EllipsisType test

.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

@@ -40,7 +40,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -53,9 +52,9 @@ jobs:
           args: --out dist
       - name: "Test sdist"
         run: |
-          pip install dist/"${PACKAGE_NAME}"-*.tar.gz --force-reinstall
-          "${MODULE_NAME}" --help
-          python -m "${MODULE_NAME}" --help
+          pip install dist/${{ env.PACKAGE_NAME }}-*.tar.gz --force-reinstall
+          ${{ env.MODULE_NAME }} --help
+          python -m ${{ env.MODULE_NAME }} --help
       - name: "Upload sdist"
         uses: actions/upload-artifact@v4
         with:
@@ -69,7 +68,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -111,7 +109,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -125,7 +122,7 @@ jobs:
           args: --release --locked --out dist
       - name: "Test wheel - aarch64"
         run: |
-          pip install dist/"${PACKAGE_NAME}"-*.whl --force-reinstall
+          pip install dist/${{ env.PACKAGE_NAME }}-*.whl --force-reinstall
           ruff --help
           python -m ruff --help
       - name: "Upload wheels"
@@ -167,7 +164,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -186,9 +182,9 @@ jobs:
         if: ${{ !startsWith(matrix.platform.target, 'aarch64') }}
         shell: bash
         run: |
-          python -m pip install dist/"${PACKAGE_NAME}"-*.whl --force-reinstall
-          "${MODULE_NAME}" --help
-          python -m "${MODULE_NAME}" --help
+          python -m pip install dist/${{ env.PACKAGE_NAME }}-*.whl --force-reinstall
+          ${{ env.MODULE_NAME }} --help
+          python -m ${{ env.MODULE_NAME }} --help
       - name: "Upload wheels"
         uses: actions/upload-artifact@v4
         with:
@@ -220,7 +216,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -236,9 +231,9 @@ jobs:
       - name: "Test wheel"
         if: ${{ startsWith(matrix.target, 'x86_64') }}
         run: |
-          pip install dist/"${PACKAGE_NAME}"-*.whl --force-reinstall
-          "${MODULE_NAME}" --help
-          python -m "${MODULE_NAME}" --help
+          pip install dist/${{ env.PACKAGE_NAME }}-*.whl --force-reinstall
+          ${{ env.MODULE_NAME }} --help
+          python -m ${{ env.MODULE_NAME }} --help
       - name: "Upload wheels"
         uses: actions/upload-artifact@v4
         with:
@@ -295,7 +290,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -360,7 +354,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -426,7 +419,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}

.github/workflows/build-docker.yml

@@ -36,7 +36,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           submodules: recursive
-          persist-credentials: false
 
       - uses: docker/setup-buildx-action@v3
 
@@ -72,7 +71,7 @@ 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
@@ -87,10 +86,9 @@ jobs:
           outputs: type=image,name=${{ env.RUFF_BASE_IMG }},push-by-digest=true,name-canonical=true,push=${{ inputs.plan != '' && !fromJson(inputs.plan).announcement_tag_is_implicit }}
 
       - name: Export digests
-        env:
-          digest: ${{ steps.build.outputs.digest }}
         run: |
           mkdir -p /tmp/digests
+          digest="${{ steps.build.outputs.digest }}"
           touch "/tmp/digests/${digest#sha256:}"
 
       - name: Upload digests
@@ -142,10 +140,9 @@ 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 " *)
+            $(printf '${{ env.RUFF_BASE_IMG }}@sha256:%s ' *)
 
   docker-publish-extra:
     name: Publish additional Docker image based on ${{ matrix.image-mapping }}
@@ -184,7 +181,7 @@ jobs:
           # Generate Dockerfile content
           cat <<EOF > Dockerfile
           FROM ${BASE_IMAGE}
-          COPY --from=${RUFF_BASE_IMG}:latest /ruff /usr/local/bin/ruff
+          COPY --from=${{ env.RUFF_BASE_IMG }}:latest /ruff /usr/local/bin/ruff
           ENTRYPOINT []
           CMD ["/usr/local/bin/ruff"]
           EOF
@@ -204,14 +201,14 @@ jobs:
           TAG_PATTERNS="${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 +284,7 @@ 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 " *)
+            $(printf '${{ env.RUFF_BASE_IMG }}@sha256:%s ' *)

.github/workflows/ci.yaml

@@ -32,13 +32,10 @@ jobs:
       # Flag that is raised when any code is changed
       # This is superset of the linter and formatter
       code: ${{ steps.changed.outputs.code_any_changed }}
-      # Flag that is raised when any code that affects the fuzzer is changed
-      fuzz: ${{ steps.changed.outputs.fuzz_any_changed }}
     steps:
       - uses: actions/checkout@v4
         with:
           fetch-depth: 0
-          persist-credentials: false
 
       - uses: tj-actions/changed-files@v45
         id: changed
@@ -82,11 +79,6 @@ jobs:
               - python/**
               - .github/workflows/ci.yaml
 
-            fuzz:
-              - fuzz/Cargo.toml
-              - fuzz/Cargo.lock
-              - fuzz/fuzz_targets/**
-
             code:
               - "**/*"
               - "!**/*.md"
@@ -100,8 +92,6 @@ jobs:
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup component add rustfmt
       - run: cargo fmt --all --check
@@ -114,8 +104,6 @@ jobs:
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: |
           rustup component add clippy
@@ -134,8 +122,6 @@ jobs:
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
@@ -180,8 +166,6 @@ jobs:
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
@@ -209,8 +193,6 @@ jobs:
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install cargo nextest"
@@ -235,8 +217,6 @@ jobs:
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup target add wasm32-unknown-unknown
       - uses: actions/setup-node@v4
@@ -264,8 +244,6 @@ jobs:
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
@@ -282,17 +260,13 @@ jobs:
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - uses: SebRollen/toml-action@v1.2.0
         id: msrv
         with:
           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"
@@ -308,19 +282,16 @@ 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' }}
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup show
       - uses: Swatinem/rust-cache@v2
@@ -347,9 +318,7 @@ jobs:
       FORCE_COLOR: 1
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v4
       - uses: actions/download-artifact@v4
         name: Download Ruff binary to test
         id: download-cached-binary
@@ -357,18 +326,16 @@ 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
           )
@@ -381,8 +348,6 @@ jobs:
     timeout-minutes: 5
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup component add rustfmt
       - uses: Swatinem/rust-cache@v2
@@ -407,8 +372,6 @@ jobs:
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -420,7 +383,7 @@ jobs:
           name: ruff
           path: target/debug
 
-      - uses: dawidd6/action-download-artifact@v7
+      - uses: dawidd6/action-download-artifact@v6
         name: Download baseline Ruff binary
         with:
           name: ruff
@@ -434,72 +397,64 @@ 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
@@ -527,8 +482,6 @@ jobs:
     if: ${{ needs.determine_changes.outputs.code == 'true' || github.ref == 'refs/heads/main' }}
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - uses: cargo-bins/cargo-binstall@main
       - run: cargo binstall --no-confirm cargo-shear
       - run: cargo shear
@@ -539,8 +492,6 @@ jobs:
     timeout-minutes: 20
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -554,7 +505,7 @@ jobs:
           args: --out dist
       - name: "Test wheel"
         run: |
-          pip install --force-reinstall --find-links dist "${PACKAGE_NAME}"
+          pip install --force-reinstall --find-links dist ${{ env.PACKAGE_NAME }}
           ruff --help
           python -m ruff --help
       - name: "Remove wheels from cache"
@@ -566,8 +517,6 @@ jobs:
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: ${{ env.PYTHON_VERSION }}
@@ -583,14 +532,13 @@ jobs:
           key: pre-commit-${{ 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"
@@ -600,8 +548,6 @@ jobs:
       MKDOCS_INSIDERS_SSH_KEY_EXISTS: ${{ secrets.MKDOCS_INSIDERS_SSH_KEY != '' }}
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - uses: actions/setup-python@v5
         with:
           python-version: "3.13"
@@ -613,7 +559,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: Install uv
-        uses: astral-sh/setup-uv@v5
+        uses: astral-sh/setup-uv@v3
       - uses: Swatinem/rust-cache@v2
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}
@@ -642,8 +588,6 @@ jobs:
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Cache rust"
@@ -651,7 +595,7 @@ jobs:
       - name: "Run checks"
         run: scripts/formatter_ecosystem_checks.sh
       - name: "Github step summary"
-        run: cat target/formatter-ecosystem/stats.txt > "$GITHUB_STEP_SUMMARY"
+        run: cat target/formatter-ecosystem/stats.txt > $GITHUB_STEP_SUMMARY
       - name: "Remove checkouts from cache"
         run: rm -r target/formatter-ecosystem
 
@@ -671,7 +615,6 @@ jobs:
       - uses: actions/checkout@v4
         name: "Download ruff-lsp source"
         with:
-          persist-credentials: false
           repository: "astral-sh/ruff-lsp"
 
       - uses: actions/setup-python@v5
@@ -690,13 +633,11 @@ 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
@@ -709,8 +650,6 @@ jobs:
     steps:
       - name: "Checkout Branch"
         uses: actions/checkout@v4
-        with:
-          persist-credentials: false
 
       - name: "Install Rust toolchain"
         run: rustup show

.github/workflows/daily_fuzz.yaml

@@ -32,9 +32,7 @@ jobs:
     if: ${{ github.repository == 'astral-sh/ruff' || github.event_name != 'schedule' }}
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
-      - uses: astral-sh/setup-uv@v5
+      - uses: astral-sh/setup-uv@v4
       - name: "Install Rust toolchain"
         run: rustup show
       - name: "Install mold"
@@ -46,7 +44,6 @@ jobs:
         run: cargo build --locked
       - name: Fuzz
         run: |
-          # shellcheck disable=SC2046
           (
             uvx \
             --python=3.12 \

.github/workflows/pr-comment.yaml

@@ -10,13 +10,14 @@ 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
+      - uses: dawidd6/action-download-artifact@v6
         name: Download pull request number
         with:
           name: pr-number
@@ -29,10 +30,10 @@ 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
+      - uses: dawidd6/action-download-artifact@v6
         name: "Download ecosystem results"
         id: download-ecosystem-result
         if: steps.pr-number.outputs.pr-number
@@ -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

@@ -26,7 +26,6 @@ jobs:
       - uses: actions/checkout@v4
         with:
           ref: ${{ inputs.ref }}
-          persist-credentials: true
 
       - uses: actions/setup-python@v5
         with:
@@ -44,19 +43,21 @@ 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: |
+          version="${{ env.version }}"
+          display_name="${{ env.display_name }}"
           timestamp="$(date +%s)"
 
           # create branch_display_name from display_name by replacing all
           # characters disallowed in git branch names with hyphens
-          branch_display_name="$(echo "${display_name}" | tr -c '[:alnum:]._' '-' | tr -s '-')"
+          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' }}
@@ -91,7 +92,9 @@ jobs:
         run: mkdocs build --strict -f mkdocs.public.yml
 
       - name: "Clone docs repo"
-        run: git clone https://${{ secrets.ASTRAL_DOCS_PAT }}@github.com/astral-sh/docs.git astral-docs
+        run: |
+          version="${{ env.version }}"
+          git clone https://${{ secrets.ASTRAL_DOCS_PAT }}@github.com/astral-sh/docs.git astral-docs
 
       - name: "Copy docs"
         run: rm -rf astral-docs/site/ruff && mkdir -p astral-docs/site && cp -r site/ruff astral-docs/site/
@@ -99,10 +102,12 @@ jobs:
       - name: "Commit docs"
         working-directory: astral-docs
         run: |
+          branch_name="${{ env.branch_name }}"
+
           git config user.name "astral-docs-bot"
           git config user.email "176161322+astral-docs-bot@users.noreply.github.com"
 
-          git checkout -b "${branch_name}"
+          git checkout -b $branch_name
           git add site/ruff
           git commit -m "Update ruff documentation for $version"
 
@@ -111,8 +116,12 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.ASTRAL_DOCS_PAT }}
         run: |
+          version="${{ env.version }}"
+          display_name="${{ env.display_name }}"
+          branch_name="${{ env.branch_name }}"
+
           # 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
@@ -121,15 +130,13 @@ jobs:
             xargs -I {} gh pr close {}
 
           # push the branch to GitHub
-          git push origin "${branch_name}"
+          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 }}
@@ -137,7 +144,9 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.ASTRAL_DOCS_PAT }}
         run: |
+          branch_name="${{ env.branch_name }}"
+
           # auto-merge the PR if the build was triggered by a release. Manual builds should be reviewed by a human.
           # give the PR a few seconds to be created before trying to auto-merge it
           sleep 10
-          gh pr merge --squash "${branch_name}"
+          gh pr merge --squash $branch_name

.github/workflows/publish-playground.yml

@@ -25,8 +25,6 @@ jobs:
       CF_API_TOKEN_EXISTS: ${{ secrets.CF_API_TOKEN != '' }}
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup target add wasm32-unknown-unknown
       - uses: actions/setup-node@v4
@@ -49,7 +47,7 @@ jobs:
         working-directory: playground
       - name: "Deploy to Cloudflare Pages"
         if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        uses: cloudflare/wrangler-action@v3.13.0
+        uses: cloudflare/wrangler-action@v3.12.1
         with:
           apiToken: ${{ secrets.CF_API_TOKEN }}
           accountId: ${{ secrets.CF_ACCOUNT_ID }}

.github/workflows/publish-pypi.yml

@@ -22,7 +22,7 @@ jobs:
       id-token: write
     steps:
       - name: "Install uv"
-        uses: astral-sh/setup-uv@v5
+        uses: astral-sh/setup-uv@v3
       - uses: actions/download-artifact@v4
         with:
           pattern: wheels-*

.github/workflows/publish-wasm.yml

@@ -30,8 +30,6 @@ jobs:
       fail-fast: false
     steps:
       - uses: actions/checkout@v4
-        with:
-          persist-credentials: false
       - name: "Install Rust toolchain"
         run: rustup target add wasm32-unknown-unknown
       - uses: jetli/wasm-pack-action@v0.4.0

.github/workflows/sync_typeshed.yaml

@@ -25,13 +25,11 @@ jobs:
         name: Checkout Ruff
         with:
           path: ruff
-          persist-credentials: true
       - uses: actions/checkout@v4
         name: Checkout typeshed
         with:
           repository: python/typeshed
           path: typeshed
-          persist-credentials: false
       - name: Setup git
         run: |
           git config --global user.name typeshedbot
@@ -59,7 +57,7 @@ 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/.*|
@@ -23,12 +22,13 @@ repos:
       - id: validate-pyproject
 
   - repo: https://github.com/executablebooks/mdformat
-    rev: 0.7.21
+    rev: 0.7.18
     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
@@ -36,7 +36,7 @@ repos:
           )$
 
   - repo: https://github.com/igorshubovych/markdownlint-cli
-    rev: v0.43.0
+    rev: v0.42.0
     hooks:
       - id: markdownlint-fix
         exclude: |
@@ -59,7 +59,7 @@ repos:
           - black==24.10.0
 
   - repo: https://github.com/crate-ci/typos
-    rev: v1.28.4
+    rev: v1.27.3
     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: v0.8.4
+    rev: v0.7.4
     hooks:
       - id: ruff-format
       - id: ruff
@@ -83,42 +83,10 @@ repos:
 
   # Prettier
   - repo: https://github.com/rbubley/mirrors-prettier
-    rev: v3.4.2
+    rev: v3.3.3
     hooks:
       - 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: v0.10.0
-    hooks:
-      - id: zizmor
-
-  - 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: v1.7.5
-    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]

BREAKING_CHANGES.md

@@ -192,7 +192,7 @@ flag or `unsafe-fixes` configuration option can be used to enable unsafe fixes.
 
 See the [docs](https://docs.astral.sh/ruff/configuration/#fix-safety) for details.
 
-### Remove formatter-conflicting rules from the default rule set ([#7900](https://github.com/astral-sh/ruff/pull/7900))
+### Remove formatter-conflicting rules from the default rule set  ([#7900](https://github.com/astral-sh/ruff/pull/7900))
 
 Previously, Ruff enabled all implemented rules in Pycodestyle (`E`) by default. Ruff now only includes the
 Pycodestyle prefixes `E4`, `E7`, and `E9` to exclude rules that conflict with automatic formatters. Consequently,

CHANGELOG.md

@@ -1,146 +1,5 @@
 # Changelog
 
-## 0.8.5
-
-### Preview features
-
-- \[`airflow`\] Extend names moved from core to provider (`AIR303`) ([#15145](https://github.com/astral-sh/ruff/pull/15145), [#15159](https://github.com/astral-sh/ruff/pull/15159), [#15196](https://github.com/astral-sh/ruff/pull/15196), [#15216](https://github.com/astral-sh/ruff/pull/15216))
-- \[`airflow`\] Extend rule to check class attributes, methods, arguments (`AIR302`) ([#15054](https://github.com/astral-sh/ruff/pull/15054), [#15083](https://github.com/astral-sh/ruff/pull/15083))
-- \[`fastapi`\] Update `FAST002` to check keyword-only arguments ([#15119](https://github.com/astral-sh/ruff/pull/15119))
-- \[`flake8-type-checking`\] Disable `TC006` and `TC007` in stub files ([#15179](https://github.com/astral-sh/ruff/pull/15179))
-- \[`pylint`\] Detect nested methods correctly (`PLW1641`) ([#15032](https://github.com/astral-sh/ruff/pull/15032))
-- \[`ruff`\] Detect more strict-integer expressions (`RUF046`) ([#14833](https://github.com/astral-sh/ruff/pull/14833))
-- \[`ruff`\] Implement `falsy-dict-get-fallback` (`RUF056`) ([#15160](https://github.com/astral-sh/ruff/pull/15160))
-- \[`ruff`\] Implement `unnecessary-round` (`RUF057`) ([#14828](https://github.com/astral-sh/ruff/pull/14828))
-
-### Rule changes
-
-- Visit PEP 764 inline `TypedDict` keys as non-type-expressions ([#15073](https://github.com/astral-sh/ruff/pull/15073))
-- \[`flake8-comprehensions`\] Skip `C416` if comprehension contains unpacking ([#14909](https://github.com/astral-sh/ruff/pull/14909))
-- \[`flake8-pie`\] Allow `cast(SomeType, ...)` (`PIE796`) ([#15141](https://github.com/astral-sh/ruff/pull/15141))
-- \[`flake8-simplify`\] More precise inference for dictionaries (`SIM300`) ([#15164](https://github.com/astral-sh/ruff/pull/15164))
-- \[`flake8-use-pathlib`\] Catch redundant joins in `PTH201` and avoid syntax errors ([#15177](https://github.com/astral-sh/ruff/pull/15177))
-- \[`pycodestyle`\] Preserve original value format (`E731`) ([#15097](https://github.com/astral-sh/ruff/pull/15097))
-- \[`pydocstyle`\] Split on first whitespace character (`D403`) ([#15082](https://github.com/astral-sh/ruff/pull/15082))
-- \[`pyupgrade`\] Add all PEP-585 names to `UP006` rule ([#5454](https://github.com/astral-sh/ruff/pull/5454))
-
-### Configuration
-
-- \[`flake8-type-checking`\] Improve flexibility of `runtime-evaluated-decorators` ([#15204](https://github.com/astral-sh/ruff/pull/15204))
-- \[`pydocstyle`\] Add setting to ignore missing documentation for `*args` and `**kwargs` parameters (`D417`) ([#15210](https://github.com/astral-sh/ruff/pull/15210))
-- \[`ruff`\] Add an allowlist for `unsafe-markup-use` (`RUF035`) ([#15076](https://github.com/astral-sh/ruff/pull/15076))
-
-### Bug fixes
-
-- Fix type subscript on older python versions ([#15090](https://github.com/astral-sh/ruff/pull/15090))
-- Use `TypeChecker` for detecting `fastapi` routes ([#15093](https://github.com/astral-sh/ruff/pull/15093))
-- \[`pycodestyle`\] Avoid false positives and negatives related to type parameter default syntax (`E225`, `E251`) ([#15214](https://github.com/astral-sh/ruff/pull/15214))
-
-### Documentation
-
-- Fix incorrect doc in `shebang-not-executable` (`EXE001`) and add git+windows solution to executable bit ([#15208](https://github.com/astral-sh/ruff/pull/15208))
-- Rename rules currently not conforming to naming convention ([#15102](https://github.com/astral-sh/ruff/pull/15102))
-
-## 0.8.4
-
-### Preview features
-
-- \[`airflow`\] 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
-
-- \[`airflow`\] Avoid deprecated values (`AIR302`) ([#14582](https://github.com/astral-sh/ruff/pull/14582))
-- \[`airflow`\] Extend removed names for `AIR302` ([#14734](https://github.com/astral-sh/ruff/pull/14734))
-- \[`ruff`\] Extend `unnecessary-regular-expression` to non-literal strings (`RUF055`) ([#14679](https://github.com/astral-sh/ruff/pull/14679))
-- \[`ruff`\] Implement `used-dummy-variable` (`RUF052`) ([#14611](https://github.com/astral-sh/ruff/pull/14611))
-- \[`ruff`\] Implement `unnecessary-cast-to-int` (`RUF046`) ([#14697](https://github.com/astral-sh/ruff/pull/14697))
-
-### Rule changes
-
-- \[`airflow`\] Check `AIR001` from builtin or providers `operators` module ([#14631](https://github.com/astral-sh/ruff/pull/14631))
-- \[`flake8-pytest-style`\] Remove `@` in `pytest.mark.parametrize` rule messages ([#14770](https://github.com/astral-sh/ruff/pull/14770))
-- \[`pandas-vet`\] Skip rules if the `panda` module hasn't been seen ([#14671](https://github.com/astral-sh/ruff/pull/14671))
-- \[`pylint`\] Fix false negatives for `ascii` and `sorted` in `len-as-condition` (`PLC1802`) ([#14692](https://github.com/astral-sh/ruff/pull/14692))
-- \[`refurb`\] Guard `hashlib` imports and mark `hashlib-digest-hex` fix as safe (`FURB181`) ([#14694](https://github.com/astral-sh/ruff/pull/14694))
-
-### Configuration
-
-- \[`flake8-import-conventions`\] Improve syntax check for aliases supplied in configuration for `unconventional-import-alias` (`ICN001`) ([#14745](https://github.com/astral-sh/ruff/pull/14745))
-
-### Bug fixes
-
-- Revert: [pyflakes] Avoid false positives in `@no_type_check` contexts (`F821`, `F722`) (#14615) ([#14726](https://github.com/astral-sh/ruff/pull/14726))
-- \[`pep8-naming`\] Avoid false positive for `class Bar(type(foo))` (`N804`) ([#14683](https://github.com/astral-sh/ruff/pull/14683))
-- \[`pycodestyle`\] Handle f-strings properly for `invalid-escape-sequence` (`W605`) ([#14748](https://github.com/astral-sh/ruff/pull/14748))
-- \[`pylint`\] Ignore `@overload` in `PLR0904` ([#14730](https://github.com/astral-sh/ruff/pull/14730))
-- \[`refurb`\] Handle non-finite decimals in `verbose-decimal-constructor` (`FURB157`) ([#14596](https://github.com/astral-sh/ruff/pull/14596))
-- \[`ruff`\] Avoid emitting `assignment-in-assert` when all references to the assigned variable are themselves inside `assert`s (`RUF018`) ([#14661](https://github.com/astral-sh/ruff/pull/14661))
-
-### Documentation
-
-- Improve docs for `flake8-use-pathlib` rules ([#14741](https://github.com/astral-sh/ruff/pull/14741))
-- Improve error messages and docs for `flake8-comprehensions` rules ([#14729](https://github.com/astral-sh/ruff/pull/14729))
-- \[`flake8-type-checking`\] Expands `TC006` docs to better explain itself ([#14749](https://github.com/astral-sh/ruff/pull/14749))
-
 ## 0.8.1
 
