_parser::{parse_expression_range, Parsed};
-use ruff_text_size::Ranged;
-
-use crate::types::diagnostic::{TypeCheckDiagnostics, TypeCheckDiagnosticsBuilder};
-use crate::Db;
-
-type AnnotationParseResult = Result<Parsed<ModExpression>, TypeCheckDiagnostics>;
-
-/// Parses the given expression as a string annotation.
-pub(crate) fn parse_string_annotation(
-    db: &dyn Db,
-    file: File,
-    string_expr: &ast::ExprStringLiteral,
-) -> AnnotationParseResult {
-    let _span = tracing::trace_span!("parse_string_annotation", string=?string_expr.range(), file=%file.path(db)).entered();
-
-    let source = source_text(db.upcast(), file);
-    let node_text = &source[string_expr.range()];
-    let mut diagnostics = TypeCheckDiagnosticsBuilder::new(db, file);
-
-    if let [string_literal] = string_expr.value.as_slice() {
-        let prefix = string_literal.flags.prefix();
-        if prefix.is_raw() {
-            diagnostics.add(
-                string_literal.into(),
-                "annotation-raw-string",
-                format_args!("Type expressions cannot use raw string literal"),
-            );
-        // Compare the raw contents (without quotes) of the expression with the parsed contents
-        // contained in the string literal.
-        } else if raw_contents(node_text)
-            .is_some_and(|raw_contents| raw_contents == string_literal.as_str())
-        {
-            let range_excluding_quotes = string_literal
-                .range()
-                .add_start(string_literal.flags.opener_len())
-                .sub_end(string_literal.flags.closer_len());
-
-            // TODO: Support multiline strings like:
-            // ```py
-            // x: """
-            //     int
-            //     | float
-            // """ = 1
-            // ```
-            match parse_expression_range(source.as_str(), range_excluding_quotes) {
-                Ok(parsed) => return Ok(parsed),
-                Err(parse_error) => diagnostics.add(
-                    string_literal.into(),
-                    "forward-annotation-syntax-error",
-                    format_args!("Syntax error in forward annotation: {}", parse_error.error),
-                ),
-            }
-        } else {
-            // The raw contents of the string doesn't match the parsed content. This could be the
-            // case for annotations that contain escape sequences.
-            diagnostics.add(
-                string_expr.into(),
-                "annotation-escape-character",
-                format_args!("Type expressions cannot contain escape characters"),
-            );
-        }
-    } else {
-        // String is implicitly concatenated.
-        diagnostics.add(
-            string_expr.into(),
-            "annotation-implicit-concat",
-            format_args!("Type expressions cannot span multiple string literals"),
-        );
-    }
-
-    Err(diagnostics.finish())
-}

crates/red_knot_python_semantic/src/types/unpacker.rs

@@ -4,16 +4,16 @@ use ruff_db::files::File;
 use ruff_python_ast::{self as ast, AnyNodeRef};
 use rustc_hash::FxHashMap;
 
-use crate::semantic_index::ast_ids::{HasScopedExpressionId, ScopedExpressionId};
+use crate::semantic_index::ast_ids::{HasScopedAstId, ScopedExpressionId};
 use crate::semantic_index::symbol::ScopeId;
-use crate::types::{todo_type, Type, TypeCheckDiagnostics, TypeCheckDiagnosticsBuilder};
+use crate::types::{TupleType, Type};
 use crate::Db;
 
 /// Unpacks the value expression type to their respective targets.
 pub(crate) struct Unpacker<'db> {
     db: &'db dyn Db,
     targets: FxHashMap<ScopedExpressionId, Type<'db>>,
-    diagnostics: TypeCheckDiagnosticsBuilder<'db>,
+    file: File,
 }
 
 impl<'db> Unpacker<'db> {
@@ -21,7 +21,7 @@ impl<'db> Unpacker<'db> {
         Self {
             db,
             targets: FxHashMap::default(),
-            diagnostics: TypeCheckDiagnosticsBuilder::new(db, file),
+            file,
         }
     }
 
@@ -29,7 +29,7 @@ impl<'db> Unpacker<'db> {
         match target {
             ast::Expr::Name(target_name) => {
                 self.targets
-                    .insert(target_name.scoped_expression_id(self.db, scope), value_ty);
+                    .insert(target_name.scoped_ast_id(self.db, scope), value_ty);
             }
             ast::Expr::Starred(ast::ExprStarred { value, .. }) => {
                 self.unpack(value, value_ty, scope);
@@ -59,7 +59,7 @@ impl<'db> Unpacker<'db> {
                             // TODO: Combine the types into a list type. If the
                             // starred_element_types is empty, then it should be `List[Any]`.
                             // combine_types(starred_element_types);
-                            element_types.push(todo_type!("starred unpacking"));
+                            element_types.push(Type::Todo);
 
