Add DisplayType trait

.github/actionlint.yaml

@@ -1,9 +0,0 @@
-# Configuration for the actionlint tool, which we run via pre-commit
-# to verify the correctness of the syntax in our GitHub Actions workflows.
-
-self-hosted-runner:
-  # Various runners we use that aren't recognized out-of-the-box by actionlint:
-  labels:
-    - depot-ubuntu-latest-8
-    - depot-ubuntu-22.04-16
-    - windows-latest-xlarge

.github/workflows/build-binaries.yml

@@ -53,7 +53,7 @@ jobs:
           args: --out dist
       - name: "Test sdist"
         run: |
-          pip install dist/"${PACKAGE_NAME}"-*.tar.gz --force-reinstall
+          pip install dist/${PACKAGE_NAME}-*.tar.gz --force-reinstall
           "${MODULE_NAME}" --help
           python -m "${MODULE_NAME}" --help
       - name: "Upload sdist"
@@ -125,7 +125,7 @@ jobs:
           args: --release --locked --out dist
       - name: "Test wheel - aarch64"
         run: |
-          pip install dist/"${PACKAGE_NAME}"-*.whl --force-reinstall
+          pip install dist/${PACKAGE_NAME}-*.whl --force-reinstall
           ruff --help
           python -m ruff --help
       - name: "Upload wheels"
@@ -186,7 +186,7 @@ jobs:
         if: ${{ !startsWith(matrix.platform.target, 'aarch64') }}
         shell: bash
         run: |
-          python -m pip install dist/"${PACKAGE_NAME}"-*.whl --force-reinstall
+          python -m pip install dist/${PACKAGE_NAME}-*.whl --force-reinstall
           "${MODULE_NAME}" --help
           python -m "${MODULE_NAME}" --help
       - name: "Upload wheels"
@@ -236,7 +236,7 @@ jobs:
       - name: "Test wheel"
         if: ${{ startsWith(matrix.target, 'x86_64') }}
         run: |
-          pip install dist/"${PACKAGE_NAME}"-*.whl --force-reinstall
+          pip install dist/${PACKAGE_NAME}-*.whl --force-reinstall
           "${MODULE_NAME}" --help
           python -m "${MODULE_NAME}" --help
       - name: "Upload wheels"

.github/workflows/build-docker.yml

@@ -72,7 +72,7 @@ jobs:
       - name: Normalize Platform Pair (replace / with -)
         run: |
           platform=${{ matrix.platform }}
-          echo "PLATFORM_TUPLE=${platform//\//-}" >> "$GITHUB_ENV"
+          echo "PLATFORM_TUPLE=${platform//\//-}" >> $GITHUB_ENV
 
       # Adapted from https://docs.docker.com/build/ci/github-actions/multi-platform/
       - name: Build and push by digest
@@ -142,10 +142,9 @@ jobs:
         # The printf will expand the base image with the `<RUFF_BASE_IMG>@sha256:<sha256> ...` for each sha256 in the directory
         # The final command becomes `docker buildx imagetools create -t tag1 -t tag2 ... <RUFF_BASE_IMG>@sha256:<sha256_1> <RUFF_BASE_IMG>@sha256:<sha256_2> ...`
         run: |
-          # shellcheck disable=SC2046
           docker buildx imagetools create \
             $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
-            $(printf "${RUFF_BASE_IMG}@sha256:%s " *)
+            $(printf '${RUFF_BASE_IMG}@sha256:%s ' *)
 
   docker-publish-extra:
     name: Publish additional Docker image based on ${{ matrix.image-mapping }}
@@ -204,14 +203,14 @@ jobs:
           TAG_PATTERNS="${TAG_PATTERNS%\\n}"
 
           # Export image cache name
-          echo "IMAGE_REF=${BASE_IMAGE//:/-}" >> "$GITHUB_ENV"
+          echo "IMAGE_REF=${BASE_IMAGE//:/-}" >> $GITHUB_ENV
 
           # Export tag patterns using the multiline env var syntax
           {
             echo "TAG_PATTERNS<<EOF"
             echo -e "${TAG_PATTERNS}"
             echo EOF
-          } >> "$GITHUB_ENV"
+          } >> $GITHUB_ENV
 
       - name: Extract metadata (tags, labels) for Docker
         id: meta
@@ -287,9 +286,7 @@ jobs:
         # The final command becomes `docker buildx imagetools create -t tag1 -t tag2 ... <RUFF_BASE_IMG>@sha256:<sha256_1> <RUFF_BASE_IMG>@sha256:<sha256_2> ...`
         run: |
           readarray -t lines <<< "$DOCKER_METADATA_OUTPUT_ANNOTATIONS"; annotations=(); for line in "${lines[@]}"; do annotations+=(--annotation "$line"); done
-
-          # shellcheck disable=SC2046
           docker buildx imagetools create \
             "${annotations[@]}" \
             $(jq -cr '.tags | map("-t " + .) | join(" ")' <<< "$DOCKER_METADATA_OUTPUT_JSON") \
-            $(printf "${RUFF_BASE_IMG}@sha256:%s " *)
+            $(printf '${RUFF_BASE_IMG}@sha256:%s ' *)

.github/workflows/ci.yaml

@@ -290,9 +290,7 @@ jobs:
           file: "Cargo.toml"
           field: "workspace.package.rust-version"
       - name: "Install Rust toolchain"
-        env:
-          MSRV: ${{ steps.msrv.outputs.value }}
-        run: rustup default "${MSRV}"
+        run: rustup default ${{ steps.msrv.outputs.value }}
       - name: "Install mold"
         uses: rui314/setup-mold@v1
       - name: "Install cargo nextest"
@@ -308,14 +306,13 @@ jobs:
         shell: bash
         env:
           NEXTEST_PROFILE: "ci"
-          MSRV: ${{ steps.msrv.outputs.value }}
-        run: cargo "+${MSRV}" insta test --all-features --unreferenced reject --test-runner nextest
+        run: cargo +${{ steps.msrv.outputs.value }} insta test --all-features --unreferenced reject --test-runner nextest
 
   cargo-fuzz-build:
     name: "cargo fuzz build"
     runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ github.ref == 'refs/heads/main' || needs.determine_changes.outputs.fuzz == 'true' || needs.determine_changes.outputs.code == 'true' }}
+    if: ${{ github.ref == 'refs/heads/main' || needs.determine_changes.outputs.fuzz == 'true' }}
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v4
@@ -357,18 +354,16 @@ jobs:
           name: ruff
           path: ruff-to-test
       - name: Fuzz
-        env:
-          DOWNLOAD_PATH: ${{ steps.download-cached-binary.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x "${DOWNLOAD_PATH}/ruff"
+          chmod +x ${{ steps.download-cached-binary.outputs.download-path }}/ruff
 
           (
             uvx \
-            --python="${PYTHON_VERSION}" \
+            --python=${{ env.PYTHON_VERSION }} \
             --from=./python/py-fuzzer \
             fuzz \
-            --test-executable="${DOWNLOAD_PATH}/ruff" \
+            --test-executable=${{ steps.download-cached-binary.outputs.download-path }}/ruff \
             --bin=ruff \
             0-500
           )
@@ -434,72 +429,64 @@ jobs:
 
       - name: Run `ruff check` stable ecosystem check
         if: ${{ needs.determine_changes.outputs.linter == 'true' }}
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x ./ruff "${DOWNLOAD_PATH}/ruff"
+          chmod +x ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff
 
           # Set pipefail to avoid hiding errors with tee
           set -eo pipefail
 
-          ruff-ecosystem check ./ruff "${DOWNLOAD_PATH}/ruff" --cache ./checkouts --output-format markdown | tee ecosystem-result-check-stable
+          ruff-ecosystem check ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff --cache ./checkouts --output-format markdown | tee ecosystem-result-check-stable
 
-          cat ecosystem-result-check-stable > "$GITHUB_STEP_SUMMARY"
+          cat ecosystem-result-check-stable > $GITHUB_STEP_SUMMARY
           echo "### Linter (stable)"  > ecosystem-result
           cat ecosystem-result-check-stable >> ecosystem-result
           echo "" >> ecosystem-result
 
       - name: Run `ruff check` preview ecosystem check
         if: ${{ needs.determine_changes.outputs.linter == 'true' }}
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x ./ruff "${DOWNLOAD_PATH}/ruff"
+          chmod +x ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff
 
           # Set pipefail to avoid hiding errors with tee
           set -eo pipefail
 
-          ruff-ecosystem check ./ruff "${DOWNLOAD_PATH}/ruff" --cache ./checkouts --output-format markdown --force-preview | tee ecosystem-result-check-preview
+          ruff-ecosystem check ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff --cache ./checkouts --output-format markdown --force-preview | tee ecosystem-result-check-preview
 
-          cat ecosystem-result-check-preview > "$GITHUB_STEP_SUMMARY"
+          cat ecosystem-result-check-preview > $GITHUB_STEP_SUMMARY
           echo "### Linter (preview)" >> ecosystem-result
           cat ecosystem-result-check-preview >> ecosystem-result
           echo "" >> ecosystem-result
 
       - name: Run `ruff format` stable ecosystem check
         if: ${{ needs.determine_changes.outputs.formatter == 'true' }}
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x ./ruff "${DOWNLOAD_PATH}/ruff"
+          chmod +x ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff
 
           # Set pipefail to avoid hiding errors with tee
           set -eo pipefail
 
-          ruff-ecosystem format ./ruff "${DOWNLOAD_PATH}/ruff" --cache ./checkouts --output-format markdown | tee ecosystem-result-format-stable
+          ruff-ecosystem format ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff --cache ./checkouts --output-format markdown | tee ecosystem-result-format-stable
 
-          cat ecosystem-result-format-stable > "$GITHUB_STEP_SUMMARY"
+          cat ecosystem-result-format-stable > $GITHUB_STEP_SUMMARY
           echo "### Formatter (stable)" >> ecosystem-result
           cat ecosystem-result-format-stable >> ecosystem-result
           echo "" >> ecosystem-result
 
       - name: Run `ruff format` preview ecosystem check
         if: ${{ needs.determine_changes.outputs.formatter == 'true' }}
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Make executable, since artifact download doesn't preserve this
-          chmod +x ./ruff "${DOWNLOAD_PATH}/ruff"
+          chmod +x ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff
 
           # Set pipefail to avoid hiding errors with tee
           set -eo pipefail
 
-          ruff-ecosystem format ./ruff "${DOWNLOAD_PATH}/ruff" --cache ./checkouts --output-format markdown --force-preview | tee ecosystem-result-format-preview
+          ruff-ecosystem format ./ruff ${{ steps.ruff-target.outputs.download-path }}/ruff --cache ./checkouts --output-format markdown --force-preview | tee ecosystem-result-format-preview
 
-          cat ecosystem-result-format-preview > "$GITHUB_STEP_SUMMARY"
+          cat ecosystem-result-format-preview > $GITHUB_STEP_SUMMARY
           echo "### Formatter (preview)" >> ecosystem-result
           cat ecosystem-result-format-preview >> ecosystem-result
           echo "" >> ecosystem-result
@@ -554,7 +541,7 @@ jobs:
           args: --out dist
       - name: "Test wheel"
         run: |
-          pip install --force-reinstall --find-links dist "${PACKAGE_NAME}"
+          pip install --force-reinstall --find-links dist ${{ env.PACKAGE_NAME }}
           ruff --help
           python -m ruff --help
       - name: "Remove wheels from cache"
@@ -583,14 +570,13 @@ jobs:
           key: pre-commit-${{ hashFiles('.pre-commit-config.yaml') }}
       - name: "Run pre-commit"
         run: |
-          echo '```console' > "$GITHUB_STEP_SUMMARY"
+          echo '```console' > $GITHUB_STEP_SUMMARY
           # Enable color output for pre-commit and remove it for the summary
-          # Use --hook-stage=manual to enable slower pre-commit hooks that are skipped by default
-          SKIP=cargo-fmt,clippy,dev-generate-all pre-commit run --all-files --show-diff-on-failure --color=always --hook-stage=manual | \
-            tee >(sed -E 's/\x1B\[([0-9]{1,2}(;[0-9]{1,2})*)?[mGK]//g' >> "$GITHUB_STEP_SUMMARY") >&1
-          exit_code="${PIPESTATUS[0]}"
-          echo '```' >> "$GITHUB_STEP_SUMMARY"
-          exit "$exit_code"
+          SKIP=cargo-fmt,clippy,dev-generate-all pre-commit run --all-files --show-diff-on-failure --color=always | \
+            tee >(sed -E 's/\x1B\[([0-9]{1,2}(;[0-9]{1,2})*)?[mGK]//g' >> $GITHUB_STEP_SUMMARY) >&1
+          exit_code=${PIPESTATUS[0]}
+          echo '```' >> $GITHUB_STEP_SUMMARY
+          exit $exit_code
 
   docs:
     name: "mkdocs"
@@ -651,7 +637,7 @@ jobs:
       - name: "Run checks"
         run: scripts/formatter_ecosystem_checks.sh
       - name: "Github step summary"
-        run: cat target/formatter-ecosystem/stats.txt > "$GITHUB_STEP_SUMMARY"
+        run: cat target/formatter-ecosystem/stats.txt > $GITHUB_STEP_SUMMARY
       - name: "Remove checkouts from cache"
         run: rm -r target/formatter-ecosystem
 
@@ -690,13 +676,11 @@ jobs:
           just install
 
       - name: Run ruff-lsp tests
-        env:
-          DOWNLOAD_PATH: ${{ steps.ruff-target.outputs.download-path }}
         run: |
           # Setup development binary
           pip uninstall --yes ruff
-          chmod +x "${DOWNLOAD_PATH}/ruff"
-          export PATH="${DOWNLOAD_PATH}:${PATH}"
+          chmod +x ${{ steps.ruff-target.outputs.download-path }}/ruff
+          export PATH=${{ steps.ruff-target.outputs.download-path }}:$PATH
           ruff version
 
           just test

.github/workflows/daily_fuzz.yaml

@@ -46,7 +46,6 @@ jobs:
         run: cargo build --locked
       - name: Fuzz
         run: |
-          # shellcheck disable=SC2046
           (
             uvx \
             --python=3.12 \

.github/workflows/pr-comment.yaml

@@ -10,11 +10,12 @@ on:
         description: The ecosystem workflow that triggers the workflow run
         required: true
 
+permissions:
+  pull-requests: write
+
 jobs:
   comment:
     runs-on: ubuntu-latest
-    permissions:
-      pull-requests: write
     steps:
       - uses: dawidd6/action-download-artifact@v7
         name: Download pull request number
@@ -29,7 +30,7 @@ jobs:
         run: |
           if [[ -f pr-number ]]
           then
-            echo "pr-number=$(<pr-number)" >> "$GITHUB_OUTPUT"
+            echo "pr-number=$(<pr-number)" >> $GITHUB_OUTPUT
           fi
 
       - uses: dawidd6/action-download-artifact@v7
@@ -65,9 +66,9 @@ jobs:
           cat pr/ecosystem/ecosystem-result >> comment.txt
           echo "" >> comment.txt
 
-          echo 'comment<<EOF' >> "$GITHUB_OUTPUT"
-          cat comment.txt >> "$GITHUB_OUTPUT"
-          echo 'EOF' >> "$GITHUB_OUTPUT"
+          echo 'comment<<EOF' >> $GITHUB_OUTPUT
+          cat comment.txt >> $GITHUB_OUTPUT
+          echo 'EOF' >> $GITHUB_OUTPUT
 
       - name: Find existing comment
         uses: peter-evans/find-comment@v3

.github/workflows/publish-docs.yml

@@ -44,8 +44,8 @@ jobs:
           # Use version as display name for now
           display_name="$version"
 
-          echo "version=$version" >> "$GITHUB_ENV"
-          echo "display_name=$display_name" >> "$GITHUB_ENV"
+          echo "version=$version" >> $GITHUB_ENV
+          echo "display_name=$display_name" >> $GITHUB_ENV
 
       - name: "Set branch name"
         run: |
@@ -55,8 +55,8 @@ jobs:
           # characters disallowed in git branch names with hyphens
           branch_display_name="$(echo "${display_name}" | tr -c '[:alnum:]._' '-' | tr -s '-')"
 
-          echo "branch_name=update-docs-$branch_display_name-$timestamp" >> "$GITHUB_ENV"
-          echo "timestamp=$timestamp" >> "$GITHUB_ENV"
+          echo "branch_name=update-docs-$branch_display_name-$timestamp" >> $GITHUB_ENV
+          echo "timestamp=$timestamp" >> $GITHUB_ENV
 
       - name: "Add SSH key"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
@@ -112,7 +112,7 @@ jobs:
           GITHUB_TOKEN: ${{ secrets.ASTRAL_DOCS_PAT }}
         run: |
           # set the PR title
-          pull_request_title="Update ruff documentation for ${display_name}"
+          pull_request_title="Update ruff documentation for "${display_name}""
 
           # Delete any existing pull requests that are open for this version
           # by checking against pull_request_title because the new PR will
@@ -124,12 +124,10 @@ jobs:
           git push origin "${branch_name}"
 
           # create the PR
-          gh pr create \
-            --base=main \
-            --head="${branch_name}" \
-            --title="${pull_request_title}" \
-            --body="Automated documentation update for ${display_name}" \
-            --label="documentation"
+          gh pr create --base main --head "${branch_name}" \
+            --title "$pull_request_title" \
+            --body "Automated documentation update for "${display_name}"" \
+            --label "documentation"
 
       - name: "Merge Pull Request"
         if: ${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}

.github/workflows/sync_typeshed.yaml

@@ -59,7 +59,7 @@ jobs:
         run: |
           cd ruff
           git push --force origin typeshedbot/sync-typeshed
-          gh pr list --repo "$GITHUB_REPOSITORY" --head typeshedbot/sync-typeshed --json id --jq length | grep 1 && exit 0 # exit if there is existing pr
+          gh pr list --repo $GITHUB_REPOSITORY --head typeshedbot/sync-typeshed --json id --jq length | grep 1 && exit 0 # exit if there is existing pr
           gh pr create --title "Sync vendored typeshed stubs" --body "Close and reopen this PR to trigger CI" --label "internal"
 
   create-issue-on-failure:

.github/zizmor.yml

@@ -1,6 +0,0 @@
-# Configuration for the zizmor static analysis tool, run via pre-commit in CI
-# https://woodruffw.github.io/zizmor/configuration/
-rules:
-  dangerous-triggers:
-    ignore:
-      - pr-comment.yaml

.markdownlint.yaml

@@ -21,11 +21,3 @@ MD014: false
 MD024:
   # Allow when nested under different parents e.g. CHANGELOG.md
   siblings_only: true
-
-# MD046/code-block-style
-#
-# Ignore this because it conflicts with the code block style used in content
-# tabs of mkdocs-material which is to add a blank line after the content title.
-#
-# Ref: https://github.com/astral-sh/ruff/pull/15011#issuecomment-2544790854
-MD046: false

.pre-commit-config.yaml

@@ -2,7 +2,6 @@ fail_fast: false
 
 exclude: |
   (?x)^(
-    .github/workflows/release.yml|
     crates/red_knot_vendored/vendor/.*|
     crates/red_knot_workspace/resources/.*|
     crates/ruff_linter/resources/.*|
@@ -27,8 +26,9 @@ repos:
     hooks:
       - id: mdformat
         additional_dependencies:
-          - mdformat-mkdocs==4.0.0
-          - mdformat-footnote==0.1.1
+          - mdformat-mkdocs
+          - mdformat-admon
+          - mdformat-footnote
         exclude: |
           (?x)^(
             docs/formatter/black\.md
@@ -59,7 +59,7 @@ repos:
           - black==24.10.0
 
   - repo: https://github.com/crate-ci/typos
-    rev: v1.28.3
+    rev: v1.28.2
     hooks:
       - id: typos
 
@@ -73,7 +73,7 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.8.3
+    rev: v0.8.2
     hooks:
       - id: ruff-format
       - id: ruff
@@ -88,37 +88,18 @@ repos:
       - id: prettier
         types: [yaml]
 
-  # zizmor detects security vulnerabilities in GitHub Actions workflows.
-  # Additional configuration for the tool is found in `.github/zizmor.yml`
   - repo: https://github.com/woodruffw/zizmor-pre-commit
-    rev: v0.9.2
+    rev: v0.8.0
     hooks:
       - id: zizmor
+        # `release.yml` is autogenerated by `dist`; security issues need to be fixed there
+        # (https://opensource.axo.dev/cargo-dist/)
+        exclude: .github/workflows/release.yml
 
   - repo: https://github.com/python-jsonschema/check-jsonschema
     rev: 0.30.0
     hooks:
       - id: check-github-workflows
 
-  # `actionlint` hook, for verifying correct syntax in GitHub Actions workflows.
-  # Some additional configuration for `actionlint` can be found in `.github/actionlint.yaml`.
-  - repo: https://github.com/rhysd/actionlint
-    rev: v1.7.4
-    hooks:
-      - id: actionlint
-        stages:
-          # This hook is disabled by default, since it's quite slow.
-          # To run all hooks *including* this hook, use `uvx pre-commit run -a --hook-stage=manual`.
-          # To run *just* this hook, use `uvx pre-commit run -a actionlint --hook-stage=manual`.
-          - manual
-        args:
-          - "-ignore=SC2129" # ignorable stylistic lint from shellcheck
-          - "-ignore=SC2016" # another shellcheck lint: seems to have false positives?
-        additional_dependencies:
-          # actionlint has a shellcheck integration which extracts shell scripts in `run:` steps from GitHub Actions
-          # and checks these with shellcheck. This is arguably its most useful feature,
-          # but the integration only works if shellcheck is installed
-          - "github.com/wasilibs/go-shellcheck/cmd/shellcheck@v0.10.0"
-
 ci:
   skip: [cargo-fmt, dev-generate-all]

CHANGELOG.md

@@ -1,68 +1,5 @@
 # Changelog
 
-## 0.8.4
-
-### Preview features
-
-- \[`airflow`\] Extend `AIR302` with additional functions and classes ([#15015](https://github.com/astral-sh/ruff/pull/15015))
-- \[`airflow`\] Implement `moved-to-provider-in-3` for modules that has been moved to Airflow providers (`AIR303`) ([#14764](https://github.com/astral-sh/ruff/pull/14764))
-- \[`flake8-use-pathlib`\] Extend check for invalid path suffix to include the case `"."` (`PTH210`) ([#14902](https://github.com/astral-sh/ruff/pull/14902))
-- \[`perflint`\] Fix panic in `PERF401` when list variable is after the `for` loop ([#14971](https://github.com/astral-sh/ruff/pull/14971))
-- \[`perflint`\] Simplify finding the loop target in `PERF401` ([#15025](https://github.com/astral-sh/ruff/pull/15025))
-- \[`pylint`\] Preserve original value format (`PLR6104`) ([#14978](https://github.com/astral-sh/ruff/pull/14978))
-- \[`ruff`\] Avoid false positives for `RUF027` for typing context bindings ([#15037](https://github.com/astral-sh/ruff/pull/15037))
-- \[`ruff`\] Check for ambiguous pattern passed to `pytest.raises()` (`RUF043`) ([#14966](https://github.com/astral-sh/ruff/pull/14966))
-
-### Rule changes
-
-- \[`flake8-bandit`\] Check `S105` for annotated assignment ([#15059](https://github.com/astral-sh/ruff/pull/15059))
-- \[`flake8-pyi`\] More autofixes for `redundant-none-literal` (`PYI061`) ([#14872](https://github.com/astral-sh/ruff/pull/14872))
-- \[`pydocstyle`\] Skip leading whitespace for `D403` ([#14963](https://github.com/astral-sh/ruff/pull/14963))
-- \[`ruff`\] Skip `SQLModel` base classes for `mutable-class-default` (`RUF012`) ([#14949](https://github.com/astral-sh/ruff/pull/14949))
-
-### Bug
-
-- \[`perflint`\] Parenthesize walrus expressions in autofix for `manual-list-comprehension` (`PERF401`) ([#15050](https://github.com/astral-sh/ruff/pull/15050))
-
-### Server
-
-- Check diagnostic refresh support from client capability which enables dynamic configuration for various editors ([#15014](https://github.com/astral-sh/ruff/pull/15014))
-
-## 0.8.3
-
-### Preview features
-
-- Fix fstring formatting removing overlong implicit concatenated string in expression part ([#14811](https://github.com/astral-sh/ruff/pull/14811))
-- \[`airflow`\] Add fix to remove deprecated keyword arguments (`AIR302`) ([#14887](https://github.com/astral-sh/ruff/pull/14887))
-- \[`airflow`\]: Extend rule to include deprecated names for Airflow 3.0 (`AIR302`) ([#14765](https://github.com/astral-sh/ruff/pull/14765) and [#14804](https://github.com/astral-sh/ruff/pull/14804))
-- \[`flake8-bugbear`\] Improve error messages for `except*` (`B025`, `B029`, `B030`, `B904`) ([#14815](https://github.com/astral-sh/ruff/pull/14815))
-- \[`flake8-bugbear`\] `itertools.batched()` without explicit `strict` (`B911`) ([#14408](https://github.com/astral-sh/ruff/pull/14408))
-- \[`flake8-use-pathlib`\] Dotless suffix passed to `Path.with_suffix()` (`PTH210`) ([#14779](https://github.com/astral-sh/ruff/pull/14779))
-- \[`pylint`\] Include parentheses and multiple comparators in check for `boolean-chained-comparison` (`PLR1716`) ([#14781](https://github.com/astral-sh/ruff/pull/14781))
-- \[`ruff`\] Do not simplify `round()` calls (`RUF046`) ([#14832](https://github.com/astral-sh/ruff/pull/14832))
-- \[`ruff`\] Don't emit `used-dummy-variable` on function parameters (`RUF052`) ([#14818](https://github.com/astral-sh/ruff/pull/14818))
-- \[`ruff`\] Implement `if-key-in-dict-del` (`RUF051`) ([#14553](https://github.com/astral-sh/ruff/pull/14553))
-- \[`ruff`\] Mark autofix for `RUF052` as always unsafe ([#14824](https://github.com/astral-sh/ruff/pull/14824))
-- \[`ruff`\] Teach autofix for `used-dummy-variable` about TypeVars etc. (`RUF052`) ([#14819](https://github.com/astral-sh/ruff/pull/14819))
-
-### Rule changes
-
-- \[`flake8-bugbear`\] Offer unsafe autofix for `no-explicit-stacklevel` (`B028`) ([#14829](https://github.com/astral-sh/ruff/pull/14829))
-- \[`flake8-pyi`\] Skip all type definitions in `string-or-bytes-too-long` (`PYI053`) ([#14797](https://github.com/astral-sh/ruff/pull/14797))
-- \[`pyupgrade`\] Do not report when a UTF-8 comment is followed by a non-UTF-8 one (`UP009`) ([#14728](https://github.com/astral-sh/ruff/pull/14728))
-- \[`pyupgrade`\] Mark fixes for `convert-typed-dict-functional-to-class` and `convert-named-tuple-functional-to-class` as unsafe if they will remove comments (`UP013`, `UP014`) ([#14842](https://github.com/astral-sh/ruff/pull/14842))
-
-### Bug fixes
-
-- Raise syntax error for mixing `except` and `except*` ([#14895](https://github.com/astral-sh/ruff/pull/14895))
-- \[`flake8-bugbear`\] Fix `B028` to allow `stacklevel` to be explicitly assigned as a positional argument ([#14868](https://github.com/astral-sh/ruff/pull/14868))
-- \[`flake8-bugbear`\] Skip `B028` if `warnings.warn` is called with `*args` or `**kwargs` ([#14870](https://github.com/astral-sh/ruff/pull/14870))
-- \[`flake8-comprehensions`\] Skip iterables with named expressions in `unnecessary-map` (`C417`) ([#14827](https://github.com/astral-sh/ruff/pull/14827))
-- \[`flake8-pyi`\] Also remove `self` and `cls`'s annotation (`PYI034`) ([#14801](https://github.com/astral-sh/ruff/pull/14801))
-- \[`flake8-pytest-style`\] Fix `pytest-parametrize-names-wrong-type` (`PT006`) to edit both `argnames` and `argvalues` if both of them are single-element tuples/lists ([#14699](https://github.com/astral-sh/ruff/pull/14699))
-- \[`perflint`\] Improve autofix for `PERF401` ([#14369](https://github.com/astral-sh/ruff/pull/14369))
-- \[`pylint`\] Fix `PLW1508` false positive for default string created via a mult operation ([#14841](https://github.com/astral-sh/ruff/pull/14841))
-
 ## 0.8.2
 