 ### Preview features
@@ -162,7 +21,6 @@
 - \[`ruff`\] Auto-add `r` prefix when string has no backslashes for `unraw-re-pattern` (`RUF039`) ([#14536](https://github.com/astral-sh/ruff/pull/14536))
 - \[`ruff`\] Implement `invalid-assert-message-literal-argument` (`RUF040`) ([#14488](https://github.com/astral-sh/ruff/pull/14488))
 - \[`ruff`\] Implement `unnecessary-nested-literal` (`RUF041`) ([#14323](https://github.com/astral-sh/ruff/pull/14323))
-- \[`ruff`\] Implement `unnecessary-regular-expression` (`RUF055`) ([#14659](https://github.com/astral-sh/ruff/pull/14659))
 
 ### Rule changes
 
@@ -176,8 +34,6 @@
 
 - Avoid fixing code to `None | None` for `redundant-none-literal` (`PYI061`) and `never-union` (`RUF020`) ([#14583](https://github.com/astral-sh/ruff/pull/14583), [#14589](https://github.com/astral-sh/ruff/pull/14589))
 - \[`flake8-bugbear`\] Fix `mutable-contextvar-default` to resolve annotated function calls properly (`B039`) ([#14532](https://github.com/astral-sh/ruff/pull/14532))
-- \[`flake8-pyi`, `ruff`\] Fix traversal of nested literals and unions (`PYI016`, `PYI051`, `PYI055`, `PYI062`, `RUF041`) ([#14641](https://github.com/astral-sh/ruff/pull/14641))
-- \[`flake8-pyi`\] Avoid rewriting invalid type expressions in `unnecessary-type-union` (`PYI055`) ([#14660](https://github.com/astral-sh/ruff/pull/14660))
 - \[`flake8-type-checking`\] Avoid syntax errors and type checking problem for quoted annotations autofix (`TC003`, `TC006`) ([#14634](https://github.com/astral-sh/ruff/pull/14634))
 - \[`pylint`\] Do not wrap function calls in parentheses in the fix for unnecessary-dunder-call (`PLC2801`) ([#14601](https://github.com/astral-sh/ruff/pull/14601))
 - \[`ruff`\] Handle `attrs`'s `auto_attribs` correctly (`RUF009`) ([#14520](https://github.com/astral-sh/ruff/pull/14520))
@@ -398,7 +254,7 @@ The following fixes have been stabilized:
 ### Preview features
 
 - Fix `E221` and `E222` to flag missing or extra whitespace around `==` operator ([#13890](https://github.com/astral-sh/ruff/pull/13890))
-- Formatter: Alternate quotes for strings inside f-strings in preview ([#13860](https://github.com/astral-sh/ruff/pull/13860))
+- Formatter: Alternate quotes for strings inside f-strings in preview  ([#13860](https://github.com/astral-sh/ruff/pull/13860))
 - Formatter: Join implicit concatenated strings when they fit on a line ([#13663](https://github.com/astral-sh/ruff/pull/13663))
 - \[`pylint`\] Restrict `iteration-over-set` to only work on sets of literals (`PLC0208`) ([#13731](https://github.com/astral-sh/ruff/pull/13731))
 
@@ -1413,7 +1269,7 @@ To read more about this exciting milestone, check out our [blog post](https://as
 ### Preview features
 
 - \[`pycodestyle`\] Ignore end-of-line comments when determining blank line rules ([#11342](https://github.com/astral-sh/ruff/pull/11342))
-- \[`pylint`\] Detect `pathlib.Path.open` calls in `unspecified-encoding` (`PLW1514`) ([#11288](https://github.com/astral-sh/ruff/pull/11288))
+- \[`pylint`\] Detect `pathlib.Path.open` calls in `unspecified-encoding` (`PLW1514`)  ([#11288](https://github.com/astral-sh/ruff/pull/11288))
 - \[`flake8-pyi`\] Implement `PYI059` (`generic-not-last-base-class`) ([#11233](https://github.com/astral-sh/ruff/pull/11233))
 - \[`flake8-pyi`\] Implement `PYI062` (`duplicate-literal-member`) ([#11269](https://github.com/astral-sh/ruff/pull/11269))
 
@@ -1788,7 +1644,7 @@ To setup `ruff server` with your editor, refer to the [README.md](https://github
 - \[`pycodestyle`\] Do not ignore lines before the first logical line in blank lines rules. ([#10382](https://github.com/astral-sh/ruff/pull/10382))
 - \[`pycodestyle`\] Do not trigger `E225` and `E275` when the next token is a ')' ([#10315](https://github.com/astral-sh/ruff/pull/10315))
 - \[`pylint`\] Avoid false-positive slot non-assignment for `__dict__` (`PLE0237`) ([#10348](https://github.com/astral-sh/ruff/pull/10348))
-- Gate f-string struct size test for Rustc < 1.76 ([#10371](https://github.com/astral-sh/ruff/pull/10371))
+- Gate f-string struct size test for Rustc \< 1.76 ([#10371](https://github.com/astral-sh/ruff/pull/10371))
 
 ### Documentation
 

CONTRIBUTING.md

@@ -467,7 +467,7 @@ cargo build --release && hyperfine --warmup 10 \
   "./target/release/ruff check ./crates/ruff_linter/resources/test/cpython/ --no-cache -e --select W505,E501"
 ```
 
-You can run `uv venv --project ./scripts/benchmarks`, activate the venv and then run `uv sync --project ./scripts/benchmarks` to create a working environment for the
+You can run `poetry install` from `./scripts/benchmarks` to create a working environment for the
 above. All reported benchmarks were computed using the versions specified by
 `./scripts/benchmarks/pyproject.toml` on Python 3.11.
 
@@ -863,7 +863,7 @@ each configuration file.
 
 The package root is used to determine a file's "module path". Consider, again, `baz.py`. In that
 case, `./my_project/src/foo` was identified as the package root, so the module path for `baz.py`
-would resolve to `foo.bar.baz` — as computed by taking the relative path from the package root
+would resolve to  `foo.bar.baz` — as computed by taking the relative path from the package root
 (inclusive of the root itself). The module path can be thought of as "the path you would use to
 import the module" (e.g., `import foo.bar.baz`).
 

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

@@ -119,10 +119,6 @@ For more, see the [documentation](https://docs.astral.sh/ruff/).
 Ruff is available as [`ruff`](https://pypi.org/project/ruff/) on PyPI:
 
 ```shell
-# With uv.
-uv add --dev ruff     # to add ruff to your project
-uv tool install ruff  # to install ruff globally
-
 # With pip.
 pip install ruff
 
@@ -140,8 +136,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"
 
 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.8.5/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.8.5/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.8.1/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.8.1/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 +170,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.8.5
+  rev: v0.8.1
   hooks:
     # Run the linter.
     - id: ruff
@@ -196,7 +192,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v4
-      - uses: astral-sh/ruff-action@v3
+      - uses: astral-sh/ruff-action@v1
 ```
 
 ### Configuration<a id="configuration"></a>

crates/red_knot/docs/tracing.md

@@ -103,7 +103,7 @@ called **once**.
 
 ## Profiling
 
-Red Knot generates a folded stack trace to the current directory named `tracing.folded` when setting the environment variable `RED_KNOT_LOG_PROFILE` to `1` or `true`.
+Red Knot generates a folded stack trace  to the current directory named `tracing.folded` when setting the environment variable `RED_KNOT_LOG_PROFILE` to `1` or `true`.
 
 ```bash
 RED_KNOT_LOG_PROFILE=1 red_knot -- --current-directory=../test -vvv

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,
+    Py39,
+    Py310,
+    Py311,
+    Py312,
+    #[default]
+    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

@@ -1,23 +1,25 @@
 #![allow(clippy::disallowed_names)]
 
 use std::io::Write;
-use std::time::{Duration, Instant};
+use std::time::Duration;
 
 use anyhow::{anyhow, Context};
 use red_knot_python_semantic::{resolve_module, ModuleName, Program, PythonVersion, SitePackages};
 use red_knot_workspace::db::{Db, RootDatabase};
-use red_knot_workspace::watch::{directory_watcher, ChangeEvent, WorkspaceWatcher};
+use red_knot_workspace::watch;
+use red_knot_workspace::watch::{directory_watcher, WorkspaceWatcher};
 use red_knot_workspace::workspace::settings::{Configuration, SearchPathConfiguration};
 use red_knot_workspace::workspace::WorkspaceMetadata;
 use ruff_db::files::{system_path_to_file, File, FileError};
 use ruff_db::source::source_text;
 use ruff_db::system::{OsSystem, SystemPath, SystemPathBuf};
+use ruff_db::testing::{setup_logging, setup_logging_with_filter};
 use ruff_db::Upcast;
 
 struct TestCase {
     db: RootDatabase,
     watcher: Option<WorkspaceWatcher>,
-    changes_receiver: crossbeam::channel::Receiver<Vec<ChangeEvent>>,
+    changes_receiver: crossbeam::channel::Receiver<Vec<watch::ChangeEvent>>,
     /// The temporary directory that contains the test files.
     /// We need to hold on to it in the test case or the temp files get deleted.
     _temp_dir: tempfile::TempDir,
@@ -38,36 +40,12 @@ impl TestCase {
         &self.db
     }
 
-    #[track_caller]
-    fn stop_watch<M>(&mut self, matcher: M) -> Vec<ChangeEvent>
-    where
-        M: MatchEvent,
-    {
-        // track_caller is unstable for lambdas -> That's why this is a fn
-        #[track_caller]
-        fn panic_with_formatted_events(events: Vec<ChangeEvent>) -> Vec<ChangeEvent> {
-            panic!(
-                "Didn't observe expected change:\n{}",
-                events
-                    .into_iter()
-                    .map(|event| format!("  - {event:?}"))
-                    .collect::<Vec<_>>()
-                    .join("\n")
-            )
-        }
-
-        self.try_stop_watch(matcher, Duration::from_secs(10))
-            .unwrap_or_else(panic_with_formatted_events)
+    fn stop_watch(&mut self) -> Vec<watch::ChangeEvent> {
+        self.try_stop_watch(Duration::from_secs(10))
+            .expect("Expected watch changes but observed none")
     }
 
-    fn try_stop_watch<M>(
-        &mut self,
-        mut matcher: M,
-        timeout: Duration,
-    ) -> Result<Vec<ChangeEvent>, Vec<ChangeEvent>>
-    where
-        M: MatchEvent,
-    {
+    fn try_stop_watch(&mut self, timeout: Duration) -> Option<Vec<watch::ChangeEvent>> {
         tracing::debug!("Try stopping watch with timeout {:?}", timeout);
 
         let watcher = self
@@ -75,50 +53,36 @@ impl TestCase {
             .take()
             .expect("Cannot call `stop_watch` more than once");
 
-        let start = Instant::now();
-        let mut all_events = Vec::new();
-
-        loop {
-            let events = self
-                .changes_receiver
-                .recv_timeout(Duration::from_millis(100))
-                .unwrap_or_default();
-
-            if events
-                .iter()
-                .any(|event| matcher.match_event(event) || event.is_rescan())
-            {
-                all_events.extend(events);
-                break;
-            }
-
-            all_events.extend(events);
-
-            if start.elapsed() > timeout {
-                return Err(all_events);
-            }
-        }
+        let mut all_events = self
+            .changes_receiver
+            .recv_timeout(timeout)
+            .unwrap_or_default();
 
         watcher.flush();
         tracing::debug!("Flushed file watcher");
         watcher.stop();
         tracing::debug!("Stopping file watcher");
 
-        // Consume remaining events
         for event in &self.changes_receiver {
             all_events.extend(event);
         }
 
-        Ok(all_events)
+        if all_events.is_empty() {
+            return None;
+        }
+
+        Some(all_events)
     }
 
-    fn take_watch_changes(&self) -> Vec<ChangeEvent> {
+    fn take_watch_changes(&self) -> Vec<watch::ChangeEvent> {
         self.try_take_watch_changes(Duration::from_secs(10))
             .expect("Expected watch changes but observed none")
     }
 
-    fn try_take_watch_changes(&self, timeout: Duration) -> Option<Vec<ChangeEvent>> {
-        let watcher = self.watcher.as_ref()?;
+    fn try_take_watch_changes(&self, timeout: Duration) -> Option<Vec<watch::ChangeEvent>> {
+        let Some(watcher) = &self.watcher else {
+            return None;
+        };
 
         let mut all_events = self
             .changes_receiver
@@ -140,7 +104,7 @@ impl TestCase {
         Some(all_events)
     }
 
-    fn apply_changes(&mut self, changes: Vec<ChangeEvent>) {
+    fn apply_changes(&mut self, changes: Vec<watch::ChangeEvent>) {
         self.db.apply_changes(changes, Some(&self.configuration));
     }
 
@@ -176,23 +140,6 @@ impl TestCase {
     }
 }
 
-trait MatchEvent {
-    fn match_event(&mut self, event: &ChangeEvent) -> bool;
-}
-
-fn event_for_file(name: &str) -> impl MatchEvent + '_ {
-    |event: &ChangeEvent| event.file_name() == Some(name)
-}
-
-impl<F> MatchEvent for F
-where
-    F: FnMut(&ChangeEvent) -> bool,
-{
-    fn match_event(&mut self, event: &ChangeEvent) -> bool {
-        (*self)(event)
-    }
-}
-
 trait SetupFiles {
     fn setup(self, root_path: &SystemPath, workspace_path: &SystemPath) -> anyhow::Result<()>;
 }
@@ -282,7 +229,7 @@ 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 +243,7 @@ where
     }
 
     let configuration = Configuration {
-        python_version: Some(PythonVersion::PY312),
+        target_version: Some(PythonVersion::PY312),
         search_paths,
     };
 
@@ -368,7 +315,7 @@ fn new_file() -> anyhow::Result<()> {
 
     std::fs::write(foo_path.as_std_path(), "print('Hello')")?;
 
-    let changes = case.stop_watch(event_for_file("foo.py"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -391,7 +338,7 @@ fn new_ignored_file() -> anyhow::Result<()> {
 
     std::fs::write(foo_path.as_std_path(), "print('Hello')")?;
 
-    let changes = case.stop_watch(event_for_file("foo.py"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -413,7 +360,7 @@ fn changed_file() -> anyhow::Result<()> {
 
     update_file(&foo_path, "print('Version 2')")?;
 
-    let changes = case.stop_watch(event_for_file("foo.py"));
+    let changes = case.stop_watch();
 
     assert!(!changes.is_empty());
 
@@ -438,7 +385,7 @@ fn deleted_file() -> anyhow::Result<()> {
 
     std::fs::remove_file(foo_path.as_std_path())?;
 
-    let changes = case.stop_watch(event_for_file("foo.py"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -470,7 +417,7 @@ fn move_file_to_trash() -> anyhow::Result<()> {
         trash_path.join("foo.py").as_std_path(),
     )?;
 
-    let changes = case.stop_watch(event_for_file("foo.py"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -502,7 +449,7 @@ fn move_file_to_workspace() -> anyhow::Result<()> {
 
     std::fs::rename(foo_path.as_std_path(), foo_in_workspace_path.as_std_path())?;
 
-    let changes = case.stop_watch(event_for_file("foo.py"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -530,7 +477,7 @@ fn rename_file() -> anyhow::Result<()> {
 
     std::fs::rename(foo_path.as_std_path(), bar_path.as_std_path())?;
 
-    let changes = case.stop_watch(event_for_file("bar.py"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -574,7 +521,7 @@ fn directory_moved_to_workspace() -> anyhow::Result<()> {
     std::fs::rename(sub_original_path.as_std_path(), sub_new_path.as_std_path())
         .with_context(|| "Failed to move sub directory")?;
 
-    let changes = case.stop_watch(event_for_file("sub"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -633,7 +580,7 @@ fn directory_moved_to_trash() -> anyhow::Result<()> {
     std::fs::rename(sub_path.as_std_path(), trashed_sub.as_std_path())
         .with_context(|| "Failed to move the sub directory to the trash")?;
 
-    let changes = case.stop_watch(event_for_file("sub"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -657,6 +604,8 @@ fn directory_moved_to_trash() -> anyhow::Result<()> {
 
 #[test]
 fn directory_renamed() -> anyhow::Result<()> {
+    let _tracing = setup_logging_with_filter("file_watching=TRACE,red_knot=TRACE");
+
     let mut case = setup([
         ("bar.py", "import sub.a"),
         ("sub/__init__.py", ""),
@@ -695,8 +644,11 @@ fn directory_renamed() -> anyhow::Result<()> {
     std::fs::rename(sub_path.as_std_path(), foo_baz.as_std_path())
         .with_context(|| "Failed to move the sub directory")?;
 