                             element_types.extend_from_slice(
                                 // SAFETY: Safe because of the length check above.
@@ -72,7 +72,7 @@ impl<'db> Unpacker<'db> {
                             // index.
                             element_types.resize(elts.len() - 1, Type::Unknown);
                             // TODO: This should be `list[Unknown]`
-                            element_types.insert(starred_index, todo_type!("starred unpacking"));
+                            element_types.insert(starred_index, Type::Todo);
                             Cow::Owned(element_types)
                         }
                     } else {
@@ -93,19 +93,22 @@ impl<'db> Unpacker<'db> {
                     // further and deconstruct to an array of `StringLiteral` 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.
-                    let value_ty = Type::tuple(
+                    let value_ty = Type::Tuple(TupleType::new(
                         self.db,
-                        &vec![Type::LiteralString; string_literal_ty.len(self.db)],
-                    );
+                        vec![Type::LiteralString; string_literal_ty.len(self.db)]
+                            .into_boxed_slice(),
+                    ));
                     self.unpack(target, value_ty, scope);
                 }
                 _ => {
                     let value_ty = if value_ty.is_literal_string() {
                         Type::LiteralString
                     } else {
-                        value_ty
-                            .iterate(self.db)
-                            .unwrap_with_diagnostic(AnyNodeRef::from(target), &mut self.diagnostics)
+                        value_ty.iterate(self.db).unwrap_with_diagnostic(
+                            self.db,
+                            AnyNodeRef::from(target),
+                            self.file,
+                        )
                     };
                     for element in elts {
                         self.unpack(element, value_ty, scope);
@@ -119,7 +122,6 @@ impl<'db> Unpacker<'db> {
     pub(crate) fn finish(mut self) -> UnpackResult<'db> {
         self.targets.shrink_to_fit();
         UnpackResult {
-            diagnostics: self.diagnostics.finish(),
             targets: self.targets,
         }
     }
@@ -128,15 +130,10 @@ impl<'db> Unpacker<'db> {
 #[derive(Debug, Default, PartialEq, Eq)]
 pub(crate) struct UnpackResult<'db> {
     targets: FxHashMap<ScopedExpressionId, Type<'db>>,
-    diagnostics: TypeCheckDiagnostics,
 }
 
 impl<'db> UnpackResult<'db> {
     pub(crate) fn get(&self, expr_id: ScopedExpressionId) -> Option<Type<'db>> {
         self.targets.get(&expr_id).copied()
     }
-
-    pub(crate) fn diagnostics(&self) -> &TypeCheckDiagnostics {
-        &self.diagnostics
-    }
 }

crates/red_knot_python_semantic/tests/mdtest.rs

@@ -1,7 +1,6 @@
-use std::ffi::OsStr;
-use std::path::Path;
-
 use dir_test::{dir_test, Fixture};
+use red_knot_test::run;
+use std::path::Path;
 
 /// See `crates/red_knot_test/README.md` for documentation on these tests.
 #[dir_test(
@@ -10,16 +9,16 @@ use dir_test::{dir_test, Fixture};
 )]
 #[allow(clippy::needless_pass_by_value)]
 fn mdtest(fixture: Fixture<&str>) {
-    let fixture_path = Path::new(fixture.path());
-    let crate_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
-    let workspace_root = crate_dir.parent().and_then(Path::parent).unwrap();
+    let path = fixture.path();
 
-    let long_title = fixture_path
-        .strip_prefix(workspace_root)
-        .unwrap()
-        .to_str()
+    let crate_dir = Path::new(env!("CARGO_MANIFEST_DIR"))
+        .join("resources/mdtest")
+        .canonicalize()
         .unwrap();
-    let short_title = fixture_path.file_name().and_then(OsStr::to_str).unwrap();
 
-    red_knot_test::run(fixture_path, long_title, short_title);
+    let relative_path = path
+        .strip_prefix(crate_dir.to_str().unwrap())
+        .unwrap_or(path);
+
+    run(Path::new(path), relative_path);
 }

crates/red_knot_server/src/server/api/requests/diagnostic.rs

@@ -7,13 +7,14 @@ use lsp_types::{
     RelatedFullDocumentDiagnosticReport, Url,
 };
 