 ### Preview features

Cargo.lock

@@ -220,9 +220,9 @@ checksum = "7f839cdf7e2d3198ac6ca003fd8ebc61715755f41c1cad15ff13df67531e00ed"
 
 [[package]]
 name = "bstr"
-version = "1.11.1"
+version = "1.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "786a307d683a5bf92e6fd5fd69a7eb613751668d1d8d67d802846dfe367c62c8"
+checksum = "1a68f1f47cdf0ec8ee4b941b2eee2a80cb796db73118c0dd09ac63fbe405be22"
 dependencies = [
  "memchr",
  "regex-automata 0.4.8",
@@ -314,9 +314,9 @@ dependencies = [
 
 [[package]]
 name = "chrono"
-version = "0.4.39"
+version = "0.4.38"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e36cc9d416881d2e24f9a963be5fb1cd90966419ac844274161d10488b3e825"
+checksum = "a21f936df1771bf62b77f047b726c4625ff2e8aa607c01ec06e5a05bd8463401"
 dependencies = [
  "android-tzdata",
  "iana-time-zone",
@@ -465,12 +465,12 @@ checksum = "acbf1af155f9b9ef647e42cdc158db4b64a1b61f743629225fde6f3e0be2a7c7"
 
 [[package]]
 name = "colored"
-version = "2.2.0"
+version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "117725a109d387c937a1533ce01b450cbde6b88abceea8473c4d7a85853cda3c"
+checksum = "cbf2150cce219b664a8a70df7a1f933836724b503f8a413af9365b4dcc4d90b8"
 dependencies = [
  "lazy_static",
- "windows-sys 0.52.0",
+ "windows-sys 0.48.0",
 ]
 
 [[package]]
@@ -923,9 +923,9 @@ checksum = "e8c02a5121d4ea3eb16a80748c74f5549a5665e4c21333c6098f283870fbdea6"
 
 [[package]]
 name = "fern"
-version = "0.7.1"
+version = "0.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "4316185f709b23713e41e3195f90edef7fb00c3ed4adc79769cf09cc762a3b29"
+checksum = "69ff9c9d5fb3e6da8ac2f77ab76fe7e8087d512ce095200f8f29ac5b656cf6dc"
 dependencies = [
  "log",
 ]
@@ -1521,9 +1521,9 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.168"
+version = "0.2.167"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5aaeb2981e0606ca11d79718f8bb01164f1d6ed75080182d3abf017e6d244b6d"
+checksum = "09d6582e104315a817dff97f75133544b2e094ee22447d2acf4a74e189ba06fc"
 
 [[package]]
 name = "libcst"
@@ -2161,7 +2161,7 @@ dependencies = [
  "newtype-uuid",
  "quick-xml",
  "strip-ansi-escapes",
- "thiserror 2.0.7",
+ "thiserror 2.0.6",
  "uuid",
 ]
 
@@ -2288,7 +2288,6 @@ dependencies = [
  "compact_str",
  "countme",
  "dir-test",
- "drop_bomb",
  "hashbrown 0.15.2",
  "indexmap",
  "insta",
@@ -2315,7 +2314,7 @@ dependencies = [
  "static_assertions",
  "tempfile",
  "test-case",
- "thiserror 2.0.7",
+ "thiserror 2.0.6",
  "tracing",
 ]
 
@@ -2412,7 +2411,7 @@ dependencies = [
  "rustc-hash 2.1.0",
  "salsa",
  "serde",
- "thiserror 2.0.7",
+ "thiserror 2.0.6",
  "toml",
  "tracing",
 ]
@@ -2518,7 +2517,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.8.4"
+version = "0.8.2"
 dependencies = [
  "anyhow",
  "argfile",
@@ -2565,7 +2564,7 @@ dependencies = [
  "strum",
  "tempfile",
  "test-case",
- "thiserror 2.0.7",
+ "thiserror 2.0.6",
  "tikv-jemallocator",
  "toml",
  "tracing",
@@ -2635,7 +2634,7 @@ dependencies = [
  "salsa",
  "serde",
  "tempfile",
- "thiserror 2.0.7",
+ "thiserror 2.0.6",
  "tracing",
  "tracing-subscriber",
  "tracing-tree",
@@ -2737,7 +2736,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_linter"
-version = "0.8.4"
+version = "0.8.2"
 dependencies = [
  "aho-corasick",
  "annotate-snippets 0.9.2",
@@ -2787,7 +2786,7 @@ dependencies = [
  "strum",
  "strum_macros",
  "test-case",
- "thiserror 2.0.7",
+ "thiserror 2.0.6",
  "toml",
  "typed-arena",
  "unicode-normalization",
@@ -2821,7 +2820,7 @@ dependencies = [
  "serde_json",
  "serde_with",
  "test-case",
- "thiserror 2.0.7",
+ "thiserror 2.0.6",
  "uuid",
 ]
 
@@ -2893,7 +2892,7 @@ dependencies = [
  "similar",
  "smallvec",
  "static_assertions",
- "thiserror 2.0.7",
+ "thiserror 2.0.6",
  "tracing",
 ]
 
@@ -3026,7 +3025,7 @@ dependencies = [
  "serde",
  "serde_json",
  "shellexpand",
- "thiserror 2.0.7",
+ "thiserror 2.0.6",
  "tracing",
  "tracing-subscriber",
 ]
@@ -3052,7 +3051,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_wasm"
-version = "0.8.4"
+version = "0.8.2"
 dependencies = [
  "console_error_panic_hook",
  "console_log",
@@ -3194,7 +3193,7 @@ checksum = "e86697c916019a8588c99b5fac3cead74ec0b4b819707a682fd4d23fa0ce1ba1"
 [[package]]
 name = "salsa"
 version = "0.18.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=3c7f1694c9efba751dbeeacfbc93b227586e316a#3c7f1694c9efba751dbeeacfbc93b227586e316a"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=254c749b02cde2fd29852a7463a33e800b771758#254c749b02cde2fd29852a7463a33e800b771758"
 dependencies = [
  "append-only-vec",
  "arc-swap",
@@ -3204,7 +3203,6 @@ dependencies = [
  "indexmap",
  "lazy_static",
  "parking_lot",
- "rayon",
  "rustc-hash 2.1.0",
  "salsa-macro-rules",
  "salsa-macros",
@@ -3215,12 +3213,12 @@ dependencies = [
 [[package]]
 name = "salsa-macro-rules"
 version = "0.1.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=3c7f1694c9efba751dbeeacfbc93b227586e316a#3c7f1694c9efba751dbeeacfbc93b227586e316a"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=254c749b02cde2fd29852a7463a33e800b771758#254c749b02cde2fd29852a7463a33e800b771758"
 
 [[package]]
 name = "salsa-macros"
 version = "0.18.0"
-source = "git+https://github.com/salsa-rs/salsa.git?rev=3c7f1694c9efba751dbeeacfbc93b227586e316a#3c7f1694c9efba751dbeeacfbc93b227586e316a"
+source = "git+https://github.com/salsa-rs/salsa.git?rev=254c749b02cde2fd29852a7463a33e800b771758#254c749b02cde2fd29852a7463a33e800b771758"
 dependencies = [
  "heck",
  "proc-macro2",
@@ -3282,9 +3280,9 @@ checksum = "1c107b6f4780854c8b126e228ea8869f4d7b71260f962fefb57b996b8959ba6b"
 
 [[package]]
 name = "serde"
-version = "1.0.216"
+version = "1.0.215"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0b9781016e935a97e8beecf0c933758c97a5520d32930e460142b4cd80c6338e"
+checksum = "6513c1ad0b11a9376da888e3e0baa0077f1aed55c17f50e7b2397136129fb88f"
 dependencies = [
  "serde_derive",
 ]
@@ -3302,9 +3300,9 @@ dependencies = [
 
 [[package]]
 name = "serde_derive"
-version = "1.0.216"
+version = "1.0.215"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "46f859dbbf73865c6627ed570e78961cd3ac92407a2d117204c49232485da55e"
+checksum = "ad1e866f866923f252f05c889987993144fb74e722403468a4ebd70c3cd756c0"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3625,11 +3623,11 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "2.0.7"
+version = "2.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "93605438cbd668185516ab499d589afb7ee1859ea3d5fc8f6b0755e1c7443767"
+checksum = "8fec2a1820ebd077e2b90c4df007bebf344cd394098a13c563957d0afc83ea47"
 dependencies = [
- "thiserror-impl 2.0.7",
+ "thiserror-impl 2.0.6",
 ]
 
 [[package]]
@@ -3645,9 +3643,9 @@ dependencies = [
 
 [[package]]
 name = "thiserror-impl"
-version = "2.0.7"
+version = "2.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e1d8749b4531af2117677a5fcd12b1348a3fe2b81e36e61ffeac5c4aa3273e36"
+checksum = "d65750cab40f4ff1929fb1ba509e9914eb756131cef4210da8d5d700d26f6312"
 dependencies = [
  "proc-macro2",
  "quote",

Cargo.toml

@@ -118,8 +118,7 @@ rand = { version = "0.8.5" }
 rayon = { version = "1.10.0" }
 regex = { version = "1.10.2" }
 rustc-hash = { version = "2.0.0" }
-# When updating salsa, make sure to also update the revision in `fuzz/Cargo.toml`
-salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "3c7f1694c9efba751dbeeacfbc93b227586e316a" }
+salsa = { git = "https://github.com/salsa-rs/salsa.git", rev = "254c749b02cde2fd29852a7463a33e800b771758" }
 schemars = { version = "0.8.16" }
 seahash = { version = "4.1.0" }
 serde = { version = "1.0.197", features = ["derive"] }

README.md

@@ -140,8 +140,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"
 
 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.8.4/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.8.4/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.8.2/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.8.2/install.ps1 | iex"
 ```
 
 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -174,7 +174,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.8.4
+  rev: v0.8.2
   hooks:
     # Run the linter.
     - id: ruff

crates/red_knot/src/main.rs

@@ -5,7 +5,6 @@ use anyhow::{anyhow, Context};
 use clap::Parser;
 use colored::Colorize;
 use crossbeam::channel as crossbeam_channel;
-use python_version::PythonVersion;
 use red_knot_python_semantic::SitePackages;
 use red_knot_server::run_server;
 use red_knot_workspace::db::RootDatabase;
@@ -16,11 +15,12 @@ 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};
 
 mod logging;
-mod python_version;
+mod target_version;
 mod verbosity;
 
 #[derive(Debug, Parser)]
@@ -34,39 +34,54 @@ struct Args {
     #[command(subcommand)]
     pub(crate) command: Option<Command>,
 
-    /// Run the command within the given project directory.
-    ///
-    /// All `pyproject.toml` files will be discovered by walking up the directory tree from the given project directory,
-    /// as will the project's virtual environment (`.venv`) unless the `venv-path` option is set.
-    ///
-    /// Other command-line arguments (such as relative paths) will be resolved relative to the current working directory.
-    #[arg(long, value_name = "PROJECT")]
-    project: Option<SystemPathBuf>,
+    #[arg(
+        long,
+        help = "Changes the current working directory.",
+        long_help = "Changes the current working directory before any specified operations. This affects the workspace and configuration discovery.",
+        value_name = "PATH"
+    )]
+    current_directory: Option<SystemPathBuf>,
 
-    /// Path to the virtual environment the project uses.
-    ///
-    /// If provided, red-knot will use the `site-packages` directory of this virtual environment
-    /// to resolve type information for the project's third-party dependencies.
-    #[arg(long, value_name = "PATH")]
+    #[arg(
+        long,
+        help = "Path to the virtual environment the project uses",
+        long_help = "\
+Path to the virtual environment the project uses. \
+If provided, red-knot will use the `site-packages` directory of this virtual environment \
+to resolve type information for the project's third-party dependencies.",
+        value_name = "PATH"
+    )]
     venv_path: Option<SystemPathBuf>,
 
-    /// Custom directory to use for stdlib typeshed stubs.
-    #[arg(long, value_name = "PATH", alias = "custom-typeshed-dir")]
-    typeshed: Option<SystemPathBuf>,
+    #[arg(
+        long,
+        value_name = "DIRECTORY",
+        help = "Custom directory to use for stdlib typeshed stubs"
+    )]
+    custom_typeshed_dir: Option<SystemPathBuf>,
 
-    /// Additional path to use as a module-resolution source (can be passed multiple times).
-    #[arg(long, value_name = "PATH")]
+    #[arg(
+        long,
+        value_name = "PATH",
+        help = "Additional path to use as a module-resolution source (can be passed multiple times)"
+    )]
     extra_search_path: Option<Vec<SystemPathBuf>>,
 
-    /// Python version to assume when resolving types.
-    #[arg(long, value_name = "VERSION", alias = "target-version")]
-    python_version: Option<PythonVersion>,
+    #[arg(
+        long,
+        help = "Python version to assume when resolving types",
+        value_name = "VERSION"
+    )]
+    target_version: Option<TargetVersion>,
 
     #[clap(flatten)]
     verbosity: Verbosity,
 
-    /// Run in watch mode by re-running whenever files change.
-    #[arg(long, short = 'W')]
+    #[arg(
+        long,
+        help = "Run in watch mode by re-running whenever files change",
+        short = 'W'
+    )]
     watch: bool,
 }
 
@@ -74,8 +89,8 @@ impl Args {
     fn to_configuration(&self, cli_cwd: &SystemPath) -> Configuration {
         let mut configuration = Configuration::default();
 
-        if let Some(python_version) = self.python_version {
-            configuration.python_version = Some(python_version.into());
+        if let Some(target_version) = self.target_version {
+            configuration.target_version = Some(target_version.into());
         }
 
         if let Some(venv_path) = &self.venv_path {
@@ -84,8 +99,9 @@ impl Args {
             });
         }
 
-        if let Some(typeshed) = &self.typeshed {
-            configuration.search_paths.typeshed = Some(SystemPath::absolute(typeshed, cli_cwd));
+        if let Some(custom_typeshed_dir) = &self.custom_typeshed_dir {
+            configuration.search_paths.custom_typeshed =
+                Some(SystemPath::absolute(custom_typeshed_dir, cli_cwd));
         }
 
         if let Some(extra_search_paths) = &self.extra_search_path {
@@ -151,13 +167,15 @@ fn run() -> anyhow::Result<ExitStatus> {
     };
 
     let cwd = args
-        .project
+        .current_directory
         .as_ref()
         .map(|cwd| {
             if cwd.as_std_path().is_dir() {
                 Ok(SystemPath::absolute(cwd, &cli_base_path))
             } else {
-                Err(anyhow!("Provided project path `{cwd}` is not a directory"))
+                Err(anyhow!(
+                    "Provided current-directory path `{cwd}` is not a directory"
+                ))
             }
         })
         .transpose()?
@@ -279,7 +297,7 @@ impl MainLoop {
         while let Ok(message) = self.receiver.recv() {
             match message {
                 MainLoopMessage::CheckWorkspace => {
-                    let db = db.clone();
+                    let db = db.snapshot();
                     let sender = self.sender.clone();
 
                     // Spawn a new task that checks the workspace. This needs to be done in a separate thread

crates/red_knot/src/python_version.rs

@@ -1,68 +0,0 @@
-/// Enumeration of all supported Python versions
-///
-/// TODO: unify with the `PythonVersion` enum in the linter/formatter crates?
-#[derive(Copy, Clone, Hash, Debug, PartialEq, Eq, PartialOrd, Ord, Default, clap::ValueEnum)]
-pub enum PythonVersion {
-    #[value(name = "3.7")]
-    Py37,
-    #[value(name = "3.8")]
-    Py38,
-    #[default]
-    #[value(name = "3.9")]
-    Py39,
-    #[value(name = "3.10")]
-    Py310,
-    #[value(name = "3.11")]
-    Py311,
-    #[value(name = "3.12")]
-    Py312,
-    #[value(name = "3.13")]
-    Py313,
-}
-
-impl PythonVersion {
-    const fn as_str(self) -> &'static str {
-        match self {
-            Self::Py37 => "3.7",
-            Self::Py38 => "3.8",
-            Self::Py39 => "3.9",
-            Self::Py310 => "3.10",
-            Self::Py311 => "3.11",
-            Self::Py312 => "3.12",
-            Self::Py313 => "3.13",
-        }
-    }
-}
-
-impl std::fmt::Display for PythonVersion {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        f.write_str(self.as_str())
-    }
-}
-
-impl From<PythonVersion> for red_knot_python_semantic::PythonVersion {
-    fn from(value: PythonVersion) -> Self {
-        match value {
-            PythonVersion::Py37 => Self::PY37,
-            PythonVersion::Py38 => Self::PY38,
-            PythonVersion::Py39 => Self::PY39,
-            PythonVersion::Py310 => Self::PY310,
-            PythonVersion::Py311 => Self::PY311,
-            PythonVersion::Py312 => Self::PY312,
-            PythonVersion::Py313 => Self::PY313,
-        }
-    }
-}
-
-#[cfg(test)]
-mod tests {
-    use crate::python_version::PythonVersion;
-
-    #[test]
-    fn same_default_as_python_version() {
-        assert_eq!(
-            red_knot_python_semantic::PythonVersion::from(PythonVersion::default()),
-            red_knot_python_semantic::PythonVersion::default()
-        );
-    }
-}

crates/red_knot/src/target_version.rs

@@ -0,0 +1,62 @@
+/// Enumeration of all supported Python versions
+///
+/// TODO: unify with the `PythonVersion` enum in the linter/formatter crates?
+#[derive(Copy, Clone, Hash, Debug, PartialEq, Eq, PartialOrd, Ord, Default, clap::ValueEnum)]
+pub enum TargetVersion {
+    Py37,
+    Py38,
+    #[default]
+    Py39,
+    Py310,
+    Py311,
+    Py312,
+    Py313,
+}
+
+impl TargetVersion {
+    const fn as_str(self) -> &'static str {
+        match self {
+            Self::Py37 => "py37",
+            Self::Py38 => "py38",
+            Self::Py39 => "py39",
+            Self::Py310 => "py310",
+            Self::Py311 => "py311",
+            Self::Py312 => "py312",
+            Self::Py313 => "py313",
+        }
+    }
+}
+
+impl std::fmt::Display for TargetVersion {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.write_str(self.as_str())
+    }
+}
+
+impl From<TargetVersion> for red_knot_python_semantic::PythonVersion {
+    fn from(value: TargetVersion) -> Self {
+        match value {
+            TargetVersion::Py37 => Self::PY37,
+            TargetVersion::Py38 => Self::PY38,
+            TargetVersion::Py39 => Self::PY39,
+            TargetVersion::Py310 => Self::PY310,
+            TargetVersion::Py311 => Self::PY311,
+            TargetVersion::Py312 => Self::PY312,
+            TargetVersion::Py313 => Self::PY313,
+        }
+    }
+}
+
+#[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

@@ -282,7 +282,7 @@ where
         .extra_paths
         .iter()
         .flatten()
-        .chain(search_paths.typeshed.iter())
+        .chain(search_paths.custom_typeshed.iter())
         .chain(search_paths.site_packages.iter().flat_map(|site_packages| {
             if let SitePackages::Known(path) = site_packages {
                 path.as_slice()
@@ -296,7 +296,7 @@ where
     }
 
     let configuration = Configuration {
-        python_version: Some(PythonVersion::PY312),
+        target_version: Some(PythonVersion::PY312),
         search_paths,
     };
 
@@ -888,7 +888,7 @@ fn changed_versions_file() -> anyhow::Result<()> {
             Ok(())
         },
         |root_path, _workspace_path| SearchPathConfiguration {
-            typeshed: Some(root_path.join("typeshed")),
+            custom_typeshed: Some(root_path.join("typeshed")),
             ..SearchPathConfiguration::default()
         },
     )?;

crates/red_knot_python_semantic/Cargo.toml

@@ -26,7 +26,6 @@ bitflags = { workspace = true }
 camino = { workspace = true }
 compact_str = { workspace = true }
 countme = { workspace = true }
-drop_bomb = { workspace = true }
 indexmap = { workspace = true }
 itertools = { workspace = true }
 ordermap = { workspace = true }
@@ -54,8 +53,5 @@ tempfile = { workspace = true }
 quickcheck = { version = "1.0.3", default-features = false }
 quickcheck_macros = { version = "1.0.0" }
 
-[features]
-serde = ["ruff_db/serde", "dep:serde"]
-
 [lints]
 workspace = true

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

@@ -1,94 +0,0 @@
-# `Annotated`
-
-`Annotated` attaches arbitrary metadata to a given type.
-
-## Usages
-
-`Annotated[T, ...]` is equivalent to `T`: All metadata arguments are simply ignored.
-
-```py
-from typing_extensions import Annotated
-
-def _(x: Annotated[int, "foo"]):
-    reveal_type(x)  # revealed: int
-
-def _(x: Annotated[int, lambda: 0 + 1 * 2 // 3, _(4)]):
-    reveal_type(x)  # revealed: int
-
-def _(x: Annotated[int, "arbitrary", "metadata", "elements", "are", "fine"]):
-    reveal_type(x)  # revealed: int
-
-def _(x: Annotated[tuple[str, int], bytes]):
-    reveal_type(x)  # revealed: tuple[str, int]
-```
-
-## Parameterization
-
-It is invalid to parameterize `Annotated` with less than two arguments.
-
-```py
-from typing_extensions import Annotated
-
-# error: [invalid-type-form] "`Annotated` requires at least two arguments when used in an annotation or type expression"
-def _(x: Annotated):
-    reveal_type(x)  # revealed: Unknown
-
-def _(flag: bool):
-    if flag:
-        X = Annotated
-    else:
-        X = bool
-
-    # error: [invalid-type-form] "`Annotated` requires at least two arguments when used in an annotation or type expression"
-    def f(y: X):
-        reveal_type(y)  # revealed: Unknown | bool
-
-# error: [invalid-type-form] "`Annotated` requires at least two arguments when used in an annotation or type expression"
-def _(x: Annotated | bool):
-    reveal_type(x)  # revealed: Unknown | bool
-
-# error: [invalid-type-form]
-def _(x: Annotated[()]):
-    reveal_type(x)  # revealed: Unknown
-
-# error: [invalid-type-form]
-def _(x: Annotated[int]):
-    # `Annotated[T]` is invalid and will raise an error at runtime,
-    # but we treat it the same as `T` to provide better diagnostics later on.
-    # The subscription itself is still reported, regardless.
-    # Same for the `(int,)` form below.
-    reveal_type(x)  # revealed: int
-
-# error: [invalid-type-form]
-def _(x: Annotated[(int,)]):
-    reveal_type(x)  # revealed: int
-```
-
-## Inheritance
-
-### Correctly parameterized
-
-Inheriting from `Annotated[T, ...]` is equivalent to inheriting from `T` itself.
-
-```py
-from typing_extensions import Annotated
-
-# TODO: False positive
-# error: [invalid-base]
-class C(Annotated[int, "foo"]): ...
-
-# TODO: Should be `tuple[Literal[C], Literal[int], Literal[object]]`
-reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Unknown, Literal[object]]
-```
-
-### Not parameterized
-
-```py
-from typing_extensions import Annotated
-
-# At runtime, this is an error.
-# error: [invalid-base]
-class C(Annotated): ...
-
-reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Unknown, Literal[object]]
-```

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

@@ -77,7 +77,7 @@ def _(s: Subclass):
 ```py
 from typing import Any
 
-# error: [invalid-type-form] "Type `typing.Any` expected no type parameter"
+# error: [invalid-type-parameter] "Type `typing.Any` expected no type parameter"
 def f(x: Any[int]):
     reveal_type(x)  # revealed: Unknown
 ```

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

@@ -27,19 +27,19 @@ def f():
 ```py
 from typing_extensions import Literal, LiteralString
 
-bad_union: Literal["hello", LiteralString]  # error: [invalid-type-form]
-bad_nesting: Literal[LiteralString]  # error: [invalid-type-form]
+bad_union: Literal["hello", LiteralString]  # error: [invalid-literal-parameter]
+bad_nesting: Literal[LiteralString]  # error: [invalid-literal-parameter]
 ```
 
-### Parameterized
+### Parametrized
 
-`LiteralString` cannot be parameterized.
+`LiteralString` cannot be parametrized.
 