-    // Linux and windows only emit an event for the newly created root directory, but not for every new component.
-    let changes = case.stop_watch(event_for_file("sub"));
+    let changes = case.stop_watch();
+
+    for event in &changes {
+        tracing::debug!("Event: {:?}", event);
+    }
 
     case.apply_changes(changes);
 
@@ -769,7 +721,7 @@ fn directory_deleted() -> anyhow::Result<()> {
     std::fs::remove_dir_all(sub_path.as_std_path())
         .with_context(|| "Failed to remove the sub directory")?;
 
-    let changes = case.stop_watch(event_for_file("sub"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -806,7 +758,7 @@ fn search_path() -> anyhow::Result<()> {
 
     std::fs::write(site_packages.join("a.py").as_std_path(), "class A: ...")?;
 
-    let changes = case.stop_watch(event_for_file("a.py"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -837,7 +789,7 @@ fn add_search_path() -> anyhow::Result<()> {
 
     std::fs::write(site_packages.join("a.py").as_std_path(), "class A: ...")?;
 
-    let changes = case.stop_watch(event_for_file("a.py"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -866,9 +818,9 @@ fn remove_search_path() -> anyhow::Result<()> {
 
     std::fs::write(site_packages.join("a.py").as_std_path(), "class A: ...")?;
 
-    let changes = case.try_stop_watch(|_: &ChangeEvent| true, Duration::from_millis(100));
+    let changes = case.try_stop_watch(Duration::from_millis(100));
 
-    assert_eq!(changes, Err(vec![]));
+    assert_eq!(changes, None);
 
     Ok(())
 }
@@ -888,7 +840,7 @@ 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()
         },
     )?;
@@ -906,7 +858,7 @@ fn changed_versions_file() -> anyhow::Result<()> {
         "os: 3.0-",
     )?;
 
-    let changes = case.stop_watch(event_for_file("VERSIONS"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -959,7 +911,7 @@ fn hard_links_in_workspace() -> anyhow::Result<()> {
     // Write to the hard link target.
     update_file(foo_path, "print('Version 2')").context("Failed to update foo.py")?;
 
-    let changes = case.stop_watch(event_for_file("foo.py"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -1030,7 +982,7 @@ fn hard_links_to_target_outside_workspace() -> anyhow::Result<()> {
     // Write to the hard link target.
     update_file(foo_path, "print('Version 2')").context("Failed to update foo.py")?;
 
-    let changes = case.stop_watch(ChangeEvent::is_changed);
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -1069,7 +1021,7 @@ mod unix {
         )
         .with_context(|| "Failed to set file permissions.")?;
 
-        let changes = case.stop_watch(event_for_file("foo.py"));
+        let changes = case.stop_watch();
 
         case.apply_changes(changes);
 
@@ -1167,7 +1119,7 @@ mod unix {
         update_file(baz_workspace, "def baz(): print('Version 3')")
             .context("Failed to update bar/baz.py")?;
 
-        let changes = case.stop_watch(event_for_file("baz.py"));
+        let changes = case.stop_watch();
 
         case.apply_changes(changes);
 
@@ -1238,7 +1190,7 @@ mod unix {
         update_file(&patched_bar_baz, "def baz(): print('Version 2')")
             .context("Failed to update bar/baz.py")?;
 
-        let changes = case.stop_watch(event_for_file("baz.py"));
+        let changes = case.stop_watch();
 
         case.apply_changes(changes);
 
@@ -1346,7 +1298,7 @@ mod unix {
         update_file(&baz_original, "def baz(): print('Version 2')")
             .context("Failed to update bar/baz.py")?;
 
-        let changes = case.stop_watch(event_for_file("baz.py"));
+        let changes = case.stop_watch();
 
         case.apply_changes(changes);
 
@@ -1400,7 +1352,7 @@ fn nested_packages_delete_root() -> anyhow::Result<()> {
 
     std::fs::remove_file(case.workspace_path("pyproject.toml").as_std_path())?;
 
-    let changes = case.stop_watch(ChangeEvent::is_deleted);
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -1412,6 +1364,7 @@ fn nested_packages_delete_root() -> anyhow::Result<()> {
 
 #[test]
 fn added_package() -> anyhow::Result<()> {
+    let _ = setup_logging();
     let mut case = setup([
         (
             "pyproject.toml",
@@ -1453,7 +1406,7 @@ fn added_package() -> anyhow::Result<()> {
     )
     .context("failed to write pyproject.toml for package b")?;
 
-    let changes = case.stop_watch(event_for_file("pyproject.toml"));
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 
@@ -1496,7 +1449,7 @@ fn removed_package() -> anyhow::Result<()> {
     std::fs::remove_dir_all(case.workspace_path("packages/b").as_std_path())
         .context("failed to remove package 'b'")?;
 
-    let changes = case.stop_watch(ChangeEvent::is_deleted);
+    let changes = case.stop_watch();
 
     case.apply_changes(changes);
 

crates/red_knot_python_semantic/Cargo.toml

@@ -13,21 +13,18 @@ license = { workspace = true }
 [dependencies]
 ruff_db = { workspace = true }
 ruff_index = { workspace = true }
-ruff_macros = { workspace = true }
 ruff_python_ast = { workspace = true }
 ruff_python_parser = { workspace = true }
 ruff_python_stdlib = { workspace = true }
 ruff_source_file = { workspace = true }
 ruff_text_size = { workspace = true }
 ruff_python_literal = { workspace = true }
-ruff_python_trivia = { workspace = true }
 
 anyhow = { workspace = true }
 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 }
@@ -52,11 +49,6 @@ anyhow = { workspace = true }
 dir-test = { workspace = true }
 insta = { workspace = true }
 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

@@ -1,83 +0,0 @@
-# Any
-
-## Annotation
-
-`typing.Any` is a way to name the Any type.
-
-```py
-from typing import Any
-
-x: Any = 1
-x = "foo"
-
-def f():
-    reveal_type(x)  # revealed: Any
-```
-
-## Aliased to a different name
-
-If you alias `typing.Any` to another name, we still recognize that as a spelling of the Any type.
-
-```py
-from typing import Any as RenamedAny
-
-x: RenamedAny = 1
-x = "foo"
-
-def f():
-    reveal_type(x)  # revealed: Any
-```
-
-## Shadowed class
-
-If you define your own class named `Any`, using that in a type expression refers to your class, and
-isn't a spelling of the Any type.
-
-```py
-class Any: ...
-
-x: Any
-
-def f():
-    reveal_type(x)  # revealed: Any
-
-# This verifies that we're not accidentally seeing typing.Any, since str is assignable
-# to that but not to our locally defined class.
-y: Any = "not an Any"  # error: [invalid-assignment]
-```
-
-## Subclass
-
-The spec allows you to define subclasses of `Any`.
-
-TODO: Handle assignments correctly. `Subclass` has an unknown superclass, which might be `int`. The
-assignment to `x` should not be allowed, even when the unknown superclass is `int`. The assignment
-to `y` should be allowed, since `Subclass` might have `int` as a superclass, and is therefore
-assignable to `int`.
-
-```py
-from typing import Any
-
-class Subclass(Any): ...
-
-reveal_type(Subclass.__mro__)  # revealed: tuple[Literal[Subclass], Any, Literal[object]]
-
-x: Subclass = 1  # error: [invalid-assignment]
-# TODO: no diagnostic
-y: int = Subclass()  # error: [invalid-assignment]
-
-def _(s: Subclass):
-    reveal_type(s)  # revealed: Subclass
-```
-
-## Invalid
-
-`Any` cannot be parameterized:
-
-```py
-from typing import Any
-
-# error: [invalid-type-form] "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

@@ -1,150 +0,0 @@
-# `LiteralString`
-
-`LiteralString` represents a string that is either defined directly within the source code or is
-made up of such components.
-
-Parts of the testcases defined here were adapted from [the specification's examples][1].
-
-## Usages
-
-### Valid places
-
-It can be used anywhere a type is accepted:
-
-```py
-from typing_extensions import LiteralString
-
-x: LiteralString
-
-def f():
-    reveal_type(x)  # revealed: LiteralString
-```
-
-### Within `Literal`
-
-`LiteralString` cannot be used within `Literal`:
-
-```py
-from typing_extensions import Literal, LiteralString
-
-bad_union: Literal["hello", LiteralString]  # error: [invalid-type-form]
-bad_nesting: Literal[LiteralString]  # error: [invalid-type-form]
-```
-
-### Parameterized
-
-`LiteralString` cannot be parameterized.
-
-```py
-from typing_extensions import LiteralString
-
-a: LiteralString[str]  # error: [invalid-type-form]
-b: LiteralString["foo"]  # error: [invalid-type-form]
-```
-
-### As a base class
-
-Subclassing `LiteralString` leads to a runtime error.
-
-```py
-from typing_extensions import LiteralString
-
-class C(LiteralString): ...  # error: [invalid-base]
-```
-
-## Inference
-
-### Common operations
-
-```py
-from typing_extensions import LiteralString
-
-foo: LiteralString = "foo"
-reveal_type(foo)  # revealed: Literal["foo"]
-
-bar: LiteralString = "bar"
-reveal_type(foo + bar)  # revealed: Literal["foobar"]
-
-baz: LiteralString = "baz"
-baz += foo
-reveal_type(baz)  # revealed: Literal["bazfoo"]
-
-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)
-
-template: LiteralString = "{}, {}"
-reveal_type(template)  # revealed: Literal["{}, {}"]
-# TODO: Infer `LiteralString`
-reveal_type(template.format(foo, bar))  # revealed: @Todo(Attribute access on `StringLiteral` types)
-```
-
-### Assignability
-
-`Literal[""]` is assignable to `LiteralString`, and `LiteralString` is assignable to `str`, but not
-vice versa.
-
-```py
-from typing_extensions import Literal, LiteralString
-
-def _(flag: bool):
-    foo_1: Literal["foo"] = "foo"
-    bar_1: LiteralString = foo_1  # fine
-
-    foo_2 = "foo" if flag else "bar"
-    reveal_type(foo_2)  # revealed: Literal["foo", "bar"]
-    bar_2: LiteralString = foo_2  # fine
-
-    foo_3: LiteralString = "foo" * 1_000_000_000
-    bar_3: str = foo_2  # fine
-
-    baz_1: str = str()
-    qux_1: LiteralString = baz_1  # error: [invalid-assignment]
-
-    baz_2: LiteralString = "baz" * 1_000_000_000
-    qux_2: Literal["qux"] = baz_2  # error: [invalid-assignment]
-
-    baz_3 = "foo" if flag else 1
-    reveal_type(baz_3)  # revealed: Literal["foo"] | Literal[1]
-    qux_3: LiteralString = baz_3  # error: [invalid-assignment]
-```
-
-### Narrowing
-
-```py
-from typing_extensions import LiteralString
-
-lorem: LiteralString = "lorem" * 1_000_000_000
-
-reveal_type(lorem)  # revealed: LiteralString
-
-if lorem == "ipsum":
-    reveal_type(lorem)  # revealed: Literal["ipsum"]
-
-reveal_type(lorem)  # revealed: LiteralString
-
-if "" < lorem == "ipsum":
-    reveal_type(lorem)  # revealed: Literal["ipsum"]
-```
-
-## `typing.LiteralString`
-
-`typing.LiteralString` is only available in Python 3.11 and later:
-
-```toml
-[environment]
-python-version = "3.11"
-```
-
-```py
-from typing import LiteralString
-
-x: LiteralString = "foo"
-
-def f():
-    reveal_type(x)  # revealed: LiteralString
-```
-
-[1]: https://typing.readthedocs.io/en/latest/spec/literal.html#literalstring

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

@@ -19,11 +19,12 @@ reveal_type(stop())
 ## Assignment
 
 ```py
-from typing_extensions import NoReturn, Never, Any
+from typing 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
+# TODO: Test `Never` is only available in python >= 3.11
 a2: Never
 b1: Any
 b2: int
@@ -45,31 +46,17 @@ def f():
     v6: Never = 1
 ```
 
-## `typing.Never`
-
-`typing.Never` is only available in Python 3.11 and later.
-
-### Python 3.11
-
-```toml
-[environment]
-python-version = "3.11"
-```
+## Typing Extensions
 
 ```py
-from typing import Never
+from typing_extensions import NoReturn, Never
 
-reveal_type(Never)  # revealed: typing.Never
-```
-
-### Python 3.10
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-# error: [unresolved-import]
-from typing import Never
+x: NoReturn
+y: Never
+
+def f():
+    # revealed: Never
+    reveal_type(x)
+    # revealed: Never
+    reveal_type(y)
 ```

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

@@ -8,8 +8,8 @@ from typing_extensions import TypeVarTuple
 Ts = TypeVarTuple("Ts")
 
 def append_int(*args: *Ts) -> tuple[*Ts, int]:
-    # TODO: tuple[*Ts]
-    reveal_type(args)  # revealed: tuple
+    # TODO: should show some representation of the variadic generic type
+    reveal_type(args)  # revealed: @Todo(function parameter type)
 
     return (*args, 1)
 

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/string.md

@@ -3,56 +3,75 @@
 ## Simple
 
 ```py
-def f(v: "int"):
-    reveal_type(v)  # revealed: int
+def f() -> "int":
+    return 1
+
+reveal_type(f())  # revealed: int
 ```
 
 ## Nested
 
 ```py
-def f(v: "'int'"):
-    reveal_type(v)  # revealed: int
+def f() -> "'int'":
+    return 1
+
+reveal_type(f())  # revealed: int
 ```
 
 ## Type expression
 
 ```py
-def f1(v: "int | str", w: "tuple[int, str]"):
-    reveal_type(v)  # revealed: int | str
-    reveal_type(w)  # revealed: tuple[int, str]
+def f1() -> "int | str":
+    return 1
+
+def f2() -> "tuple[int, str]":
+    return 1
+
+reveal_type(f1())  # revealed: int | str
+reveal_type(f2())  # revealed: tuple[int, str]
 ```
 
 ## Partial
 
 ```py
-def f(v: tuple[int, "str"]):
-    reveal_type(v)  # revealed: tuple[int, str]
+def f() -> tuple[int, "str"]:
+    return 1
+
+reveal_type(f())  # revealed: tuple[int, str]
 ```
 
 ## Deferred
 
 ```py
-def f(v: "Foo"):
-    reveal_type(v)  # revealed: Foo
+def f() -> "Foo":
+    return Foo()
 
-class Foo: ...
+class Foo:
+    pass
+
+reveal_type(f())  # revealed: Foo
 ```
 
 ## Deferred (undefined)
 
 ```py
 # error: [unresolved-reference]
-def f(v: "Foo"):
-    reveal_type(v)  # revealed: Unknown
+def f() -> "Foo":
+    pass
+
+reveal_type(f())  # revealed: Unknown
 ```
 
 ## Partial deferred
 
 ```py
-def f(v: int | "Foo"):
-    reveal_type(v)  # revealed: int | Foo
+def f() -> int | "Foo":
+    return 1
 
-class Foo: ...
+class Foo:
+    pass
+
+reveal_type(f())  # revealed: int | Foo
 ```
 
 ## `typing.Literal`
@@ -60,43 +79,65 @@ class Foo: ...
 ```py
 from typing import Literal
 
-def f1(v: Literal["Foo", "Bar"], w: 'Literal["Foo", "Bar"]'):
-    reveal_type(v)  # revealed: Literal["Foo", "Bar"]
-    reveal_type(w)  # revealed: Literal["Foo", "Bar"]
+def f1() -> Literal["Foo", "Bar"]:
+    return "Foo"
 
-class Foo: ...
+def f2() -> 'Literal["Foo", "Bar"]':
+    return "Foo"
+
+class Foo:
+    pass
+
+reveal_type(f1())  # revealed: Literal["Foo", "Bar"]
+reveal_type(f2())  # revealed: Literal["Foo", "Bar"]
 ```
 
 ## Various string kinds
 
 ```py
-def f1(
-    # error: [raw-string-type-annotation] "Type expressions cannot use raw string literal"
-    a: r"int",
-    # error: [fstring-type-annotation] "Type expressions cannot use f-strings"
-    b: f"int",
-    # error: [byte-string-type-annotation] "Type expressions cannot use bytes literal"
-    c: b"int",
-    d: "int",
-    # error: [implicit-concatenated-string-type-annotation] "Type expressions cannot span multiple string literals"
-    e: "in" "t",
-    # error: [escape-character-in-forward-annotation] "Type expressions cannot contain escape characters"
-    f: "\N{LATIN SMALL LETTER I}nt",
-    # error: [escape-character-in-forward-annotation] "Type expressions cannot contain escape characters"
-    g: "\x69nt",
-    h: """int""",
-    # error: [byte-string-type-annotation] "Type expressions cannot use bytes literal"
-    i: "b'int'",
-):
-    reveal_type(a)  # revealed: Unknown
-    reveal_type(b)  # revealed: Unknown
-    reveal_type(c)  # revealed: Unknown
-    reveal_type(d)  # revealed: int
-    reveal_type(e)  # revealed: Unknown
-    reveal_type(f)  # revealed: Unknown
-    reveal_type(g)  # revealed: Unknown
-    reveal_type(h)  # revealed: int
-    reveal_type(i)  # revealed: Unknown
+# error: [annotation-raw-string] "Type expressions cannot use raw string literal"
+def f1() -> r"int":
+    return 1
+
+# error: [annotation-f-string] "Type expressions cannot use f-strings"
+def f2() -> f"int":
+    return 1
+
+# error: [annotation-byte-string] "Type expressions cannot use bytes literal"
+def f3() -> b"int":
+    return 1
+
+def f4() -> "int":
+    return 1
+
+# error: [annotation-implicit-concat] "Type expressions cannot span multiple string literals"
+def f5() -> "in" "t":
+    return 1
+
+# error: [annotation-escape-character] "Type expressions cannot contain escape characters"
+def f6() -> "\N{LATIN SMALL LETTER I}nt":
+    return 1
+
+# error: [annotation-escape-character] "Type expressions cannot contain escape characters"
+def f7() -> "\x69nt":
+    return 1
+
+def f8() -> """int""":
+    return 1
+
+# error: [annotation-byte-string] "Type expressions cannot use bytes literal"
+def f9() -> "b'int'":
+    return 1
+
+reveal_type(f1())  # revealed: Unknown
+reveal_type(f2())  # revealed: Unknown
+reveal_type(f3())  # revealed: Unknown
+reveal_type(f4())  # revealed: int
+reveal_type(f5())  # revealed: Unknown
+reveal_type(f6())  # revealed: Unknown
+reveal_type(f7())  # revealed: Unknown
+reveal_type(f8())  # revealed: int
+reveal_type(f9())  # revealed: Unknown
 ```
 
 ## Various string kinds in `typing.Literal`
@@ -104,8 +145,10 @@ def f1(
 ```py
 from typing import Literal
 
-def f(v: Literal["a", r"b", b"c", "d" "e", "\N{LATIN SMALL LETTER F}", "\x67", """h"""]):
-    reveal_type(v)  # revealed: Literal["a", "b", "de", "f", "g", "h"] | Literal[b"c"]
+def f() -> Literal["a", r"b", b"c", "d" "e", "\N{LATIN SMALL LETTER F}", "\x67", """h"""]:
+    return "normal"
+
+reveal_type(f())  # revealed: Literal["a", "b", "de", "f", "g", "h"] | Literal[b"c"]
 ```
 
 ## Class variables
@@ -132,7 +175,8 @@ c: "Foo"
 # error: [invalid-assignment] "Object of type `Literal[1]` is not assignable to `Foo`"
 d: "Foo" = 1
 
-class Foo: ...
+class Foo:
+    pass
 
 c = Foo()
 
@@ -164,9 +208,9 @@ i: "{i for i in range(5)}"
 j: "{i: i for i in range(5)}"
 k: "(i for i in range(5))"
 l: "await 1"
-# error: [invalid-syntax-in-forward-annotation]
+# error: [forward-annotation-syntax-error]
 m: "yield 1"
-# error: [invalid-syntax-in-forward-annotation]
+# error: [forward-annotation-syntax-error]
 n: "yield from 1"
 o: "1 < 2"
 p: "call()"