-use crate::edit::ToRangeExt;
+use red_knot_workspace::db::{Db, RootDatabase};
+use ruff_db::diagnostic::{CompileDiagnostic, Diagnostic as _, Severity};
+use ruff_db::source::{line_index, source_text};
+
+use crate::edit::ToRangeExt as _;
 use crate::server::api::traits::{BackgroundDocumentRequestHandler, RequestHandler};
 use crate::server::{client::Notifier, Result};
 use crate::session::DocumentSnapshot;
-use red_knot_workspace::db::{Db, RootDatabase};
-use ruff_db::diagnostic::Severity;
-use ruff_db::source::{line_index, source_text};
 
 pub(crate) struct DocumentDiagnosticRequestHandler;
 
@@ -72,7 +73,7 @@ fn compute_diagnostics(snapshot: &DocumentSnapshot, db: &RootDatabase) -> Vec<Di
 
 fn to_lsp_diagnostic(
     db: &dyn Db,
-    diagnostic: &dyn ruff_db::diagnostic::Diagnostic,
+    diagnostic: &CompileDiagnostic,
     encoding: crate::PositionEncoding,
 ) -> Diagnostic {
     let range = if let Some(range) = diagnostic.range() {

crates/red_knot_server/src/session.rs

@@ -68,7 +68,7 @@ impl Session {
             let system = LSPSystem::new(index.clone());
 
             // TODO(dhruvmanila): Get the values from the client settings
-            let metadata = WorkspaceMetadata::discover(system_path, &system, None)?;
+            let metadata = WorkspaceMetadata::from_path(system_path, &system, None)?;
             // TODO(micha): Handle the case where the program settings are incorrect more gracefully.
             workspaces.insert(path, RootDatabase::new(metadata, system)?);
         }

crates/red_knot_server/src/system.rs

@@ -7,8 +7,8 @@ use lsp_types::Url;
 use ruff_db::file_revision::FileRevision;
 use ruff_db::system::walk_directory::WalkDirectoryBuilder;
 use ruff_db::system::{
-    DirectoryEntry, FileType, GlobError, Metadata, OsSystem, PatternError, Result, System,
-    SystemPath, SystemPathBuf, SystemVirtualPath, SystemVirtualPathBuf,
+    DirectoryEntry, FileType, Metadata, OsSystem, Result, System, SystemPath, SystemPathBuf,
+    SystemVirtualPath, SystemVirtualPathBuf,
 };
 use ruff_notebook::{Notebook, NotebookError};
 
@@ -198,16 +198,6 @@ impl System for LSPSystem {
         self.os_system.walk_directory(path)
     }
 
-    fn glob(
-        &self,
-        pattern: &str,
-    ) -> std::result::Result<
-        Box<dyn Iterator<Item = std::result::Result<SystemPathBuf, GlobError>>>,
-        PatternError,
-    > {
-        self.os_system.glob(pattern)
-    }
-
     fn as_any(&self) -> &dyn Any {
         self
     }

crates/red_knot_test/src/diagnostic.rs

@@ -27,9 +27,8 @@ where
             .map(|diagnostic| DiagnosticWithLine {
                 line_number: diagnostic
                     .range()
-                    .map_or(OneIndexed::from_zero_indexed(0), |range| {
-                        line_index.line_index(range.start())
-                    }),
+                    .map(|range| line_index.line_index(range.start()))
+                    .unwrap_or(OneIndexed::from_zero_indexed(0)),
                 diagnostic,
             })
             .collect();
@@ -143,14 +142,13 @@ struct DiagnosticWithLine<T> {
 #[cfg(test)]
 mod tests {
     use crate::db::Db;
-    use crate::diagnostic::Diagnostic;
-    use ruff_db::diagnostic::Severity;
+    use ruff_db::diagnostic::{Diagnostic, Severity};
     use ruff_db::files::{system_path_to_file, File};
     use ruff_db::source::line_index;
     use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
     use ruff_source_file::OneIndexed;
     use ruff_text_size::{TextRange, TextSize};
-    use std::borrow::Cow;
+    use std::fmt::Debug;
 
     #[test]
     fn sort_and_group() {
@@ -167,7 +165,7 @@ mod tests {
 
         let diagnostics: Vec<_> = ranges
             .into_iter()
-            .map(|range| DummyDiagnostic { range, file })
+            .map(|range| DummyDiagnostic { file, range })
             .collect();
 
         let sorted = super::SortedDiagnostics::new(diagnostics, &lines);
@@ -185,8 +183,8 @@ mod tests {
 