 ```py
 from typing_extensions import LiteralString
 
-a: LiteralString[str]  # error: [invalid-type-form]
-b: LiteralString["foo"]  # error: [invalid-type-form]
+a: LiteralString[str]  # error: [invalid-type-parameter]
+b: LiteralString["foo"]  # error: [invalid-type-parameter]
 ```
 
 ### As a base class
@@ -73,12 +73,12 @@ qux = (foo, bar)
 reveal_type(qux)  # revealed: tuple[Literal["foo"], Literal["bar"]]
 
 # TODO: Infer "LiteralString"
-reveal_type(foo.join(qux))  # revealed: @Todo(Attribute access on `StringLiteral` types)
+reveal_type(foo.join(qux))  # revealed: @Todo(call todo)
 
 template: LiteralString = "{}, {}"
 reveal_type(template)  # revealed: Literal["{}, {}"]
 # TODO: Infer `LiteralString`
-reveal_type(template.format(foo, bar))  # revealed: @Todo(Attribute access on `StringLiteral` types)
+reveal_type(template.format(foo, bar))  # revealed: @Todo(call todo)
 ```
 
 ### Assignability
@@ -135,7 +135,7 @@ if "" < lorem == "ipsum":
 
 ```toml
 [environment]
-python-version = "3.11"
+target-version = "3.11"
 ```
 
 ```py

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

@@ -21,7 +21,7 @@ reveal_type(stop())
 ```py
 from typing_extensions import NoReturn, Never, Any
 
-# error: [invalid-type-form] "Type `typing.Never` expected no type parameter"
+# error: [invalid-type-parameter] "Type `typing.Never` expected no type parameter"
 x: Never[int]
 a1: NoReturn
 a2: Never
@@ -51,7 +51,7 @@ def f():
 
 ```toml
 [environment]
-python-version = "3.11"
+target-version = "3.11"
 ```
 
 ```py

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

@@ -1,127 +0,0 @@
-# Typing-module aliases to other stdlib classes
-
-The `typing` module has various aliases to other stdlib classes. These are a legacy feature, but
-still need to be supported by a type checker.
-
-## Correspondence
-
-All of the following symbols can be mapped one-to-one with the actual type:
-
-```py
-import typing
-
-def f(
-    list_bare: typing.List,
-    list_parametrized: typing.List[int],
-    dict_bare: typing.Dict,
-    dict_parametrized: typing.Dict[int, str],
-    set_bare: typing.Set,
-    set_parametrized: typing.Set[int],
-    frozen_set_bare: typing.FrozenSet,
-    frozen_set_parametrized: typing.FrozenSet[str],
-    chain_map_bare: typing.ChainMap,
-    chain_map_parametrized: typing.ChainMap[int],
-    counter_bare: typing.Counter,
-    counter_parametrized: typing.Counter[int],
-    default_dict_bare: typing.DefaultDict,
-    default_dict_parametrized: typing.DefaultDict[str, int],
-    deque_bare: typing.Deque,
-    deque_parametrized: typing.Deque[str],
-    ordered_dict_bare: typing.OrderedDict,
-    ordered_dict_parametrized: typing.OrderedDict[int, str],
-):
-    reveal_type(list_bare)  # revealed: list
-    reveal_type(list_parametrized)  # revealed: list
-
-    reveal_type(dict_bare)  # revealed: dict
-    reveal_type(dict_parametrized)  # revealed: dict
-
-    reveal_type(set_bare)  # revealed: set
-    reveal_type(set_parametrized)  # revealed: set
-
-    reveal_type(frozen_set_bare)  # revealed: frozenset
-    reveal_type(frozen_set_parametrized)  # revealed: frozenset
-
-    reveal_type(chain_map_bare)  # revealed: ChainMap
-    reveal_type(chain_map_parametrized)  # revealed: ChainMap
-
-    reveal_type(counter_bare)  # revealed: Counter
-    reveal_type(counter_parametrized)  # revealed: Counter
-
-    reveal_type(default_dict_bare)  # revealed: defaultdict
-    reveal_type(default_dict_parametrized)  # revealed: defaultdict
-
-    reveal_type(deque_bare)  # revealed: deque
-    reveal_type(deque_parametrized)  # revealed: deque
-
-    reveal_type(ordered_dict_bare)  # revealed: OrderedDict
-    reveal_type(ordered_dict_parametrized)  # revealed: OrderedDict
-```
-
-## Inheritance
-
-The aliases can be inherited from. Some of these are still partially or wholly TODOs.
-
-```py
-import typing
-
-####################
-### Built-ins
-
-class ListSubclass(typing.List): ...
-
-# TODO: should have `Generic`, should not have `Unknown`
-# revealed: tuple[Literal[ListSubclass], Literal[list], Unknown, Literal[object]]
-reveal_type(ListSubclass.__mro__)
-
-class DictSubclass(typing.Dict): ...
-
-# TODO: should have `Generic`, should not have `Unknown`
-# revealed: tuple[Literal[DictSubclass], Literal[dict], Unknown, Literal[object]]
-reveal_type(DictSubclass.__mro__)
-
-class SetSubclass(typing.Set): ...
-
-# TODO: should have `Generic`, should not have `Unknown`
-# revealed: tuple[Literal[SetSubclass], Literal[set], Unknown, Literal[object]]
-reveal_type(SetSubclass.__mro__)
-
-class FrozenSetSubclass(typing.FrozenSet): ...
-
-# TODO: should have `Generic`, should not have `Unknown`
-# revealed: tuple[Literal[FrozenSetSubclass], Literal[frozenset], Unknown, Literal[object]]
-reveal_type(FrozenSetSubclass.__mro__)
-
-####################
-### `collections`
-
-class ChainMapSubclass(typing.ChainMap): ...
-
-# TODO: Should be (ChainMapSubclass, ChainMap, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
-# revealed: tuple[Literal[ChainMapSubclass], Literal[ChainMap], Unknown, Literal[object]]
-reveal_type(ChainMapSubclass.__mro__)
-
-class CounterSubclass(typing.Counter): ...
-
-# TODO: Should be (CounterSubclass, Counter, dict, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
-# revealed: tuple[Literal[CounterSubclass], Literal[Counter], Unknown, Literal[object]]
-reveal_type(CounterSubclass.__mro__)
-
-class DefaultDictSubclass(typing.DefaultDict): ...
-
-# TODO: Should be (DefaultDictSubclass, defaultdict, dict, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
-# revealed: tuple[Literal[DefaultDictSubclass], Literal[defaultdict], Unknown, Literal[object]]
-reveal_type(DefaultDictSubclass.__mro__)
-
-class DequeSubclass(typing.Deque): ...
-
-# TODO: Should be (DequeSubclass, deque, MutableSequence, Sequence, Reversible, Collection, Sized, Iterable, Container, Generic, object)
-# revealed: tuple[Literal[DequeSubclass], Literal[deque], Unknown, Literal[object]]
-reveal_type(DequeSubclass.__mro__)
-
-class OrderedDictSubclass(typing.OrderedDict): ...
-
-# TODO: Should be (OrderedDictSubclass, OrderedDict, dict, MutableMapping, Mapping, Collection, Sized, Iterable, Container, Generic, object)
-# revealed: tuple[Literal[OrderedDictSubclass], Literal[OrderedDict], Unknown, Literal[object]]
-reveal_type(OrderedDictSubclass.__mro__)
-```

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

@@ -1,71 +0,0 @@
-# Unsupported special forms
-
-## Not yet supported
-
-Several special forms are unsupported by red-knot currently. However, we also don't emit
-false-positive errors if you use one in an annotation:
-
-```py
-from typing_extensions import Self, TypeVarTuple, Unpack, TypeGuard, TypeIs, Concatenate, ParamSpec, TypeAlias, Callable, TypeVar
-
-P = ParamSpec("P")
-Ts = TypeVarTuple("Ts")
-R_co = TypeVar("R_co", covariant=True)
-
-Alias: TypeAlias = int
-
-def f(*args: Unpack[Ts]) -> tuple[Unpack[Ts]]:
-    # TODO: should understand the annotation
-    reveal_type(args)  # revealed: tuple
-
-    reveal_type(Alias)  # revealed: @Todo(Unsupported or invalid type in a type expression)
-
-def g() -> TypeGuard[int]: ...
-def h() -> TypeIs[int]: ...
-def i(callback: Callable[Concatenate[int, P], R_co], *args: P.args, **kwargs: P.kwargs) -> R_co:
-    # TODO: should understand the annotation
-    reveal_type(args)  # revealed: tuple
-
-    # TODO: should understand the annotation
-    reveal_type(kwargs)  # revealed: dict
-
-    return callback(42, *args, **kwargs)
-
-class Foo:
-    def method(self, x: Self):
-        reveal_type(x)  # revealed: @Todo(Unsupported or invalid type in a type expression)
-```
-
-## Inheritance
-
-You can't inherit from most of these. `typing.Callable` is an exception.
-
-```py
-from typing import Callable
-from typing_extensions import Self, Unpack, TypeGuard, TypeIs, Concatenate
-
-class A(Self): ...  # error: [invalid-base]
-class B(Unpack): ...  # error: [invalid-base]
-class C(TypeGuard): ...  # error: [invalid-base]
-class D(TypeIs): ...  # error: [invalid-base]
-class E(Concatenate): ...  # error: [invalid-base]
-class F(Callable): ...
-
-reveal_type(F.__mro__)  # revealed: tuple[Literal[F], @Todo(Support for Callable as a base class), Literal[object]]
-```
-
-## Subscriptability
-
-Some of these are not subscriptable:
-
-```py
-from typing_extensions import Self, TypeAlias
-
-X: TypeAlias[T] = int  # error: [invalid-type-form]
-
-class Foo[T]:
-    # error: [invalid-type-form] "Special form `typing.Self` expected no type parameter"
-    # error: [invalid-type-form] "Special form `typing.Self` expected no type parameter"
-    def method(self: Self[int]) -> Self[int]:
-        reveal_type(self)  # revealed: Unknown
-```

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

@@ -1,37 +0,0 @@
-# Unsupported type qualifiers
-
-## Not yet supported
-
-Several type qualifiers are unsupported by red-knot currently. However, we also don't emit
-false-positive errors if you use one in an annotation:
-
-```py
-from typing_extensions import Final, ClassVar, Required, NotRequired, ReadOnly, TypedDict
-
-X: Final = 42
-Y: Final[int] = 42
-
-class Foo:
-    A: ClassVar[int] = 42
-
-# TODO: `TypedDict` is actually valid as a base
-# error: [invalid-base]
-class Bar(TypedDict):
-    x: Required[int]
-    y: NotRequired[str]
-    z: ReadOnly[bytes]
-```
-
-## Inheritance
-
-You can't inherit from a type qualifier.
-
-```py
-from typing_extensions import Final, ClassVar, Required, NotRequired, ReadOnly
-
-class A(Final): ...  # error: [invalid-base]
-class B(ClassVar): ...  # error: [invalid-base]
-class C(Required): ...  # error: [invalid-base]
-class D(NotRequired): ...  # error: [invalid-base]
-class E(ReadOnly): ...  # error: [invalid-base]
-```

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

@@ -67,6 +67,6 @@ def _(flag: bool):
             def __call__(self) -> int: ...
 
     a = NonCallable()
-    # error: "Object of type `Literal[__call__] | Literal[1]` is not callable (due to union element `Literal[1]`)"
-    reveal_type(a())  # revealed: int | Unknown
+    # error: "Object of type `Literal[1] | Literal[__call__]` is not callable (due to union element `Literal[1]`)"
+    reveal_type(a())  # revealed: Unknown | int
 ```

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

@@ -3,43 +3,40 @@
 ## With wildcard
 
 ```py
-def _(target: int):
-    match target:
-        case 1:
-            y = 2
-        case _:
-            y = 3
+match 0:
+    case 1:
+        y = 2
+    case _:
+        y = 3
 
-    reveal_type(y)  # revealed: Literal[2, 3]
+reveal_type(y)  # revealed: Literal[2, 3]
 ```
 
 ## Without wildcard
 
 ```py
-def _(target: int):
-    match target:
-        case 1:
-            y = 2
-        case 2:
-            y = 3
+match 0:
+    case 1:
+        y = 2
+    case 2:
+        y = 3
 
-    # revealed: Literal[2, 3]
-    # error: [possibly-unresolved-reference]
-    reveal_type(y)
+# revealed: Literal[2, 3]
+# error: [possibly-unresolved-reference]
+reveal_type(y)
 ```
 
 ## Basic match
 
 ```py
-def _(target: int):
-    y = 1
-    y = 2
+y = 1
+y = 2
 
-    match target:
-        case 1:
-            y = 3
-        case 2:
-            y = 4
+match 0:
+    case 1:
+        y = 3
+    case 2:
+        y = 4
 
-    reveal_type(y)  # revealed: Literal[2, 3, 4]
+reveal_type(y)  # revealed: Literal[2, 3, 4]
 ```

crates/red_knot_python_semantic/resources/mdtest/declaration/error.md

@@ -19,17 +19,14 @@ def _(flag: bool):
     x = 1  # error: [conflicting-declarations] "Conflicting declared types for `x`: str, int"
 ```
 
-## Incompatible declarations for 2 (out of 3) types
+## Partial declarations
 
 ```py
-def _(flag1: bool, flag2: bool):
-    if flag1:
-        x: str
-    elif flag2:
+def _(flag: bool):
+    if flag:
         x: int
 
-    # Here, the declared type for `x` is `int | str | Unknown`.
-    x = 1  # error: [conflicting-declarations] "Conflicting declared types for `x`: str, int"
+    x = 1  # error: [conflicting-declarations] "Conflicting declared types for `x`: Unknown, int"
 ```
 
 ## Incompatible declarations with bad assignment
@@ -45,31 +42,3 @@ def _(flag: bool):
     # error: [invalid-assignment]
     x = b"foo"
 ```
-
-## No errors
-
-Currently, we avoid raising the conflicting-declarations for the following cases:
-
-### Partial declarations
-
-```py
-def _(flag: bool):
-    if flag:
-        x: int
-
-    x = 1
-```
-
-### Partial declarations in try-except
-
-Refer to <https://github.com/astral-sh/ruff/issues/13966>
-
-```py
-def _():
-    try:
-        x: int = 1
-    except:
-        x = 2
-
-    x = 3
-```

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

@@ -90,83 +90,3 @@ def foo(
         # TODO: should emit a diagnostic here:
         reveal_type(g)  # revealed: @Todo(full tuple[...] support)
 ```
-
-## Object raised is not an exception
-
-```py
-try:
-    raise AttributeError()  # fine
-except:
-    ...
-
-try:
-    raise FloatingPointError  # fine
-except:
-    ...
-
-try:
-    raise 1  # error: [invalid-raise]
-except:
-    ...
-
-try:
-    raise int  # error: [invalid-raise]
-except:
-    ...
-
-def _(e: Exception | type[Exception]):
-    raise e  # fine
-
-def _(e: Exception | type[Exception] | None):
-    raise e  # error: [invalid-raise]
-```
-
-## Exception cause is not an exception
-
-```py
-try:
-    raise EOFError() from GeneratorExit  # fine
-except:
-    ...
-
-try:
-    raise StopIteration from MemoryError()  # fine
-except:
-    ...
-
-try:
-    raise BufferError() from None  # fine
-except:
-    ...
-
-try:
-    raise ZeroDivisionError from False  # error: [invalid-raise]
-except:
-    ...
-
-try:
-    raise SystemExit from bool()  # error: [invalid-raise]
-except:
-    ...
-
-try:
-    raise
-except KeyboardInterrupt as e:  # fine
-    reveal_type(e)  # revealed: KeyboardInterrupt
-    raise LookupError from e  # fine
-
-try:
-    raise
-except int as e:  # error: [invalid-exception-caught]
-    reveal_type(e)  # revealed: Unknown
-    raise KeyError from e
-
-def _(e: Exception | type[Exception]):
-    raise ModuleNotFoundError from e  # fine
-
-def _(e: Exception | type[Exception] | None):
-    raise IndexError from e  # fine
-
-def _(e: int | None):
-    raise IndexError from e  # error: [invalid-raise]
-```

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

@@ -1,12 +1,5 @@
 # `except*`
 
-`except*` is only available in Python 3.11 and later:
-
-```toml
-[environment]
-python-version = "3.11"
-```
-
 ## `except*` with `BaseException`
 
 ```py

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

@@ -25,82 +25,3 @@ reveal_type(D)  # revealed: Literal[C]
 ```py path=b.py
 class C: ...
 ```
-
-## Nested
-
-```py
-import a.b
-
-reveal_type(a.b.C)  # revealed: Literal[C]
-```
-
-```py path=a/__init__.py
-```
-
-```py path=a/b.py
-class C: ...
-```
-
-## Deeply nested
-
-```py
-import a.b.c
-
-reveal_type(a.b.c.C)  # revealed: Literal[C]
-```
-
-```py path=a/__init__.py
-```
-
-```py path=a/b/__init__.py
-```
-
-```py path=a/b/c.py
-class C: ...
-```
-
-## Nested with rename
-
-```py
-import a.b as b
-
-reveal_type(b.C)  # revealed: Literal[C]
-```
-
-```py path=a/__init__.py
-```
-
-```py path=a/b.py
-class C: ...
-```
-
-## Deeply nested with rename
-
-```py
-import a.b.c as c
-
-reveal_type(c.C)  # revealed: Literal[C]
-```
-
-```py path=a/__init__.py
-```
-
-```py path=a/b/__init__.py
-```
-
-```py path=a/b/c.py
-class C: ...
-```
-
-## Unresolvable submodule imports
-
-```py
-# Topmost component resolvable, submodule not resolvable:
-import a.foo  # error: [unresolved-import] "Cannot resolve import `a.foo`"
-
-# Topmost component unresolvable:
-import b.foo  # error: [unresolved-import] "Cannot resolve import `b.foo`"
-```
-
-```py path=a/__init__.py
-```

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

@@ -3,6 +3,6 @@
 ```py
 import builtins
 
-x = builtins.chr
-reveal_type(x)  # revealed: Literal[chr]
+x = builtins.copyright
+reveal_type(x)  # revealed: Literal[copyright]
 ```

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

@@ -1,75 +0,0 @@
-# Conflicting attributes and submodules
-
-## Via import
-
-```py
-import a.b
-
-reveal_type(a.b)  # revealed: <module 'a.b'>
-```
-
-```py path=a/__init__.py
-b = 42
-```
-
-```py path=a/b.py
-```
-
-## Via from/import
-
-```py
-from a import b
-
-reveal_type(b)  # revealed: Literal[42]
-```
-
-```py path=a/__init__.py
-b = 42
-```
-
-```py path=a/b.py
-```
-
-## Via both
-
-```py
-import a.b
-from a import b
-
-reveal_type(b)  # revealed: <module 'a.b'>
-reveal_type(a.b)  # revealed: <module 'a.b'>
-```
-
-```py path=a/__init__.py
-b = 42
-```
-
-```py path=a/b.py
-```
-
-## Via both (backwards)
-
-In this test, we infer a different type for `b` than the runtime behavior of the Python interpreter.
-The interpreter will not load the submodule `a.b` during the `from a import b` statement, since `a`
-contains a non-module attribute named `b`. (See the [definition][from-import] of a `from...import`
-statement for details.) However, because our import tracking is flow-insensitive, we will see that
-`a.b` is imported somewhere in the file, and therefore assume that the `from...import` statement
-sees the submodule as the value of `b` instead of the integer.
-
-```py
-from a import b
-import a.b
-
-# Python would say `Literal[42]` for `b`
-reveal_type(b)  # revealed: <module 'a.b'>
-reveal_type(a.b)  # revealed: <module 'a.b'>
-```
-
-```py path=a/__init__.py
-b = 42
-```
-
-```py path=a/b.py
-```
-
-[from-import]: https://docs.python.org/3/reference/simple_stmts.html#the-import-statement

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

@@ -7,25 +7,3 @@ from import bar  # error: [invalid-syntax]
 
 reveal_type(bar)  # revealed: Unknown
 ```
-
-## Invalid nested module import
-
-TODO: This is correctly flagged as an error, but we could clean up the diagnostics that we report.
-
-```py
-# TODO: No second diagnostic
-# error: [invalid-syntax] "Expected ',', found '.'"
-# error: [unresolved-import] "Module `a` has no member `c`"
-from a import b.c
-
-# TODO: Should these be inferred as Unknown?
-reveal_type(b)  # revealed: <module 'a.b'>
-reveal_type(b.c)  # revealed: Literal[1]
-```
-
-```py path=a/__init__.py
-```
-
-```py path=a/b.py
-c = 1
-```

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

@@ -121,44 +121,23 @@ X = 42
 ```
 
 ```py path=package/bar.py
-from . import foo
+# TODO: support submodule imports
+from . import foo  # error: [unresolved-import]
 
-reveal_type(foo.X)  # revealed: Literal[42]
+y = foo.X
+
+# TODO: should be `Literal[42]`
+reveal_type(y)  # revealed: Unknown
 ```
 
 ## Non-existent + bare to module
 
-This test verifies that we emit an error when we try to import a symbol that is neither a submodule
-nor an attribute of `package`.
-
 ```py path=package/__init__.py
 ```
 
 ```py path=package/bar.py
+# TODO: support submodule imports
 from . import foo  # error: [unresolved-import]
 
 reveal_type(foo)  # revealed: Unknown
 ```
-
-## Import submodule from self
-
-We don't currently consider `from...import` statements when building up the `imported_modules` set
-in the semantic index. When accessing an attribute of a module, we only consider it a potential
-submodule when that submodule name appears in the `imported_modules` set. That means that submodules
-that are imported via `from...import` are not visible to our type inference if you also access that
-submodule via the attribute on its parent package.
-
-```py path=package/__init__.py
-```
-
-```py path=package/foo.py
-X = 42
-```
-
-```py path=package/bar.py
-from . import foo
-import package
-
-# error: [unresolved-attribute] "Type `<module 'package'>` has no attribute `foo`"
-reveal_type(package.foo.X)  # revealed: Unknown
-```

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

@@ -1,100 +0,0 @@
-# Tracking imported modules
-
-These tests depend on how we track which modules have been imported. There are currently two
-characteristics of our module tracking that can lead to inaccuracies:
-
-- Imports are tracked on a per-file basis. At runtime, importing a submodule in one file makes that
-    submodule globally available via any reference to the containing package. We will flag an error
-    if a file tries to access a submodule without there being an import of that submodule _in that
-    same file_.
-
-    This is a purposeful decision, and not one we plan to change. If a module wants to re-export some
-    other module that it imports, there are ways to do that (tested below) that are blessed by the
-    typing spec and that are visible to our file-scoped import tracking.
-
-- Imports are tracked flow-insensitively: submodule accesses are allowed and resolved if that
-    submodule is imported _anywhere in the file_. This handles the common case where all imports are
-    grouped at the top of the file, and is easiest to implement. We might revisit this decision and
-    track submodule imports flow-sensitively, in which case we will have to update the assertions in
-    some of these tests.
-
-## Import submodule later in file
-
-This test highlights our flow-insensitive analysis, since we access the `a.b` submodule before it
-has been imported.
-
-```py
-import a
-
-# Would be an error with flow-sensitive tracking
-reveal_type(a.b.C)  # revealed: Literal[C]
-
-import a.b
-```
-
-```py path=a/__init__.py
-```
-
-```py path=a/b.py
-class C: ...
-```
-
-## Rename a re-export
-
-This test highlights how import tracking is local to each file, but specifically to the file where a
-containing module is first referenced. This allows the main module to see that `q.a` contains a
-submodule `b`, even though `a.b` is never imported in the main module.
-
-```py
-from q import a, b
-
-reveal_type(b)  # revealed: <module 'a.b'>
-reveal_type(b.C)  # revealed: Literal[C]
-
-reveal_type(a.b)  # revealed: <module 'a.b'>
-reveal_type(a.b.C)  # revealed: Literal[C]
-```
-
-```py path=a/__init__.py
-```
-
-```py path=a/b.py
-class C: ...
-```
-
-```py path=q.py
-import a as a
-import a.b as b
-```
-
-## Attribute overrides submodule
-
-Technically, either a submodule or a non-module attribute could shadow the other, depending on the
-ordering of when the submodule is loaded relative to the parent module's `__init__.py` file being
-evaluated. We have chosen to always have the submodule take priority. (This matches pyright's
-current behavior, and opposite of mypy's current behavior.)
-
-```py
-import sub.b
-import attr.b
-
-# In the Python interpreter, `attr.b` is Literal[1]
-reveal_type(sub.b)  # revealed: <module 'sub.b'>
-reveal_type(attr.b)  # revealed: <module 'attr.b'>
-```
-
-```py path=sub/__init__.py
-b = 1
-```
-
-```py path=sub/b.py
-```
-
-```py path=attr/__init__.py
-from . import b as _
-
-b = 1
-```
-
-```py path=attr/b.py
-```

crates/red_knot_python_semantic/resources/mdtest/known_constants.md

@@ -1,52 +0,0 @@
-# Known constants
-
-## `typing.TYPE_CHECKING`
-
-This constant is `True` when in type-checking mode, `False` otherwise. The symbol is defined to be
-`False` at runtime. In typeshed, it is annotated as `bool`. This test makes sure that we infer
-`Literal[True]` for it anyways.
-
-### Basic
-
-```py
-from typing import TYPE_CHECKING
-import typing
-
-reveal_type(TYPE_CHECKING)  # revealed: Literal[True]
-reveal_type(typing.TYPE_CHECKING)  # revealed: Literal[True]
-```
-
-### Aliased
-
-Make sure that we still infer the correct type if the constant has been given a different name:
-
-```py
-from typing import TYPE_CHECKING as TC
-
-reveal_type(TC)  # revealed: Literal[True]
-```
-
-### Must originate from `typing`
-
-Make sure we only use our special handling for `typing.TYPE_CHECKING` and not for other constants
-with the same name:
-
-```py path=constants.py
-TYPE_CHECKING: bool = False
-```
-
-```py
-from constants import TYPE_CHECKING
-
-reveal_type(TYPE_CHECKING)  # revealed: bool
-```
-
-### `typing_extensions` re-export
-
-This should behave in the same way as `typing.TYPE_CHECKING`:
-
-```py
-from typing_extensions import TYPE_CHECKING
-
-reveal_type(TYPE_CHECKING)  # revealed: Literal[True]
-```

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

@@ -45,19 +45,19 @@ def f():
     # TODO: This should be Color.RED
     reveal_type(b1)  # revealed: Literal[0]
 
-# error: [invalid-type-form]
+# error: [invalid-literal-parameter]
 invalid1: Literal[3 + 4]
-# error: [invalid-type-form]
+# error: [invalid-literal-parameter]
 invalid2: Literal[4 + 3j]
-# error: [invalid-type-form]
+# error: [invalid-literal-parameter]
 invalid3: Literal[(3, 4)]
 
 hello = "hello"
 invalid4: Literal[
-    1 + 2,  # error: [invalid-type-form]
+    1 + 2,  # error: [invalid-literal-parameter]
     "foo",
-    hello,  # error: [invalid-type-form]
-    (1, 2, 3),  # error: [invalid-type-form]
+    hello,  # error: [invalid-literal-parameter]
+    (1, 2, 3),  # error: [invalid-literal-parameter]
 ]
 ```
 
@@ -91,13 +91,3 @@ a1: Literal[26]
 def f():
     reveal_type(a1)  # revealed: Literal[26]
 ```
-
-## Invalid
-
-```py
-from typing import Literal
-
-# error: [invalid-type-form] "`Literal` requires at least one argument when used in a type expression"
-def _(x: Literal):
-    reveal_type(x)  # revealed: Unknown
-```

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

@@ -1,6 +1,6 @@
 # While loops
 
-## Basic `while` loop
+## Basic While Loop
 
 ```py
 def _(flag: bool):
@@ -11,7 +11,7 @@ def _(flag: bool):
     reveal_type(x)  # revealed: Literal[1, 2]
 ```
 
-## `while` with `else` (no `break`)
+## While with else (no break)
 
 ```py
 def _(flag: bool):
@@ -25,7 +25,7 @@ def _(flag: bool):
     reveal_type(x)  # revealed: Literal[3]
 ```
 
-## `while` with `else` (may `break`)
+## While with Else (may break)
 
 ```py
 def _(flag: bool, flag2: bool):
@@ -44,7 +44,7 @@ def _(flag: bool, flag2: bool):
     reveal_type(y)  # revealed: Literal[1, 2, 4]
 ```
 
-## Nested `while` loops
+## Nested while loops
 
 ```py
 def flag() -> bool:
@@ -69,50 +69,3 @@ else:
 
 reveal_type(x)  # revealed: Literal[3, 4, 5]
 ```
-
-## Boundness
-
-Make sure that the boundness information is correctly tracked in `while` loop control flow.
-
-### Basic `while` loop
-
-```py
-def _(flag: bool):
-    while flag:
-        x = 1
-
-    # error: [possibly-unresolved-reference]
-    x
-```
-
-### `while` with `else` (no `break`)
-
-```py
-def _(flag: bool):
-    while flag:
-        y = 1
-    else:
-        x = 1
-
-    # no error, `x` is always bound
-    x
-    # error: [possibly-unresolved-reference]
-    y
-```
-
-### `while` with `else` (may `break`)
-
-```py
-def _(flag: bool, flag2: bool):
-    while flag:
-        x = 1
-        if flag2:
-            break
-    else:
-        y = 1
-
-    # error: [possibly-unresolved-reference]
-    x
-    # error: [possibly-unresolved-reference]
-    y
-```

crates/red_knot_python_semantic/resources/mdtest/mdtest_config.md

@@ -5,7 +5,7 @@ The following configuration will be attached to the *root* section (without any
 
 ```toml
 [environment]
-python-version = "3.10"
+target-version = "3.10"
 ```
 
 # Basic
@@ -34,7 +34,7 @@ Here, we make sure that we can overwrite the global configuration in a child sec
 
 ```toml
 [environment]
-python-version = "3.11"
+target-version = "3.11"
 ```
 
 ```py
@@ -55,7 +55,7 @@ Children in this section should all use the section configuration:
 
 ```toml
 [environment]
-python-version = "3.12"
+target-version = "3.12"
 ```
 
 ## Child

crates/red_knot_python_semantic/resources/mdtest/metaclass.md

@@ -68,7 +68,7 @@ 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: type[Unknown]
+reveal_type(C.__class__)  # revealed: Unknown
 ```
 
 ## Conflict (2)
@@ -85,7 +85,7 @@ 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: type[Unknown]
+reveal_type(B.__class__)  # revealed: Unknown
 ```
 
 ## Common metaclass
@@ -129,7 +129,7 @@ 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: type[Unknown]
+reveal_type(D.__class__)  # revealed: Unknown
 ```
 