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/assignment/annotations.md

@@ -33,6 +33,8 @@ b: tuple[int] = (42,)
 c: tuple[str, int] = ("42", 42)
 d: tuple[tuple[str, str], tuple[int, int]] = (("foo", "foo"), (42, 42))
 e: tuple[str, ...] = ()
+# TODO: we should not emit this error
+# error: [call-possibly-unbound-method] "Method `__class_getitem__` of type `Literal[tuple]` is possibly unbound"
 f: tuple[str, *tuple[int, ...], bytes] = ("42", b"42")
 g: tuple[str, Unpack[tuple[int, ...]], bytes] = ("42", b"42")
 h: tuple[list[int], list[int]] = ([], [])
@@ -48,7 +50,7 @@ reveal_type(b)  # revealed: tuple[int]
 reveal_type(c)  # revealed: tuple[str, int]
 reveal_type(d)  # revealed: tuple[tuple[str, str], tuple[int, int]]
 
-# TODO: homogeneous tuples, PEP-646 tuples
+# TODO: homogenous tuples, PEP-646 tuples
 reveal_type(e)  # revealed: @Todo(full tuple[...] support)
 reveal_type(f)  # revealed: @Todo(full tuple[...] support)
 reveal_type(g)  # revealed: @Todo(full tuple[...] support)
@@ -76,10 +78,20 @@ c: tuple[str | int, str] = ([], "foo")
 ## PEP-604 annotations are supported
 
 ```py
-def foo(v: str | int | None, w: str | str | None, x: str | str):
-    reveal_type(v)  # revealed: str | int | None
-    reveal_type(w)  # revealed: str | None
-    reveal_type(x)  # revealed: str
+def foo() -> str | int | None:
+    return None
+
+reveal_type(foo())  # revealed: str | int | None
+
+def bar() -> str | str | None:
+    return None
+
+reveal_type(bar())  # revealed: str | None
+
+def baz() -> str | str:
+    return "Hello, world!"
+
+reveal_type(baz())  # revealed: str
 ```
 
 ## Attribute expressions in type annotations are understood
@@ -106,7 +118,8 @@ from __future__ import annotations
 
 x: Foo
 
-class Foo: ...
+class Foo:
+    pass
 
 x = Foo()
 reveal_type(x)  # revealed: Foo
@@ -117,7 +130,8 @@ reveal_type(x)  # revealed: Foo
 ```pyi path=main.pyi
 x: Foo
 
-class Foo: ...
+class Foo:
+    pass
 
 x = Foo()
 reveal_type(x)  # revealed: Foo

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

@@ -49,116 +49,134 @@ reveal_type(x)  # revealed: int
 ## Method union
 
 ```py
-def _(flag: bool):
-    class Foo:
-        if flag:
-            def __iadd__(self, other: int) -> str:
-                return "Hello, world!"
-        else:
-            def __iadd__(self, other: int) -> int:
-                return 42
+def bool_instance() -> bool:
+    return True
 
-    f = Foo()
-    f += 12
+flag = bool_instance()
 
-    reveal_type(f)  # revealed: str | int
+class Foo:
+    if bool_instance():
+        def __iadd__(self, other: int) -> str:
+            return "Hello, world!"
+    else:
+        def __iadd__(self, other: int) -> int:
+            return 42
+
+f = Foo()
+f += 12
+
+reveal_type(f)  # revealed: str | int
 ```
 
 ## Partially bound `__iadd__`
 
 ```py
-def _(flag: bool):
-    class Foo:
-        if flag:
-            def __iadd__(self, other: str) -> int:
-                return 42
+def bool_instance() -> bool:
+    return True
 
-    f = Foo()
+class Foo:
+    if bool_instance():
+        def __iadd__(self, other: str) -> int:
+            return 42
 
-    # TODO: We should emit an `unsupported-operator` error here, possibly with the information
-    # that `Foo.__iadd__` may be unbound as additional context.
-    f += "Hello, world!"
+f = Foo()
 
-    reveal_type(f)  # revealed: int | Unknown
+# TODO: We should emit an `unsupported-operator` error here, possibly with the information
+# that `Foo.__iadd__` may be unbound as additional context.
+f += "Hello, world!"
+
+reveal_type(f)  # revealed: int | Unknown
 ```
 
 ## Partially bound with `__add__`
 
 ```py
-def _(flag: bool):
-    class Foo:
-        def __add__(self, other: str) -> str:
-            return "Hello, world!"
-        if flag:
-            def __iadd__(self, other: str) -> int:
-                return 42
+def bool_instance() -> bool:
+    return True
 
-    f = Foo()
-    f += "Hello, world!"
+class Foo:
+    def __add__(self, other: str) -> str:
+        return "Hello, world!"
+    if bool_instance():
+        def __iadd__(self, other: str) -> int:
+            return 42
 
-    reveal_type(f)  # revealed: int | str
+f = Foo()
+f += "Hello, world!"
+
+reveal_type(f)  # revealed: int | str
 ```
 
 ## Partially bound target union
 
 ```py
-def _(flag1: bool, flag2: bool):
-    class Foo:
-        def __add__(self, other: int) -> str:
-            return "Hello, world!"
-        if flag1:
-            def __iadd__(self, other: int) -> int:
-                return 42
+def bool_instance() -> bool:
+    return True
 
-    if flag2:
-        f = Foo()
-    else:
-        f = 42.0
-    f += 12
+class Foo:
+    def __add__(self, other: int) -> str:
+        return "Hello, world!"
+    if bool_instance():
+        def __iadd__(self, other: int) -> int:
+            return 42
 
-    reveal_type(f)  # revealed: int | str | float
+if bool_instance():
+    f = Foo()
+else:
+    f = 42.0
+f += 12
+
+reveal_type(f)  # revealed: int | str | float
 ```
 
 ## Target union
 
 ```py
-def _(flag: bool):
-    class Foo:
-        def __iadd__(self, other: int) -> str:
-            return "Hello, world!"
+def bool_instance() -> bool:
+    return True
 
-    if flag:
-        f = Foo()
-    else:
-        f = 42.0
-    f += 12
+flag = bool_instance()
 
-    reveal_type(f)  # revealed: str | float
+class Foo:
+    def __iadd__(self, other: int) -> str:
+        return "Hello, world!"
+
+if flag:
+    f = Foo()
+else:
+    f = 42.0
+f += 12
+
+reveal_type(f)  # revealed: str | float
 ```
 
 ## Partially bound target union with `__add__`
 
 ```py
-def f(flag: bool, flag2: bool):
-    class Foo:
-        def __add__(self, other: int) -> str:
-            return "Hello, world!"
-        if flag:
-            def __iadd__(self, other: int) -> int:
-                return 42
+def bool_instance() -> bool:
+    return True
 
-    class Bar:
-        def __add__(self, other: int) -> bytes:
-            return b"Hello, world!"
+flag = bool_instance()
 
-        def __iadd__(self, other: int) -> float:
-            return 42.0
+class Foo:
+    def __add__(self, other: int) -> str:
+        return "Hello, world!"
+    if bool_instance():
+        def __iadd__(self, other: int) -> int:
+            return 42
 
-    if flag2:
-        f = Foo()
-    else:
-        f = Bar()
-    f += 12
+class Bar:
+    def __add__(self, other: int) -> bytes:
+        return b"Hello, world!"
 
-    reveal_type(f)  # revealed: int | str | float
+    def __iadd__(self, other: int) -> float:
+        return 42.0
+
+if flag:
+    f = Foo()
+else:
+    f = Bar()
+f += 12
+
+reveal_type(f)  # revealed: int | str | float
 ```

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

@@ -18,3 +18,43 @@ Note: in this particular example, one could argue that the most likely error wou
 of the `x`/`foo` definitions, and so it could be desirable to infer `Literal[1]` for the type of
 `x`. On the other hand, there might be a variable `fob` a little higher up in this file, and the
 actual error might have been just a typo. Inferring `Unknown` thus seems like the safest option.
+
+## Unbound class variable
+
+Name lookups within a class scope fall back to globals, but lookups of class attributes don't.
+
+```py
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+x = 1
+
+class C:
+    y = x
+    if flag:
+        x = 2
+
+# error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C]` is possibly unbound"
+reveal_type(C.x)  # revealed: Literal[2]
+reveal_type(C.y)  # revealed: Literal[1]
+```
+
+## Possibly unbound in class and global scope
+
+```py
+def bool_instance() -> bool:
+    return True
+
+if bool_instance():
+    x = "abc"
+
+class C:
+    if bool_instance():
+        x = 1
+
+    # error: [possibly-unresolved-reference]
+    y = x
+
+reveal_type(C.y)  # revealed: Literal[1] | Literal["abc"]
+```

crates/red_knot_python_semantic/resources/mdtest/attributes.md

@@ -1,27 +1,29 @@
-# Attributes
-
-Tests for attribute access on various kinds of types.
+# Class attributes
 
 ## Union of attributes
 
 ```py
-def _(flag: bool):
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+
+if flag:
+    class C1:
+        x = 1
+
+else:
+    class C1:
+        x = 2
+
+class C2:
     if flag:
-        class C1:
-            x = 1
-
+        x = 3
     else:
-        class C1:
-            x = 2
+        x = 4
 
-    class C2:
-        if flag:
-            x = 3
-        else:
-            x = 4
-
-    reveal_type(C1.x)  # revealed: Literal[1, 2]
-    reveal_type(C2.x)  # revealed: Literal[3, 4]
+reveal_type(C1.x)  # revealed: Literal[1, 2]
+reveal_type(C2.x)  # revealed: Literal[3, 4]
 ```
 
 ## Inherited attributes
@@ -66,19 +68,24 @@ reveal_type(A.X)  # revealed: Literal[42]
 In this example, the `x` attribute is not defined in the `C2` element of the union:
 
 ```py
-def _(flag1: bool, flag2: bool):
-    class C1:
-        x = 1
+def bool_instance() -> bool:
+    return True
 
-    class C2: ...
+class C1:
+    x = 1
 
-    class C3:
-        x = 3
+class C2: ...
 
-    C = C1 if flag1 else C2 if flag2 else C3
+class C3:
+    x = 3
 
-    # error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
-    reveal_type(C.x)  # revealed: Literal[1, 3]
+flag1 = bool_instance()
+flag2 = bool_instance()
+
+C = C1 if flag1 else C2 if flag2 else C3
+
+# error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
+reveal_type(C.x)  # revealed: Literal[1, 3]
 ```
 
 ### Possibly-unbound within a class
@@ -87,21 +94,26 @@ We raise the same diagnostic if the attribute is possibly-unbound in at least on
 union:
 
 ```py
-def _(flag: bool, flag1: bool, flag2: bool):
-    class C1:
-        x = 1
+def bool_instance() -> bool:
+    return True
 
-    class C2:
-        if flag:
-            x = 2
+class C1:
+    x = 1
 
-    class C3:
-        x = 3
+class C2:
+    if bool_instance():
+        x = 2
 
-    C = C1 if flag1 else C2 if flag2 else C3
+class C3:
+    x = 3
 
-    # error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
-    reveal_type(C.x)  # revealed: Literal[1, 2, 3]
+flag1 = bool_instance()
+flag2 = bool_instance()
+
+C = C1 if flag1 else C2 if flag2 else C3
+
+# error: [possibly-unbound-attribute] "Attribute `x` on type `Literal[C1, C2, C3]` is possibly unbound"
+reveal_type(C.x)  # revealed: Literal[1, 2, 3]
 ```
 
 ## Unions with all paths unbound
@@ -109,115 +121,16 @@ def _(flag: bool, flag1: bool, flag2: bool):
 If the symbol is unbound in all elements of the union, we detect that:
 
 ```py
-def _(flag: bool):
-    class C1: ...
-    class C2: ...
-    C = C1 if flag else C2
+def bool_instance() -> bool:
+    return True
 
-    # error: [unresolved-attribute] "Type `Literal[C1, C2]` has no attribute `x`"
-    reveal_type(C.x)  # revealed: Unknown
-```
-
-## Objects of all types have a `__class__` method
-
-```py
-import typing_extensions
-
-reveal_type(typing_extensions.__class__)  # revealed: Literal[ModuleType]
-
-a = 42
-reveal_type(a.__class__)  # revealed: Literal[int]
-
-b = "42"
-reveal_type(b.__class__)  # revealed: Literal[str]
-
-c = b"42"
-reveal_type(c.__class__)  # revealed: Literal[bytes]
-
-d = True
-reveal_type(d.__class__)  # revealed: Literal[bool]
-
-e = (42, 42)
-reveal_type(e.__class__)  # revealed: Literal[tuple]
-
-def f(a: int, b: typing_extensions.LiteralString, c: int | str, d: type[str]):
-    reveal_type(a.__class__)  # revealed: type[int]
-    reveal_type(b.__class__)  # revealed: Literal[str]
-    reveal_type(c.__class__)  # revealed: type[int] | type[str]
-
-    # `type[type]`, a.k.a., either the class `type` or some subclass of `type`.
-    # It would be incorrect to infer `Literal[type]` here,
-    # as `c` could be some subclass of `str` with a custom metaclass.
-    # All we know is that the metaclass must be a (non-strict) subclass of `type`.
-    reveal_type(d.__class__)  # revealed: type[type]
-
-reveal_type(f.__class__)  # revealed: Literal[FunctionType]
-
-class Foo: ...
-
-reveal_type(Foo.__class__)  # revealed: Literal[type]
-```
-
-## Function-literal attributes
-
-Most attribute accesses on function-literal types are delegated to `types.FunctionType`, since all
-functions are instances of that class:
-
-```py path=a.py
-def f(): ...
-
-reveal_type(f.__defaults__)  # revealed: @Todo(instance attributes)
-reveal_type(f.__kwdefaults__)  # revealed: @Todo(instance attributes)
-```
-
-Some attributes are special-cased, however:
-
-```py path=b.py
-def f(): ...
-
-reveal_type(f.__get__)  # revealed: @Todo(`__get__` method on functions)
-reveal_type(f.__call__)  # revealed: @Todo(`__call__` method on functions)
-```
-
-## Int-literal attributes
-
-Most attribute accesses on int-literal types are delegated to `builtins.int`, since all literal
-integers are instances of that class:
-
-```py path=a.py
-reveal_type((2).bit_length)  # revealed: @Todo(instance attributes)
-reveal_type((2).denominator)  # revealed: @Todo(instance attributes)
-```
-
-Some attributes are special-cased, however:
-
-```py path=b.py
-reveal_type((2).numerator)  # revealed: Literal[2]
-reveal_type((2).real)  # revealed: Literal[2]
-```
-
-## Literal `bool` attributes
-
-Most attribute accesses on bool-literal types are delegated to `builtins.bool`, since all literal
-bols are instances of that class:
-
-```py path=a.py
-reveal_type(True.__and__)  # revealed: @Todo(instance attributes)
-reveal_type(False.__or__)  # revealed: @Todo(instance attributes)
-```
-
-Some attributes are special-cased, however:
-
-```py path=b.py
-reveal_type(True.numerator)  # revealed: Literal[1]
-reveal_type(False.real)  # revealed: Literal[0]
-```
-
-## Bytes-literal attributes
-
-All attribute access on literal `bytes` types is currently delegated to `buitins.bytes`:
-
-```py
-reveal_type(b"foo".join)  # revealed: @Todo(instance attributes)
-reveal_type(b"foo".endswith)  # revealed: @Todo(instance attributes)
+class C1: ...
+class C2: ...
+
+flag = bool_instance()
+
+C = C1 if flag else C2
+
+# error: [unresolved-attribute] "Type `Literal[C1, C2]` has no attribute `x`"
+reveal_type(C.x)  # revealed: Unknown
 ```

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

@@ -281,12 +281,20 @@ reveal_type(42 + 4.2)  # revealed: int
 # TODO should be complex, need to check arg type and fall back to `rhs.__radd__`
 reveal_type(3 + 3j)  # revealed: int
 
-def _(x: bool, y: int):
-    reveal_type(x + y)  # revealed: int
-    reveal_type(4.2 + x)  # revealed: float
+def returns_int() -> int:
+    return 42
 
-    # TODO should be float, need to check arg type and fall back to `rhs.__radd__`
-    reveal_type(y + 4.12)  # revealed: int
+def returns_bool() -> bool:
+    return True
+
+x = returns_bool()
+y = returns_int()
+
+reveal_type(x + y)  # revealed: int
+reveal_type(4.2 + x)  # revealed: float
+
+# TODO should be float, need to check arg type and fall back to `rhs.__radd__`
+reveal_type(y + 4.12)  # revealed: int
 ```
 
 ## With literal types

crates/red_knot_python_semantic/resources/mdtest/boolean/short_circuit.md

@@ -7,61 +7,72 @@ Similarly, in `and` expressions, if the left-hand side is falsy, the right-hand
 evaluated.
 
 ```py
-def _(flag: bool):
-    if flag or (x := 1):
-        # error: [possibly-unresolved-reference]
-        reveal_type(x)  # revealed: Literal[1]
+def bool_instance() -> bool:
+    return True
 
-    if flag and (x := 1):
-        # error: [possibly-unresolved-reference]
-        reveal_type(x)  # revealed: Literal[1]
+if bool_instance() or (x := 1):
+    # error: [possibly-unresolved-reference]
+    reveal_type(x)  # revealed: Literal[1]
+
+if bool_instance() and (x := 1):
+    # error: [possibly-unresolved-reference]
+    reveal_type(x)  # revealed: Literal[1]
 ```
 
 ## First expression is always evaluated
 
 ```py
-def _(flag: bool):
-    if (x := 1) or flag:
-        reveal_type(x)  # revealed: Literal[1]
+def bool_instance() -> bool:
+    return True
 
-    if (x := 1) and flag:
-        reveal_type(x)  # revealed: Literal[1]
+if (x := 1) or bool_instance():
+    reveal_type(x)  # revealed: Literal[1]
+
+if (x := 1) and bool_instance():
+    reveal_type(x)  # revealed: Literal[1]
 ```
 
 ## Statically known truthiness
 
 ```py
 if True or (x := 1):
-    # error: [unresolved-reference]
-    reveal_type(x)  # revealed: Unknown
+    # TODO: infer that the second arm is never executed, and raise `unresolved-reference`.
+    # error: [possibly-unresolved-reference]
+    reveal_type(x)  # revealed: Never
 
 if True and (x := 1):
+    # TODO: infer that the second arm is always executed, do not raise a diagnostic
+    # error: [possibly-unresolved-reference]
     reveal_type(x)  # revealed: Literal[1]
 ```
 
 ## Later expressions can always use variables from earlier expressions
 
 ```py
-def _(flag: bool):
-    flag or (x := 1) or reveal_type(x)  # revealed: Literal[1]
+def bool_instance() -> bool:
+    return True
 
-    # error: [unresolved-reference]
-    flag or reveal_type(y) or (y := 1)  # revealed: Unknown
+bool_instance() or (x := 1) or reveal_type(x)  # revealed: Literal[1]
+
+# error: [unresolved-reference]
+bool_instance() or reveal_type(y) or (y := 1)  # revealed: Unknown
 ```
 
 ## Nested expressions
 
 ```py
-def _(flag1: bool, flag2: bool):
-    if flag1 or ((x := 1) and flag2):
-        # error: [possibly-unresolved-reference]
-        reveal_type(x)  # revealed: Literal[1]
-
-    if ((y := 1) and flag1) or flag2:
-        reveal_type(y)  # revealed: Literal[1]
+def bool_instance() -> bool:
+    return True
 
+if bool_instance() or ((x := 1) and bool_instance()):
     # error: [possibly-unresolved-reference]
-    if (flag1 and (z := 1)) or reveal_type(z):  # revealed: Literal[1]
-        # error: [possibly-unresolved-reference]
-        reveal_type(z)  # revealed: Literal[1]
+    reveal_type(x)  # revealed: Literal[1]
+
+if ((y := 1) and bool_instance()) or bool_instance():
+    reveal_type(y)  # revealed: Literal[1]
+
+# error: [possibly-unresolved-reference]
+if (bool_instance() and (z := 1)) or reveal_type(z):  # revealed: Literal[1]
+    # error: [possibly-unresolved-reference]
+    reveal_type(z)  # revealed: Literal[1]
 ```