     #[derive(Debug)]
     struct DummyDiagnostic {
-        range: TextRange,
         file: File,
+        range: TextRange,
     }
 
     impl Diagnostic for DummyDiagnostic {
@@ -194,8 +192,8 @@ mod tests {
             "dummy"
         }
 
-        fn message(&self) -> Cow<str> {
-            "dummy".into()
+        fn message(&self) -> std::borrow::Cow<str> {
+            "Dummy error".into()
         }
 
         fn file(&self) -> File {

crates/red_knot_test/src/lib.rs

@@ -1,9 +1,8 @@
 use colored::Colorize;
 use parser as test_parser;
 use red_knot_python_semantic::types::check_types;
-use ruff_db::diagnostic::{Diagnostic, ParseDiagnostic};
+use ruff_db::diagnostic::{CompileDiagnostic, Diagnostic as _};
 use ruff_db::files::{system_path_to_file, File, Files};
-use ruff_db::parsed::parsed_module;
 use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
 use ruff_source_file::LineIndex;
 use ruff_text_size::TextSize;
@@ -19,9 +18,9 @@ mod parser;
 ///
 /// Panic on test failure, and print failure details.
 #[allow(clippy::print_stdout)]
-pub fn run(path: &Path, long_title: &str, short_title: &str) {
+pub fn run(path: &Path, title: &str) {
     let source = std::fs::read_to_string(path).unwrap();
-    let suite = match test_parser::parse(short_title, &source) {
+    let suite = match test_parser::parse(title, &source) {
         Ok(suite) => suite,
         Err(err) => {
             panic!("Error parsing `{}`: {err}", path.to_str().unwrap())
@@ -49,8 +48,8 @@ pub fn run(path: &Path, long_title: &str, short_title: &str) {
                     for failure in failures {
                         let absolute_line_number =
                             backtick_line.checked_add(relative_line_number).unwrap();
-                        let line_info = format!("{long_title}:{absolute_line_number}").cyan();
-                        println!("  {line_info} {failure}");
+                        let line_info = format!("{title}:{absolute_line_number}").cyan();
+                        println!("    {line_info} {failure}");
                     }
                 }
             }
@@ -86,24 +85,13 @@ fn run_test(db: &mut db::Db, test: &parser::MarkdownTest) -> Result<(), Failures
     let failures: Failures = test_files
         .into_iter()
         .filter_map(|test_file| {
-            let parsed = parsed_module(db, test_file.file);
-
-            let mut diagnostics: Vec<Box<_>> = parsed
-                .errors()
-                .iter()
-                .cloned()
-                .map(|error| {
-                    let diagnostic: Box<dyn Diagnostic> =
-                        Box::new(ParseDiagnostic::new(test_file.file, error));
-                    diagnostic
-                })
-                .collect();
-
-            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
-            }));
+            let diagnostics: Vec<_> =
+                // The accumulator returns all diagnostics from all files. We're only interested in
+                // diagnostics from this file.
+                check_types::accumulated::<CompileDiagnostic>(db, test_file.file)
+                    .into_iter()
+                    .filter(|diagnostic| diagnostic.file() == test_file.file)
+                    .collect();
 
             match matcher::match_file(db, test_file.file, diagnostics) {
                 Ok(()) => None,

crates/red_knot_test/src/matcher.rs

@@ -180,16 +180,6 @@ where
     }
 }
 
-/// Discard `@Todo`-type metadata from expected types, which is not available
-/// when running in release mode.
-#[cfg(not(debug_assertions))]
-fn discard_todo_metadata(ty: &str) -> std::borrow::Cow<'_, str> {
-    static TODO_METADATA_REGEX: std::sync::LazyLock<regex::Regex> =
-        std::sync::LazyLock::new(|| regex::Regex::new(r"@Todo\([^)]*\)").unwrap());
-
-    TODO_METADATA_REGEX.replace_all(ty, "@Todo")
-}
-
 struct Matcher {
     line_index: LineIndex,
     source: SourceText,
@@ -286,9 +276,6 @@ impl Matcher {
                 }
             }
             Assertion::Revealed(expected_type) => {
-                #[cfg(not(debug_assertions))]
-                let expected_type = discard_todo_metadata(&expected_type);
-
                 let mut matched_revealed_type = None;
                 let mut matched_undefined_reveal = None;
                 let expected_reveal_type_message = format!("Revealed type is `{expected_type}`");
@@ -331,6 +318,7 @@ mod tests {
     use ruff_text_size::TextRange;
     use std::borrow::Cow;
 