 ## Unknown
@@ -183,7 +183,7 @@ class A(B): ...  # error: [cyclic-class-definition]
 class B(C): ...  # error: [cyclic-class-definition]
 class C(A): ...  # error: [cyclic-class-definition]
 
-reveal_type(A.__class__)  # revealed: type[Unknown]
+reveal_type(A.__class__)  # revealed: Unknown
 ```
 
 ## PEP 695 generic
@@ -194,26 +194,3 @@ class A[T: str](metaclass=M): ...
 
 reveal_type(A.__class__)  # revealed: Literal[M]
 ```
-
-## Metaclasses of metaclasses
-
-```py
-class Foo(type): ...
-class Bar(type, metaclass=Foo): ...
-class Baz(type, metaclass=Bar): ...
-class Spam(metaclass=Baz): ...
-
-reveal_type(Spam.__class__)  # revealed: Literal[Baz]
-reveal_type(Spam.__class__.__class__)  # revealed: Literal[Bar]
-reveal_type(Spam.__class__.__class__.__class__)  # revealed: Literal[Foo]
-
-def test(x: Spam):
-    reveal_type(x.__class__)  # revealed: type[Spam]
-    reveal_type(x.__class__.__class__)  # revealed: type[Baz]
-    reveal_type(x.__class__.__class__.__class__)  # revealed: type[Bar]
-    reveal_type(x.__class__.__class__.__class__.__class__)  # revealed: type[Foo]
-    reveal_type(x.__class__.__class__.__class__.__class__.__class__)  # revealed: type[type]
-
-    # revealed: type[type]
-    reveal_type(x.__class__.__class__.__class__.__class__.__class__.__class__.__class__.__class__)
-```

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

@@ -1,221 +0,0 @@
-# Narrowing For Truthiness Checks (`if x` or `if not x`)
-
-## Value Literals
-
-```py
-def foo() -> Literal[0, -1, True, False, "", "foo", b"", b"bar", None] | tuple[()]:
-    return 0
-
-x = foo()
-
-if x:
-    reveal_type(x)  # revealed: Literal[-1] | Literal[True] | Literal["foo"] | Literal[b"bar"]
-else:
-    reveal_type(x)  # revealed: Literal[0] | Literal[False] | Literal[""] | Literal[b""] | None | tuple[()]
-
-if not x:
-    reveal_type(x)  # revealed: Literal[0] | Literal[False] | Literal[""] | Literal[b""] | None | tuple[()]
-else:
-    reveal_type(x)  # revealed: Literal[-1] | Literal[True] | Literal["foo"] | Literal[b"bar"]
-
-if x and not x:
-    reveal_type(x)  # revealed: Never
-else:
-    reveal_type(x)  # revealed: Literal[-1, 0] | bool | Literal["", "foo"] | Literal[b"", b"bar"] | None | tuple[()]
-
-if not (x and not x):
-    reveal_type(x)  # revealed: Literal[-1, 0] | bool | Literal["", "foo"] | Literal[b"", b"bar"] | None | tuple[()]
-else:
-    reveal_type(x)  # revealed: Never
-
-if x or not x:
-    reveal_type(x)  # revealed: Literal[-1, 0] | bool | Literal["foo", ""] | Literal[b"bar", b""] | None | tuple[()]
-else:
-    reveal_type(x)  # revealed: Never
-
-if not (x or not x):
-    reveal_type(x)  # revealed: Never
-else:
-    reveal_type(x)  # revealed: Literal[-1, 0] | bool | Literal["foo", ""] | Literal[b"bar", b""] | None | tuple[()]
-
-if (isinstance(x, int) or isinstance(x, str)) and x:
-    reveal_type(x)  # revealed: Literal[-1] | Literal[True] | Literal["foo"]
-else:
-    reveal_type(x)  # revealed: Literal[b"", b"bar"] | None | tuple[()] | Literal[0] | Literal[False] | Literal[""]
-```
-
-## Function Literals
-
-Basically functions are always truthy.
-
-```py
-def flag() -> bool:
-    return True
-
-def foo(hello: int) -> bytes:
-    return b""
-
-def bar(world: str, *args, **kwargs) -> float:
-    return 0.0
-
-x = foo if flag() else bar
-
-if x:
-    reveal_type(x)  # revealed: Literal[foo, bar]
-else:
-    reveal_type(x)  # revealed: Never
-```
-
-## Mutable Truthiness
-
-### Truthiness of Instances
-
-The boolean value of an instance is not always consistent. For example, `__bool__` can be customized
-to return random values, or in the case of a `list()`, the result depends on the number of elements
-in the list. Therefore, these types should not be narrowed by `if x` or `if not x`.
-
-```py
-class A: ...
-class B: ...
-
-def f(x: A | B):
-    if x:
-        reveal_type(x)  # revealed: A & ~AlwaysFalsy | B & ~AlwaysFalsy
-    else:
-        reveal_type(x)  # revealed: A & ~AlwaysTruthy | B & ~AlwaysTruthy
-
-    if x and not x:
-        reveal_type(x)  # revealed: A & ~AlwaysFalsy & ~AlwaysTruthy | B & ~AlwaysFalsy & ~AlwaysTruthy
-    else:
-        reveal_type(x)  # revealed: A & ~AlwaysTruthy | B & ~AlwaysTruthy | A & ~AlwaysFalsy | B & ~AlwaysFalsy
-
-    if x or not x:
-        reveal_type(x)  # revealed: A & ~AlwaysFalsy | B & ~AlwaysFalsy | A & ~AlwaysTruthy | B & ~AlwaysTruthy
-    else:
-        reveal_type(x)  # revealed: A & ~AlwaysTruthy & ~AlwaysFalsy | B & ~AlwaysTruthy & ~AlwaysFalsy
-```
-
-### Truthiness of Types
-
-Also, types may not be Truthy. This is because `__bool__` can be customized via a metaclass.
-Although this is a very rare case, we may consider metaclass checks in the future to handle this
-more accurately.
-
-```py
-def flag() -> bool:
-    return True
-
-x = int if flag() else str
-reveal_type(x)  # revealed: Literal[int, str]
-
-if x:
-    reveal_type(x)  # revealed: Literal[int] & ~AlwaysFalsy | Literal[str] & ~AlwaysFalsy
-else:
-    reveal_type(x)  # revealed: Literal[int] & ~AlwaysTruthy | Literal[str] & ~AlwaysTruthy
-```
-
-## Determined Truthiness
-
-Some custom classes can have a boolean value that is consistently determined as either `True` or
-`False`, regardless of the instance's state. This is achieved by defining a `__bool__` method that
-always returns a fixed value.
-
-These types can always be fully narrowed in boolean contexts, as shown below:
-
-```py
-class T:
-    def __bool__(self) -> Literal[True]:
-        return True
-
-class F:
-    def __bool__(self) -> Literal[False]:
-        return False
-
-t = T()
-
-if t:
-    reveal_type(t)  # revealed: T
-else:
-    reveal_type(t)  # revealed: Never
-
-f = F()
-
-if f:
-    reveal_type(f)  # revealed: Never
-else:
-    reveal_type(f)  # revealed: F
-```
-
-## Narrowing Complex Intersection and Union
-
-```py
-class A: ...
-class B: ...
-
-def flag() -> bool:
-    return True
-
-def instance() -> A | B:
-    return A()
-
-def literals() -> Literal[0, 42, "", "hello"]:
-    return 42
-
-x = instance()
-y = literals()
-
-if isinstance(x, str) and not isinstance(x, B):
-    reveal_type(x)  # revealed: A & str & ~B
-    reveal_type(y)  # revealed: Literal[0, 42] | Literal["", "hello"]
-
-    z = x if flag() else y
-
-    reveal_type(z)  # revealed: A & str & ~B | Literal[0, 42] | Literal["", "hello"]
-
-    if z:
-        reveal_type(z)  # revealed: A & str & ~B & ~AlwaysFalsy | Literal[42] | Literal["hello"]
-    else:
-        reveal_type(z)  # revealed: A & str & ~B & ~AlwaysTruthy | Literal[0] | Literal[""]
-```
-
-## Narrowing Multiple Variables
-
-```py
-def f(x: Literal[0, 1], y: Literal["", "hello"]):
-    if x and y and not x and not y:
-        reveal_type(x)  # revealed: Never
-        reveal_type(y)  # revealed: Never
-    else:
-        # ~(x or not x) and ~(y or not y)
-        reveal_type(x)  # revealed: Literal[0, 1]
-        reveal_type(y)  # revealed: Literal["", "hello"]
-
-    if (x or not x) and (y and not y):
-        reveal_type(x)  # revealed: Literal[0, 1]
-        reveal_type(y)  # revealed: Never
-    else:
-        # ~(x or not x) or ~(y and not y)
-        reveal_type(x)  # revealed: Literal[0, 1]
-        reveal_type(y)  # revealed: Literal["", "hello"]
-```
-
-## ControlFlow Merging
-
-After merging control flows, when we take the union of all constraints applied in each branch, we
-should return to the original state.
-
-```py
-class A: ...
-
-x = A()
-
-if x and not x:
-    y = x
-    reveal_type(y)  # revealed: A & ~AlwaysFalsy & ~AlwaysTruthy
-else:
-    y = x
-    reveal_type(y)  # revealed: A & ~AlwaysTruthy | A & ~AlwaysFalsy
-
-# TODO: It should be A. We should improve UnionBuilder or IntersectionBuilder. (issue #15023)
-reveal_type(y)  # revealed: A & ~AlwaysTruthy | A & ~AlwaysFalsy
-```

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

@@ -1,58 +0,0 @@
-# Narrowing in `while` loops
-
-We only make sure that narrowing works for `while` loops in general, we do not exhaustively test all
-narrowing forms here, as they are covered in other tests.
-
-Note how type narrowing works subtly different from `if` ... `else`, because the negated constraint
-is retained after the loop.
-
-## Basic `while` loop
-
-```py
-def next_item() -> int | None: ...
-
-x = next_item()
-
-while x is not None:
-    reveal_type(x)  # revealed: int
-    x = next_item()
-
-reveal_type(x)  # revealed: None
-```
-
-## `while` loop with `else`
-
-```py
-def next_item() -> int | None: ...
-
-x = next_item()
-
-while x is not None:
-    reveal_type(x)  # revealed: int
-    x = next_item()
-else:
-    reveal_type(x)  # revealed: None
-
-reveal_type(x)  # revealed: None
-```
-
-## Nested `while` loops
-
-```py
-from typing import Literal
-
-def next_item() -> Literal[1, 2, 3]: ...
-
-x = next_item()
-
-while x != 1:
-    reveal_type(x)  # revealed: Literal[2, 3]
-
-    while x != 2:
-        # TODO: this should be Literal[1, 3]; Literal[3] is only correct
-        # in the first loop iteration
-        reveal_type(x)  # revealed: Literal[3]
-        x = next_item()
-
-    x = next_item()
-```

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

@@ -10,10 +10,10 @@ def returns_bool() -> bool:
     return True
 
 if returns_bool():
-    chr = 1
+    copyright = 1
 
 def f():
-    reveal_type(chr)  # revealed: Literal[chr] | Literal[1]
+    reveal_type(copyright)  # revealed: Literal[copyright] | Literal[1]
 ```
 
 ## Conditionally global or builtin, with annotation
@@ -25,8 +25,8 @@ def returns_bool() -> bool:
     return True
 
 if returns_bool():
-    chr: int = 1
+    copyright: int = 1
 
 def f():
-    reveal_type(chr)  # revealed: Literal[chr] | int
+    reveal_type(copyright)  # revealed: Literal[copyright] | int
 ```

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

@@ -77,7 +77,7 @@ def _(m: int, n: int):
 
 ```toml
 [environment]
-python-version = "3.9"
+target-version = "3.9"
 ```
 
 ```py

crates/red_knot_python_semantic/resources/mdtest/sys_version_info.md

@@ -2,7 +2,7 @@
 
 ```toml
 [environment]
-python-version = "3.9"
+target-version = "3.9"
 ```
 
 ## The type of `sys.version_info`

crates/red_knot_python_semantic/resources/mdtest/type_alias.md

@@ -1,11 +1,4 @@
-# PEP 695 type aliases
-
-PEP 695 type aliases are only available in Python 3.12 and later:
-
-```toml
-[environment]
-python-version = "3.12"
-```
+# Type aliases
 
 ## Basic
 

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

@@ -0,0 +1,53 @@
+# type[Any]
+
+## Simple
+
+```py
+def f(x: type[Any]):
+    reveal_type(x)  # revealed: type[Any]
+    # TODO: could be `<object.__repr__ type> & Any`
+    reveal_type(x.__repr__)  # revealed: Any
+
+class A: ...
+
+x: type[Any] = object
+x: type[Any] = type
+x: type[Any] = A
+x: type[Any] = A()  # error: [invalid-assignment]
+```
+
+## Bare type
+
+The interpretation of bare `type` is not clear: existing wording in the spec does not match the
+behavior of mypy or pyright. For now we interpret it as simply "an instance of `builtins.type`",
+which is equivalent to `type[object]`. This is similar to the current behavior of mypy, and pyright
+in strict mode.
+
+```py
+def f(x: type):
+    reveal_type(x)  # revealed: type
+    reveal_type(x.__repr__)  # revealed: @Todo(instance attributes)
+
+class A: ...
+
+x: type = object
+x: type = type
+x: type = A
+x: type = A()  # error: [invalid-assignment]
+```
+
+## type[object] != type[Any]
+
+```py
+def f(x: type[object]):
+    reveal_type(x)  # revealed: type[object]
+    # TODO: bound method types
+    reveal_type(x.__repr__)  # revealed: Literal[__repr__]
+
+class A: ...
+
+x: type[object] = object
+x: type[object] = type
+x: type[object] = A
+x: type[object] = A()  # error: [invalid-assignment]
+```

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

@@ -61,8 +61,10 @@ class B: ...
 ```py path=a/test.py
 import a.b
 
+# TODO: no diagnostic
+# error: [unresolved-attribute]
 def f(c: type[a.b.C]):
-    reveal_type(c)  # revealed: type[C]
+    reveal_type(c)  # revealed: @Todo(unsupported type[X] special form)
 ```
 
 ```py path=a/__init__.py

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

@@ -1,102 +0,0 @@
-# `type[Any]`
-
-This file contains tests for non-fully-static `type[]` types, such as `type[Any]` and
-`type[Unknown]`.
-
-## Simple
-
-```py
-def f(x: type[Any], y: type[str]):
-    reveal_type(x)  # revealed: type[Any]
-    # TODO: could be `<object.__repr__ type> & Any`
-    reveal_type(x.__repr__)  # revealed: Any
-
-    # type[str] and type[Any] are assignable to each other
-    a: type[str] = x
-    b: type[Any] = y
-
-class A: ...
-
-x: type[Any] = object
-x: type[Any] = type
-x: type[Any] = A
-x: type[Any] = A()  # error: [invalid-assignment]
-```
-
-## Bare type
-
-The interpretation of bare `type` is not clear: existing wording in the spec does not match the
-behavior of mypy or pyright. For now we interpret it as simply "an instance of `builtins.type`",
-which is equivalent to `type[object]`. This is similar to the current behavior of mypy, and pyright
-in strict mode.
-
-```py
-def f(x: type):
-    reveal_type(x)  # revealed: type
-    reveal_type(x.__repr__)  # revealed: @Todo(instance attributes)
-
-class A: ...
-
-x: type = object
-x: type = type
-x: type = A
-x: type = A()  # error: [invalid-assignment]
-```
-
-## type[object] != type[Any]
-
-```py
-def f(x: type[object]):
-    reveal_type(x)  # revealed: type[object]
-    # TODO: bound method types
-    reveal_type(x.__repr__)  # revealed: Literal[__repr__]
-
-class A: ...
-
-x: type[object] = object
-x: type[object] = type
-x: type[object] = A
-x: type[object] = A()  # error: [invalid-assignment]
-```
-
-## The type of `Any` is `type[Any]`
-
-`Any` represents an unknown set of possible runtime values. If `x` is of type `Any`, the type of
-`x.__class__` is also unknown and remains dynamic, *except* that we know it must be a class object
-of some kind. As such, the type of `x.__class__` is `type[Any]` rather than `Any`:
-
-```py
-from typing import Any
-from does_not_exist import SomethingUnknown  # error: [unresolved-import]
-
-reveal_type(SomethingUnknown)  # revealed: Unknown
-
-def test(x: Any, y: SomethingUnknown):
-    reveal_type(x.__class__)  # revealed: type[Any]
-    reveal_type(x.__class__.__class__.__class__.__class__)  # revealed: type[Any]
-    reveal_type(y.__class__)  # revealed: type[Unknown]
-    reveal_type(y.__class__.__class__.__class__.__class__)  # revealed: type[Unknown]
-```
-
-## `type[Unknown]` has similar properties to `type[Any]`
-
-```py
-import abc
-from typing import Any
-from does_not_exist import SomethingUnknown  # error: [unresolved-import]
-
-has_unknown_type = SomethingUnknown.__class__
-reveal_type(has_unknown_type)  # revealed: type[Unknown]
-
-def test(x: type[str], y: type[Any]):
-    """Both `type[Any]` and `type[Unknown]` are assignable to all `type[]` types"""
-    a: type[Any] = x
-    b: type[str] = y
-    c: type[Any] = has_unknown_type
-    d: type[str] = has_unknown_type
-
-def test2(a: type[Any]):
-    """`type[Any]` and `type[Unknown]` are also assignable to all instances of `type` subclasses"""
-    b: abc.ABCMeta = a
-    b: abc.ABCMeta = has_unknown_type
-```

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

@@ -9,7 +9,7 @@ from typing import Type
 
 class A: ...
 
-def _(c: Type, d: Type[A]):
+def _(c: Type, d: Type[A], e: Type[A]):
     reveal_type(c)  # revealed: type
     reveal_type(d)  # revealed: type[A]
     c = d  # fine

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

@@ -1,165 +0,0 @@
-# Custom unary operations
-
-## Class instances
-
-```py
-class Yes:
-    def __pos__(self) -> bool:
-        return False
-
-    def __neg__(self) -> str:
-        return "negative"
-
-    def __invert__(self) -> int:
-        return 17
-
-class Sub(Yes): ...
-class No: ...
-
-reveal_type(+Yes())  # revealed: bool
-reveal_type(-Yes())  # revealed: str
-reveal_type(~Yes())  # revealed: int
-
-reveal_type(+Sub())  # revealed: bool
-reveal_type(-Sub())  # revealed: str
-reveal_type(~Sub())  # revealed: int
-
-# error: [unsupported-operator] "Unary operator `+` is unsupported for type `No`"
-reveal_type(+No())  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `-` is unsupported for type `No`"
-reveal_type(-No())  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `~` is unsupported for type `No`"
-reveal_type(~No())  # revealed: Unknown
-```
-
-## Classes
-
-```py
-class Yes:
-    def __pos__(self) -> bool:
-        return False
-
-    def __neg__(self) -> str:
-        return "negative"
-
-    def __invert__(self) -> int:
-        return 17
-
-class Sub(Yes): ...
-class No: ...
-
-# error: [unsupported-operator] "Unary operator `+` is unsupported for type `Literal[Yes]`"
-reveal_type(+Yes)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `-` is unsupported for type `Literal[Yes]`"
-reveal_type(-Yes)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `~` is unsupported for type `Literal[Yes]`"
-reveal_type(~Yes)  # revealed: Unknown
-
-# error: [unsupported-operator] "Unary operator `+` is unsupported for type `Literal[Sub]`"
-reveal_type(+Sub)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `-` is unsupported for type `Literal[Sub]`"
-reveal_type(-Sub)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `~` is unsupported for type `Literal[Sub]`"
-reveal_type(~Sub)  # revealed: Unknown
-
-# error: [unsupported-operator] "Unary operator `+` is unsupported for type `Literal[No]`"
-reveal_type(+No)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `-` is unsupported for type `Literal[No]`"
-reveal_type(-No)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `~` is unsupported for type `Literal[No]`"
-reveal_type(~No)  # revealed: Unknown
-```
-
-## Function literals
-
-```py
-def f():
-    pass
-
-# error: [unsupported-operator] "Unary operator `+` is unsupported for type `Literal[f]`"
-reveal_type(+f)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `-` is unsupported for type `Literal[f]`"
-reveal_type(-f)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `~` is unsupported for type `Literal[f]`"
-reveal_type(~f)  # revealed: Unknown
-```
-
-## Subclass
-
-```py
-class Yes:
-    def __pos__(self) -> bool:
-        return False
-
-    def __neg__(self) -> str:
-        return "negative"
-
-    def __invert__(self) -> int:
-        return 17
-
-class Sub(Yes): ...
-class No: ...
-
-def yes() -> type[Yes]:
-    return Yes
-
-def sub() -> type[Sub]:
-    return Sub
-
-def no() -> type[No]:
-    return No
-
-# error: [unsupported-operator] "Unary operator `+` is unsupported for type `type[Yes]`"
-reveal_type(+yes())  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `-` is unsupported for type `type[Yes]`"
-reveal_type(-yes())  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `~` is unsupported for type `type[Yes]`"
-reveal_type(~yes())  # revealed: Unknown
-
-# error: [unsupported-operator] "Unary operator `+` is unsupported for type `type[Sub]`"
-reveal_type(+sub())  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `-` is unsupported for type `type[Sub]`"
-reveal_type(-sub())  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `~` is unsupported for type `type[Sub]`"
-reveal_type(~sub())  # revealed: Unknown
-
-# error: [unsupported-operator] "Unary operator `+` is unsupported for type `type[No]`"
-reveal_type(+no())  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `-` is unsupported for type `type[No]`"
-reveal_type(-no())  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `~` is unsupported for type `type[No]`"
-reveal_type(~no())  # revealed: Unknown
-```
-
-## Metaclass
-
-```py
-class Meta(type):
-    def __pos__(self) -> bool:
-        return False
-
-    def __neg__(self) -> str:
-        return "negative"
-
-    def __invert__(self) -> int:
-        return 17
-
-class Yes(metaclass=Meta): ...
-class Sub(Yes): ...
-class No: ...
-
-reveal_type(+Yes)  # revealed: bool
-reveal_type(-Yes)  # revealed: str
-reveal_type(~Yes)  # revealed: int
-
-reveal_type(+Sub)  # revealed: bool
-reveal_type(-Sub)  # revealed: str
-reveal_type(~Sub)  # revealed: int
-
-# error: [unsupported-operator] "Unary operator `+` is unsupported for type `Literal[No]`"
-reveal_type(+No)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `-` is unsupported for type `Literal[No]`"
-reveal_type(-No)  # revealed: Unknown
-# error: [unsupported-operator] "Unary operator `~` is unsupported for type `Literal[No]`"
-reveal_type(~No)  # revealed: Unknown
-```