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

@@ -22,27 +22,29 @@ reveal_type(b)  # revealed: Unknown
 ## Possibly unbound `__call__` method
 
 ```py
-def _(flag: bool):
-    class PossiblyNotCallable:
-        if flag:
-            def __call__(self) -> int: ...
+def flag() -> bool: ...
 
-    a = PossiblyNotCallable()
-    result = a()  # error: "Object of type `PossiblyNotCallable` is not callable (possibly unbound `__call__` method)"
-    reveal_type(result)  # revealed: int
+class PossiblyNotCallable:
+    if flag():
+        def __call__(self) -> int: ...
+
+a = PossiblyNotCallable()
+result = a()  # error: "Object of type `PossiblyNotCallable` is not callable (possibly unbound `__call__` method)"
+reveal_type(result)  # revealed: int
 ```
 
 ## Possibly unbound callable
 
 ```py
-def _(flag: bool):
-    if flag:
-        class PossiblyUnbound:
-            def __call__(self) -> int: ...
+def flag() -> bool: ...
 
-    # error: [possibly-unresolved-reference]
-    a = PossiblyUnbound()
-    reveal_type(a())  # revealed: int
+if flag():
+    class PossiblyUnbound:
+        def __call__(self) -> int: ...
+
+# error: [possibly-unresolved-reference]
+a = PossiblyUnbound()
+reveal_type(a())  # revealed: int
 ```
 
 ## Non-callable `__call__`
@@ -59,14 +61,15 @@ reveal_type(a())  # revealed: Unknown
 ## Possibly non-callable `__call__`
 
 ```py
-def _(flag: bool):
-    class NonCallable:
-        if flag:
-            __call__ = 1
-        else:
-            def __call__(self) -> int: ...
+def flag() -> bool: ...
 
-    a = NonCallable()
-    # error: "Object of type `Literal[1] | Literal[__call__]` is not callable (due to union element `Literal[1]`)"
-    reveal_type(a())  # revealed: Unknown | int
+class NonCallable:
+    if flag():
+        __call__ = 1
+    else:
+        def __call__(self) -> int: ...
+
+a = NonCallable()
+# error: "Object of type `Literal[1] | Literal[__call__]` is not callable (due to union element `Literal[1]`)"
+reveal_type(a())  # revealed: Unknown | int
 ```

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

@@ -57,10 +57,12 @@ x = nonsense()  # error: "Object of type `Literal[123]` is not callable"
 ## Potentially unbound function
 
 ```py
-def _(flag: bool):
-    if flag:
-        def foo() -> int:
-            return 42
-    # error: [possibly-unresolved-reference]
-    reveal_type(foo())  # revealed: int
+def flag() -> bool: ...
+
+if flag():
+    def foo() -> int:
+        return 42
+
+# error: [possibly-unresolved-reference]
+reveal_type(foo())  # revealed: int
 ```

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

@@ -3,14 +3,22 @@
 ## Union of return types
 
 ```py
-def _(flag: bool):
-    if flag:
-        def f() -> int:
-            return 1
-    else:
-        def f() -> str:
-            return "foo"
-    reveal_type(f())  # revealed: int | str
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+
+if flag:
+
+    def f() -> int:
+        return 1
+
+else:
+
+    def f() -> str:
+        return "foo"
+
+reveal_type(f())  # revealed: int | str
 ```
 
 ## Calling with an unknown union
@@ -18,10 +26,13 @@ def _(flag: bool):
 ```py
 from nonexistent import f  # error: [unresolved-import] "Cannot resolve import `nonexistent`"
 
-def coinflip() -> bool:
+def bool_instance() -> bool:
     return True
 
-if coinflip():
+flag = bool_instance()
+
+if flag:
+
     def f() -> int:
         return 1
 
@@ -33,14 +44,20 @@ reveal_type(f())  # revealed: Unknown | int
 Calling a union with a non-callable element should emit a diagnostic.
 
 ```py
-def _(flag: bool):
-    if flag:
-        f = 1
-    else:
-        def f() -> int:
-            return 1
-    x = f()  # error: "Object of type `Literal[1] | Literal[f]` is not callable (due to union element `Literal[1]`)"
-    reveal_type(x)  # revealed: Unknown | int
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+
+if flag:
+    f = 1
+else:
+
+    def f() -> int:
+        return 1
+
+x = f()  # error: "Object of type `Literal[1] | Literal[f]` is not callable (due to union element `Literal[1]`)"
+reveal_type(x)  # revealed: Unknown | int
 ```
 
 ## Multiple non-callable elements in a union
@@ -48,17 +65,23 @@ def _(flag: bool):
 Calling a union with multiple non-callable elements should mention all of them in the diagnostic.
 
 ```py
-def _(flag: bool, flag2: bool):
-    if flag:
-        f = 1
-    elif flag2:
-        f = "foo"
-    else:
-        def f() -> int:
-            return 1
-    # error: "Object of type `Literal[1] | Literal["foo"] | Literal[f]` is not callable (due to union elements Literal[1], Literal["foo"])"
-    # revealed: Unknown | int
-    reveal_type(f())
+def bool_instance() -> bool:
+    return True
+
+flag, flag2 = bool_instance(), bool_instance()
+
+if flag:
+    f = 1
+elif flag2:
+    f = "foo"
+else:
+
+    def f() -> int:
+        return 1
+
+# error: "Object of type `Literal[1] | Literal["foo"] | Literal[f]` is not callable (due to union elements Literal[1], Literal["foo"])"
+# revealed: Unknown | int
+reveal_type(f())
 ```
 
 ## All non-callable union elements
@@ -66,12 +89,16 @@ def _(flag: bool, flag2: bool):
 Calling a union with no callable elements can emit a simpler diagnostic.
 
 ```py
-def _(flag: bool):
-    if flag:
-        f = 1
-    else:
-        f = "foo"
+def bool_instance() -> bool:
+    return True
 
-    x = f()  # error: "Object of type `Literal[1] | Literal["foo"]` is not callable"
-    reveal_type(x)  # revealed: Unknown
+flag = bool_instance()
+
+if flag:
+    f = 1
+else:
+    f = "foo"
+
+x = f()  # error: "Object of type `Literal[1] | Literal["foo"]` is not callable"
+reveal_type(x)  # revealed: Unknown
 ```

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

@@ -3,31 +3,38 @@
 ```py
 class A: ...
 
-def _(a1: A, a2: A, o: object):
-    n1 = None
-    n2 = None
+def get_a() -> A: ...
+def get_object() -> object: ...
 
-    reveal_type(a1 is a1)  # revealed: bool
-    reveal_type(a1 is a2)  # revealed: bool
+a1 = get_a()
+a2 = get_a()
 
-    reveal_type(n1 is n1)  # revealed: Literal[True]
-    reveal_type(n1 is n2)  # revealed: Literal[True]
+n1 = None
+n2 = None
 
-    reveal_type(a1 is n1)  # revealed: Literal[False]
-    reveal_type(n1 is a1)  # revealed: Literal[False]
+o = get_object()
 
-    reveal_type(a1 is o)  # revealed: bool
-    reveal_type(n1 is o)  # revealed: bool
+reveal_type(a1 is a1)  # revealed: bool
+reveal_type(a1 is a2)  # revealed: bool
 
-    reveal_type(a1 is not a1)  # revealed: bool
-    reveal_type(a1 is not a2)  # revealed: bool
+reveal_type(n1 is n1)  # revealed: Literal[True]
+reveal_type(n1 is n2)  # revealed: Literal[True]
 
-    reveal_type(n1 is not n1)  # revealed: Literal[False]
-    reveal_type(n1 is not n2)  # revealed: Literal[False]
+reveal_type(a1 is n1)  # revealed: Literal[False]
+reveal_type(n1 is a1)  # revealed: Literal[False]
 
-    reveal_type(a1 is not n1)  # revealed: Literal[True]
-    reveal_type(n1 is not a1)  # revealed: Literal[True]
+reveal_type(a1 is o)  # revealed: bool
+reveal_type(n1 is o)  # revealed: bool
 
-    reveal_type(a1 is not o)  # revealed: bool
-    reveal_type(n1 is not o)  # revealed: bool
+reveal_type(a1 is not a1)  # revealed: bool
+reveal_type(a1 is not a2)  # revealed: bool
+
+reveal_type(n1 is not n1)  # revealed: Literal[False]
+reveal_type(n1 is not n2)  # revealed: Literal[False]
+
+reveal_type(a1 is not n1)  # revealed: Literal[True]
+reveal_type(n1 is not a1)  # revealed: Literal[True]
+
+reveal_type(a1 is not o)  # revealed: bool
+reveal_type(n1 is not o)  # revealed: bool
 ```

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

@@ -312,9 +312,17 @@ reveal_type(1 <= 2j)  # revealed: bool
 reveal_type(1 > 2j)  # revealed: bool
 reveal_type(1 >= 2j)  # revealed: bool
 
-def f(x: bool, y: int):
-    reveal_type(x < y)  # revealed: bool
-    reveal_type(y < x)  # revealed: bool
-    reveal_type(4.2 < x)  # revealed: bool
-    reveal_type(x < 4.2)  # revealed: bool
+def bool_instance() -> bool:
+    return True
+
+def int_instance() -> int:
+    return 42
+
+x = bool_instance()
+y = int_instance()
+
+reveal_type(x < y)  # revealed: bool
+reveal_type(y < x)  # revealed: bool
+reveal_type(4.2 < x)  # revealed: bool
+reveal_type(x < 4.2)  # revealed: bool
 ```

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

@@ -20,8 +20,10 @@ reveal_type(1 <= "" and 0 < 1)  # revealed: bool
 
 ```py
 # TODO: implement lookup of `__eq__` on typeshed `int` stub.
-def _(a: int, b: int):
-    reveal_type(1 == a)  # revealed: bool
-    reveal_type(9 < a)  # revealed: bool
-    reveal_type(a < b)  # revealed: bool
+def int_instance() -> int:
+    return 42
+
+reveal_type(1 == int_instance())  # revealed: bool
+reveal_type(9 < int_instance())  # revealed: bool
+reveal_type(int_instance() < int_instance())  # revealed: bool
 ```

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

@@ -14,19 +14,21 @@ class Child1(Base):
 
 class Child2(Base): ...
 
-def _(x: Base):
-    c1 = Child1()
+def get_base() -> Base: ...
 
-    # Create an intersection type through narrowing:
-    if isinstance(x, Child1):
-        if isinstance(x, Child2):
-            reveal_type(x)  # revealed: Child1 & Child2
+x = get_base()
+c1 = Child1()
 
-            reveal_type(x == 1)  # revealed: Literal[True]
+# Create an intersection type through narrowing:
+if isinstance(x, Child1):
+    if isinstance(x, Child2):
+        reveal_type(x)  # revealed: Child1 & Child2
 
-            # Other comparison operators fall back to the base type:
-            reveal_type(x > 1)  # revealed: bool
-            reveal_type(x is c1)  # revealed: bool
+        reveal_type(x == 1)  # revealed: Literal[True]
+
+        # Other comparison operators fall back to the base type:
+        reveal_type(x > 1)  # revealed: bool
+        reveal_type(x is c1)  # revealed: bool
 ```
 
 ## Negative contributions
@@ -71,15 +73,18 @@ if x != "abc":
 #### Integers
 
 ```py
-def _(x: int):
-    if x != 1:
-        reveal_type(x)  # revealed: int & ~Literal[1]
+def get_int() -> int: ...
 
-        reveal_type(x != 1)  # revealed: Literal[True]
-        reveal_type(x != 2)  # revealed: bool
+x = get_int()
 
-        reveal_type(x == 1)  # revealed: Literal[False]
-        reveal_type(x == 2)  # revealed: bool
+if x != 1:
+    reveal_type(x)  # revealed: int & ~Literal[1]
+
+    reveal_type(x != 1)  # revealed: Literal[True]
+    reveal_type(x != 2)  # revealed: bool
+
+    reveal_type(x == 1)  # revealed: Literal[False]
+    reveal_type(x == 2)  # revealed: bool
 ```
 
 ### Identity comparisons
@@ -87,15 +92,18 @@ def _(x: int):
 ```py
 class A: ...
 
-def _(o: object):
-    a = A()
-    n = None
+def get_object() -> object: ...
 
-    if o is not None:
-        reveal_type(o)  # revealed: object & ~None
+o = object()
 
-        reveal_type(o is n)  # revealed: Literal[False]
-        reveal_type(o is not n)  # revealed: Literal[True]
+a = A()
+n = None
+
+if o is not None:
+    reveal_type(o)  # revealed: object & ~None
+
+    reveal_type(o is n)  # revealed: Literal[False]
+    reveal_type(o is not n)  # revealed: Literal[True]
 ```
 
 ## Diagnostics
@@ -111,13 +119,16 @@ class Container:
 
 class NonContainer: ...
 
-def _(x: object):
-    if isinstance(x, Container):
-        if isinstance(x, NonContainer):
-            reveal_type(x)  # revealed: Container & NonContainer
+def get_object() -> object: ...
 
-            # error: [unsupported-operator] "Operator `in` is not supported for types `int` and `NonContainer`"
-            reveal_type(2 in x)  # revealed: bool
+x = get_object()
+
+if isinstance(x, Container):
+    if isinstance(x, NonContainer):
+        reveal_type(x)  # revealed: Container & NonContainer
+
+        # error: [unsupported-operator] "Operator `in` is not supported for types `int` and `NonContainer`"
+        reveal_type(2 in x)  # revealed: bool
 ```
 
 ### Unsupported operators for negative contributions
@@ -131,11 +142,14 @@ class Container:
 
 class NonContainer: ...
 
-def _(x: object):
-    if isinstance(x, Container):
-        if not isinstance(x, NonContainer):
-            reveal_type(x)  # revealed: Container & ~NonContainer
+def get_object() -> object: ...
 
-            # No error here!
-            reveal_type(2 in x)  # revealed: bool
+x = get_object()
+
+if isinstance(x, Container):
+    if not isinstance(x, NonContainer):
+        reveal_type(x)  # revealed: Container & ~NonContainer
+
+        # No error here!
+        reveal_type(2 in x)  # revealed: bool
 ```

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

@@ -31,10 +31,10 @@ class C:
     def __lt__(self, other) -> C: ...
 
 x = A() < B() < C()
-reveal_type(x)  # revealed: A & ~AlwaysTruthy | B
+reveal_type(x)  # revealed: A | B
 
 y = 0 < 1 < A() < 3
-reveal_type(y)  # revealed: Literal[False] | A
+reveal_type(y)  # revealed: bool | A
 
 z = 10 < 0 < A() < B() < C()
 reveal_type(z)  # revealed: Literal[False]

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

@@ -3,17 +3,18 @@
 ## String literals
 
 ```py
-def _(x: str):
-    reveal_type("abc" == "abc")  # revealed: Literal[True]
-    reveal_type("ab_cd" <= "ab_ce")  # revealed: Literal[True]
-    reveal_type("abc" in "ab cd")  # revealed: Literal[False]
-    reveal_type("" not in "hello")  # revealed: Literal[False]
-    reveal_type("--" is "--")  # revealed: bool
-    reveal_type("A" is "B")  # revealed: Literal[False]
-    reveal_type("--" is not "--")  # revealed: bool
-    reveal_type("A" is not "B")  # revealed: Literal[True]
-    reveal_type(x < "...")  # revealed: bool
+def str_instance() -> str: ...
 
-    # ensure we're not comparing the interned salsa symbols, which compare by order of declaration.
-    reveal_type("ab" < "ab_cd")  # revealed: Literal[True]
+reveal_type("abc" == "abc")  # revealed: Literal[True]
+reveal_type("ab_cd" <= "ab_ce")  # revealed: Literal[True]
+reveal_type("abc" in "ab cd")  # revealed: Literal[False]
+reveal_type("" not in "hello")  # revealed: Literal[False]
+reveal_type("--" is "--")  # revealed: bool
+reveal_type("A" is "B")  # revealed: Literal[False]
+reveal_type("--" is not "--")  # revealed: bool
+reveal_type("A" is not "B")  # revealed: Literal[True]
+reveal_type(str_instance() < "...")  # revealed: bool
+
+# ensure we're not comparing the interned salsa symbols, which compare by order of declaration.
+reveal_type("ab" < "ab_cd")  # revealed: Literal[True]
 ```

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

@@ -58,23 +58,28 @@ reveal_type(c >= d)  # revealed: Literal[True]
 #### Results with Ambiguity
 
 ```py
-def _(x: bool, y: int):
-    a = (x,)
-    b = (y,)
+def bool_instance() -> bool:
+    return True
 
-    reveal_type(a == a)  # revealed: bool
-    reveal_type(a != a)  # revealed: bool
-    reveal_type(a < a)  # revealed: bool
-    reveal_type(a <= a)  # revealed: bool
-    reveal_type(a > a)  # revealed: bool
-    reveal_type(a >= a)  # revealed: bool
+def int_instance() -> int:
+    return 42
 
-    reveal_type(a == b)  # revealed: bool
-    reveal_type(a != b)  # revealed: bool
-    reveal_type(a < b)  # revealed: bool
-    reveal_type(a <= b)  # revealed: bool
-    reveal_type(a > b)  # revealed: bool
-    reveal_type(a >= b)  # revealed: bool
+a = (bool_instance(),)
+b = (int_instance(),)
+
+reveal_type(a == a)  # revealed: bool
+reveal_type(a != a)  # revealed: bool
+reveal_type(a < a)  # revealed: bool
+reveal_type(a <= a)  # revealed: bool
+reveal_type(a > a)  # revealed: bool
+reveal_type(a >= a)  # revealed: bool
+
+reveal_type(a == b)  # revealed: bool
+reveal_type(a != b)  # revealed: bool
+reveal_type(a < b)  # revealed: bool
+reveal_type(a <= b)  # revealed: bool
+reveal_type(a > b)  # revealed: bool
+reveal_type(a >= b)  # revealed: bool
 ```
 
 #### Comparison Unsupported
@@ -192,7 +197,7 @@ reveal_type((A(), B()) < (A(), B()))  # revealed: float | set | Literal[False]
 
 #### Special Handling of Eq and NotEq in Lexicographic Comparisons
 
-> Example: `(<int instance>, "foo") == (<int instance>, "bar")`
+> Example: `(int_instance(), "foo") == (int_instance(), "bar")`
 
 `Eq` and `NotEq` have unique behavior compared to other operators in lexicographic comparisons.
 Specifically, for `Eq`, if any non-equal pair exists within the tuples being compared, we can
@@ -203,38 +208,42 @@ In contrast, with operators like `<` and `>`, the comparison must consider each
 sequentially, and the final outcome might remain ambiguous until all pairs are compared.
 