+    #[derive(Clone, Debug)]
     struct ExpectedDiagnostic {
         rule: &'static str,
         message: &'static str,
@@ -349,20 +337,20 @@ mod tests {
 
         fn into_diagnostic(self, file: File) -> TestDiagnostic {
             TestDiagnostic {
+                file,
                 rule: self.rule,
                 message: self.message,
                 range: self.range,
-                file,
             }
         }
     }
 
     #[derive(Debug)]
     struct TestDiagnostic {
+        file: File,
         rule: &'static str,
         message: &'static str,
         range: TextRange,
-        file: File,
     }
 
     impl Diagnostic for TestDiagnostic {
@@ -371,7 +359,7 @@ mod tests {
         }
 
         fn message(&self) -> Cow<str> {
-            self.message.into()
+            Cow::Borrowed(self.message)
         }
 
         fn file(&self) -> File {
@@ -397,15 +385,15 @@ mod tests {
         db.write_file("/src/test.py", source).unwrap();
         let file = system_path_to_file(&db, "/src/test.py").unwrap();
 
-        super::match_file(
-            &db,
-            file,
-            diagnostics
-                .into_iter()
-                .map(|diagnostic| diagnostic.into_diagnostic(file)),
-        )
+        let diagnostics: Vec<_> = diagnostics
+            .into_iter()
+            .map(|diagnostic| diagnostic.into_diagnostic(file))
+            .collect();
+
+        super::match_file(&db, file, diagnostics)
     }
 
+    #[track_caller]
     fn assert_fail(result: Result<(), FailuresByLine>, messages: &[(usize, &[&str])]) {
         let Err(failures) = result else {
             panic!("expected a failure");
@@ -428,6 +416,7 @@ mod tests {
         assert_eq!(failures, expected);
     }
 
+    #[track_caller]
     fn assert_ok(result: &Result<(), FailuresByLine>) {
         assert!(result.is_ok(), "{result:?}");
     }

crates/red_knot_vendored/vendor/typeshed/source_commit.txt

@@ -1 +1 @@
-5052fa2f18db4493892e0f2775030683c9d06531
+d262beb07502cda412db2179fb406d45d1a9486f

crates/red_knot_vendored/vendor/typeshed/stdlib/VERSIONS

@@ -24,22 +24,18 @@ _asyncio: 3.0-
 _bisect: 3.0-
 _blake2: 3.6-
 _bootlocale: 3.4-3.9
-_bz2: 3.3-
 _codecs: 3.0-
 _collections_abc: 3.3-
 _compat_pickle: 3.1-
 _compression: 3.5-
-_contextvars: 3.7-
 _csv: 3.0-
 _ctypes: 3.0-
 _curses: 3.0-
-_dbm: 3.0-
 _decimal: 3.3-
 _dummy_thread: 3.0-3.8
 _dummy_threading: 3.0-3.8
 _frozen_importlib: 3.0-
 _frozen_importlib_external: 3.5-
-_gdbm: 3.0-
 _heapq: 3.0-
 _imp: 3.0-
 _interpchannels: 3.13-
@@ -49,7 +45,6 @@ _io: 3.0-
 _json: 3.0-
 _locale: 3.0-
 _lsprof: 3.0-
-_lzma: 3.3-
 _markupbase: 3.0-
 _msi: 3.0-3.12
 _operator: 3.4-
@@ -57,14 +52,12 @@ _osx_support: 3.0-
 _posixsubprocess: 3.2-
 _py_abc: 3.7-
 _pydecimal: 3.5-
-_queue: 3.7-
 _random: 3.0-
 _sitebuiltins: 3.4-
 _socket: 3.0-  # present in 3.0 at runtime, but not in typeshed
 _sqlite3: 3.0-
 _ssl: 3.0-
 _stat: 3.4-
-_struct: 3.0-
 _thread: 3.0-
 _threading_local: 3.0-
 _tkinter: 3.0-

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

@@ -1,18 +0,0 @@
-from _typeshed import ReadableBuffer
-from typing import final
-
-@final
-class BZ2Compressor:
-    def __init__(self, compresslevel: int = 9) -> None: ...
-    def compress(self, data: ReadableBuffer, /) -> bytes: ...
-    def flush(self) -> bytes: ...
-
-@final
-class BZ2Decompressor:
-    def decompress(self, data: ReadableBuffer, max_length: int = -1) -> bytes: ...
-    @property
-    def eof(self) -> bool: ...
-    @property
-    def needs_input(self) -> bool: ...
-    @property
-    def unused_data(self) -> bytes: ...