crates/red_knot_python_semantic/resources/mdtest/with/async.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(async with statement)
 ```

crates/red_knot_python_semantic/src/db.rs

@@ -27,7 +27,6 @@ pub(crate) mod tests {
     use ruff_db::{Db as SourceDb, Upcast};
 
     #[salsa::db]
-    #[derive(Clone)]
     pub(crate) struct TestDb {
         storage: salsa::Storage<Self>,
         files: Files,
@@ -167,12 +166,12 @@ pub(crate) mod tests {
                 .context("Failed to write test files")?;
 
             let mut search_paths = SearchPathSettings::new(src_root);
-            search_paths.typeshed = self.custom_typeshed;
+            search_paths.custom_typeshed = self.custom_typeshed;
 
             Program::from_settings(
                 &db,
                 &ProgramSettings {
-                    python_version: self.python_version,
+                    target_version: self.python_version,
                     search_paths,
                 },
             )

crates/red_knot_python_semantic/src/module_name.rs

@@ -186,26 +186,6 @@ impl ModuleName {
         self.0.push('.');
         self.0.push_str(other);
     }
-
-    /// Returns an iterator of this module name and all of its parent modules.
-    ///
-    /// # Examples
-    ///
-    /// ```
-    /// use red_knot_python_semantic::ModuleName;
-    ///
-    /// assert_eq!(
-    ///     ModuleName::new_static("foo.bar.baz").unwrap().ancestors().collect::<Vec<_>>(),
-    ///     vec![
-    ///         ModuleName::new_static("foo.bar.baz").unwrap(),
-    ///         ModuleName::new_static("foo.bar").unwrap(),
-    ///         ModuleName::new_static("foo").unwrap(),
-    ///     ],
-    /// );
-    /// ```
-    pub fn ancestors(&self) -> impl Iterator<Item = Self> {
-        std::iter::successors(Some(self.clone()), Self::parent)
-    }
 }
 
 impl Deref for ModuleName {

crates/red_knot_python_semantic/src/module_resolver/module.rs

@@ -7,7 +7,7 @@ use super::path::SearchPath;
 use crate::module_name::ModuleName;
 
 /// Representation of a Python module.
-#[derive(Clone, PartialEq, Eq, Hash)]
+#[derive(Clone, PartialEq, Eq)]
 pub struct Module {
     inner: Arc<ModuleInner>,
 }
@@ -61,7 +61,7 @@ impl std::fmt::Debug for Module {
     }
 }
 
-#[derive(PartialEq, Eq, Hash)]
+#[derive(PartialEq, Eq)]
 struct ModuleInner {
     name: ModuleName,
     kind: ModuleKind,

crates/red_knot_python_semantic/src/module_resolver/path.rs

@@ -283,9 +283,9 @@ fn query_stdlib_version(
     let Some(module_name) = stdlib_path_to_module_name(relative_path) else {
         return TypeshedVersionsQueryResult::DoesNotExist;
     };
-    let ResolverContext { db, python_version } = context;
+    let ResolverContext { db, target_version } = context;
 
-    typeshed_versions(*db).query_module(&module_name, *python_version)
+    typeshed_versions(*db).query_module(&module_name, *target_version)
 }
 
 /// Enumeration describing the various ways in which validation of a search path might fail.
@@ -658,7 +658,7 @@ mod tests {
         let TestCase {
             db, src, stdlib, ..
         } = TestCaseBuilder::new()
-            .with_mocked_typeshed(MockedTypeshed::default())
+            .with_custom_typeshed(MockedTypeshed::default())
             .build();
 
         assert_eq!(
@@ -779,7 +779,7 @@ mod tests {
     #[should_panic(expected = "Extension must be `pyi`; got `py`")]
     fn stdlib_path_invalid_join_py() {
         let TestCase { db, stdlib, .. } = TestCaseBuilder::new()
-            .with_mocked_typeshed(MockedTypeshed::default())
+            .with_custom_typeshed(MockedTypeshed::default())
             .build();
         SearchPath::custom_stdlib(&db, stdlib.parent().unwrap())
             .unwrap()
@@ -791,7 +791,7 @@ mod tests {
     #[should_panic(expected = "Extension must be `pyi`; got `rs`")]
     fn stdlib_path_invalid_join_rs() {
         let TestCase { db, stdlib, .. } = TestCaseBuilder::new()
-            .with_mocked_typeshed(MockedTypeshed::default())
+            .with_custom_typeshed(MockedTypeshed::default())
             .build();
         SearchPath::custom_stdlib(&db, stdlib.parent().unwrap())
             .unwrap()
@@ -822,7 +822,7 @@ mod tests {
     #[test]
     fn relativize_stdlib_path_errors() {
         let TestCase { db, stdlib, .. } = TestCaseBuilder::new()
-            .with_mocked_typeshed(MockedTypeshed::default())
+            .with_custom_typeshed(MockedTypeshed::default())
             .build();
 
         let root = SearchPath::custom_stdlib(&db, stdlib.parent().unwrap()).unwrap();
@@ -867,11 +867,11 @@ mod tests {
 
     fn typeshed_test_case(
         typeshed: MockedTypeshed,
-        python_version: PythonVersion,
+        target_version: PythonVersion,
     ) -> (TestDb, SearchPath) {
         let TestCase { db, stdlib, .. } = TestCaseBuilder::new()
-            .with_mocked_typeshed(typeshed)
-            .with_python_version(python_version)
+            .with_custom_typeshed(typeshed)
+            .with_target_version(target_version)
             .build();
         let stdlib = SearchPath::custom_stdlib(&db, stdlib.parent().unwrap()).unwrap();
         (db, stdlib)

crates/red_knot_python_semantic/src/module_resolver/resolver.rs

@@ -73,15 +73,6 @@ enum SystemOrVendoredPathRef<'a> {
     Vendored(&'a VendoredPath),
 }
 
-impl std::fmt::Display for SystemOrVendoredPathRef<'_> {
-    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-        match self {
-            SystemOrVendoredPathRef::System(system) => system.fmt(f),
-            SystemOrVendoredPathRef::Vendored(vendored) => vendored.fmt(f),
-        }
-    }
-}
-
 /// Resolves the module for the file with the given id.
 ///
 /// Returns `None` if the file is not a module locatable via any of the known search paths.
@@ -169,7 +160,7 @@ impl SearchPaths {
         let SearchPathSettings {
             extra_paths,
             src_root,
-            typeshed,
+            custom_typeshed,
             site_packages: site_packages_paths,
         } = settings;
 
@@ -189,13 +180,17 @@ impl SearchPaths {
         tracing::debug!("Adding first-party search path '{src_root}'");
         static_paths.push(SearchPath::first_party(system, src_root.to_path_buf())?);
 
-        let (typeshed_versions, stdlib_path) = if let Some(typeshed) = typeshed {
-            let typeshed = canonicalize(typeshed, system);
-            tracing::debug!("Adding custom-stdlib search path '{typeshed}'");
+        let (typeshed_versions, stdlib_path) = if let Some(custom_typeshed) = custom_typeshed {
+            let custom_typeshed = canonicalize(custom_typeshed, system);
+            tracing::debug!("Adding custom-stdlib search path '{custom_typeshed}'");
 
-            files.try_add_root(db.upcast(), &typeshed, FileRootKind::LibrarySearchPath);
+            files.try_add_root(
+                db.upcast(),
+                &custom_typeshed,
+                FileRootKind::LibrarySearchPath,
+            );
 
-            let versions_path = typeshed.join("stdlib/VERSIONS");
+            let versions_path = custom_typeshed.join("stdlib/VERSIONS");
 
             let versions_content = system.read_to_string(&versions_path).map_err(|error| {
                 SearchPathValidationError::FailedToReadVersionsFile {
@@ -206,7 +201,7 @@ impl SearchPaths {
 
             let parsed: TypeshedVersions = versions_content.parse()?;
 
-            let search_path = SearchPath::custom_stdlib(db, &typeshed)?;
+            let search_path = SearchPath::custom_stdlib(db, &custom_typeshed)?;
 
             (parsed, search_path)
         } else {
@@ -535,10 +530,10 @@ struct ModuleNameIngredient<'db> {
 /// attempt to resolve the module name
 fn resolve_name(db: &dyn Db, name: &ModuleName) -> Option<(SearchPath, File, ModuleKind)> {
     let program = Program::get(db);
-    let python_version = program.python_version(db);
-    let resolver_state = ResolverContext::new(db, python_version);
+    let target_version = program.target_version(db);
+    let resolver_state = ResolverContext::new(db, target_version);
     let is_builtin_module =
-        ruff_python_stdlib::sys::is_builtin_module(python_version.minor, name.as_str());
+        ruff_python_stdlib::sys::is_builtin_module(target_version.minor, name.as_str());
 
     for search_path in search_paths(db) {
         // When a builtin module is imported, standard module resolution is bypassed:
@@ -695,12 +690,12 @@ impl PackageKind {
 
 pub(super) struct ResolverContext<'db> {
     pub(super) db: &'db dyn Db,
-    pub(super) python_version: PythonVersion,
+    pub(super) target_version: PythonVersion,
 }
 
 impl<'db> ResolverContext<'db> {
-    pub(super) fn new(db: &'db dyn Db, python_version: PythonVersion) -> Self {
-        Self { db, python_version }
+    pub(super) fn new(db: &'db dyn Db, target_version: PythonVersion) -> Self {
+        Self { db, target_version }
     }
 
     pub(super) fn vendored(&self) -> &VendoredFileSystem {
@@ -776,8 +771,8 @@ mod tests {
 
         let TestCase { db, stdlib, .. } = TestCaseBuilder::new()
             .with_src_files(SRC)
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY38)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY38)
             .build();
 
         let builtins_module_name = ModuleName::new_static("builtins").unwrap();
@@ -794,8 +789,8 @@ mod tests {
         };
 
         let TestCase { db, stdlib, .. } = TestCaseBuilder::new()
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY38)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY38)
             .build();
 
         let functools_module_name = ModuleName::new_static("functools").unwrap();
@@ -847,8 +842,8 @@ mod tests {
         };
 
         let TestCase { db, stdlib, .. } = TestCaseBuilder::new()
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY38)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY38)
             .build();
 
         let existing_modules = create_module_names(&["asyncio", "functools", "xml.etree"]);
@@ -892,8 +887,8 @@ mod tests {
         };
 
         let TestCase { db, .. } = TestCaseBuilder::new()
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY38)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY38)
             .build();
 
         let nonexisting_modules = create_module_names(&[
@@ -936,8 +931,8 @@ mod tests {
         };
 
         let TestCase { db, stdlib, .. } = TestCaseBuilder::new()
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY39)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY39)
             .build();
 
         let existing_modules = create_module_names(&[
@@ -978,8 +973,8 @@ mod tests {
         };
 
         let TestCase { db, .. } = TestCaseBuilder::new()
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY39)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY39)
             .build();
 
         let nonexisting_modules = create_module_names(&["importlib", "xml", "xml.etree"]);
@@ -1002,8 +997,8 @@ mod tests {
 
         let TestCase { db, src, .. } = TestCaseBuilder::new()
             .with_src_files(SRC)
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY38)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY38)
             .build();
 
         let functools_module_name = ModuleName::new_static("functools").unwrap();
@@ -1027,7 +1022,7 @@ mod tests {
     fn stdlib_uses_vendored_typeshed_when_no_custom_typeshed_supplied() {
         let TestCase { db, stdlib, .. } = TestCaseBuilder::new()
             .with_vendored_typeshed()
-            .with_python_version(PythonVersion::default())
+            .with_target_version(PythonVersion::default())
             .build();
 
         let pydoc_data_topics_name = ModuleName::new_static("pydoc_data.topics").unwrap();
@@ -1295,11 +1290,11 @@ mod tests {
         Program::from_settings(
             &db,
             &ProgramSettings {
-                python_version: PythonVersion::PY38,
+                target_version: PythonVersion::PY38,
                 search_paths: SearchPathSettings {
                     extra_paths: vec![],
                     src_root: src.clone(),
-                    typeshed: Some(custom_typeshed),
+                    custom_typeshed: Some(custom_typeshed),
                     site_packages: SitePackages::Known(vec![site_packages]),
                 },
             },
@@ -1338,7 +1333,7 @@ mod tests {
     fn deleting_an_unrelated_file_doesnt_change_module_resolution() {
         let TestCase { mut db, src, .. } = TestCaseBuilder::new()
             .with_src_files(&[("foo.py", "x = 1"), ("bar.py", "x = 2")])
-            .with_python_version(PythonVersion::PY38)
+            .with_target_version(PythonVersion::PY38)
             .build();
 
         let foo_module_name = ModuleName::new_static("foo").unwrap();
@@ -1425,8 +1420,8 @@ mod tests {
             site_packages,
             ..
         } = TestCaseBuilder::new()
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY38)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY38)
             .build();
 
         let functools_module_name = ModuleName::new_static("functools").unwrap();
@@ -1473,8 +1468,8 @@ mod tests {
             src,
             ..
         } = TestCaseBuilder::new()
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY38)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY38)
             .build();
 
         let functools_module_name = ModuleName::new_static("functools").unwrap();
@@ -1513,8 +1508,8 @@ mod tests {
             ..
         } = TestCaseBuilder::new()
             .with_src_files(SRC)
-            .with_mocked_typeshed(TYPESHED)
-            .with_python_version(PythonVersion::PY38)
+            .with_custom_typeshed(TYPESHED)
+            .with_target_version(PythonVersion::PY38)
             .build();
 
         let functools_module_name = ModuleName::new_static("functools").unwrap();
@@ -1800,11 +1795,11 @@ not_a_directory
         Program::from_settings(
             &db,
             &ProgramSettings {
-                python_version: PythonVersion::default(),
+                target_version: PythonVersion::default(),
                 search_paths: SearchPathSettings {
                     extra_paths: vec![],
                     src_root: SystemPathBuf::from("/src"),
-                    typeshed: None,
+                    custom_typeshed: None,
                     site_packages: SitePackages::Known(vec![
                         venv_site_packages,
                         system_site_packages,

crates/red_knot_python_semantic/src/module_resolver/testing.rs

@@ -18,7 +18,7 @@ pub(crate) struct TestCase<T> {
     // so this is a single directory instead of a `Vec` of directories,
     // like it is in `ruff_db::Program`.
     pub(crate) site_packages: SystemPathBuf,
-    pub(crate) python_version: PythonVersion,
+    pub(crate) target_version: PythonVersion,
 }
 
 /// A `(file_name, file_contents)` tuple
@@ -67,7 +67,7 @@ pub(crate) struct UnspecifiedTypeshed;
 /// ```rs
 /// let test_case = TestCaseBuilder::new()
 ///     .with_src_files(...)
-///     .with_python_version(...)
+///     .with_target_version(...)
 ///     .build();
 /// ```
 ///
@@ -85,13 +85,13 @@ pub(crate) struct UnspecifiedTypeshed;
 /// const TYPESHED = MockedTypeshed { ... };
 ///
 /// let test_case = resolver_test_case()
-///     .with_mocked_typeshed(TYPESHED)
-///     .with_python_version(...)
+///     .with_custom_typeshed(TYPESHED)
+///     .with_target_version(...)
 ///     .build();
 ///
 /// let test_case2 = resolver_test_case()
 ///     .with_vendored_typeshed()
-///     .with_python_version(...)
+///     .with_target_version(...)
 ///     .build();
 /// ```
 ///
@@ -100,7 +100,7 @@ pub(crate) struct UnspecifiedTypeshed;
 /// to `()`.
 pub(crate) struct TestCaseBuilder<T> {
     typeshed_option: T,
-    python_version: PythonVersion,
+    target_version: PythonVersion,
     first_party_files: Vec<FileSpec>,
     site_packages_files: Vec<FileSpec>,
 }
@@ -118,9 +118,9 @@ impl<T> TestCaseBuilder<T> {
         self
     }
 
-    /// Specify the Python version the module resolver should assume
-    pub(crate) fn with_python_version(mut self, python_version: PythonVersion) -> Self {
-        self.python_version = python_version;
+    /// Specify the target Python version the module resolver should assume
+    pub(crate) fn with_target_version(mut self, target_version: PythonVersion) -> Self {
+        self.target_version = target_version;
         self
     }
 
@@ -146,7 +146,7 @@ impl TestCaseBuilder<UnspecifiedTypeshed> {
     pub(crate) fn new() -> TestCaseBuilder<UnspecifiedTypeshed> {
         Self {
             typeshed_option: UnspecifiedTypeshed,
-            python_version: PythonVersion::default(),
+            target_version: PythonVersion::default(),
             first_party_files: vec![],
             site_packages_files: vec![],
         }
@@ -156,33 +156,33 @@ impl TestCaseBuilder<UnspecifiedTypeshed> {
     pub(crate) fn with_vendored_typeshed(self) -> TestCaseBuilder<VendoredTypeshed> {
         let TestCaseBuilder {
             typeshed_option: _,
-            python_version,
+            target_version,
             first_party_files,
             site_packages_files,
         } = self;
         TestCaseBuilder {
             typeshed_option: VendoredTypeshed,
-            python_version,
+            target_version,
             first_party_files,
             site_packages_files,
         }
     }
 
     /// Use a mock typeshed directory for this test case
-    pub(crate) fn with_mocked_typeshed(
+    pub(crate) fn with_custom_typeshed(
         self,
         typeshed: MockedTypeshed,
     ) -> TestCaseBuilder<MockedTypeshed> {
         let TestCaseBuilder {
             typeshed_option: _,
-            python_version,
+            target_version,
             first_party_files,
             site_packages_files,
         } = self;
 
         TestCaseBuilder {
             typeshed_option: typeshed,
-            python_version,
+            target_version,
             first_party_files,
             site_packages_files,
         }
@@ -194,15 +194,15 @@ impl TestCaseBuilder<UnspecifiedTypeshed> {
             src,
             stdlib: _,
             site_packages,
-            python_version,
-        } = self.with_mocked_typeshed(MockedTypeshed::default()).build();
+            target_version,
+        } = self.with_custom_typeshed(MockedTypeshed::default()).build();
 
         TestCase {
             db,
             src,
             stdlib: (),
             site_packages,
-            python_version,
+            target_version,
         }
     }
 }
@@ -211,7 +211,7 @@ impl TestCaseBuilder<MockedTypeshed> {
     pub(crate) fn build(self) -> TestCase<SystemPathBuf> {
         let TestCaseBuilder {
             typeshed_option,
-            python_version,
+            target_version,
             first_party_files,
             site_packages_files,
         } = self;
@@ -226,11 +226,11 @@ impl TestCaseBuilder<MockedTypeshed> {
         Program::from_settings(
             &db,
             &ProgramSettings {
-                python_version,
+                target_version,
                 search_paths: SearchPathSettings {
                     extra_paths: vec![],
                     src_root: src.clone(),
-                    typeshed: Some(typeshed.clone()),
+                    custom_typeshed: Some(typeshed.clone()),
                     site_packages: SitePackages::Known(vec![site_packages.clone()]),
                 },
             },
@@ -242,7 +242,7 @@ impl TestCaseBuilder<MockedTypeshed> {
             src,
             stdlib: typeshed.join("stdlib"),
             site_packages,
-            python_version,
+            target_version,
         }
     }
 
@@ -268,7 +268,7 @@ impl TestCaseBuilder<VendoredTypeshed> {
     pub(crate) fn build(self) -> TestCase<VendoredPathBuf> {
         let TestCaseBuilder {
             typeshed_option: VendoredTypeshed,
-            python_version,
+            target_version,
             first_party_files,
             site_packages_files,
         } = self;
@@ -282,7 +282,7 @@ impl TestCaseBuilder<VendoredTypeshed> {
         Program::from_settings(
             &db,
             &ProgramSettings {
-                python_version,
+                target_version,
                 search_paths: SearchPathSettings {
                     site_packages: SitePackages::Known(vec![site_packages.clone()]),
                     ..SearchPathSettings::new(src.clone())
@@ -296,7 +296,7 @@ impl TestCaseBuilder<VendoredTypeshed> {
             src,
             stdlib: VendoredPathBuf::from("stdlib"),
             site_packages,
-            python_version,
+            target_version,
         }
     }
 }

crates/red_knot_python_semantic/src/module_resolver/typeshed.rs

@@ -112,10 +112,10 @@ impl TypeshedVersions {
     pub(in crate::module_resolver) fn query_module(
         &self,
         module: &ModuleName,
-        python_version: PythonVersion,
+        target_version: PythonVersion,
     ) -> TypeshedVersionsQueryResult {
         if let Some(range) = self.exact(module) {
-            if range.contains(python_version) {
+            if range.contains(target_version) {
                 TypeshedVersionsQueryResult::Exists
             } else {
                 TypeshedVersionsQueryResult::DoesNotExist
@@ -125,7 +125,7 @@ impl TypeshedVersions {
             while let Some(module_to_try) = module {
                 if let Some(range) = self.exact(&module_to_try) {
                     return {
-                        if range.contains(python_version) {
+                        if range.contains(target_version) {
                             TypeshedVersionsQueryResult::MaybeExists
                         } else {
                             TypeshedVersionsQueryResult::DoesNotExist

crates/red_knot_python_semantic/src/program.rs

@@ -10,7 +10,7 @@ use crate::Db;
 
 #[salsa::input(singleton)]
 pub struct Program {
-    pub python_version: PythonVersion,
+    pub target_version: PythonVersion,
 
     #[return_ref]
     pub(crate) search_paths: SearchPaths,
@@ -19,16 +19,16 @@ pub struct Program {
 impl Program {
     pub fn from_settings(db: &dyn Db, settings: &ProgramSettings) -> anyhow::Result<Self> {
         let ProgramSettings {
-            python_version,
+            target_version,
             search_paths,
         } = settings;
 
-        tracing::info!("Python version: Python {python_version}");
+        tracing::info!("Target version: Python {target_version}");
 
         let search_paths = SearchPaths::from_settings(db, search_paths)
             .with_context(|| "Invalid search path settings")?;
 
-        Ok(Program::builder(settings.python_version, search_paths)
+        Ok(Program::builder(settings.target_version, search_paths)
             .durability(Durability::HIGH)
             .new(db))
     }
@@ -56,7 +56,7 @@ impl Program {
 #[derive(Clone, Debug, Eq, PartialEq)]
 #[cfg_attr(feature = "serde", derive(serde::Serialize))]
 pub struct ProgramSettings {
-    pub python_version: PythonVersion,
+    pub target_version: PythonVersion,
     pub search_paths: SearchPathSettings,
 }
 
@@ -75,7 +75,7 @@ pub struct SearchPathSettings {
     /// Optional path to a "custom typeshed" directory on disk for us to use for standard-library types.
     /// If this is not provided, we will fallback to our vendored typeshed stubs for the stdlib,
     /// bundled as a zip file in the binary
-    pub typeshed: Option<SystemPathBuf>,
+    pub custom_typeshed: Option<SystemPathBuf>,
 
     /// The path to the user's `site-packages` directory, where third-party packages from ``PyPI`` are installed.
     pub site_packages: SitePackages,
@@ -86,7 +86,7 @@ impl SearchPathSettings {
         Self {
             src_root,
             extra_paths: vec![],
-            typeshed: None,
+            custom_typeshed: None,
             site_packages: SitePackages::Known(vec![]),
         }
     }

crates/red_knot_python_semantic/src/python_version.rs

@@ -5,6 +5,7 @@ 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,
@@ -67,42 +68,3 @@ impl fmt::Display for PythonVersion {
         write!(f, "{major}.{minor}")
     }
 }
-
-#[cfg(feature = "serde")]
-impl<'de> serde::Deserialize<'de> for PythonVersion {
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: serde::Deserializer<'de>,
-    {
-        let as_str = String::deserialize(deserializer)?;
-
-        if let Some((major, minor)) = as_str.split_once('.') {
-            let major = major
-                .parse()
-                .map_err(|err| serde::de::Error::custom(format!("invalid major version: {err}")))?;
-            let minor = minor
-                .parse()
-                .map_err(|err| serde::de::Error::custom(format!("invalid minor version: {err}")))?;
-
-            Ok((major, minor).into())
-        } else {
-            let major = as_str.parse().map_err(|err| {
-                serde::de::Error::custom(format!(
-                    "invalid python-version: {err}, expected: `major.minor`"
-                ))
-            })?;
-
-            Ok((major, 0).into())
-        }
-    }
-}
-
-#[cfg(feature = "serde")]
-impl serde::Serialize for PythonVersion {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: serde::Serializer,
-    {
-        serializer.serialize_str(&self.to_string())
-    }
-}

crates/red_knot_python_semantic/src/semantic_index.rs

@@ -1,14 +1,13 @@
 use std::iter::FusedIterator;
 use std::sync::Arc;
 
-use rustc_hash::{FxBuildHasher, FxHashMap, FxHashSet};
+use rustc_hash::{FxBuildHasher, FxHashMap};
 use salsa::plumbing::AsId;
 
 use ruff_db::files::File;
 use ruff_db::parsed::parsed_module;
 use ruff_index::{IndexSlice, IndexVec};
 
-use crate::module_name::ModuleName;
 use crate::semantic_index::ast_ids::node_key::ExpressionNodeKey;
 use crate::semantic_index::ast_ids::AstIds;
 use crate::semantic_index::builder::SemanticIndexBuilder;
@@ -61,22 +60,6 @@ pub(crate) fn symbol_table<'db>(db: &'db dyn Db, scope: ScopeId<'db>) -> Arc<Sym
     index.symbol_table(scope.file_scope_id(db))
 }
 
-/// Returns the set of modules that are imported anywhere in `file`.
-///
-/// This set only considers `import` statements, not `from...import` statements, because:
-///
-///   - In `from foo import bar`, we cannot determine whether `foo.bar` is a submodule (and is
-///     therefore imported) without looking outside the content of this file.  (We could turn this
-///     into a _potentially_ imported modules set, but that would change how it's used in our type
-///     inference logic.)
-///
-///   - We cannot resolve relative imports (which aren't allowed in `import` statements) without
-///     knowing the name of the current module, and whether it's a package.
-#[salsa::tracked]
-pub(crate) fn imported_modules<'db>(db: &'db dyn Db, file: File) -> Arc<FxHashSet<ModuleName>> {
-    semantic_index(db, file).imported_modules.clone()
-}
-
 /// Returns the use-def map for a specific `scope`.
 ///
 /// Using [`use_def_map`] over [`semantic_index`] has the advantage that
@@ -133,9 +116,6 @@ pub(crate) struct SemanticIndex<'db> {
     /// changing a file invalidates all dependents.
     ast_ids: IndexVec<FileScopeId, AstIds>,
 
-    /// The set of modules that are imported anywhere within this file.
-    imported_modules: Arc<FxHashSet<ModuleName>>,
-
     /// Flags about the global scope (code usage impacting inference)
     has_future_annotations: bool,
 }

crates/red_knot_python_semantic/src/semantic_index/builder.rs

@@ -1,7 +1,7 @@
 use std::sync::Arc;
 
 use except_handlers::TryNodeContextStackManager;
-use rustc_hash::{FxHashMap, FxHashSet};
+use rustc_hash::FxHashMap;
 
 use ruff_db::files::File;
 use ruff_db::parsed::ParsedModule;
@@ -12,7 +12,6 @@ use ruff_python_ast::visitor::{walk_expr, walk_pattern, walk_stmt, Visitor};
 use ruff_python_ast::{BoolOp, Expr};
 
 use crate::ast_node_ref::AstNodeRef;
-use crate::module_name::ModuleName;
 use crate::semantic_index::ast_ids::node_key::ExpressionNodeKey;
 use crate::semantic_index::ast_ids::AstIdsBuilder;
 use crate::semantic_index::definition::{
@@ -80,7 +79,6 @@ pub(super) struct SemanticIndexBuilder<'db> {
     scopes_by_expression: FxHashMap<ExpressionNodeKey, FileScopeId>,
     definitions_by_node: FxHashMap<DefinitionNodeKey, Definition<'db>>,
     expressions_by_node: FxHashMap<ExpressionNodeKey, Expression<'db>>,
-    imported_modules: FxHashSet<ModuleName>,
 }
 
 impl<'db> SemanticIndexBuilder<'db> {
@@ -107,8 +105,6 @@ impl<'db> SemanticIndexBuilder<'db> {
             scopes_by_node: FxHashMap::default(),
             definitions_by_node: FxHashMap::default(),
             expressions_by_node: FxHashMap::default(),
-
-            imported_modules: FxHashSet::default(),
         };
 
         builder.push_scope_with_parent(NodeWithScopeRef::Module, None);
@@ -562,7 +558,6 @@ impl<'db> SemanticIndexBuilder<'db> {
             scopes_by_expression: self.scopes_by_expression,
             scopes_by_node: self.scopes_by_node,
             use_def_maps,
-            imported_modules: Arc::new(self.imported_modules),
             has_future_annotations: self.has_future_annotations,