 ```py
-def _(x: str, y: int):
-    reveal_type("foo" == "bar")  # revealed: Literal[False]
-    reveal_type(("foo",) == ("bar",))  # revealed: Literal[False]
-    reveal_type((4, "foo") == (4, "bar"))  # revealed: Literal[False]
-    reveal_type((y, "foo") == (y, "bar"))  # revealed: Literal[False]
+def str_instance() -> str:
+    return "hello"
 
-    a = (x, y, "foo")
+def int_instance() -> int:
+    return 42
 
-    reveal_type(a == a)  # revealed: bool
-    reveal_type(a != a)  # revealed: bool
-    reveal_type(a < a)  # revealed: bool
-    reveal_type(a <= a)  # revealed: bool
-    reveal_type(a > a)  # revealed: bool
-    reveal_type(a >= a)  # revealed: bool
+reveal_type("foo" == "bar")  # revealed: Literal[False]
+reveal_type(("foo",) == ("bar",))  # revealed: Literal[False]
+reveal_type((4, "foo") == (4, "bar"))  # revealed: Literal[False]
+reveal_type((int_instance(), "foo") == (int_instance(), "bar"))  # revealed: Literal[False]
 
-    b = (x, y, "bar")
+a = (str_instance(), int_instance(), "foo")
 
-    reveal_type(a == b)  # revealed: Literal[False]
-    reveal_type(a != b)  # revealed: Literal[True]
-    reveal_type(a < b)  # revealed: bool
-    reveal_type(a <= b)  # revealed: bool
-    reveal_type(a > b)  # revealed: bool
-    reveal_type(a >= b)  # revealed: bool
+reveal_type(a == a)  # revealed: bool
+reveal_type(a != a)  # revealed: bool
+reveal_type(a < a)  # revealed: bool
+reveal_type(a <= a)  # revealed: bool
+reveal_type(a > a)  # revealed: bool
+reveal_type(a >= a)  # revealed: bool
 
-    c = (x, y, "foo", "different_length")
+b = (str_instance(), int_instance(), "bar")
 
-    reveal_type(a == c)  # revealed: Literal[False]
-    reveal_type(a != c)  # revealed: Literal[True]
-    reveal_type(a < c)  # revealed: bool
-    reveal_type(a <= c)  # revealed: bool
-    reveal_type(a > c)  # revealed: bool
-    reveal_type(a >= c)  # revealed: bool
+reveal_type(a == b)  # revealed: Literal[False]
+reveal_type(a != b)  # revealed: Literal[True]
+reveal_type(a < b)  # revealed: bool
+reveal_type(a <= b)  # revealed: bool
+reveal_type(a > b)  # revealed: bool
+reveal_type(a >= b)  # revealed: bool
+
+c = (str_instance(), int_instance(), "foo", "different_length")
+reveal_type(a == c)  # revealed: Literal[False]
+reveal_type(a != c)  # revealed: Literal[True]
+reveal_type(a < c)  # revealed: bool
+reveal_type(a <= c)  # revealed: bool
+reveal_type(a > c)  # revealed: bool
+reveal_type(a >= c)  # revealed: bool
 ```
 
 #### Error Propagation
@@ -243,36 +252,42 @@ Errors occurring within a tuple comparison should propagate outward. However, if
 comparison can clearly conclude before encountering an error, the error should not be raised.
 
 ```py
-def _(n: int, s: str):
-    class A: ...
-    # error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`"
-    A() < A()
-    # error: [unsupported-operator] "Operator `<=` is not supported for types `A` and `A`"
-    A() <= A()
-    # error: [unsupported-operator] "Operator `>` is not supported for types `A` and `A`"
-    A() > A()
-    # error: [unsupported-operator] "Operator `>=` is not supported for types `A` and `A`"
-    A() >= A()
+def int_instance() -> int:
+    return 42
 
-    a = (0, n, A())
+def str_instance() -> str:
+    return "hello"
 
-    # error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
-    reveal_type(a < a)  # revealed: Unknown
-    # error: [unsupported-operator] "Operator `<=` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
-    reveal_type(a <= a)  # revealed: Unknown
-    # error: [unsupported-operator] "Operator `>` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
-    reveal_type(a > a)  # revealed: Unknown
-    # error: [unsupported-operator] "Operator `>=` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
-    reveal_type(a >= a)  # revealed: Unknown
+class A: ...
 
-    # Comparison between `a` and `b` should only involve the first elements, `Literal[0]` and `Literal[99999]`,
-    # and should terminate immediately.
-    b = (99999, n, A())
+# error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`"
+A() < A()
+# error: [unsupported-operator] "Operator `<=` is not supported for types `A` and `A`"
+A() <= A()
+# error: [unsupported-operator] "Operator `>` is not supported for types `A` and `A`"
+A() > A()
+# error: [unsupported-operator] "Operator `>=` is not supported for types `A` and `A`"
+A() >= A()
 
-    reveal_type(a < b)  # revealed: Literal[True]
-    reveal_type(a <= b)  # revealed: Literal[True]
-    reveal_type(a > b)  # revealed: Literal[False]
-    reveal_type(a >= b)  # revealed: Literal[False]
+a = (0, int_instance(), A())
+
+# error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
+reveal_type(a < a)  # revealed: Unknown
+# error: [unsupported-operator] "Operator `<=` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
+reveal_type(a <= a)  # revealed: Unknown
+# error: [unsupported-operator] "Operator `>` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
+reveal_type(a > a)  # revealed: Unknown
+# error: [unsupported-operator] "Operator `>=` is not supported for types `A` and `A`, in comparing `tuple[Literal[0], int, A]` with `tuple[Literal[0], int, A]`"
+reveal_type(a >= a)  # revealed: Unknown
+
+# Comparison between `a` and `b` should only involve the first elements, `Literal[0]` and `Literal[99999]`,
+# and should terminate immediately.
+b = (99999, int_instance(), A())
+
+reveal_type(a < b)  # revealed: Literal[True]
+reveal_type(a <= b)  # revealed: Literal[True]
+reveal_type(a > b)  # revealed: Literal[False]
+reveal_type(a >= b)  # revealed: Literal[False]
 ```
 
 ### Membership Test Comparisons
@@ -280,20 +295,22 @@ def _(n: int, s: str):
 "Membership Test Comparisons" refers to the operators `in` and `not in`.
 
 ```py
-def _(n: int):
-    a = (1, 2)
-    b = ((3, 4), (1, 2))
-    c = ((1, 2, 3), (4, 5, 6))
-    d = ((n, n), (n, n))
+def int_instance() -> int:
+    return 42
 
-    reveal_type(a in b)  # revealed: Literal[True]
-    reveal_type(a not in b)  # revealed: Literal[False]
+a = (1, 2)
+b = ((3, 4), (1, 2))
+c = ((1, 2, 3), (4, 5, 6))
+d = ((int_instance(), int_instance()), (int_instance(), int_instance()))
 
-    reveal_type(a in c)  # revealed: Literal[False]
-    reveal_type(a not in c)  # revealed: Literal[True]
+reveal_type(a in b)  # revealed: Literal[True]
+reveal_type(a not in b)  # revealed: Literal[False]
 
-    reveal_type(a in d)  # revealed: bool
-    reveal_type(a not in d)  # revealed: bool
+reveal_type(a in c)  # revealed: Literal[False]
+reveal_type(a not in c)  # revealed: Literal[True]
+
+reveal_type(a in d)  # revealed: bool
+reveal_type(a not in d)  # revealed: bool
 ```
 
 ### Identity Comparisons

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

@@ -5,46 +5,49 @@
 Comparisons on union types need to consider all possible cases:
 
 ```py
-def _(flag: bool):
-    one_or_two = 1 if flag else 2
+def bool_instance() -> bool:
+    return True
 
-    reveal_type(one_or_two <= 2)  # revealed: Literal[True]
-    reveal_type(one_or_two <= 1)  # revealed: bool
-    reveal_type(one_or_two <= 0)  # revealed: Literal[False]
+flag = bool_instance()
+one_or_two = 1 if flag else 2
 
-    reveal_type(2 >= one_or_two)  # revealed: Literal[True]
-    reveal_type(1 >= one_or_two)  # revealed: bool
-    reveal_type(0 >= one_or_two)  # revealed: Literal[False]
+reveal_type(one_or_two <= 2)  # revealed: Literal[True]
+reveal_type(one_or_two <= 1)  # revealed: bool
+reveal_type(one_or_two <= 0)  # revealed: Literal[False]
 
-    reveal_type(one_or_two < 1)  # revealed: Literal[False]
-    reveal_type(one_or_two < 2)  # revealed: bool
-    reveal_type(one_or_two < 3)  # revealed: Literal[True]
+reveal_type(2 >= one_or_two)  # revealed: Literal[True]
+reveal_type(1 >= one_or_two)  # revealed: bool
+reveal_type(0 >= one_or_two)  # revealed: Literal[False]
 
-    reveal_type(one_or_two > 0)  # revealed: Literal[True]
-    reveal_type(one_or_two > 1)  # revealed: bool
-    reveal_type(one_or_two > 2)  # revealed: Literal[False]
+reveal_type(one_or_two < 1)  # revealed: Literal[False]
+reveal_type(one_or_two < 2)  # revealed: bool
+reveal_type(one_or_two < 3)  # revealed: Literal[True]
 
-    reveal_type(one_or_two == 3)  # revealed: Literal[False]
-    reveal_type(one_or_two == 1)  # revealed: bool
+reveal_type(one_or_two > 0)  # revealed: Literal[True]
+reveal_type(one_or_two > 1)  # revealed: bool
+reveal_type(one_or_two > 2)  # revealed: Literal[False]
 
-    reveal_type(one_or_two != 3)  # revealed: Literal[True]
-    reveal_type(one_or_two != 1)  # revealed: bool
+reveal_type(one_or_two == 3)  # revealed: Literal[False]
+reveal_type(one_or_two == 1)  # revealed: bool
 
-    a_or_ab = "a" if flag else "ab"
+reveal_type(one_or_two != 3)  # revealed: Literal[True]
+reveal_type(one_or_two != 1)  # revealed: bool
 
-    reveal_type(a_or_ab in "ab")  # revealed: Literal[True]
-    reveal_type("a" in a_or_ab)  # revealed: Literal[True]
+a_or_ab = "a" if flag else "ab"
 
-    reveal_type("c" not in a_or_ab)  # revealed: Literal[True]
-    reveal_type("a" not in a_or_ab)  # revealed: Literal[False]
+reveal_type(a_or_ab in "ab")  # revealed: Literal[True]
+reveal_type("a" in a_or_ab)  # revealed: Literal[True]
 
-    reveal_type("b" in a_or_ab)  # revealed: bool
-    reveal_type("b" not in a_or_ab)  # revealed: bool
+reveal_type("c" not in a_or_ab)  # revealed: Literal[True]
+reveal_type("a" not in a_or_ab)  # revealed: Literal[False]
 
-    one_or_none = 1 if flag else None
+reveal_type("b" in a_or_ab)  # revealed: bool
+reveal_type("b" not in a_or_ab)  # revealed: bool
 
-    reveal_type(one_or_none is None)  # revealed: bool
-    reveal_type(one_or_none is not None)  # revealed: bool
+one_or_none = 1 if flag else None
+
+reveal_type(one_or_none is None)  # revealed: bool
+reveal_type(one_or_none is not None)  # revealed: bool
 ```
 
 ## Union on both sides of the comparison
@@ -53,15 +56,18 @@ With unions on both sides, we need to consider the full cross product of options
 resulting (union) type:
 
 ```py
-def _(flag_s: bool, flag_l: bool):
-    small = 1 if flag_s else 2
-    large = 2 if flag_l else 3
+def bool_instance() -> bool:
+    return True
 
-    reveal_type(small <= large)  # revealed: Literal[True]
-    reveal_type(small >= large)  # revealed: bool
+flag_s, flag_l = bool_instance(), bool_instance()
+small = 1 if flag_s else 2
+large = 2 if flag_l else 3
 
-    reveal_type(small < large)  # revealed: bool
-    reveal_type(small > large)  # revealed: Literal[False]
+reveal_type(small <= large)  # revealed: Literal[True]
+reveal_type(small >= large)  # revealed: bool
+
+reveal_type(small < large)  # revealed: bool
+reveal_type(small > large)  # revealed: Literal[False]
 ```
 
 ## Unsupported operations
@@ -71,9 +77,12 @@ back to `bool` for the result type instead of trying to infer something more pre
 (supported) variants:
 
 ```py
-def _(flag: bool):
-    x = [1, 2] if flag else 1
+def bool_instance() -> bool:
+    return True
 
-    result = 1 in x  # error: "Operator `in` is not supported"
-    reveal_type(result)  # revealed: bool
+flag = bool_instance()
+x = [1, 2] if flag else 1
+
+result = 1 in x  # error: "Operator `in` is not supported"
+reveal_type(result)  # revealed: bool
 ```

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

@@ -1,38 +1,42 @@
 # Comparison: Unsupported operators
 
 ```py
-def _(flag: bool, flag1: bool, flag2: bool):
-    class A: ...
-    a = 1 in 7  # error: "Operator `in` is not supported for types `Literal[1]` and `Literal[7]`"
-    reveal_type(a)  # revealed: bool
+def bool_instance() -> bool:
+    return True
 
-    b = 0 not in 10  # error: "Operator `not in` is not supported for types `Literal[0]` and `Literal[10]`"
-    reveal_type(b)  # revealed: bool
+class A: ...
 
-    # TODO: should error, once operand type check is implemented
-    # ("Operator `<` is not supported for types `object` and `int`")
-    c = object() < 5
-    # TODO: should be Unknown, once operand type check is implemented
-    reveal_type(c)  # revealed: bool
+a = 1 in 7  # error: "Operator `in` is not supported for types `Literal[1]` and `Literal[7]`"
+reveal_type(a)  # revealed: bool
 
-    # TODO: should error, once operand type check is implemented
-    # ("Operator `<` is not supported for types `int` and `object`")
-    d = 5 < object()
-    # TODO: should be Unknown, once operand type check is implemented
-    reveal_type(d)  # revealed: bool
+b = 0 not in 10  # error: "Operator `not in` is not supported for types `Literal[0]` and `Literal[10]`"
+reveal_type(b)  # revealed: bool
 
-    int_literal_or_str_literal = 1 if flag else "foo"
-    # error: "Operator `in` is not supported for types `Literal[42]` and `Literal[1]`, in comparing `Literal[42]` with `Literal[1] | Literal["foo"]`"
-    e = 42 in int_literal_or_str_literal
-    reveal_type(e)  # revealed: bool
+# TODO: should error, once operand type check is implemented
+# ("Operator `<` is not supported for types `object` and `int`")
+c = object() < 5
+# TODO: should be Unknown, once operand type check is implemented
+reveal_type(c)  # revealed: bool
 
-    # TODO: should error, need to check if __lt__ signature is valid for right operand
-    # error may be "Operator `<` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`
-    f = (1, 2) < (1, "hello")
-    # TODO: should be Unknown, once operand type check is implemented
-    reveal_type(f)  # revealed: bool
+# TODO: should error, once operand type check is implemented
+# ("Operator `<` is not supported for types `int` and `object`")
+d = 5 < object()
+# TODO: should be Unknown, once operand type check is implemented
+reveal_type(d)  # revealed: bool
 
-    # error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`, in comparing `tuple[bool, A]` with `tuple[bool, A]`"
-    g = (flag1, A()) < (flag2, A())
-    reveal_type(g)  # revealed: Unknown
+flag = bool_instance()
+int_literal_or_str_literal = 1 if flag else "foo"
+# error: "Operator `in` is not supported for types `Literal[42]` and `Literal[1]`, in comparing `Literal[42]` with `Literal[1] | Literal["foo"]`"
+e = 42 in int_literal_or_str_literal
+reveal_type(e)  # revealed: bool
+
+# TODO: should error, need to check if __lt__ signature is valid for right operand
+# error may be "Operator `<` is not supported for types `int` and `str`, in comparing `tuple[Literal[1], Literal[2]]` with `tuple[Literal[1], Literal["hello"]]`
+f = (1, 2) < (1, "hello")
+# TODO: should be Unknown, once operand type check is implemented
+reveal_type(f)  # revealed: bool
+
+# error: [unsupported-operator] "Operator `<` is not supported for types `A` and `A`, in comparing `tuple[bool, A]` with `tuple[bool, A]`"
+g = (bool_instance(), A()) < (bool_instance(), A())
+reveal_type(g)  # revealed: Unknown
 ```

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

@@ -3,35 +3,47 @@
 ## Simple if-expression
 
 ```py
-def _(flag: bool):
-    x = 1 if flag else 2
-    reveal_type(x)  # revealed: Literal[1, 2]
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+x = 1 if flag else 2
+reveal_type(x)  # revealed: Literal[1, 2]
 ```
 
 ## If-expression with walrus operator
 
 ```py
-def _(flag: bool):
-    y = 0
-    z = 0
-    x = (y := 1) if flag else (z := 2)
-    reveal_type(x)  # revealed: Literal[1, 2]
-    reveal_type(y)  # revealed: Literal[0, 1]
-    reveal_type(z)  # revealed: Literal[0, 2]
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+y = 0
+z = 0
+x = (y := 1) if flag else (z := 2)
+reveal_type(x)  # revealed: Literal[1, 2]
+reveal_type(y)  # revealed: Literal[0, 1]
+reveal_type(z)  # revealed: Literal[0, 2]
 ```
 
 ## Nested if-expression
 
 ```py
-def _(flag: bool, flag2: bool):
-    x = 1 if flag else 2 if flag2 else 3
-    reveal_type(x)  # revealed: Literal[1, 2, 3]
+def bool_instance() -> bool:
+    return True
+
+flag, flag2 = bool_instance(), bool_instance()
+x = 1 if flag else 2 if flag2 else 3
+reveal_type(x)  # revealed: Literal[1, 2, 3]
 ```
 
 ## None
 
 ```py
-def _(flag: bool):
-    x = 1 if flag else None
-    reveal_type(x)  # revealed: Literal[1] | None
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+x = 1 if flag else None
+reveal_type(x)  # revealed: Literal[1] | None
 ```

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

@@ -3,115 +3,128 @@
 ## Simple if
 
 ```py
-def _(flag: bool):
-    y = 1
-    y = 2
+def bool_instance() -> bool:
+    return True
 
-    if flag:
-        y = 3
+flag = bool_instance()
+y = 1
+y = 2
 
-    reveal_type(y)  # revealed: Literal[2, 3]
+if flag:
+    y = 3
+
+reveal_type(y)  # revealed: Literal[2, 3]
 ```
 
 ## Simple if-elif-else
 
 ```py
-def _(flag: bool, flag2: bool):
-    y = 1
-    y = 2
+def bool_instance() -> bool:
+    return True
 
-    if flag:
-        y = 3
-    elif flag2:
-        y = 4
-    else:
-        r = y
-        y = 5
-        s = y
-    x = y
+flag, flag2 = bool_instance(), bool_instance()
+y = 1
+y = 2
+if flag:
+    y = 3
+elif flag2:
+    y = 4
+else:
+    r = y
+    y = 5
+    s = y
+x = y
 
-    reveal_type(x)  # revealed: Literal[3, 4, 5]
+reveal_type(x)  # revealed: Literal[3, 4, 5]
 
-    # revealed: Literal[2]
-    # error: [possibly-unresolved-reference]
-    reveal_type(r)
+# revealed: Literal[2]
+# error: [possibly-unresolved-reference]
+reveal_type(r)
 
-    # revealed: Literal[5]
-    # error: [possibly-unresolved-reference]
-    reveal_type(s)
+# revealed: Literal[5]
+# error: [possibly-unresolved-reference]
+reveal_type(s)
 ```
 
 ## Single symbol across if-elif-else
 
 ```py
-def _(flag: bool, flag2: bool):
-    if flag:
-        y = 1
-    elif flag2:
-        y = 2
-    else:
-        y = 3
+def bool_instance() -> bool:
+    return True
 
-    reveal_type(y)  # revealed: Literal[1, 2, 3]
+flag, flag2 = bool_instance(), bool_instance()
+
+if flag:
+    y = 1
+elif flag2:
+    y = 2
+else:
+    y = 3
+reveal_type(y)  # revealed: Literal[1, 2, 3]
 ```
 
 ## if-elif-else without else assignment
 
 ```py
-def _(flag: bool, flag2: bool):
-    y = 0
+def bool_instance() -> bool:
+    return True
 
-    if flag:
-        y = 1
-    elif flag2:
-        y = 2
-    else:
-        pass
-
-    reveal_type(y)  # revealed: Literal[0, 1, 2]
+flag, flag2 = bool_instance(), bool_instance()
+y = 0
+if flag:
+    y = 1
+elif flag2:
+    y = 2
+else:
+    pass
+reveal_type(y)  # revealed: Literal[0, 1, 2]
 ```
 
 ## if-elif-else with intervening assignment
 
 ```py
-def _(flag: bool, flag2: bool):
-    y = 0
+def bool_instance() -> bool:
+    return True
 
-    if flag:
-        y = 1
-        z = 3
-    elif flag2:
-        y = 2
-    else:
-        pass
-
-    reveal_type(y)  # revealed: Literal[0, 1, 2]
+flag, flag2 = bool_instance(), bool_instance()
+y = 0
+if flag:
+    y = 1
+    z = 3
+elif flag2:
+    y = 2
+else:
+    pass
+reveal_type(y)  # revealed: Literal[0, 1, 2]
 ```
 
 ## Nested if statement
 