         }
     }
@@ -666,12 +661,6 @@ where
             }
             ast::Stmt::Import(node) => {
                 for alias in &node.names {
-                    // Mark the imported module, and all of its parents, as being imported in this
-                    // file.
-                    if let Some(module_name) = ModuleName::new(&alias.name) {
-                        self.imported_modules.extend(module_name.ancestors());
-                    }
-
                     let symbol_name = if let Some(asname) = &alias.asname {
                         asname.id.clone()
                     } else {
@@ -844,7 +833,6 @@ where
                 self.visit_expr(test);
 
                 let pre_loop = self.flow_snapshot();
-                let constraint = self.record_expression_constraint(test);
 
                 // Save aside any break states from an outer loop
                 let saved_break_states = std::mem::take(&mut self.loop_break_states);
@@ -864,7 +852,6 @@ where
                 // We may execute the `else` clause without ever executing the body, so merge in
                 // the pre-loop state before visiting `else`.
                 self.flow_merge(pre_loop);
-                self.record_negated_constraint(constraint);
                 self.visit_body(orelse);
 
                 // Breaking out of a while loop bypasses the `else` clause, so merge in the break

crates/red_knot_python_semantic/src/semantic_index/definition.rs

@@ -1,7 +1,6 @@
 use ruff_db::files::File;
 use ruff_db::parsed::ParsedModule;
 use ruff_python_ast as ast;
-use ruff_text_size::{Ranged, TextRange};
 
 use crate::ast_node_ref::AstNodeRef;
 use crate::module_resolver::file_to_module;
@@ -466,33 +465,6 @@ pub enum DefinitionKind<'db> {
     TypeVarTuple(AstNodeRef<ast::TypeParamTypeVarTuple>),
 }
 
-impl Ranged for DefinitionKind<'_> {
-    fn range(&self) -> TextRange {
-        match self {
-            DefinitionKind::Import(alias) => alias.range(),
-            DefinitionKind::ImportFrom(import) => import.alias().range(),
-            DefinitionKind::Function(function) => function.name.range(),
-            DefinitionKind::Class(class) => class.name.range(),
-            DefinitionKind::TypeAlias(type_alias) => type_alias.name.range(),
-            DefinitionKind::NamedExpression(named) => named.target.range(),
-            DefinitionKind::Assignment(assignment) => assignment.name().range(),
-            DefinitionKind::AnnotatedAssignment(assign) => assign.target.range(),
-            DefinitionKind::AugmentedAssignment(aug_assign) => aug_assign.target.range(),
-            DefinitionKind::For(for_stmt) => for_stmt.target().range(),
-            DefinitionKind::Comprehension(comp) => comp.target().range(),
-            DefinitionKind::VariadicPositionalParameter(parameter) => parameter.name.range(),
-            DefinitionKind::VariadicKeywordParameter(parameter) => parameter.name.range(),
-            DefinitionKind::Parameter(parameter) => parameter.parameter.name.range(),
-            DefinitionKind::WithItem(with_item) => with_item.target().range(),
-            DefinitionKind::MatchPattern(match_pattern) => match_pattern.identifier.range(),
-            DefinitionKind::ExceptHandler(handler) => handler.node().range(),
-            DefinitionKind::TypeVar(type_var) => type_var.name.range(),
-            DefinitionKind::ParamSpec(param_spec) => param_spec.name.range(),
-            DefinitionKind::TypeVarTuple(type_var_tuple) => type_var_tuple.name.range(),
-        }
-    }
-}
-
 impl DefinitionKind<'_> {
     pub(crate) fn category(&self) -> DefinitionCategory {
         match self {

crates/red_knot_python_semantic/src/site_packages.rs

@@ -321,7 +321,7 @@ fn site_packages_directory_from_sys_prefix(
     // the parsed version
     //
     // Note: the `python3.x` part of the `site-packages` path can't be computed from
-    // the `--python-version` the user has passed, as they might be running Python 3.12 locally
+    // the `--target-version` the user has passed, as they might be running Python 3.12 locally
     // even if they've requested that we type check their code "as if" they're running 3.8.
     for entry_result in system
         .read_directory(&sys_prefix_path.join("lib"))

crates/red_knot_python_semantic/src/stdlib.rs

@@ -15,9 +15,6 @@ pub(crate) enum CoreStdlibModule {
     TypingExtensions,
     Typing,
     Sys,
-    #[allow(dead_code)]
-    Abc, // currently only used in tests
-    Collections,
 }
 
 impl CoreStdlibModule {
@@ -29,8 +26,6 @@ impl CoreStdlibModule {
             Self::Typeshed => "_typeshed",
             Self::TypingExtensions => "typing_extensions",
             Self::Sys => "sys",
-            Self::Abc => "abc",
-            Self::Collections => "collections",
         }
     }
 

crates/red_knot_python_semantic/src/suppression.rs

@@ -1,50 +0,0 @@
-use salsa;
-
-use ruff_db::{files::File, parsed::comment_ranges, source::source_text};
-use ruff_index::{newtype_index, IndexVec};
-
-use crate::{lint::LintId, Db};
-
-#[salsa::tracked(return_ref)]
-pub(crate) fn suppressions(db: &dyn Db, file: File) -> IndexVec<SuppressionIndex, Suppression> {
-    let comments = comment_ranges(db.upcast(), file);
-    let source = source_text(db.upcast(), file);
-
-    let mut suppressions = IndexVec::default();
-
-    for range in comments {
-        let text = &source[range];
-
-        if text.starts_with("# type: ignore") {
-            suppressions.push(Suppression {
-                target: None,
-                kind: SuppressionKind::TypeIgnore,
-            });
-        } else if text.starts_with("# knot: ignore") {
-            suppressions.push(Suppression {
-                target: None,
-                kind: SuppressionKind::KnotIgnore,
-            });
-        }
-    }
-
-    suppressions
-}
-
-#[newtype_index]
-pub(crate) struct SuppressionIndex;
-
-#[derive(Clone, Debug, Eq, PartialEq, Hash)]
-pub(crate) struct Suppression {
-    target: Option<LintId>,
-    kind: SuppressionKind,
-}
-
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Hash)]
-pub(crate) enum SuppressionKind {
-    /// A `type: ignore` comment
-    TypeIgnore,
-
-    /// A `knot: ignore` comment
-    KnotIgnore,
-}

crates/red_knot_python_semantic/src/types/builder.rs

@@ -30,8 +30,6 @@ use crate::types::{InstanceType, IntersectionType, KnownClass, Type, UnionType};
 use crate::{Db, FxOrderSet};
 use smallvec::SmallVec;
 
-use super::Truthiness;
-
 pub(crate) struct UnionBuilder<'db> {
     elements: Vec<Type<'db>>,
     db: &'db dyn Db,
@@ -245,22 +243,15 @@ impl<'db> InnerIntersectionBuilder<'db> {
             }
         } else {
             // ~Literal[True] & bool = Literal[False]
-            // ~AlwaysTruthy & bool = Literal[False]
             if let Type::Instance(InstanceType { class }) = new_positive {
                 if class.is_known(db, KnownClass::Bool) {
-                    if let Some(new_type) = self
+                    if let Some(&Type::BooleanLiteral(value)) = self
                         .negative
                         .iter()
-                        .find(|element| {
-                            element.is_boolean_literal()
-                                | matches!(element, Type::AlwaysFalsy | Type::AlwaysTruthy)
-                        })
-                        .map(|element| {
-                            Type::BooleanLiteral(element.bool(db) != Truthiness::AlwaysTrue)
-                        })
+                        .find(|element| element.is_boolean_literal())
                     {
                         *self = Self::default();
-                        self.positive.insert(new_type);
+                        self.positive.insert(Type::BooleanLiteral(!value));
                         return;
                     }
                 }
@@ -327,15 +318,15 @@ impl<'db> InnerIntersectionBuilder<'db> {
                 // simplify the representation.
                 self.add_positive(db, ty);
             }
-            // bool & ~Literal[True] = Literal[False]
-            // bool & ~AlwaysTruthy = Literal[False]
-            Type::BooleanLiteral(_) | Type::AlwaysFalsy | Type::AlwaysTruthy
-                if self.positive.contains(&KnownClass::Bool.to_instance(db)) =>
+            // ~Literal[True] & bool = Literal[False]
+            Type::BooleanLiteral(bool)
+                if self
+                    .positive
+                    .iter()
+                    .any(|pos| *pos == KnownClass::Bool.to_instance(db)) =>
             {
                 *self = Self::default();
-                self.positive.insert(Type::BooleanLiteral(
-                    new_negative.bool(db) != Truthiness::AlwaysTrue,
-                ));
+                self.positive.insert(Type::BooleanLiteral(!bool));
             }
             _ => {
                 let mut to_remove = SmallVec::<[usize; 1]>::new();
@@ -389,7 +380,7 @@ mod tests {
     use super::{IntersectionBuilder, IntersectionType, Type, UnionType};
 
     use crate::db::tests::{setup_db, TestDb};
-    use crate::types::{global_symbol, todo_type, KnownClass, Truthiness, UnionBuilder};
+    use crate::types::{global_symbol, todo_type, KnownClass, UnionBuilder};
 
     use ruff_db::files::system_path_to_file;
     use ruff_db::system::DbWithTestSystem;
@@ -1006,43 +997,42 @@ mod tests {
         assert_eq!(ty, expected);
     }
 
-    #[test_case(Type::BooleanLiteral(true))]
-    #[test_case(Type::BooleanLiteral(false))]
-    #[test_case(Type::AlwaysTruthy)]
-    #[test_case(Type::AlwaysFalsy)]
-    fn build_intersection_simplify_split_bool(t_splitter: Type) {
+    #[test_case(true)]
+    #[test_case(false)]
+    fn build_intersection_simplify_split_bool(bool_value: bool) {
         let db = setup_db();
-        let bool_value = t_splitter.bool(&db) == Truthiness::AlwaysTrue;
+
+        let t_bool = KnownClass::Bool.to_instance(&db);
+        let t_boolean_literal = Type::BooleanLiteral(bool_value);
 
         // We add t_object in various orders (in first or second position) in
         // the tests below to ensure that the boolean simplification eliminates
         // everything from the intersection, not just `bool`.
         let t_object = KnownClass::Object.to_instance(&db);
-        let t_bool = KnownClass::Bool.to_instance(&db);
 
         let ty = IntersectionBuilder::new(&db)
             .add_positive(t_object)
             .add_positive(t_bool)
-            .add_negative(t_splitter)
+            .add_negative(t_boolean_literal)
             .build();
         assert_eq!(ty, Type::BooleanLiteral(!bool_value));
 
         let ty = IntersectionBuilder::new(&db)
             .add_positive(t_bool)
             .add_positive(t_object)
-            .add_negative(t_splitter)
+            .add_negative(t_boolean_literal)
             .build();
         assert_eq!(ty, Type::BooleanLiteral(!bool_value));
 
         let ty = IntersectionBuilder::new(&db)
             .add_positive(t_object)
-            .add_negative(t_splitter)
+            .add_negative(t_boolean_literal)
             .add_positive(t_bool)
             .build();
         assert_eq!(ty, Type::BooleanLiteral(!bool_value));
 
         let ty = IntersectionBuilder::new(&db)
-            .add_negative(t_splitter)
+            .add_negative(t_boolean_literal)
             .add_positive(t_object)
             .add_positive(t_bool)
             .build();

crates/red_knot_python_semantic/src/types/call.rs

@@ -1,6 +1,5 @@
-use super::context::InferContext;
-use super::diagnostic::CALL_NON_CALLABLE;
-use super::{Severity, Type, TypeArrayDisplay, UnionBuilder};
+use super::diagnostic::{TypeCheckDiagnosticsBuilder, CALL_NON_CALLABLE};
+use super::{Severity, Type, UnionBuilder};
 use crate::Db;
 use ruff_db::diagnostic::DiagnosticId;
 use ruff_python_ast as ast;
@@ -87,23 +86,24 @@ impl<'db> CallOutcome<'db> {
     }
 
     /// Get the return type of the call, emitting default diagnostics if needed.
-    pub(super) fn unwrap_with_diagnostic(
+    pub(super) fn unwrap_with_diagnostic<'a>(
         &self,
-        context: &InferContext<'db>,
+        db: &'db dyn Db,
         node: ast::AnyNodeRef,
+        diagnostics: &'a mut TypeCheckDiagnosticsBuilder<'db>,
     ) -> Type<'db> {
-        match self.return_ty_result(context, node) {
+        match self.return_ty_result(db, node, diagnostics) {
             Ok(return_ty) => return_ty,
             Err(NotCallableError::Type {
                 not_callable_ty,
                 return_ty,
             }) => {
-                context.report_lint(
+                diagnostics.add_lint(
                     &CALL_NON_CALLABLE,
                     node,
                     format_args!(
                         "Object of type `{}` is not callable",
-                        not_callable_ty.display(context.db())
+                        not_callable_ty.display(db)
                     ),
                 );
                 return_ty
@@ -113,13 +113,13 @@ impl<'db> CallOutcome<'db> {
                 called_ty,
                 return_ty,
             }) => {
-                context.report_lint(
+                diagnostics.add_lint(
                     &CALL_NON_CALLABLE,
                     node,
                     format_args!(
                         "Object of type `{}` is not callable (due to union element `{}`)",
-                        called_ty.display(context.db()),
-                        not_callable_ty.display(context.db()),
+                        called_ty.display(db),
+                        not_callable_ty.display(db),
                     ),
                 );
                 return_ty
@@ -129,13 +129,13 @@ impl<'db> CallOutcome<'db> {
                 called_ty,
                 return_ty,
             }) => {
-                context.report_lint(
+                diagnostics.add_lint(
                     &CALL_NON_CALLABLE,
                     node,
                     format_args!(
                         "Object of type `{}` is not callable (due to union elements {})",
-                        called_ty.display(context.db()),
-                        not_callable_tys.display(context.db()),
+                        called_ty.display(db),
+                        Type::display_slice(db, &not_callable_tys),
                     ),
                 );
                 return_ty
@@ -144,12 +144,12 @@ impl<'db> CallOutcome<'db> {
                 callable_ty: called_ty,
                 return_ty,
             }) => {
-                context.report_lint(
+                diagnostics.add_lint(
                     &CALL_NON_CALLABLE,
                     node,
                     format_args!(
                         "Object of type `{}` is not callable (possibly unbound `__call__` method)",
-                        called_ty.display(context.db())
+                        called_ty.display(db)
                     ),
                 );
                 return_ty
@@ -158,10 +158,11 @@ impl<'db> CallOutcome<'db> {
     }
 
     /// Get the return type of the call as a result.
-    pub(super) fn return_ty_result(
+    pub(super) fn return_ty_result<'a>(
         &self,
-        context: &InferContext<'db>,
+        db: &'db dyn Db,
         node: ast::AnyNodeRef,
+        diagnostics: &'a mut TypeCheckDiagnosticsBuilder<'db>,
     ) -> Result<Type<'db>, NotCallableError<'db>> {
         match self {
             Self::Callable { return_ty } => Ok(*return_ty),
@@ -169,11 +170,11 @@ impl<'db> CallOutcome<'db> {
                 return_ty,
                 revealed_ty,
             } => {
-                context.report_diagnostic(
+                diagnostics.add(
                     node,
                     DiagnosticId::RevealedType,
                     Severity::Info,
-                    format_args!("Revealed type is `{}`", revealed_ty.display(context.db())),
+                    format_args!("Revealed type is `{}`", revealed_ty.display(db)),
                 );
                 Ok(*return_ty)
             }
@@ -186,16 +187,14 @@ impl<'db> CallOutcome<'db> {
                 call_outcome,
             } => Err(NotCallableError::PossiblyUnboundDunderCall {
                 callable_ty: *called_ty,
-                return_ty: call_outcome
-                    .return_ty(context.db())
-                    .unwrap_or(Type::Unknown),
+                return_ty: call_outcome.return_ty(db).unwrap_or(Type::Unknown),
             }),
             Self::Union {
                 outcomes,
                 called_ty,
             } => {
                 let mut not_callable = vec![];
-                let mut union_builder = UnionBuilder::new(context.db());
+                let mut union_builder = UnionBuilder::new(db);
                 let mut revealed = false;
                 for outcome in outcomes {
                     let return_ty = match outcome {
@@ -211,10 +210,10 @@ impl<'db> CallOutcome<'db> {
                                 *return_ty
                             } else {
                                 revealed = true;
-                                outcome.unwrap_with_diagnostic(context, node)
+                                outcome.unwrap_with_diagnostic(db, node, diagnostics)
                             }
                         }
-                        _ => outcome.unwrap_with_diagnostic(context, node),
+                        _ => outcome.unwrap_with_diagnostic(db, node, diagnostics),
                     };
                     union_builder = union_builder.add(return_ty);
                 }

crates/red_knot_python_semantic/src/types/class_base.rs

@@ -1,185 +0,0 @@
-use crate::types::{
-    todo_type, Class, ClassLiteralType, KnownClass, KnownInstanceType, TodoType, Type,
-};
-use crate::Db;
-use itertools::Either;
-
-/// Enumeration of the possible kinds of types we allow in class bases.
-///
-/// This is much more limited than the [`Type`] enum:
-/// all types that would be invalid to have as a class base are
-/// transformed into [`ClassBase::Unknown`]
-#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, salsa::Update)]
-pub enum ClassBase<'db> {
-    Any,
-    Unknown,
-    Todo(TodoType),
-    Class(Class<'db>),
-}
-
-impl<'db> ClassBase<'db> {
-    pub fn display(self, db: &'db dyn Db) -> impl std::fmt::Display + 'db {
-        struct Display<'db> {
-            base: ClassBase<'db>,
-            db: &'db dyn Db,
-        }
-
-        impl std::fmt::Display for Display<'_> {
-            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
-                match self.base {
-                    ClassBase::Any => f.write_str("Any"),
-                    ClassBase::Todo(todo) => todo.fmt(f),
-                    ClassBase::Unknown => f.write_str("Unknown"),
-                    ClassBase::Class(class) => write!(f, "<class '{}'>", class.name(self.db)),
-                }
-            }
-        }
-
-        Display { base: self, db }
-    }
-
-    /// Return a `ClassBase` representing the class `builtins.object`
-    pub(super) fn object(db: &'db dyn Db) -> Self {
-        KnownClass::Object
-            .to_class_literal(db)
-            .into_class_literal()
-            .map_or(Self::Unknown, |ClassLiteralType { class }| {
-                Self::Class(class)
-            })
-    }
-
-    /// Attempt to resolve `ty` into a `ClassBase`.
-    ///
-    /// Return `None` if `ty` is not an acceptable type for a class base.
-    pub(super) fn try_from_ty(db: &'db dyn Db, ty: Type<'db>) -> Option<Self> {
-        match ty {
-            Type::Any => Some(Self::Any),
-            Type::Unknown => Some(Self::Unknown),
-            Type::Todo(todo) => Some(Self::Todo(todo)),
-            Type::ClassLiteral(ClassLiteralType { class }) => Some(Self::Class(class)),
-            Type::Union(_) => None, // TODO -- forces consideration of multiple possible MROs?
-            Type::Intersection(_) => None, // TODO -- probably incorrect?
-            Type::Instance(_) => None, // TODO -- handle `__mro_entries__`?
-            Type::Never
-            | Type::BooleanLiteral(_)
-            | Type::FunctionLiteral(_)
-            | Type::BytesLiteral(_)
-            | Type::IntLiteral(_)
-            | Type::StringLiteral(_)
-            | Type::LiteralString
-            | Type::Tuple(_)
-            | Type::SliceLiteral(_)
-            | Type::ModuleLiteral(_)
-            | Type::SubclassOf(_)
-            | Type::AlwaysFalsy
-            | Type::AlwaysTruthy => None,
-            Type::KnownInstance(known_instance) => match known_instance {
-                KnownInstanceType::TypeVar(_)
-                | KnownInstanceType::TypeAliasType(_)
-                | KnownInstanceType::Annotated
-                | KnownInstanceType::Literal
-                | KnownInstanceType::LiteralString
-                | KnownInstanceType::Union
-                | KnownInstanceType::NoReturn
-                | KnownInstanceType::Never
-                | KnownInstanceType::Final
-                | KnownInstanceType::NotRequired
-                | KnownInstanceType::TypeGuard
-                | KnownInstanceType::TypeIs
-                | KnownInstanceType::TypingSelf
-                | KnownInstanceType::Unpack
-                | KnownInstanceType::ClassVar
-                | KnownInstanceType::Concatenate
-                | KnownInstanceType::Required
-                | KnownInstanceType::TypeAlias
-                | KnownInstanceType::ReadOnly
-                | KnownInstanceType::Optional => None,
-                KnownInstanceType::Any => Some(Self::Any),
-                // TODO: Classes inheriting from `typing.Type` et al. also have `Generic` in their MRO
-                KnownInstanceType::Dict => {
-                    Self::try_from_ty(db, KnownClass::Dict.to_class_literal(db))
-                }
-                KnownInstanceType::List => {
-                    Self::try_from_ty(db, KnownClass::List.to_class_literal(db))
-                }
-                KnownInstanceType::Type => {
-                    Self::try_from_ty(db, KnownClass::Type.to_class_literal(db))
-                }
-                KnownInstanceType::Tuple => {
-                    Self::try_from_ty(db, KnownClass::Tuple.to_class_literal(db))
-                }
-                KnownInstanceType::Set => {
-                    Self::try_from_ty(db, KnownClass::Set.to_class_literal(db))
-                }
-                KnownInstanceType::FrozenSet => {
-                    Self::try_from_ty(db, KnownClass::FrozenSet.to_class_literal(db))
-                }
-                KnownInstanceType::ChainMap => {
-                    Self::try_from_ty(db, KnownClass::ChainMap.to_class_literal(db))
-                }
-                KnownInstanceType::Counter => {
-                    Self::try_from_ty(db, KnownClass::Counter.to_class_literal(db))
-                }
-                KnownInstanceType::DefaultDict => {
-                    Self::try_from_ty(db, KnownClass::DefaultDict.to_class_literal(db))
-                }
-                KnownInstanceType::Deque => {
-                    Self::try_from_ty(db, KnownClass::Deque.to_class_literal(db))
-                }
-                KnownInstanceType::OrderedDict => {
-                    Self::try_from_ty(db, KnownClass::OrderedDict.to_class_literal(db))
-                }
-                KnownInstanceType::Callable => {
-                    Self::try_from_ty(db, todo_type!("Support for Callable as a base class"))
-                }
-            },
-        }
-    }
-
-    pub(super) fn into_class(self) -> Option<Class<'db>> {
-        match self {
-            Self::Class(class) => Some(class),
-            _ => None,
-        }
-    }
-
-    /// Iterate over the MRO of this base
-    pub(super) fn mro(
-        self,
-        db: &'db dyn Db,
-    ) -> Either<impl Iterator<Item = ClassBase<'db>>, impl Iterator<Item = ClassBase<'db>>> {
-        match self {
-            ClassBase::Any => Either::Left([ClassBase::Any, ClassBase::object(db)].into_iter()),
-            ClassBase::Unknown => {
-                Either::Left([ClassBase::Unknown, ClassBase::object(db)].into_iter())
-            }
-            ClassBase::Todo(todo) => {
-                Either::Left([ClassBase::Todo(todo), ClassBase::object(db)].into_iter())
-            }
-            ClassBase::Class(class) => Either::Right(class.iter_mro(db)),
-        }
-    }
-}
-
-impl<'db> From<Class<'db>> for ClassBase<'db> {
-    fn from(value: Class<'db>) -> Self {
-        ClassBase::Class(value)
-    }
-}
-
-impl<'db> From<ClassBase<'db>> for Type<'db> {
-    fn from(value: ClassBase<'db>) -> Self {
-        match value {
-            ClassBase::Any => Type::Any,
-            ClassBase::Todo(todo) => Type::Todo(todo),
-            ClassBase::Unknown => Type::Unknown,
-            ClassBase::Class(class) => Type::class_literal(class),
-        }
-    }
-}
-
-impl<'db> From<&ClassBase<'db>> for Type<'db> {
-    fn from(value: &ClassBase<'db>) -> Self {
-        Self::from(*value)
-    }
-}

crates/red_knot_python_semantic/src/types/context.rs

@@ -1,131 +0,0 @@
-use std::fmt;
-
-use drop_bomb::DebugDropBomb;
-use ruff_db::{
-    diagnostic::{DiagnosticId, Severity},
-    files::File,
-};
-use ruff_python_ast::AnyNodeRef;
-use ruff_text_size::Ranged;
-
-use crate::{
-    lint::{LintId, LintMetadata},
-    Db,
-};
-
-use super::{TypeCheckDiagnostic, TypeCheckDiagnostics};
-
-/// Context for inferring the types of a single file.
-///
-/// One context exists for at least for every inferred region but it's
-/// possible that inferring a sub-region, like an unpack assignment, creates
-/// a sub-context.
-///
-/// Tracks the reported diagnostics of the inferred region.
-///
-/// ## Consuming
-/// It's important that the context is explicitly consumed before dropping by calling
-/// [`InferContext::finish`] and the returned diagnostics must be stored
-/// on the current [`TypeInference`](super::infer::TypeInference) result.
-pub(crate) struct InferContext<'db> {
-    db: &'db dyn Db,
-    file: File,
-    diagnostics: std::cell::RefCell<TypeCheckDiagnostics>,
-    bomb: DebugDropBomb,
-}
-
-impl<'db> InferContext<'db> {
-    pub(crate) fn new(db: &'db dyn Db, file: File) -> Self {
-        Self {
-            db,
-            file,
-            diagnostics: std::cell::RefCell::new(TypeCheckDiagnostics::default()),
-            bomb: DebugDropBomb::new("`InferContext` needs to be explicitly consumed by calling `::finish` to prevent accidental loss of diagnostics."),
-        }
-    }
-
-    /// The file for which the types are inferred.
-    pub(crate) fn file(&self) -> File {
-        self.file
-    }
-
-    pub(crate) fn db(&self) -> &'db dyn Db {
-        self.db
-    }
-
-    pub(crate) fn extend<T>(&mut self, other: &T)
-    where
-        T: WithDiagnostics,
-    {
-        self.diagnostics
-            .get_mut()
-            .extend(other.diagnostics().iter().cloned());
-    }
-
-    /// Reports a lint located at `node`.
-    pub(super) fn report_lint(
-        &self,
-        lint: &'static LintMetadata,
-        node: AnyNodeRef,
-        message: std::fmt::Arguments,
-    ) {
-        // Skip over diagnostics if the rule is disabled.
-        let Some(severity) = self.db.rule_selection().severity(LintId::of(lint)) else {
-            return;
-        };
-
-        self.report_diagnostic(node, DiagnosticId::Lint(lint.name()), severity, message);
-    }
-
-    /// Adds a new diagnostic.
-    ///
-    /// The diagnostic does not get added if the rule isn't enabled for this file.
-    pub(super) fn report_diagnostic(
-        &self,
-        node: AnyNodeRef,
-        id: DiagnosticId,
-        severity: Severity,
-        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.
-        // * Check for suppression comments, bump a counter if the diagnostic is suppressed.
-
-        self.diagnostics.borrow_mut().push(TypeCheckDiagnostic {
-            file: self.file,
-            id,
-            message: message.to_string(),
-            range: node.range(),
-            severity,
-        });
-    }
-
-    #[must_use]
-    pub(crate) fn finish(mut self) -> TypeCheckDiagnostics {
-        self.bomb.defuse();
-        let mut diagnostics = self.diagnostics.into_inner();
-        diagnostics.shrink_to_fit();
-        diagnostics
-    }
-}
-
-impl fmt::Debug for InferContext<'_> {
-    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
-        f.debug_struct("TyContext")
-            .field("file", &self.file)
-            .field("diagnostics", &self.diagnostics)
-            .field("defused", &self.bomb)
-            .finish()
-    }
-}
-
-pub(crate) trait WithDiagnostics {
-    fn diagnostics(&self) -> &TypeCheckDiagnostics;
-}

crates/red_knot_python_semantic/src/types/display.rs

@@ -1,12 +1,10 @@
 //! Display implementations for types.
 
-use std::fmt::{self, Display, Formatter, Write};
-
-use ruff_db::display::FormatterJoinExtension;
 use ruff_python_ast::str::Quote;
 use ruff_python_literal::escape::AsciiEscape;
+use std::fmt::{self, Arguments, Formatter, Write};
 
-use crate::types::class_base::ClassBase;
+use crate::types::mro::ClassBase;
 use crate::types::{
     ClassLiteralType, InstanceType, IntersectionType, KnownClass, StringLiteralType,
     SubclassOfType, Type, UnionType,
@@ -15,25 +13,33 @@ use crate::Db;
 use rustc_hash::FxHashMap;
 
 impl<'db> Type<'db> {
-    pub fn display(&self, db: &'db dyn Db) -> DisplayType {
-        DisplayType { ty: self, db }
+    fn representation(self) -> Representation<'db> {
+        Representation { ty: self }
     }
-    fn representation(self, db: &'db dyn Db) -> DisplayRepresentation<'db> {
-        DisplayRepresentation { db, ty: self }
+
+    pub fn display(self, db: &'db dyn Db) -> DisplayWrapper<'db, Type<'db>> {
+        DisplayWrapper::new(db, self)
+    }
+
+    pub fn display_slice<'types>(
+        db: &'db dyn Db,
+        types: &'types [Type<'db>],
+    ) -> DisplayWrapper<'db, &'types [Type<'db>]> {
+        DisplayWrapper::new(db, types)
     }
 }
 
-#[derive(Copy, Clone)]
-pub struct DisplayType<'db> {
-    ty: &'db Type<'db>,
-    db: &'db dyn Db,
-}
+impl<'db> DisplayType<'db> for Type<'db> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
+        if f.visited.contains(self) {
+            return f.write_str("<recursion>");
+        }
+        f.visited.push(*self);
+
+        let representation = self.representation();
 
-impl Display for DisplayType<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        let representation = self.ty.representation(self.db);
         if matches!(
-            self.ty,
+            self,
             Type::IntLiteral(_)
                 | Type::BooleanLiteral(_)
                 | Type::StringLiteral(_)
@@ -41,76 +47,76 @@ impl Display for DisplayType<'_> {
                 | Type::ClassLiteral(_)
                 | Type::FunctionLiteral(_)
         ) {
-            write!(f, "Literal[{representation}]")
+            f.write_str("Literal[")?;
+            representation.fmt(f)?;
+            f.write_str("]")?;
         } else {
-            representation.fmt(f)
+            representation.fmt(f)?;
         }
-    }
-}
 
-impl fmt::Debug for DisplayType<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        Display::fmt(self, f)
+        let removed = f.visited.pop();
+        debug_assert_eq!(removed, Some(*self));
+
+        Ok(())
     }
 }
 
 /// Writes the string representation of a type, which is the value displayed either as
 /// `Literal[<repr>]` or `Literal[<repr1>, <repr2>]` for literal types or as `<repr>` for
 /// non literals
-struct DisplayRepresentation<'db> {
+struct Representation<'db> {
     ty: Type<'db>,
-    db: &'db dyn Db,
 }
 
-impl Display for DisplayRepresentation<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+impl<'db> DisplayType<'db> for Representation<'db> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
         match self.ty {
             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) {
+                let representation = match class.known(f.db()) {
                     Some(KnownClass::NoneType) => "None",
                     Some(KnownClass::NoDefaultType) => "NoDefault",
-                    _ => class.name(self.db),
+                    _ => class.name(f.db()),
                 };
                 f.write_str(representation)
             }
             // `[Type::Todo]`'s display should be explicit that is not a valid display of
             // any other type
             Type::Todo(todo) => write!(f, "@Todo{todo}"),
-            Type::ModuleLiteral(module) => {
-                write!(f, "<module '{}'>", module.module(self.db).name())
+            Type::ModuleLiteral(file) => {
+                write!(f, "<module '{:?}'>", file.path(f.db()))
             }
             // TODO functions and classes should display using a fully qualified name
-            Type::ClassLiteral(ClassLiteralType { class }) => f.write_str(class.name(self.db)),
+            Type::ClassLiteral(ClassLiteralType { class }) => f.write_str(class.name(f.db())),
             Type::SubclassOf(SubclassOfType {
                 base: ClassBase::Class(class),
             }) => {
                 // Only show the bare class name here; ClassBase::display would render this as
                 // type[<class 'Foo'>] instead of type[Foo].
-                write!(f, "type[{}]", class.name(self.db))
+                write!(f, "type[{}]", class.name(f.db()))
             }
             Type::SubclassOf(SubclassOfType { base }) => {
-                write!(f, "type[{}]", base.display(self.db))
+                write!(f, "type[{}]", base.display(f.db()))
             }
-            Type::KnownInstance(known_instance) => f.write_str(known_instance.repr(self.db)),
-            Type::FunctionLiteral(function) => f.write_str(function.name(self.db)),
-            Type::Union(union) => union.display(self.db).fmt(f),
-            Type::Intersection(intersection) => intersection.display(self.db).fmt(f),
-            Type::IntLiteral(n) => n.fmt(f),
+            Type::KnownInstance(known_instance) => f.write_str(known_instance.repr(f.db())),
+            Type::FunctionLiteral(function) => f.write_str(function.name(f.db())),
+            Type::Union(union) => union.fmt(f),
+            Type::Intersection(intersection) => intersection.fmt(f),
+            Type::IntLiteral(n) => write!(f, "{n}"),
             Type::BooleanLiteral(boolean) => f.write_str(if boolean { "True" } else { "False" }),
-            Type::StringLiteral(string) => string.display(self.db).fmt(f),
+            Type::StringLiteral(string) => string.fmt(f),
             Type::LiteralString => f.write_str("LiteralString"),
             Type::BytesLiteral(bytes) => {
                 let escape =
-                    AsciiEscape::with_preferred_quote(bytes.value(self.db).as_ref(), Quote::Double);
+                    AsciiEscape::with_preferred_quote(bytes.value(f.db()).as_ref(), Quote::Double);
 
                 escape.bytes_repr().write(f)
             }
             Type::SliceLiteral(slice) => {
                 f.write_str("slice[")?;
-                if let Some(start) = slice.start(self.db) {
+                if let Some(start) = slice.start(f.db()) {
                     write!(f, "Literal[{start}]")?;
                 } else {
                     f.write_str("None")?;
@@ -118,13 +124,13 @@ impl Display for DisplayRepresentation<'_> {
 
                 f.write_str(", ")?;
 
-                if let Some(stop) = slice.stop(self.db) {
+                if let Some(stop) = slice.stop(f.db()) {
                     write!(f, "Literal[{stop}]")?;
                 } else {
                     f.write_str("None")?;
                 }
 
-                if let Some(step) = slice.step(self.db) {
+                if let Some(step) = slice.step(f.db()) {
                     write!(f, ", Literal[{step}]")?;
                 }
 
@@ -132,34 +138,21 @@ impl Display for DisplayRepresentation<'_> {
             }
             Type::Tuple(tuple) => {
                 f.write_str("tuple[")?;
-                let elements = tuple.elements(self.db);
+                let elements = tuple.elements(f.db());
                 if elements.is_empty() {
                     f.write_str("()")?;
                 } else {
-                    elements.display(self.db).fmt(f)?;
+                    elements.fmt(f)?;
                 }
                 f.write_str("]")
             }
-            Type::AlwaysTruthy => f.write_str("AlwaysTruthy"),
-            Type::AlwaysFalsy => f.write_str("AlwaysFalsy"),
         }
     }
 }
 
-impl<'db> UnionType<'db> {
-    fn display(&'db self, db: &'db dyn Db) -> DisplayUnionType<'db> {
-        DisplayUnionType { db, ty: self }
-    }
-}
-
-struct DisplayUnionType<'db> {
-    ty: &'db UnionType<'db>,
-    db: &'db dyn Db,
-}
-
-impl Display for DisplayUnionType<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        let elements = self.ty.elements(self.db);
+impl<'db> DisplayType<'db> for UnionType<'db> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
+        let elements = self.elements(f.db());
 
         // Group condensed-display types by kind.
         let mut grouped_condensed_kinds = FxHashMap::default();
@@ -183,12 +176,11 @@ impl Display for DisplayUnionType<'_> {
                 if kind == CondensedDisplayTypeKind::Int {
                     condensed_kind.sort_unstable_by_key(|ty| ty.expect_int_literal());
                 }
-                join.entry(&DisplayLiteralGroup {
+                join.entry(&LiteralGroup {
                     literals: condensed_kind,
-                    db: self.db,
                 });
             } else {
-                join.entry(&element.display(self.db));
+                join.entry(element);
             }
         }
 
@@ -200,22 +192,15 @@ impl Display for DisplayUnionType<'_> {
     }
 }
 
-impl fmt::Debug for DisplayUnionType<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        Display::fmt(self, f)
-    }
-}
-
-struct DisplayLiteralGroup<'db> {
+struct LiteralGroup<'db> {
     literals: Vec<Type<'db>>,
-    db: &'db dyn Db,
 }
 
-impl Display for DisplayLiteralGroup<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+impl<'db> DisplayType<'db> for LiteralGroup<'db> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
         f.write_str("Literal[")?;
         f.join(", ")
-            .entries(self.literals.iter().map(|ty| ty.representation(self.db)))
+            .entries(self.literals.iter().map(|ty| ty.representation()))
             .finish()?;
         f.write_str("]")
     }
@@ -251,106 +236,63 @@ impl TryFrom<Type<'_>> for CondensedDisplayTypeKind {
     }
 }
 
-impl<'db> IntersectionType<'db> {
-    fn display(&'db self, db: &'db dyn Db) -> DisplayIntersectionType<'db> {
-        DisplayIntersectionType { db, ty: self }
-    }
-}
-
-struct DisplayIntersectionType<'db> {
-    ty: &'db IntersectionType<'db>,
-    db: &'db dyn Db,
-}
-
-impl Display for DisplayIntersectionType<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+impl<'db> DisplayType<'db> for IntersectionType<'db> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
         let tys = self
-            .ty
-            .positive(self.db)
+            .positive(f.db())
             .iter()
-            .map(|&ty| DisplayMaybeNegatedType {
-                ty,
-                db: self.db,
-                negated: false,
-            })
+            .map(|&ty| MaybeNegatedType { ty, negated: false })
             .chain(
-                self.ty
-                    .negative(self.db)
+                self.negative(f.db())
                     .iter()
-                    .map(|&ty| DisplayMaybeNegatedType {
-                        ty,
-                        db: self.db,
-                        negated: true,
-                    }),
+                    .map(|&ty| MaybeNegatedType { ty, negated: true }),
             );
         f.join(" & ").entries(tys).finish()
     }
 }
 
-impl fmt::Debug for DisplayIntersectionType<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        Display::fmt(self, f)
-    }
-}
-
-struct DisplayMaybeNegatedType<'db> {
+struct MaybeNegatedType<'db> {
     ty: Type<'db>,
-    db: &'db dyn Db,
     negated: bool,
 }
 
-impl Display for DisplayMaybeNegatedType<'_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
+impl<'db> DisplayType<'db> for MaybeNegatedType<'db> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
         if self.negated {
             f.write_str("~")?;
         }
-        self.ty.display(self.db).fmt(f)
+
+        self.ty.fmt(f)
     }
 }
 
-pub(crate) trait TypeArrayDisplay<'db> {
-    fn display(&self, db: &'db dyn Db) -> DisplayTypeArray;
-}
-
-impl<'db> TypeArrayDisplay<'db> for Box<[Type<'db>]> {
-    fn display(&self, db: &'db dyn Db) -> DisplayTypeArray {
-        DisplayTypeArray { types: self, db }
+impl<'db> DisplayType<'db> for [Type<'db>] {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
+        f.join(", ").entries(self.iter().copied()).finish()
     }
 }
 
-impl<'db> TypeArrayDisplay<'db> for Vec<Type<'db>> {
-    fn display(&self, db: &'db dyn Db) -> DisplayTypeArray {
-        DisplayTypeArray { types: self, db }
+impl<'db> DisplayType<'db> for &[Type<'db>] {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
+        (**self).fmt(f)
     }
 }
 
-pub(crate) struct DisplayTypeArray<'b, 'db> {
-    types: &'b [Type<'db>],
-    db: &'db dyn Db,
-}
-
-impl Display for DisplayTypeArray<'_, '_> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        f.join(", ")
-            .entries(self.types.iter().map(|ty| ty.display(self.db)))
-            .finish()
+impl<'db> DisplayType<'db> for Box<[Type<'db>]> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
+        (**self).fmt(f)
     }
 }
 
-impl<'db> StringLiteralType<'db> {
-    fn display(&'db self, db: &'db dyn Db) -> DisplayStringLiteralType<'db> {
-        DisplayStringLiteralType { db, ty: self }
+impl<'db> DisplayType<'db> for Vec<Type<'db>> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
+        (**self).fmt(f)
     }
 }
 
-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);
+impl<'db> DisplayType<'db> for StringLiteralType<'db> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
+        let value = self.value(f.db());
         f.write_char('"')?;
         for ch in value.chars() {
             match ch {
@@ -364,6 +306,119 @@ impl Display for DisplayStringLiteralType<'_> {
     }
 }
 
+struct TypeFormatter<'db, 'write> {
+    db: &'db dyn Db,
+    write: &'write mut dyn Write,
+    visited: Vec<Type<'db>>,
+}
+
+impl<'db, 'write> TypeFormatter<'db, 'write> {
+    pub(crate) fn new(db: &'db dyn Db, write: &'write mut dyn Write) -> Self {
+        Self {
+            db,
+            write,
+            visited: Vec::default(),
+        }
+    }
+
+    pub(crate) fn join<'f>(&'f mut self, separator: &'static str) -> Join<'db, 'f, 'write> {
+        Join {
+            fmt: self,
+            separator,
+            result: Ok(()),
+            seen_first: false,
+        }
+    }
+
+    pub(crate) fn db(&self) -> &'db dyn Db {
+        self.db
+    }
+}
+
+impl Write for TypeFormatter<'_, '_> {
+    fn write_str(&mut self, s: &str) -> fmt::Result {
+        self.write.write_str(s)
+    }
+
+    fn write_char(&mut self, c: char) -> fmt::Result {
+        self.write.write_char(c)
+    }
+
+    fn write_fmt(&mut self, args: Arguments<'_>) -> fmt::Result {
+        self.write.write_fmt(args)
+    }
+}
+
+trait DisplayType<'db> {
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result;
+}
+
+pub struct DisplayWrapper<'db, T> {
+    db: &'db dyn Db,
+    inner: T,
+}
+
+impl<'db, T> DisplayWrapper<'db, T> {
+    fn new(db: &'db dyn Db, inner: T) -> Self {
+        Self { db, inner }
+    }
+}
+
+impl<'db, T> DisplayType<'db> for DisplayWrapper<'db, T>
+where
+    T: DisplayType<'db>,
+{
+    fn fmt(&self, f: &mut TypeFormatter<'db, '_>) -> fmt::Result {
+        self.inner.fmt(f)
+    }
+}
+
+impl<'db, T> fmt::Display for DisplayWrapper<'db, T>
+where
+    T: DisplayType<'db>,
+{
+    fn fmt(&self, f: &mut Formatter) -> fmt::Result {
+        let mut f = TypeFormatter::new(self.db, f);
+        DisplayType::fmt(self, &mut f)
+    }
+}
+
+struct Join<'db, 'f, 'write> {
+    fmt: &'f mut TypeFormatter<'db, 'write>,
+    separator: &'static str,
+    result: fmt::Result,
+    seen_first: bool,
+}
+
+impl<'db> Join<'db, '_, '_> {
+    fn entry(&mut self, item: &dyn DisplayType<'db>) -> &mut Self {
+        if self.seen_first {
+            self.result = self
+                .result
+                .and_then(|()| self.fmt.write_str(self.separator));
+        } else {
+            self.seen_first = true;
+        }
+        self.result = self.result.and_then(|()| item.fmt(self.fmt));
+        self
+    }
+
+    fn entries<I, F>(&mut self, items: I) -> &mut Self
+    where
+        I: IntoIterator<Item = F>,
+        F: DisplayType<'db>,
+    {
+        for item in items {
+            self.entry(&item);
+        }
+        self
+    }
+
+    fn finish(&mut self) -> fmt::Result {
+        self.result
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use ruff_db::files::system_path_to_file;
@@ -408,7 +463,7 @@ mod tests {
             Type::none(&db),
         ];
         let union = UnionType::from_elements(&db, union_elements).expect_union();
-        let display = format!("{}", union.display(&db));
+        let display = format!("{}", Type::Union(union).display(&db));
         assert_eq!(
             display,
             concat!(

crates/red_knot_python_semantic/src/types/mro.rs

@@ -1,10 +1,10 @@
 use std::collections::VecDeque;
 use std::ops::Deref;
 
+use itertools::Either;
 use rustc_hash::FxHashSet;
 
-use crate::types::class_base::ClassBase;
-use crate::types::{Class, KnownClass, Type};
+use super::{Class, ClassLiteralType, KnownClass, KnownInstanceType, TodoType, Type};
 use crate::Db;
 
 /// The inferred method resolution order of a given class.
@@ -117,7 +117,7 @@ impl<'db> Mro<'db> {
                     for (index, base) in valid_bases
                         .iter()
                         .enumerate()
-                        .filter_map(|(index, base)| Some((index, base.into_class()?)))
+                        .filter_map(|(index, base)| Some((index, base.into_class_literal_type()?)))
                     {
                         if !seen_bases.insert(base) {
                             duplicate_bases.push((index, base));
@@ -287,6 +287,136 @@ pub(super) enum MroErrorKind<'db> {
     UnresolvableMro { bases_list: Box<[ClassBase<'db>]> },
 }
 
+/// Enumeration of the possible kinds of types we allow in class bases.
+///
+/// This is much more limited than the [`Type`] enum:
+/// all types that would be invalid to have as a class base are
+/// transformed into [`ClassBase::Unknown`]
+#[derive(Debug, Copy, Clone, Hash, PartialEq, Eq, salsa::Update)]
+pub enum ClassBase<'db> {
+    Any,
+    Unknown,
+    Todo(TodoType),
+    Class(Class<'db>),
+}
+
+impl<'db> ClassBase<'db> {
+    pub fn display(self, db: &'db dyn Db) -> impl std::fmt::Display + 'db {
+        struct Display<'db> {
+            base: ClassBase<'db>,
+            db: &'db dyn Db,
+        }
+
+        impl std::fmt::Display for Display<'_> {
+            fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+                match self.base {
+                    ClassBase::Any => f.write_str("Any"),
+                    ClassBase::Todo(todo) => todo.fmt(f),
+                    ClassBase::Unknown => f.write_str("Unknown"),
+                    ClassBase::Class(class) => write!(f, "<class '{}'>", class.name(self.db)),
+                }
+            }
+        }
+
+        Display { base: self, db }
+    }
+
+    /// Return a `ClassBase` representing the class `builtins.object`
+    fn object(db: &'db dyn Db) -> Self {
+        KnownClass::Object
+            .to_class_literal(db)
+            .into_class_literal()
+            .map_or(Self::Unknown, |ClassLiteralType { class }| {
+                Self::Class(class)
+            })
+    }
+
+    /// Attempt to resolve `ty` into a `ClassBase`.
+    ///
+    /// Return `None` if `ty` is not an acceptable type for a class base.
+    fn try_from_ty(db: &'db dyn Db, ty: Type<'db>) -> Option<Self> {
+        match ty {
+            Type::Any => Some(Self::Any),
+            Type::Unknown => Some(Self::Unknown),
+            Type::Todo(todo) => Some(Self::Todo(todo)),
+            Type::ClassLiteral(ClassLiteralType { class }) => Some(Self::Class(class)),
+            Type::Union(_) => None, // TODO -- forces consideration of multiple possible MROs?
+            Type::Intersection(_) => None, // TODO -- probably incorrect?
+            Type::Instance(_) => None, // TODO -- handle `__mro_entries__`?
+            Type::Never
+            | Type::BooleanLiteral(_)
+            | Type::FunctionLiteral(_)
+            | Type::BytesLiteral(_)
+            | Type::IntLiteral(_)
+            | Type::StringLiteral(_)
+            | 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::LiteralString
+                | KnownInstanceType::Union
+                | KnownInstanceType::NoReturn
+                | KnownInstanceType::Never
+                | KnownInstanceType::Optional => None,
+                KnownInstanceType::Any => Some(Self::Any),
+                // TODO: Classes inheriting from `typing.Type` et al. also have `Generic` in their MRO
+                KnownInstanceType::Type => {
+                    ClassBase::try_from_ty(db, KnownClass::Type.to_class_literal(db))
+                }
+                KnownInstanceType::Tuple => {
+                    ClassBase::try_from_ty(db, KnownClass::Tuple.to_class_literal(db))
+                }
+            },
+        }
+    }
+
+    fn into_class_literal_type(self) -> Option<Class<'db>> {
+        match self {
+            Self::Class(class) => Some(class),
+            _ => None,
+        }
+    }
+
+    /// Iterate over the MRO of this base
+    fn mro(
+        self,
+        db: &'db dyn Db,
+    ) -> Either<impl Iterator<Item = ClassBase<'db>>, impl Iterator<Item = ClassBase<'db>>> {
+        match self {
+            ClassBase::Any => Either::Left([ClassBase::Any, ClassBase::object(db)].into_iter()),
+            ClassBase::Unknown => {
+                Either::Left([ClassBase::Unknown, ClassBase::object(db)].into_iter())
+            }
+            ClassBase::Todo(todo) => {
+                Either::Left([ClassBase::Todo(todo), ClassBase::object(db)].into_iter())
+            }
+            ClassBase::Class(class) => Either::Right(class.iter_mro(db)),
+        }
+    }
+}
+
+impl<'db> From<Class<'db>> for ClassBase<'db> {
+    fn from(value: Class<'db>) -> Self {
+        ClassBase::Class(value)
+    }
+}
+
+impl<'db> From<ClassBase<'db>> for Type<'db> {
+    fn from(value: ClassBase<'db>) -> Self {
+        match value {
+            ClassBase::Any => Type::Any,
+            ClassBase::Todo(todo) => Type::Todo(todo),
+            ClassBase::Unknown => Type::Unknown,
+            ClassBase::Class(class) => Type::class_literal(class),
+        }
+    }
+}
+
 /// Implementation of the [C3-merge algorithm] for calculating a Python class's
 /// [method resolution order].
 ///

crates/red_knot_python_semantic/src/types/narrow.rs

@@ -196,7 +196,6 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
         is_positive: bool,
     ) -> Option<NarrowingConstraints<'db>> {
         match expression_node {
-            ast::Expr::Name(name) => Some(self.evaluate_expr_name(name, is_positive)),
             ast::Expr::Compare(expr_compare) => {
                 self.evaluate_expr_compare(expr_compare, expression, is_positive)
             }
@@ -255,31 +254,6 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
         }
     }
 
-    fn evaluate_expr_name(
-        &mut self,
-        expr_name: &ast::ExprName,
-        is_positive: bool,
-    ) -> NarrowingConstraints<'db> {
-        let ast::ExprName { id, .. } = expr_name;
-
-        let symbol = self
-            .symbols()
-            .symbol_id_by_name(id)
-            .expect("Should always have a symbol for every Name node");
-        let mut constraints = NarrowingConstraints::default();
-
-        constraints.insert(
-            symbol,
-            if is_positive {
-                Type::AlwaysFalsy.negate(self.db)
-            } else {
-                Type::AlwaysTruthy.negate(self.db)
-            },
-        );
-
-        constraints
-    }
-
     fn evaluate_expr_compare(
         &mut self,
         expr_compare: &ast::ExprCompare,

crates/red_knot_python_semantic/src/types/property_tests.rs

@@ -65,18 +65,9 @@ fn arbitrary_core_type(g: &mut Gen) -> Ty {
         Ty::BuiltinClassLiteral("bool"),
         Ty::BuiltinClassLiteral("object"),
         Ty::BuiltinInstance("type"),
-        Ty::AbcInstance("ABC"),
-        Ty::AbcInstance("ABCMeta"),
         Ty::SubclassOfAny,
         Ty::SubclassOfBuiltinClass("object"),
         Ty::SubclassOfBuiltinClass("str"),
-        Ty::SubclassOfBuiltinClass("type"),
-        Ty::AbcClassLiteral("ABC"),
-        Ty::AbcClassLiteral("ABCMeta"),
-        Ty::SubclassOfAbcClass("ABC"),
-        Ty::SubclassOfAbcClass("ABCMeta"),
-        Ty::AlwaysTruthy,
-        Ty::AlwaysFalsy,
     ])
     .unwrap()
     .clone()

crates/red_knot_python_semantic/src/types/string_annotation.rs

@@ -1,13 +1,13 @@
+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::declare_lint;
 use crate::lint::{Level, LintStatus};
-
-use super::context::InferContext;
+use crate::types::diagnostic::{TypeCheckDiagnostics, TypeCheckDiagnosticsBuilder};
+use crate::{declare_lint, Db};
 
 declare_lint! {
     /// ## What it does
@@ -127,23 +127,24 @@ declare_lint! {
     }
 }
 
+type AnnotationParseResult = Result<Parsed<ModExpression>, TypeCheckDiagnostics>;
+
 /// Parses the given expression as a string annotation.
 pub(crate) fn parse_string_annotation(
-    context: &InferContext,
+    db: &dyn Db,
+    file: File,
     string_expr: &ast::ExprStringLiteral,
-) -> Option<Parsed<ModExpression>> {
-    let file = context.file();
-    let db = context.db();
-
+) -> 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() {
-            context.report_lint(
+            diagnostics.add_lint(
                 &RAW_STRING_TYPE_ANNOTATION,
                 string_literal.into(),
                 format_args!("Type expressions cannot use raw string literal"),
@@ -166,8 +167,8 @@ pub(crate) fn parse_string_annotation(
             // """ = 1
             // ```
             match parse_expression_range(source.as_str(), range_excluding_quotes) {
-                Ok(parsed) => return Some(parsed),
-                Err(parse_error) => context.report_lint(
+                Ok(parsed) => return Ok(parsed),
+                Err(parse_error) => diagnostics.add_lint(
                     &INVALID_SYNTAX_IN_FORWARD_ANNOTATION,
                     string_literal.into(),
                     format_args!("Syntax error in forward annotation: {}", parse_error.error),
@@ -176,7 +177,7 @@ pub(crate) fn parse_string_annotation(
         } else {
             // The raw contents of the string doesn't match the parsed content. This could be the
             // case for annotations that contain escape sequences.
-            context.report_lint(
+            diagnostics.add_lint(
                 &ESCAPE_CHARACTER_IN_FORWARD_ANNOTATION,
                 string_expr.into(),
                 format_args!("Type expressions cannot contain escape characters"),
@@ -184,12 +185,12 @@ pub(crate) fn parse_string_annotation(
         }
     } else {
         // String is implicitly concatenated.
-        context.report_lint(
+        diagnostics.add_lint(
             &IMPLICIT_CONCATENATED_STRING_TYPE_ANNOTATION,
             string_expr.into(),
             format_args!("Type expressions cannot span multiple string literals"),
         );
     }
 
-    None
+    Err(diagnostics.finish())
 }

crates/red_knot_python_semantic/src/types/unpacker.rs

@@ -6,34 +6,30 @@ use rustc_hash::FxHashMap;
 
 use crate::semantic_index::ast_ids::{HasScopedExpressionId, ScopedExpressionId};
 use crate::semantic_index::symbol::ScopeId;
-use crate::types::{todo_type, Type, TypeCheckDiagnostics};
+use crate::types::{todo_type, Type, TypeCheckDiagnostics, TypeCheckDiagnosticsBuilder};
 use crate::Db;
 
-use super::context::{InferContext, WithDiagnostics};
-
 /// Unpacks the value expression type to their respective targets.
 pub(crate) struct Unpacker<'db> {
-    context: InferContext<'db>,
+    db: &'db dyn Db,
     targets: FxHashMap<ScopedExpressionId, Type<'db>>,
+    diagnostics: TypeCheckDiagnosticsBuilder<'db>,
 }
 
 impl<'db> Unpacker<'db> {
     pub(crate) fn new(db: &'db dyn Db, file: File) -> Self {
         Self {
-            context: InferContext::new(db, file),
+            db,
             targets: FxHashMap::default(),
+            diagnostics: TypeCheckDiagnosticsBuilder::new(db, file),
         }
     }
 
-    fn db(&self) -> &'db dyn Db {
-        self.context.db()
-    }
-
     pub(crate) fn unpack(&mut self, target: &ast::Expr, value_ty: Type<'db>, scope: ScopeId<'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_expression_id(self.db, scope), value_ty);
             }
             ast::Expr::Starred(ast::ExprStarred { value, .. }) => {
                 self.unpack(value, value_ty, scope);
@@ -44,11 +40,11 @@ impl<'db> Unpacker<'db> {
                     let starred_index = elts.iter().position(ast::Expr::is_starred_expr);
 
                     let element_types = if let Some(starred_index) = starred_index {
-                        if tuple_ty.len(self.db()) >= elts.len() - 1 {
+                        if tuple_ty.len(self.db) >= elts.len() - 1 {
                             let mut element_types = Vec::with_capacity(elts.len());
                             element_types.extend_from_slice(
                                 // SAFETY: Safe because of the length check above.
-                                &tuple_ty.elements(self.db())[..starred_index],
+                                &tuple_ty.elements(self.db)[..starred_index],
                             );
 
                             // E.g., in `(a, *b, c, d) = ...`, the index of starred element `b`