 ```py
-def _(flag: bool, flag2: bool):
-    y = 0
+def bool_instance() -> bool:
+    return True
 
-    if flag:
-        if flag2:
-            y = 1
-
-    reveal_type(y)  # revealed: Literal[0, 1]
+flag, flag2 = bool_instance(), bool_instance()
+y = 0
+if flag:
+    if flag2:
+        y = 1
+reveal_type(y)  # revealed: Literal[0, 1]
 ```
 
 ## if-elif without else
 
 ```py
-def _(flag: bool, flag2: bool):
-    y = 1
-    y = 2
+def bool_instance() -> bool:
+    return True
 
-    if flag:
-        y = 3
-    elif flag2:
-        y = 4
+flag, flag2 = bool_instance(), bool_instance()
+y = 1
+y = 2
+if flag:
+    y = 3
+elif flag2:
+    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/conditional/match.md

@@ -3,43 +3,39 @@
 ## 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 0:
+    case 1:
+        y = 3
+    case 2:
+        y = 4
 
-    match target:
-        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

@@ -10,66 +10,42 @@ x: str  # error: [invalid-declaration] "Cannot declare type `str` for inferred t
 ## Incompatible declarations
 
 ```py
-def _(flag: bool):
-    if flag:
-        x: str
-    else:
-        x: int
+def bool_instance() -> bool:
+    return True
 
-    x = 1  # error: [conflicting-declarations] "Conflicting declared types for `x`: str, int"
+flag = bool_instance()
+if flag:
+    x: str
+else:
+    x: int
+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:
-        x: int
+def bool_instance() -> bool:
+    return True
 
-    # Here, the declared type for `x` is `int | str | Unknown`.
-    x = 1  # error: [conflicting-declarations] "Conflicting declared types for `x`: str, int"
+flag = bool_instance()
+if flag:
+    x: int
+x = 1  # error: [conflicting-declarations] "Conflicting declared types for `x`: Unknown, int"
 ```
 
 ## Incompatible declarations with bad assignment
 
 ```py
-def _(flag: bool):
-    if flag:
-        x: str
-    else:
-        x: int
+def bool_instance() -> bool:
+    return True
 
-    # error: [conflicting-declarations]
-    # 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
+flag = bool_instance()
+if flag:
+    x: str
+else:
+    x: int
+
+# error: [conflicting-declarations]
+# error: [invalid-assignment]
+x = b"foo"
 ```

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

@@ -49,124 +49,12 @@ def foo(
     try:
         help()
     except x as e:
-        reveal_type(e)  # revealed: AttributeError
+        # TODO: should be `AttributeError`
+        reveal_type(e)  # revealed: @Todo(exception type)
     except y as f:
-        reveal_type(f)  # revealed: OSError | RuntimeError
+        # TODO: should be `OSError | RuntimeError`
+        reveal_type(f)  # revealed: @Todo(exception type)
     except z as g:
         # TODO: should be `BaseException`
-        reveal_type(g)  # revealed: @Todo(full tuple[...] support)
-```
-
-## Invalid exception handlers
-
-```py
-try:
-    pass
-# error: [invalid-exception-caught] "Cannot catch object of type `Literal[3]` in an exception handler (must be a `BaseException` subclass or a tuple of `BaseException` subclasses)"
-except 3 as e:
-    reveal_type(e)  # revealed: Unknown
-
-try:
-    pass
-# error: [invalid-exception-caught] "Cannot catch object of type `Literal["foo"]` in an exception handler (must be a `BaseException` subclass or a tuple of `BaseException` subclasses)"
-# error: [invalid-exception-caught] "Cannot catch object of type `Literal[b"bar"]` in an exception handler (must be a `BaseException` subclass or a tuple of `BaseException` subclasses)"
-except (ValueError, OSError, "foo", b"bar") as e:
-    reveal_type(e)  # revealed: ValueError | OSError | Unknown
-
-def foo(
-    x: type[str],
-    y: tuple[type[OSError], type[RuntimeError], int],
-    z: tuple[type[str], ...],
-):
-    try:
-        help()
-    # error: [invalid-exception-caught]
-    except x as e:
-        reveal_type(e)  # revealed: Unknown
-    # error: [invalid-exception-caught]
-    except y as f:
-        reveal_type(f)  # revealed: OSError | RuntimeError | Unknown
-    except z as g:
-        # 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]
+        reveal_type(g)  # revealed: @Todo(exception type)
 ```

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

@@ -1,66 +1,30 @@
-# `except*`
+# Except star
 
-`except*` is only available in Python 3.11 and later:
-
-```toml
-[environment]
-python-version = "3.11"
-```
-
-## `except*` with `BaseException`
+## Except\* with BaseException
 
 ```py
 try:
     help()
 except* BaseException as e:
-    # TODO: should be `BaseExceptionGroup[BaseException]` --Alex
     reveal_type(e)  # revealed: BaseExceptionGroup
 ```
 
-## `except*` with specific exception
+## Except\* with specific exception
 
 ```py
 try:
     help()
 except* OSError as e:
-    # TODO: more precise would be `ExceptionGroup[OSError]` --Alex
-    # (needs homogenous tuples + generics)
+    # TODO(Alex): more precise would be `ExceptionGroup[OSError]`
     reveal_type(e)  # revealed: BaseExceptionGroup
 ```
 
-## `except*` with multiple exceptions
+## Except\* with multiple exceptions
 
 ```py
 try:
     help()
 except* (TypeError, AttributeError) as e:
-    # TODO: more precise would be `ExceptionGroup[TypeError | AttributeError]` --Alex
-    # (needs homogenous tuples + generics)
-    reveal_type(e)  # revealed: BaseExceptionGroup
-```
-
-## `except*` with mix of `Exception`s and `BaseException`s
-
-```py
-try:
-    help()
-except* (KeyboardInterrupt, AttributeError) as e:
-    # TODO: more precise would be `BaseExceptionGroup[KeyboardInterrupt | AttributeError]` --Alex
-    reveal_type(e)  # revealed: BaseExceptionGroup
-```
-
-## Invalid `except*` handlers
-
-```py
-try:
-    help()
-except* 3 as e:  # error: [invalid-exception-caught]
-    # TODO: Should be `BaseExceptionGroup[Unknown]` --Alex
-    reveal_type(e)  # revealed: BaseExceptionGroup
-
-try:
-    help()
-except* (AttributeError, 42) as e:  # error: [invalid-exception-caught]
-    # TODO: Should be `BaseExceptionGroup[AttributeError | Unknown]` --Alex
+    # TODO(Alex): more precise would be `ExceptionGroup[TypeError | AttributeError]`.
     reveal_type(e)  # revealed: BaseExceptionGroup
 ```

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

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

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

@@ -3,25 +3,26 @@
 ## Boundness
 
 ```py
-def _(flag: bool):
-    class A:
-        always_bound = 1
+def flag() -> bool: ...
 
-        if flag:
-            union = 1
-        else:
-            union = "abc"
+class A:
+    always_bound = 1
 
-        if flag:
-            possibly_unbound = "abc"
+    if flag():
+        union = 1
+    else:
+        union = "abc"
 
-    reveal_type(A.always_bound)  # revealed: Literal[1]
+    if flag():
+        possibly_unbound = "abc"
 
-    reveal_type(A.union)  # revealed: Literal[1] | Literal["abc"]
+reveal_type(A.always_bound)  # revealed: Literal[1]
 
-    # error: [possibly-unbound-attribute] "Attribute `possibly_unbound` on type `Literal[A]` is possibly unbound"
-    reveal_type(A.possibly_unbound)  # revealed: Literal["abc"]
+reveal_type(A.union)  # revealed: Literal[1] | Literal["abc"]
 
-    # error: [unresolved-attribute] "Type `Literal[A]` has no attribute `non_existent`"
-    reveal_type(A.non_existent)  # revealed: Unknown
+# error: [possibly-unbound-attribute] "Attribute `possibly_unbound` on type `Literal[A]` is possibly unbound"
+reveal_type(A.possibly_unbound)  # revealed: Literal["abc"]
+
+# error: [unresolved-attribute] "Type `Literal[A]` has no attribute `non_existent`"
+reveal_type(A.non_existent)  # revealed: Unknown
 ```

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

@@ -3,45 +3,54 @@
 ## OR
 
 ```py
-def _(foo: str):
-    reveal_type(True or False)  # revealed: Literal[True]
-    reveal_type("x" or "y" or "z")  # revealed: Literal["x"]
-    reveal_type("" or "y" or "z")  # revealed: Literal["y"]
-    reveal_type(False or "z")  # revealed: Literal["z"]
-    reveal_type(False or True)  # revealed: Literal[True]
-    reveal_type(False or False)  # revealed: Literal[False]
-    reveal_type(foo or False)  # revealed: str & ~AlwaysFalsy | Literal[False]
-    reveal_type(foo or True)  # revealed: str & ~AlwaysFalsy | Literal[True]
+def foo() -> str:
+    pass
+
+reveal_type(True or False)  # revealed: Literal[True]
+reveal_type("x" or "y" or "z")  # revealed: Literal["x"]
+reveal_type("" or "y" or "z")  # revealed: Literal["y"]
+reveal_type(False or "z")  # revealed: Literal["z"]
+reveal_type(False or True)  # revealed: Literal[True]
+reveal_type(False or False)  # revealed: Literal[False]
+reveal_type(foo() or False)  # revealed: str | Literal[False]
+reveal_type(foo() or True)  # revealed: str | Literal[True]
 ```
 
 ## AND
 
 ```py
-def _(foo: str):
-    reveal_type(True and False)  # revealed: Literal[False]
-    reveal_type(False and True)  # revealed: Literal[False]
-    reveal_type(foo and False)  # revealed: str & ~AlwaysTruthy | Literal[False]
-    reveal_type(foo and True)  # revealed: str & ~AlwaysTruthy | Literal[True]
-    reveal_type("x" and "y" and "z")  # revealed: Literal["z"]
-    reveal_type("x" and "y" and "")  # revealed: Literal[""]
-    reveal_type("" and "y")  # revealed: Literal[""]
+def foo() -> str:
+    pass
+
+reveal_type(True and False)  # revealed: Literal[False]
+reveal_type(False and True)  # revealed: Literal[False]
+reveal_type(foo() and False)  # revealed: str | Literal[False]
+reveal_type(foo() and True)  # revealed: str | Literal[True]
+reveal_type("x" and "y" and "z")  # revealed: Literal["z"]
+reveal_type("x" and "y" and "")  # revealed: Literal[""]
+reveal_type("" and "y")  # revealed: Literal[""]
 ```
 
 ## Simple function calls to bool
 
 ```py
-def _(flag: bool):
-    if flag:
-        x = True
-    else:
-        x = False
+def returns_bool() -> bool:
+    return True
 
-    reveal_type(x)  # revealed: bool
+if returns_bool():
+    x = True
+else:
+    x = False
+
+reveal_type(x)  # revealed: bool
 ```
 
 ## Complex
 
 ```py
+def foo() -> str:
+    pass
+
 reveal_type("x" and "y" or "z")  # revealed: Literal["y"]
 reveal_type("x" or "y" and "z")  # revealed: Literal["x"]
 reveal_type("" and "y" or "z")  # revealed: Literal["z"]

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

@@ -3,11 +3,13 @@
 ## Union
 
 ```py
-def _(flag: bool):
-    reveal_type(1 if flag else 2)  # revealed: Literal[1, 2]
+def bool_instance() -> bool:
+    return True
+
+reveal_type(1 if bool_instance() else 2)  # revealed: Literal[1, 2]
 ```
 
-## Statically known conditions in if-expressions
+## Statically known branches
 
 ```py
 reveal_type(1 if True else 2)  # revealed: Literal[1]
@@ -28,12 +30,14 @@ reveal_type(1 if 0 else 2)  # revealed: Literal[2]
 The test inside an if expression should not affect code outside of the expression.
 
 ```py
-def _(flag: bool):
-    x: Literal[42, "hello"] = 42 if flag else "hello"
+def bool_instance() -> bool:
+    return True
 
-    reveal_type(x)  # revealed: Literal[42] | Literal["hello"]
+x: Literal[42, "hello"] = 42 if bool_instance() else "hello"
 
-    _ = ... if isinstance(x, str) else ...
+reveal_type(x)  # revealed: Literal[42] | Literal["hello"]
 
-    reveal_type(x)  # revealed: Literal[42] | Literal["hello"]
+_ = ... if isinstance(x, str) else ...
+
+reveal_type(x)  # revealed: Literal[42] | Literal["hello"]
 ```

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

@@ -1,218 +0,0 @@
-# Length (`len()`)
-
-## Literal and constructed iterables
-
-### Strings and bytes literals
-
-```py
-reveal_type(len("no\rmal"))  # revealed: Literal[6]
-reveal_type(len(r"aw stri\ng"))  # revealed: Literal[10]
-reveal_type(len(r"conca\t" "ena\tion"))  # revealed: Literal[14]
-reveal_type(len(b"ytes lite" rb"al"))  # revealed: Literal[11]
-reveal_type(len("𝒰𝕹🄸©🕲𝕕ℇ"))  # revealed: Literal[7]
-
-reveal_type(  # revealed: Literal[7]
-    len(
-        """foo
-bar"""
-    )
-)
-reveal_type(  # revealed: Literal[9]
-    len(
-        r"""foo\r
-bar"""
-    )
-)
-reveal_type(  # revealed: Literal[7]
-    len(
-        b"""foo
-bar"""
-    )
-)
-reveal_type(  # revealed: Literal[9]
-    len(
-        rb"""foo\r
-bar"""
-    )
-)
-```
-
-### Tuples
-
-```py
-reveal_type(len(()))  # revealed: Literal[0]
-reveal_type(len((1,)))  # revealed: Literal[1]
-reveal_type(len((1, 2)))  # revealed: Literal[2]
-
-# TODO: Handle constructor calls
-reveal_type(len(tuple()))  # revealed: int
-
-# TODO: Handle star unpacks; Should be: Literal[0]
-reveal_type(len((*[],)))  # revealed: Literal[1]
-
-# TODO: Handle star unpacks; Should be: Literal[1]
-reveal_type(  # revealed: Literal[2]
-    len(
-        (
-            *[],
-            1,
-        )
-    )
-)
-
-# TODO: Handle star unpacks; Should be: Literal[2]
-reveal_type(len((*[], 1, 2)))  # revealed: Literal[3]
-
-# TODO: Handle star unpacks; Should be: Literal[0]
-reveal_type(len((*[], *{})))  # revealed: Literal[2]
-```
-
-### Lists, sets and dictionaries
-
-```py
-reveal_type(len([]))  # revealed: int
-reveal_type(len([1]))  # revealed: int
-reveal_type(len([1, 2]))  # revealed: int
-reveal_type(len([*{}, *dict()]))  # revealed: int
-
-reveal_type(len({}))  # revealed: int
-reveal_type(len({**{}}))  # revealed: int
-reveal_type(len({**{}, **{}}))  # revealed: int
-
-reveal_type(len({1}))  # revealed: int
-reveal_type(len({1, 2}))  # revealed: int
-reveal_type(len({*[], 2}))  # revealed: int
-
-reveal_type(len(list()))  # revealed: int
-reveal_type(len(set()))  # revealed: int
-reveal_type(len(dict()))  # revealed: int
-reveal_type(len(frozenset()))  # revealed: int
-```
-
-## `__len__`
-
-The returned value of `__len__` is implicitly and recursively converted to `int`.
-
-### Literal integers
-
-```py
-from typing import Literal
-
-class Zero:
-    def __len__(self) -> Literal[0]: ...
-
-class ZeroOrOne:
-    def __len__(self) -> Literal[0, 1]: ...
-
-class ZeroOrTrue:
-    def __len__(self) -> Literal[0, True]: ...
-
-class OneOrFalse:
-    def __len__(self) -> Literal[1] | Literal[False]: ...
-
-class OneOrFoo:
-    def __len__(self) -> Literal[1, "foo"]: ...
-
-class ZeroOrStr:
-    def __len__(self) -> Literal[0] | str: ...
-
-reveal_type(len(Zero()))  # revealed: Literal[0]
-reveal_type(len(ZeroOrOne()))  # revealed: Literal[0, 1]
-reveal_type(len(ZeroOrTrue()))  # revealed: Literal[0, 1]
-reveal_type(len(OneOrFalse()))  # revealed: Literal[0, 1]
-
-# TODO: Emit a diagnostic
-reveal_type(len(OneOrFoo()))  # revealed: int
-
-# TODO: Emit a diagnostic
-reveal_type(len(ZeroOrStr()))  # revealed: int
-```
-
-### Literal booleans
-
-```py
-from typing import Literal
-
-class LiteralTrue:
-    def __len__(self) -> Literal[True]: ...
-
-class LiteralFalse:
-    def __len__(self) -> Literal[False]: ...
-
-reveal_type(len(LiteralTrue()))  # revealed: Literal[1]
-reveal_type(len(LiteralFalse()))  # revealed: Literal[0]
-```
-
-### Enums
-
-```py
-from enum import Enum, auto
-from typing import Literal
-
-class SomeEnum(Enum):
-    AUTO = auto()
-    INT = 2
-    STR = "4"
-    TUPLE = (8, "16")
-    INT_2 = 3_2
-
-class Auto:
-    def __len__(self) -> Literal[SomeEnum.AUTO]: ...
-
-class Int:
-    def __len__(self) -> Literal[SomeEnum.INT]: ...
-
-class Str:
-    def __len__(self) -> Literal[SomeEnum.STR]: ...
-
-class Tuple:
-    def __len__(self) -> Literal[SomeEnum.TUPLE]: ...
-
-class IntUnion:
-    def __len__(self) -> Literal[SomeEnum.INT, SomeEnum.INT_2]: ...
-
-reveal_type(len(Auto()))  # revealed: int
-reveal_type(len(Int()))  # revealed: Literal[2]
-reveal_type(len(Str()))  # revealed: int
-reveal_type(len(Tuple()))  # revealed: int
-reveal_type(len(IntUnion()))  # revealed: Literal[2, 32]
-```
-
-### Negative integers
-
-```py
-from typing import Literal
-
-class Negative:
-    def __len__(self) -> Literal[-1]: ...
-
-# TODO: Emit a diagnostic
-reveal_type(len(Negative()))  # revealed: int
-```
-
-### Wrong signature
-
-```py
-from typing import Literal
-
-class SecondOptionalArgument:
-    def __len__(self, v: int = 0) -> Literal[0]: ...
-
-class SecondRequiredArgument:
-    def __len__(self, v: int) -> Literal[1]: ...
-
-# TODO: Emit a diagnostic
-reveal_type(len(SecondOptionalArgument()))  # revealed: Literal[0]
-
-# TODO: Emit a diagnostic
-reveal_type(len(SecondRequiredArgument()))  # revealed: Literal[1]
-```
-
-### No `__len__`
-
-```py
-class NoDunderLen: ...
-
-# TODO: Emit a diagnostic
-reveal_type(len(NoDunderLen()))  # revealed: int
-```

crates/red_knot_python_semantic/resources/mdtest/final.md

@@ -1,31 +0,0 @@
-# Tests for the `@typing(_extensions).final` decorator
-
-## Cannot subclass
-
-Don't do this:
-
-```py
-import typing_extensions
-from typing import final
-
-@final
-class A: ...
-
-class B(A): ...  # error: 9 [subclass-of-final-class] "Class `B` cannot inherit from final class `A`"
-
-@typing_extensions.final
-class C: ...
-
-class D(C): ...  # error: [subclass-of-final-class]
-class E: ...
-class F: ...
-class G: ...
-
-# fmt: off
-class H(
-    E,
-    F,
-    A,  # error: [subclass-of-final-class]
-    G,
-): ...
-```

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

@@ -1,75 +0,0 @@
-# Function parameter types
-
-Within a function scope, the declared type of each parameter is its annotated type (or Unknown if
-not annotated). The initial inferred type is the union of the declared type with the type of the
-default value expression (if any). If both are fully static types, this union should simplify to the
-annotated type (since the default value type must be assignable to the annotated type, and for fully
-static types this means subtype-of, which simplifies in unions). But if the annotated type is
-Unknown or another non-fully-static type, the default value type may still be relevant as lower
-bound.
-
-The variadic parameter is a variadic tuple of its annotated type; the variadic-keywords parameter is
-a dictionary from strings to its annotated type.
-
-## Parameter kinds
-
-```py
-from typing import Literal
-
-def f(a, b: int, c=1, d: int = 2, /, e=3, f: Literal[4] = 4, *args: object, g=5, h: Literal[6] = 6, **kwargs: str):
-    reveal_type(a)  # revealed: Unknown
-    reveal_type(b)  # revealed: int
-    reveal_type(c)  # revealed: Unknown | Literal[1]
-    reveal_type(d)  # revealed: int
-    reveal_type(e)  # revealed: Unknown | Literal[3]
-    reveal_type(f)  # revealed: Literal[4]
-    reveal_type(g)  # revealed: Unknown | Literal[5]
-    reveal_type(h)  # revealed: Literal[6]
-
-    # TODO: should be `tuple[object, ...]` (needs generics)
-    reveal_type(args)  # revealed: tuple
-
-    # TODO: should be `dict[str, str]` (needs generics)
-    reveal_type(kwargs)  # revealed: dict
-```
-
-## Unannotated variadic parameters
-
-...are inferred as tuple of Unknown or dict from string to Unknown.
-
-```py
-def g(*args, **kwargs):
-    # TODO: should be `tuple[Unknown, ...]` (needs generics)
-    reveal_type(args)  # revealed: tuple
-
-    # TODO: should be `dict[str, Unknown]` (needs generics)
-    reveal_type(kwargs)  # revealed: dict
-```
-
-## Annotation is present but not a fully static type
-
-The default value type should be a lower bound on the inferred type.
-
-```py
-from typing import Any
-
-def f(x: Any = 1):
-    reveal_type(x)  # revealed: Any | Literal[1]
-```
-
-## Default value type must be assignable to annotated type
-
-The default value type must be assignable to the annotated type. If not, we emit a diagnostic, and
-fall back to inferring the annotated type, ignoring the default value type.
-
-```py
-# error: [invalid-parameter-default]
-def f(x: int = "foo"):
-    reveal_type(x)  # revealed: int
-
-# The check is assignable-to, not subtype-of, so this is fine:
-from typing import Any
-
-def g(x: Any = "foo"):
-    reveal_type(x)  # revealed: Any | Literal["foo"]
-```

crates/red_knot_python_semantic/resources/mdtest/generics.md

@@ -73,7 +73,7 @@ def f[T]():
 A typevar with less than two constraints emits a diagnostic:
 