@@ -56,10 +52,10 @@ impl<'db> Unpacker<'db> {
                             let remaining = elts.len() - (starred_index + 1);
                             // This index represents the type of the last element that belongs
                             // to the starred expression, in an exclusive manner.
-                            let starred_end_index = tuple_ty.len(self.db()) - remaining;
+                            let starred_end_index = tuple_ty.len(self.db) - remaining;
                             // SAFETY: Safe because of the length check above.
                             let _starred_element_types =
-                                &tuple_ty.elements(self.db())[starred_index..starred_end_index];
+                                &tuple_ty.elements(self.db)[starred_index..starred_end_index];
                             // 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);
@@ -67,11 +63,11 @@ impl<'db> Unpacker<'db> {
 
                             element_types.extend_from_slice(
                                 // SAFETY: Safe because of the length check above.
-                                &tuple_ty.elements(self.db())[starred_end_index..],
+                                &tuple_ty.elements(self.db)[starred_end_index..],
                             );
                             Cow::Owned(element_types)
                         } else {
-                            let mut element_types = tuple_ty.elements(self.db()).to_vec();
+                            let mut element_types = tuple_ty.elements(self.db).to_vec();
                             // Subtract 1 to insert the starred expression type at the correct
                             // index.
                             element_types.resize(elts.len() - 1, Type::Unknown);
@@ -80,7 +76,7 @@ impl<'db> Unpacker<'db> {
                             Cow::Owned(element_types)
                         }
                     } else {
-                        Cow::Borrowed(tuple_ty.elements(self.db()).as_ref())
+                        Cow::Borrowed(tuple_ty.elements(self.db).as_ref())
                     };
 
                     for (index, element) in elts.iter().enumerate() {
@@ -98,9 +94,9 @@ impl<'db> Unpacker<'db> {
                     // 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(
-                        self.db(),
+                        self.db,
                         std::iter::repeat(Type::LiteralString)
-                            .take(string_literal_ty.python_len(self.db())),
+                            .take(string_literal_ty.python_len(self.db)),
                     );
                     self.unpack(target, value_ty, scope);
                 }
@@ -109,8 +105,8 @@ impl<'db> Unpacker<'db> {
                         Type::LiteralString
                     } else {
                         value_ty
-                            .iterate(self.db())
-                            .unwrap_with_diagnostic(&self.context, AnyNodeRef::from(target))
+                            .iterate(self.db)
+                            .unwrap_with_diagnostic(AnyNodeRef::from(target), &mut self.diagnostics)
                     };
                     for element in elts {
                         self.unpack(element, value_ty, scope);
@@ -124,7 +120,7 @@ impl<'db> Unpacker<'db> {
     pub(crate) fn finish(mut self) -> UnpackResult<'db> {
         self.targets.shrink_to_fit();
         UnpackResult {
-            diagnostics: self.context.finish(),
+            diagnostics: self.diagnostics.finish(),
             targets: self.targets,
         }
     }
@@ -140,10 +136,8 @@ impl<'db> UnpackResult<'db> {
     pub(crate) fn get(&self, expr_id: ScopedExpressionId) -> Option<Type<'db>> {
         self.targets.get(&expr_id).copied()
     }
-}
 
-impl WithDiagnostics for UnpackResult<'_> {
-    fn diagnostics(&self) -> &TypeCheckDiagnostics {
+    pub(crate) fn diagnostics(&self) -> &TypeCheckDiagnostics {
         &self.diagnostics
     }
 }

crates/red_knot_server/src/server/api.rs

@@ -91,11 +91,11 @@ fn background_request_task<'a, R: traits::BackgroundDocumentRequestHandler>(
         let db = match path {
             AnySystemPath::System(path) => {
                 match session.workspace_db_for_path(path.as_std_path()) {
-                    Some(db) => db.clone(),
-                    None => session.default_workspace_db().clone(),
+                    Some(db) => db.snapshot(),
+                    None => session.default_workspace_db().snapshot(),
                 }
             }
-            AnySystemPath::SystemVirtual(_) => session.default_workspace_db().clone(),
+            AnySystemPath::SystemVirtual(_) => session.default_workspace_db().snapshot(),
         };
 
         let Some(snapshot) = session.take_snapshot(url) else {

crates/red_knot_test/Cargo.toml

@@ -11,9 +11,9 @@ authors.workspace = true
 license.workspace = true
 
 [dependencies]
-red_knot_python_semantic = { workspace = true, features = ["serde"] }
+red_knot_python_semantic = { workspace = true }
 red_knot_vendored = { workspace = true }
-ruff_db = { workspace = true, features = ["testing"] }
+ruff_db = { workspace = true }
 ruff_index = { workspace = true }
 ruff_python_trivia = { workspace = true }
 ruff_source_file = { workspace = true }
@@ -30,5 +30,7 @@ smallvec = { workspace = true }
 serde = { workspace = true }
 toml = { workspace = true }
 
+[dev-dependencies]
+
 [lints]
 workspace = true

crates/red_knot_test/README.md

@@ -234,15 +234,13 @@ language tag:
 ````markdown
 ```toml
 [environment]
-python-version = "3.10"
+target-version = "3.10"
 ```
 ````
 
 This configuration will apply to all tests in the same section, and all nested sections within that
 section. Nested sections can override configurations from their parent sections.
 
-See [`MarkdownTestConfig`](https://github.com/astral-sh/ruff/blob/main/crates/red_knot_test/src/config.rs) for the full list of supported configuration options.
-
 ## Documentation of tests
 
 Arbitrary Markdown syntax (including of course normal prose paragraphs) is permitted (and ignored by

crates/red_knot_test/src/config.rs

@@ -3,45 +3,26 @@
 //! following limited structure:
 //!
 //! ```toml
-//! log = true # or log = "red_knot=WARN"
 //! [environment]
-//! python-version = "3.10"
+//! target-version = "3.10"
 //! ```
 
 use anyhow::Context;
-use red_knot_python_semantic::PythonVersion;
 use serde::Deserialize;
 
-#[derive(Deserialize, Debug, Default, Clone)]
-#[serde(rename_all = "kebab-case", deny_unknown_fields)]
+#[derive(Deserialize)]
 pub(crate) struct MarkdownTestConfig {
-    pub(crate) environment: Option<Environment>,
-
-    pub(crate) log: Option<Log>,
+    pub(crate) environment: Environment,
 }
 
 impl MarkdownTestConfig {
     pub(crate) fn from_str(s: &str) -> anyhow::Result<Self> {
         toml::from_str(s).context("Error while parsing Markdown TOML config")
     }
-
-    pub(crate) fn python_version(&self) -> Option<PythonVersion> {
-        self.environment.as_ref().and_then(|env| env.python_version)
-    }
 }
 
-#[derive(Deserialize, Debug, Default, Clone)]
-#[serde(rename_all = "kebab-case", deny_unknown_fields)]
+#[derive(Deserialize)]
 pub(crate) struct Environment {
-    /// Python version to assume when resolving types.
-    pub(crate) python_version: Option<PythonVersion>,
-}
-
-#[derive(Deserialize, Debug, Clone)]
-#[serde(untagged)]
-pub(crate) enum Log {
-    /// Enable logging with tracing when `true`.
-    Bool(bool),
-    /// Enable logging and only show filters that match the given [env-filter](https://docs.rs/tracing-subscriber/latest/tracing_subscriber/filter/struct.EnvFilter.html)
-    Filter(String),
+    #[serde(rename = "target-version")]
+    pub(crate) target_version: String,
 }

crates/red_knot_test/src/db.rs

@@ -9,7 +9,6 @@ use ruff_db::vendored::VendoredFileSystem;
 use ruff_db::{Db as SourceDb, Upcast};
 
 #[salsa::db]
-#[derive(Clone)]
 pub(crate) struct Db {
     workspace_root: SystemPathBuf,
     storage: salsa::Storage<Self>,
@@ -39,7 +38,7 @@ impl Db {
         Program::from_settings(
             &db,
             &ProgramSettings {
-                python_version: PythonVersion::default(),
+                target_version: PythonVersion::default(),
                 search_paths: SearchPathSettings::new(db.workspace_root.clone()),
             },
         )

crates/red_knot_test/src/lib.rs

@@ -1,4 +1,3 @@
-use crate::config::Log;
 use camino::Utf8Path;
 use colored::Colorize;
 use parser as test_parser;
@@ -8,7 +7,6 @@ use ruff_db::diagnostic::{Diagnostic, ParseDiagnostic};
 use ruff_db::files::{system_path_to_file, File, Files};
 use ruff_db::parsed::parsed_module;
 use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
-use ruff_db::testing::{setup_logging, setup_logging_with_filter};
 use ruff_source_file::LineIndex;
 use ruff_text_size::TextSize;
 use salsa::Setter;
@@ -44,14 +42,9 @@ pub fn run(path: &Utf8Path, long_title: &str, short_title: &str, test_name: &str
             continue;
         }
 
-        let _tracing = test.configuration().log.as_ref().and_then(|log| match log {
-            Log::Bool(enabled) => enabled.then(setup_logging),
-            Log::Filter(filter) => setup_logging_with_filter(filter),
-        });
-
         Program::get(&db)
-            .set_python_version(&mut db)
-            .to(test.configuration().python_version().unwrap_or_default());
+            .set_target_version(&mut db)
+            .to(test.target_version());
 
         // Remove all files so that the db is in a "fresh" state.
         db.memory_file_system().remove_all();

crates/red_knot_test/src/parser.rs

@@ -1,14 +1,14 @@
 use std::sync::LazyLock;
 
-use anyhow::bail;
+use anyhow::{bail, Context};
 use memchr::memchr2;
+use red_knot_python_semantic::PythonVersion;
 use regex::{Captures, Match, Regex};
 use rustc_hash::{FxHashMap, FxHashSet};
 
 use ruff_index::{newtype_index, IndexVec};
 use ruff_python_trivia::Cursor;
-use ruff_source_file::LineRanges;
-use ruff_text_size::{TextLen, TextRange, TextSize};
+use ruff_text_size::{TextLen, TextSize};
 
 use crate::config::MarkdownTestConfig;
 
@@ -74,8 +74,8 @@ impl<'m, 's> MarkdownTest<'m, 's> {
         self.files.iter()
     }
 
-    pub(crate) fn configuration(&self) -> &MarkdownTestConfig {
-        &self.section.config
+    pub(crate) fn target_version(&self) -> PythonVersion {
+        self.section.target_version
     }
 }
 
@@ -125,7 +125,7 @@ struct Section<'s> {
     title: &'s str,
     level: u8,
     parent_id: Option<SectionId>,
-    config: MarkdownTestConfig,
+    target_version: PythonVersion,
 }
 
 #[newtype_index]
@@ -157,14 +157,8 @@ static HEADER_RE: LazyLock<Regex> =
 /// Matches a code block fenced by triple backticks, possibly with language and `key=val`
 /// configuration items following the opening backticks (in the "tag string" of the code block).
 static CODE_RE: LazyLock<Regex> = LazyLock::new(|| {
-    Regex::new(
-        r"(?x)
-        ^```(?<lang>(?-u:\w)+)?(?<config>(?:\x20+\S+)*)\s*\n
-        (?<code>(?:.|\n)*?)\n?
-        (?<end>```|\z)
-        ",
-    )
-    .unwrap()
+    Regex::new(r"^```(?<lang>(?-u:\w)+)?(?<config>(?: +\S+)*)\s*\n(?<code>(?:.|\n)*?)\n?```\s*\n?")
+        .unwrap()
 });
 
 #[derive(Debug)]
@@ -209,7 +203,6 @@ struct Parser<'s> {
     /// The unparsed remainder of the Markdown source.
     cursor: Cursor<'s>,
 
-    source: &'s str,
     source_len: TextSize,
 
     /// Stack of ancestor sections.
@@ -229,11 +222,10 @@ impl<'s> Parser<'s> {
             title,
             level: 0,
             parent_id: None,
-            config: MarkdownTestConfig::default(),
+            target_version: PythonVersion::default(),
         });
         Self {
             sections,
-            source,
             files: IndexVec::default(),
             cursor: Cursor::new(source),
             source_len: source.text_len(),
@@ -313,7 +305,7 @@ impl<'s> Parser<'s> {
             title,
             level: header_level.try_into()?,
             parent_id: Some(parent),
-            config: self.sections[parent].config.clone(),
+            target_version: self.sections[parent].target_version,
         };
 
         if self.current_section_files.is_some() {
@@ -337,13 +329,6 @@ impl<'s> Parser<'s> {
         // We never pop the implicit root section.
         let section = self.stack.top();
 
-        if captures.name("end").unwrap().is_empty() {
-            let code_block_start = self.cursor.token_len();
-            let line = self.source.count_lines(TextRange::up_to(code_block_start)) + 1;
-
-            return Err(anyhow::anyhow!("Unterminated code block at line {line}."));
-        }
-
         let mut config: FxHashMap<&'s str, &'s str> = FxHashMap::default();
 
         if let Some(config_match) = captures.name("config") {
@@ -413,8 +398,23 @@ impl<'s> Parser<'s> {
             bail!("Multiple TOML configuration blocks in the same section are not allowed.");
         }
 
+        let config = MarkdownTestConfig::from_str(code)?;
+        let target_version = config.environment.target_version;
+
+        let parts = target_version
+            .split('.')
+            .map(str::parse)
+            .collect::<Result<Vec<_>, _>>()
+            .context(format!(
+                "Invalid 'target-version' component: '{target_version}'"
+            ))?;
+
+        if parts.len() != 2 {
+            bail!("Invalid 'target-version': expected MAJOR.MINOR, got '{target_version}'.",);
+        }
+
         let current_section = &mut self.sections[self.stack.top()];
-        current_section.config = MarkdownTestConfig::from_str(code)?;
+        current_section.target_version = PythonVersion::from((parts[0], parts[1]));
 
         self.current_section_has_config = true;
 
@@ -680,38 +680,6 @@ mod tests {
         assert_eq!(file.code, "x = 10");
     }
 
-    #[test]
-    fn unterminated_code_block_1() {
-        let source = dedent(
-            "
-            ```
-            x = 1
-            ",
-        );
-        let err = super::parse("file.md", &source).expect_err("Should fail to parse");
-        assert_eq!(err.to_string(), "Unterminated code block at line 2.");
-    }
-
-    #[test]
-    fn unterminated_code_block_2() {
-        let source = dedent(
-            "
-            ## A well-fenced block
-
-            ```
-            y = 2
-            ```
-
-            ## A not-so-well-fenced block
-
-            ```
-            x = 1
-            ",
-        );
-        let err = super::parse("file.md", &source).expect_err("Should fail to parse");
-        assert_eq!(err.to_string(), "Unterminated code block at line 10.");
-    }
-
     #[test]
     fn no_header_inside_test() {
         let source = dedent(

crates/red_knot_vendored/vendor/typeshed/source_commit.txt

@@ -1 +1 @@
-fc11e835108394728930059c8db5b436209bc957
+0a2da01946a406ede42e9c66f416a7e7758991d6

crates/red_knot_vendored/vendor/typeshed/stdlib/VERSIONS

@@ -57,7 +57,6 @@ _msi: 3.0-3.12
 _multibytecodec: 3.0-
 _operator: 3.4-
 _osx_support: 3.0-
-_pickle: 3.0-
 _posixsubprocess: 3.2-
 _py_abc: 3.7-
 _pydecimal: 3.5-

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

@@ -1,23 +1,11 @@
-from _threading_local import local as local
+import sys
+from _thread import _excepthook, _ExceptHookArgs
 from _typeshed import ProfileFunction, TraceFunction
-from threading import (
-    TIMEOUT_MAX as TIMEOUT_MAX,
-    Barrier as Barrier,
-    BoundedSemaphore as BoundedSemaphore,
-    BrokenBarrierError as BrokenBarrierError,
-    Condition as Condition,
-    Event as Event,
-    ExceptHookArgs as ExceptHookArgs,
-    Lock as Lock,
-    RLock as RLock,
-    Semaphore as Semaphore,
-    Thread as Thread,
-    ThreadError as ThreadError,
-    Timer as Timer,
-    _DummyThread as _DummyThread,
-    _RLock as _RLock,
-    excepthook as excepthook,
-)
+from collections.abc import Callable, Iterable, Mapping
+from types import TracebackType
+from typing import Any, TypeVar
+
+_T = TypeVar("_T")
 
 __all__ = [
     "get_ident",
@@ -54,3 +42,123 @@ def main_thread() -> Thread: ...
 def settrace(func: TraceFunction) -> None: ...
 def setprofile(func: ProfileFunction | None) -> None: ...
 def stack_size(size: int | None = None) -> int: ...
+
+TIMEOUT_MAX: float
+
+class ThreadError(Exception): ...
+
+class local:
+    def __getattribute__(self, name: str) -> Any: ...
+    def __setattr__(self, name: str, value: Any) -> None: ...
+    def __delattr__(self, name: str) -> None: ...
+
+class Thread:
+    name: str
+    daemon: bool
+    @property
+    def ident(self) -> int | None: ...
+    def __init__(
+        self,
+        group: None = None,
+        target: Callable[..., object] | None = None,
+        name: str | None = None,
+        args: Iterable[Any] = (),
+        kwargs: Mapping[str, Any] | None = None,
+        *,
+        daemon: bool | None = None,
+    ) -> None: ...
+    def start(self) -> None: ...
+    def run(self) -> None: ...
+    def join(self, timeout: float | None = None) -> None: ...
+    def getName(self) -> str: ...
+    def setName(self, name: str) -> None: ...
+    @property
+    def native_id(self) -> int | None: ...  # only available on some platforms
+    def is_alive(self) -> bool: ...
+    if sys.version_info < (3, 9):
+        def isAlive(self) -> bool: ...
+
+    def isDaemon(self) -> bool: ...
+    def setDaemon(self, daemonic: bool) -> None: ...
+
+class _DummyThread(Thread): ...
+
+class Lock:
+    def __enter__(self) -> bool: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> bool | None: ...
+    def acquire(self, blocking: bool = ..., timeout: float = ...) -> bool: ...
+    def release(self) -> None: ...
+    def locked(self) -> bool: ...
+
+class _RLock:
+    def __enter__(self) -> bool: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> bool | None: ...
+    def acquire(self, blocking: bool = True, timeout: float = -1) -> bool: ...
+    def release(self) -> None: ...
+
+RLock = _RLock
+
+class Condition:
+    def __init__(self, lock: Lock | _RLock | None = None) -> None: ...
+    def __enter__(self) -> bool: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> bool | None: ...
+    def acquire(self, blocking: bool = ..., timeout: float = ...) -> bool: ...
+    def release(self) -> None: ...
+    def wait(self, timeout: float | None = None) -> bool: ...
+    def wait_for(self, predicate: Callable[[], _T], timeout: float | None = None) -> _T: ...
+    def notify(self, n: int = 1) -> None: ...
+    def notify_all(self) -> None: ...
+    def notifyAll(self) -> None: ...
+
+class Semaphore:
+    def __init__(self, value: int = 1) -> None: ...
+    def __exit__(
+        self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
+    ) -> bool | None: ...
+    def acquire(self, blocking: bool = True, timeout: float | None = None) -> bool: ...
+    def __enter__(self, blocking: bool = True, timeout: float | None = None) -> bool: ...
+    if sys.version_info >= (3, 9):
+        def release(self, n: int = ...) -> None: ...
+    else:
+        def release(self) -> None: ...
+
+class BoundedSemaphore(Semaphore): ...
+
+class Event:
+    def is_set(self) -> bool: ...
+    def set(self) -> None: ...
+    def clear(self) -> None: ...
+    def wait(self, timeout: float | None = None) -> bool: ...
+
+excepthook = _excepthook
+ExceptHookArgs = _ExceptHookArgs
+
+class Timer(Thread):
+    def __init__(
+        self,
+        interval: float,
+        function: Callable[..., object],
+        args: Iterable[Any] | None = None,
+        kwargs: Mapping[str, Any] | None = None,
+    ) -> None: ...
+    def cancel(self) -> None: ...
+
+class Barrier:
+    @property
+    def parties(self) -> int: ...
+    @property
+    def n_waiting(self) -> int: ...
+    @property
+    def broken(self) -> bool: ...
+    def __init__(self, parties: int, action: Callable[[], None] | None = None, timeout: float | None = None) -> None: ...
+    def wait(self, timeout: float | None = None) -> int: ...
+    def reset(self) -> None: ...
+    def abort(self) -> None: ...
+
+class BrokenBarrierError(RuntimeError): ...

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

@@ -1,108 +0,0 @@
-import sys
-from _typeshed import ReadableBuffer, SupportsWrite
-from collections.abc import Callable, Iterable, Iterator, Mapping
-from pickle import PickleBuffer as PickleBuffer
-from typing import Any, Protocol, type_check_only
-from typing_extensions import TypeAlias
-
-class _ReadableFileobj(Protocol):
-    def read(self, n: int, /) -> bytes: ...
-    def readline(self) -> bytes: ...
-
-_BufferCallback: TypeAlias = Callable[[PickleBuffer], Any] | None
-
-_ReducedType: TypeAlias = (
-    str
-    | tuple[Callable[..., Any], tuple[Any, ...]]
-    | tuple[Callable[..., Any], tuple[Any, ...], Any]
-    | tuple[Callable[..., Any], tuple[Any, ...], Any, Iterator[Any] | None]
-    | tuple[Callable[..., Any], tuple[Any, ...], Any, Iterator[Any] | None, Iterator[Any] | None]
-)
-
-def dump(
-    obj: Any,
-    file: SupportsWrite[bytes],
-    protocol: int | None = None,
-    *,
-    fix_imports: bool = True,
-    buffer_callback: _BufferCallback = None,
-) -> None: ...
-def dumps(
-    obj: Any, protocol: int | None = None, *, fix_imports: bool = True, buffer_callback: _BufferCallback = None
-) -> bytes: ...
-def load(
-    file: _ReadableFileobj,
-    *,
-    fix_imports: bool = True,
-    encoding: str = "ASCII",
-    errors: str = "strict",
-    buffers: Iterable[Any] | None = (),
-) -> Any: ...
-def loads(
-    data: ReadableBuffer,
-    /,
-    *,
-    fix_imports: bool = True,
-    encoding: str = "ASCII",
-    errors: str = "strict",
-    buffers: Iterable[Any] | None = (),
-) -> Any: ...
-
-class PickleError(Exception): ...
-class PicklingError(PickleError): ...
-class UnpicklingError(PickleError): ...
-
-@type_check_only
-class PicklerMemoProxy:
-    def clear(self, /) -> None: ...
-    def copy(self, /) -> dict[int, tuple[int, Any]]: ...
-
-class Pickler:
-    fast: bool
-    dispatch_table: Mapping[type, Callable[[Any], _ReducedType]]
-    reducer_override: Callable[[Any], Any]
-    bin: bool  # undocumented
-    def __init__(
-        self,
-        file: SupportsWrite[bytes],
-        protocol: int | None = None,
-        *,
-        fix_imports: bool = True,
-        buffer_callback: _BufferCallback = None,
-    ) -> None: ...
-    @property
-    def memo(self) -> PicklerMemoProxy: ...
-    @memo.setter
-    def memo(self, value: PicklerMemoProxy | dict[int, tuple[int, Any]]) -> None: ...
-    def dump(self, obj: Any, /) -> None: ...
-    def clear_memo(self) -> None: ...
-    if sys.version_info >= (3, 13):
-        def persistent_id(self, obj: Any, /) -> Any: ...
-    else:
-        persistent_id: Callable[[Any], Any]
-
-@type_check_only
-class UnpicklerMemoProxy:
-    def clear(self, /) -> None: ...
-    def copy(self, /) -> dict[int, tuple[int, Any]]: ...
-
-class Unpickler:
-    def __init__(
-        self,
-        file: _ReadableFileobj,
-        *,
-        fix_imports: bool = True,
-        encoding: str = "ASCII",
-        errors: str = "strict",
-        buffers: Iterable[Any] | None = (),
-    ) -> None: ...
-    @property
-    def memo(self) -> UnpicklerMemoProxy: ...
-    @memo.setter
-    def memo(self, value: UnpicklerMemoProxy | dict[int, tuple[int, Any]]) -> None: ...
-    def load(self) -> Any: ...
-    def find_class(self, module_name: str, global_name: str, /) -> Any: ...
-    if sys.version_info >= (3, 13):
-        def persistent_load(self, pid: Any, /) -> Any: ...
-    else:
-        persistent_load: Callable[[Any], Any]

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

@@ -1,4 +1,3 @@
-import sys
 from collections.abc import Iterable
 from typing import ClassVar, Literal, NoReturn
 
@@ -6,7 +5,7 @@ class Quitter:
     name: str
     eof: str
     def __init__(self, name: str, eof: str) -> None: ...
-    def __call__(self, code: sys._ExitCode = None) -> NoReturn: ...
+    def __call__(self, code: int | None = None) -> NoReturn: ...
 
 class _Printer:
     MAXLINES: ClassVar[Literal[23]]
@@ -14,4 +13,4 @@ class _Printer:
     def __call__(self) -> None: ...
 
 class _Helper:
-    def __call__(self, request: object = ...) -> None: ...
+    def __call__(self, request: object) -> None: ...

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

@@ -78,10 +78,8 @@ if sys.platform == "win32":
     SO_EXCLUSIVEADDRUSE: int
 if sys.platform != "win32":
     SO_REUSEPORT: int
-    if sys.platform != "darwin" or sys.version_info >= (3, 13):
-        SO_BINDTODEVICE: int
-
 if sys.platform != "win32" and sys.platform != "darwin":
+    SO_BINDTODEVICE: int
     SO_DOMAIN: int
     SO_MARK: int
     SO_PASSCRED: int

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

@@ -113,31 +113,16 @@ TK_VERSION: Final[str]
 class TkttType:
     def deletetimerhandler(self): ...
 
-if sys.version_info >= (3, 13):
-    def create(
-        screenName: str | None = None,
-        baseName: str = "",
-        className: str = "Tk",
-        interactive: bool = False,
-        wantobjects: int = 0,
-        wantTk: bool = True,
-        sync: bool = False,
-        use: str | None = None,
-        /,
-    ): ...
-
-else:
-    def create(
-        screenName: str | None = None,
-        baseName: str = "",
-        className: str = "Tk",
-        interactive: bool = False,
-        wantobjects: bool = False,
-        wantTk: bool = True,
-        sync: bool = False,
-        use: str | None = None,
-        /,
-    ): ...
-
+def create(
+    screenName: str | None = None,
+    baseName: str = "",
+    className: str = "Tk",
+    interactive: bool = False,
+    wantobjects: bool = False,
+    wantTk: bool = True,
+    sync: bool = False,
+    use: str | None = None,
+    /,
+): ...
 def getbusywaitinterval(): ...
 def setbusywaitinterval(new_val, /): ...

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

@@ -182,30 +182,30 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
     def add_subparsers(
         self: _ArgumentParserT,
         *,
-        title: str = "subcommands",
-        description: str | None = None,
-        prog: str | None = None,
+        title: str = ...,
+        description: str | None = ...,
+        prog: str = ...,
         action: type[Action] = ...,
         option_string: str = ...,
-        dest: str | None = None,
-        required: bool = False,
-        help: str | None = None,
-        metavar: str | None = None,
+        dest: str | None = ...,
+        required: bool = ...,
+        help: str | None = ...,
+        metavar: str | None = ...,
     ) -> _SubParsersAction[_ArgumentParserT]: ...
     @overload
     def add_subparsers(
         self,
         *,
-        title: str = "subcommands",
-        description: str | None = None,
-        prog: str | None = None,
+        title: str = ...,
+        description: str | None = ...,
+        prog: str = ...,
         parser_class: type[_ArgumentParserT],
         action: type[Action] = ...,
         option_string: str = ...,
-        dest: str | None = None,
-        required: bool = False,
-        help: str | None = None,
-        metavar: str | None = None,
+        dest: str | None = ...,
+        required: bool = ...,
+        help: str | None = ...,
+        metavar: str | None = ...,
     ) -> _SubParsersAction[_ArgumentParserT]: ...
     def print_usage(self, file: IO[str] | None = None) -> None: ...
     def print_help(self, file: IO[str] | None = None) -> None: ...
@@ -237,13 +237,7 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
     # undocumented
     def _get_optional_actions(self) -> list[Action]: ...
     def _get_positional_actions(self) -> list[Action]: ...
-    if sys.version_info >= (3, 12):
-        def _parse_known_args(
-            self, arg_strings: list[str], namespace: Namespace, intermixed: bool
-        ) -> tuple[Namespace, list[str]]: ...
-    else:
-        def _parse_known_args(self, arg_strings: list[str], namespace: Namespace) -> tuple[Namespace, list[str]]: ...
-
+    def _parse_known_args(self, arg_strings: list[str], namespace: Namespace) -> tuple[Namespace, list[str]]: ...
     def _read_args_from_files(self, arg_strings: list[str]) -> list[str]: ...
     def _match_argument(self, action: Action, arg_strings_pattern: str) -> int: ...
     def _match_arguments_partial(self, actions: Sequence[Action], arg_strings_pattern: str) -> list[int]: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/asyncio/proactor_events.pyi

@@ -62,4 +62,3 @@ class _ProactorSocketTransport(_ProactorReadPipeTransport, _ProactorBaseWritePip
 
 class BaseProactorEventLoop(base_events.BaseEventLoop):
     def __init__(self, proactor: Any) -> None: ...
-    async def sock_recv(self, sock: socket, n: int) -> bytes: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/asyncio/selector_events.pyi

@@ -1,5 +1,4 @@
 import selectors
-from socket import socket
 
 from . import base_events
 
@@ -7,4 +6,3 @@ __all__ = ("BaseSelectorEventLoop",)
 
 class BaseSelectorEventLoop(base_events.BaseEventLoop):
     def __init__(self, selector: selectors.BaseSelector | None = None) -> None: ...
-    async def sock_recv(self, sock: socket, n: int) -> bytes: ...