 ```py
-# error: [invalid-type-variable-constraints] "TypeVar must have at least two constrained types"
+# error: [invalid-typevar-constraints] "TypeVar must have at least two constrained types"
 def f[T: (int,)]():
     pass
 ```

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

@@ -3,10 +3,11 @@
 ## Maybe unbound
 
 ```py path=maybe_unbound.py
-def coinflip() -> bool:
+def bool_instance() -> bool:
     return True
 
-if coinflip():
+flag = bool_instance()
+if flag:
     y = 3
 
 x = y  # error: [possibly-unresolved-reference]
@@ -30,12 +31,13 @@ reveal_type(y)  # revealed: Literal[3]
 ## Maybe unbound annotated
 
 ```py path=maybe_unbound_annotated.py
-def coinflip() -> bool:
+def bool_instance() -> bool:
     return True
 
-if coinflip():
-    y: int = 3
+flag = bool_instance()
 
+if flag:
+    y: int = 3
 x = y  # error: [possibly-unresolved-reference]
 
 # revealed: Literal[3]
@@ -61,10 +63,10 @@ reveal_type(y)  # revealed: int
 Importing a possibly undeclared name still gives us its declared type:
 
 ```py path=maybe_undeclared.py
-def coinflip() -> bool:
+def bool_instance() -> bool:
     return True
 
-if coinflip():
+if bool_instance():
     x: int
 ```
 
@@ -81,12 +83,14 @@ def f(): ...
 ```
 
 ```py path=b.py
-def coinflip() -> bool:
+def bool_instance() -> bool:
     return True
 
-if coinflip():
+flag = bool_instance()
+if flag:
     from c import f
 else:
+
     def f(): ...
 ```
 
@@ -107,10 +111,11 @@ x: int
 ```
 
 ```py path=b.py
-def coinflip() -> bool:
+def bool_instance() -> bool:
     return True
 
-if coinflip():
+flag = bool_instance()
+if flag:
     from c import x
 else:
     x = 1

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/errors.md

@@ -55,24 +55,3 @@ from b import x
 
 x = "foo"  # error: [invalid-assignment] "Object of type `Literal["foo"]"
 ```
-
-## Import cycle
-
-```py path=a.py
-class A: ...
-
-reveal_type(A.__mro__)  # revealed: tuple[Literal[A], Literal[object]]
-import b
-
-class C(b.B): ...
-
-reveal_type(C.__mro__)  # revealed: tuple[Literal[C], Literal[B], Literal[A], Literal[object]]
-```
-
-```py path=b.py
-from a import A
-
-class B(A): ...
-
-reveal_type(B.__mro__)  # revealed: tuple[Literal[B], Literal[A], Literal[object]]
-```

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

@@ -1,31 +0,0 @@
-# Invalid syntax
-
-## Missing module name
-
-```py
-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/invalid_syntax.md

@@ -1,93 +0,0 @@
-# Syntax errors
-
-Test cases to ensure that red knot does not panic if there are syntax errors in the source code.
-
-The parser cannot recover from certain syntax errors completely which is why the number of syntax
-errors could be more than expected in the following examples. For instance, if there's a keyword
-(like `for`) in the middle of another statement (like function definition), then it's more likely
-that the rest of the tokens are going to be part of the `for` statement and not the function
-definition. But, it's not necessary that the remaining tokens are valid in the context of a `for`
-statement.
-
-## Keyword as identifiers
-
-When keywords are used as identifiers, the parser recovers from this syntax error by emitting an
-error and including the text value of the keyword to create the `Identifier` node.
-
-### Name expression
-
-#### Assignment
-
-```py
-# error: [invalid-syntax]
-pass = 1
-```
-
-#### Type alias
-
-```py
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-type pass = 1
-```
-
-#### Function definition
-
-```py
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-def True(for):
-    # error: [invalid-syntax]
-    # error: [invalid-syntax]
-    pass
-```
-
-#### For
-
-```py
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-# error: [unresolved-reference] "Name `pass` used when not defined"
-for while in pass:
-    pass
-```
-
-#### While
-
-```py
-# error: [invalid-syntax]
-# error: [unresolved-reference] "Name `in` used when not defined"
-while in:
-    pass
-```
-
-#### Match
-
-```py
-# error: [invalid-syntax]
-# error: [invalid-syntax]
-# error: [unresolved-reference] "Name `match` used when not defined"
-match while:
-    # error: [invalid-syntax]
-    # error: [invalid-syntax]
-    # error: [invalid-syntax]
-    # error: [unresolved-reference] "Name `case` used when not defined"
-    case in:
-        # error: [invalid-syntax]
-        # error: [invalid-syntax]
-        pass
-```
-
-### Attribute expression
-
-```py
-# TODO: Check when support for attribute expressions is added
-
-# error: [invalid-syntax]
-# error: [unresolved-reference] "Name `foo` used when not defined"
-for x in foo.pass:
-    pass
-```

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/ellipsis.md

@@ -1,23 +0,0 @@
-# Ellipsis literals
-
-## Python 3.9
-
-```toml
-[environment]
-python-version = "3.9"
-```
-
-```py
-reveal_type(...)  # revealed: ellipsis
-```
-
-## Python 3.10
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-```py
-reveal_type(...)  # revealed: EllipsisType
-```

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/for.md

@@ -106,19 +106,23 @@ reveal_type(x)
 ## With non-callable iterator
 
 ```py
-def _(flag: bool):
-    class NotIterable:
-        if flag:
-            __iter__ = 1
-        else:
-            __iter__ = None
+def bool_instance() -> bool:
+    return True
 
-    for x in NotIterable():  # error: "Object of type `NotIterable` is not iterable"
-        pass
+flag = bool_instance()
 
-    # revealed: Unknown
-    # error: [possibly-unresolved-reference]
-    reveal_type(x)
+class NotIterable:
+    if flag:
+        __iter__ = 1
+    else:
+        __iter__ = None
+
+for x in NotIterable():  # error: "Object of type `NotIterable` is not iterable"
+    pass
+
+# revealed: Unknown
+# error: [possibly-unresolved-reference]
+reveal_type(x)
 ```
 
 ## Invalid iterable
@@ -156,9 +160,13 @@ class Test2:
     def __iter__(self) -> TestIter:
         return TestIter()
 
-def _(flag: bool):
-    for x in Test() if flag else Test2():
-        reveal_type(x)  # revealed: int
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+
+for x in Test() if flag else Test2():
+    reveal_type(x)  # revealed: int
 ```
 
 ## Union type as iterator
@@ -207,9 +215,13 @@ class Test2:
     def __iter__(self) -> TestIter3 | TestIter4:
         return TestIter3()
 
-def _(flag: bool):
-    for x in Test() if flag else Test2():
-        reveal_type(x)  # revealed: int | Exception | str | tuple[int, int] | bytes | memoryview
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+
+for x in Test() if flag else Test2():
+    reveal_type(x)  # revealed: int | Exception | str | tuple[int, int] | bytes | memoryview
 ```
 
 ## Union type as iterable where one union element has no `__iter__` method
@@ -223,10 +235,12 @@ class Test:
     def __iter__(self) -> TestIter:
         return TestIter()
 
-def _(flag: bool):
-    # error: [not-iterable] "Object of type `Test | Literal[42]` is not iterable because its `__iter__` method is possibly unbound"
-    for x in Test() if flag else 42:
-        reveal_type(x)  # revealed: int
+def coinflip() -> bool:
+    return True
+
+# error: [not-iterable] "Object of type `Test | Literal[42]` is not iterable because its `__iter__` method is possibly unbound"
+for x in Test() if coinflip() else 42:
+    reveal_type(x)  # revealed: int
 ```
 
 ## Union type as iterable where one union element has invalid `__iter__` method
@@ -244,10 +258,12 @@ class Test2:
     def __iter__(self) -> int:
         return 42
 
-def _(flag: bool):
-    # error: "Object of type `Test | Test2` is not iterable"
-    for x in Test() if flag else Test2():
-        reveal_type(x)  # revealed: Unknown
+def coinflip() -> bool:
+    return True
+
+# error: "Object of type `Test | Test2` is not iterable"
+for x in Test() if coinflip() else Test2():
+    reveal_type(x)  # revealed: Unknown
 ```
 
 ## Union type as iterator where one union element has no `__next__` method

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

@@ -1,50 +1,59 @@
 # While loops
 
-## Basic `while` loop
+## Basic While Loop
 
 ```py
-def _(flag: bool):
-    x = 1
-    while flag:
-        x = 2
+def bool_instance() -> bool:
+    return True
 
+flag = bool_instance()
+x = 1
+while flag:
+    x = 2
+
+reveal_type(x)  # revealed: Literal[1, 2]
+```
+
+## While with else (no break)
+
+```py
+def bool_instance() -> bool:
+    return True
+
+flag = bool_instance()
+x = 1
+while flag:
+    x = 2
+else:
     reveal_type(x)  # revealed: Literal[1, 2]
+    x = 3
+
+reveal_type(x)  # revealed: Literal[3]
 ```
 
-## `while` with `else` (no `break`)
+## While with Else (may break)
 
 ```py
-def _(flag: bool):
-    x = 1
-    while flag:
-        x = 2
-    else:
-        reveal_type(x)  # revealed: Literal[1, 2]
-        x = 3
+def bool_instance() -> bool:
+    return True
 
-    reveal_type(x)  # revealed: Literal[3]
+flag, flag2 = bool_instance(), bool_instance()
+x = 1
+y = 0
+while flag:
+    x = 2
+    if flag2:
+        y = 4
+        break
+else:
+    y = x
+    x = 3
+
+reveal_type(x)  # revealed: Literal[2, 3]
+reveal_type(y)  # revealed: Literal[1, 2, 4]
 ```
 
-## `while` with `else` (may `break`)
-
-```py
-def _(flag: bool, flag2: bool):
-    x = 1
-    y = 0
-    while flag:
-        x = 2
-        if flag2:
-            y = 4
-            break
-    else:
-        y = x
-        x = 3
-
-    reveal_type(x)  # revealed: Literal[2, 3]
-    reveal_type(y)  # revealed: Literal[1, 2, 4]
-```
-
-## Nested `while` loops
+## Nested while loops
 
 ```py
 def flag() -> bool:
@@ -69,50 +78,3 @@ 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

@@ -1,67 +0,0 @@
-This test makes sure that `red_knot_test` correctly parses the TOML configuration blocks and applies
-the correct settings hierarchically.
-
-The following configuration will be attached to the *root* section (without any heading):
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
-# Basic
-
-Here, we simply make sure that we pick up the global configuration from the root section:
-
-```py
-reveal_type(sys.version_info[:2] == (3, 10))  # revealed: Literal[True]
-```
-
-# Inheritance
-
-## Child
-
-### Grandchild
-
-The same should work for arbitrarily nested sections:
-
-```py
-reveal_type(sys.version_info[:2] == (3, 10))  # revealed: Literal[True]
-```
-
-# Overwriting
-
-Here, we make sure that we can overwrite the global configuration in a child section:
-
-```toml
-[environment]
-python-version = "3.11"
-```
-
-```py
-reveal_type(sys.version_info[:2] == (3, 11))  # revealed: Literal[True]
-```
-
-# No global state
-
-There is no global state. This section should again use the root configuration:
-
-```py
-reveal_type(sys.version_info[:2] == (3, 10))  # revealed: Literal[True]
-```
-
-# Overwriting affects children
-
-Children in this section should all use the section configuration:
-
-```toml
-[environment]
-python-version = "3.12"
-```
-
-## Child
-
-### Grandchild
-
-```py
-reveal_type(sys.version_info[:2] == (3, 12))  # revealed: Literal[True]
-```

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
@@ -179,11 +179,11 @@ reveal_type(A.__class__)  # revealed: @Todo(metaclass not a class)
 Retrieving the metaclass of a cyclically defined class should not cause an infinite loop.
 
 ```py path=a.pyi
-class A(B): ...  # error: [cyclic-class-definition]
-class B(C): ...  # error: [cyclic-class-definition]
-class C(A): ...  # error: [cyclic-class-definition]
+class A(B): ...  # error: [cyclic-class-def]
+class B(C): ...  # error: [cyclic-class-def]
+class C(A): ...  # error: [cyclic-class-def]
 
-reveal_type(A.__class__)  # revealed: 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/mro.md

@@ -348,14 +348,14 @@ reveal_type(unknown_object.__mro__)  # revealed: Unknown
 These are invalid, but we need to be able to handle them gracefully without panicking.
 
 ```py path=a.pyi
-class Foo(Foo): ...  # error: [cyclic-class-definition]
+class Foo(Foo): ...  # error: [cyclic-class-def]
 
 reveal_type(Foo)  # revealed: Literal[Foo]
 reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
 
 class Bar: ...
 class Baz: ...
-class Boz(Bar, Baz, Boz): ...  # error: [cyclic-class-definition]
+class Boz(Bar, Baz, Boz): ...  # error: [cyclic-class-def]
 
 reveal_type(Boz)  # revealed: Literal[Boz]
 reveal_type(Boz.__mro__)  # revealed: tuple[Literal[Boz], Unknown, Literal[object]]
@@ -366,9 +366,9 @@ reveal_type(Boz.__mro__)  # revealed: tuple[Literal[Boz], Unknown, Literal[objec
 These are similarly unlikely, but we still shouldn't crash:
 
 ```py path=a.pyi
-class Foo(Bar): ...  # error: [cyclic-class-definition]
-class Bar(Baz): ...  # error: [cyclic-class-definition]
-class Baz(Foo): ...  # error: [cyclic-class-definition]
+class Foo(Bar): ...  # error: [cyclic-class-def]
+class Bar(Baz): ...  # error: [cyclic-class-def]
+class Baz(Foo): ...  # error: [cyclic-class-def]
 
 reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
 reveal_type(Bar.__mro__)  # revealed: tuple[Literal[Bar], Unknown, Literal[object]]
@@ -379,9 +379,9 @@ reveal_type(Baz.__mro__)  # revealed: tuple[Literal[Baz], Unknown, Literal[objec
 
 ```py path=a.pyi
 class Spam: ...
-class Foo(Bar): ...  # error: [cyclic-class-definition]
-class Bar(Baz): ...  # error: [cyclic-class-definition]
-class Baz(Foo, Spam): ...  # error: [cyclic-class-definition]
+class Foo(Bar): ...  # error: [cyclic-class-def]
+class Bar(Baz): ...  # error: [cyclic-class-def]
+class Baz(Foo, Spam): ...  # error: [cyclic-class-def]
 
 reveal_type(Foo.__mro__)  # revealed: tuple[Literal[Foo], Unknown, Literal[object]]
 reveal_type(Bar.__mro__)  # revealed: tuple[Literal[Bar], Unknown, Literal[object]]
@@ -391,16 +391,16 @@ reveal_type(Baz.__mro__)  # revealed: tuple[Literal[Baz], Unknown, Literal[objec
 ## Classes with cycles in their MRO, and a sub-graph
 
 ```py path=a.pyi
-class FooCycle(BarCycle): ...  # error: [cyclic-class-definition]
+class FooCycle(BarCycle): ...  # error: [cyclic-class-def]
 class Foo: ...
-class BarCycle(FooCycle): ...  # error: [cyclic-class-definition]
+class BarCycle(FooCycle): ...  # error: [cyclic-class-def]
 class Bar(Foo): ...
 
 # TODO: can we avoid emitting the errors for these?
 # The classes have cyclic superclasses,
 # but are not themselves cyclic...
-class Baz(Bar, BarCycle): ...  # error: [cyclic-class-definition]
-class Spam(Baz): ...  # error: [cyclic-class-definition]
+class Baz(Bar, BarCycle): ...  # error: [cyclic-class-def]
+class Spam(Baz): ...  # error: [cyclic-class-def]
 
 reveal_type(FooCycle.__mro__)  # revealed: tuple[Literal[FooCycle], Unknown, Literal[object]]
 reveal_type(BarCycle.__mro__)  # revealed: tuple[Literal[BarCycle], Unknown, Literal[object]]

crates/red_knot_python_semantic/resources/mdtest/narrow/bool-call.md

@@ -1,32 +0,0 @@
-## Narrowing for `bool(..)` checks
-
-```py
-def _(flag: bool):
-
-    x = 1 if flag else None
-
-    # valid invocation, positive
-    reveal_type(x)  # revealed: Literal[1] | None
-    if bool(x is not None):
-        reveal_type(x)  # revealed: Literal[1]
-
-    # valid invocation, negative
-    reveal_type(x)  # revealed: Literal[1] | None
-    if not bool(x is not None):
-        reveal_type(x)  # revealed: None
-
-    # no args/narrowing
-    reveal_type(x)  # revealed: Literal[1] | None
-    if not bool():
-        reveal_type(x)  # revealed: Literal[1] | None
-
-    # invalid invocation, too many positional args
-    reveal_type(x)  # revealed: Literal[1] | None
-    if bool(x is not None, 5):  # TODO diagnostic
-        reveal_type(x)  # revealed: Literal[1] | None
-
-    # invalid invocation, too many kwargs
-    reveal_type(x)  # revealed: Literal[1] | None
-    if bool(x is not None, y=5):  # TODO diagnostic
-        reveal_type(x)  # revealed: Literal[1] | None
-```

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

@@ -9,67 +9,85 @@ Similarly, in `and` expressions, the right-hand side is evaluated only if the le
 ## Narrowing in `or`
 
 ```py
-def _(flag: bool):
-    class A: ...
-    x: A | None = A() if flag else None
+def bool_instance() -> bool:
+    return True
 
-    isinstance(x, A) or reveal_type(x)  # revealed: None
-    x is None or reveal_type(x)  # revealed: A
-    reveal_type(x)  # revealed: A | None
+class A: ...
+
+x: A | None = A() if bool_instance() else None
+
+isinstance(x, A) or reveal_type(x)  # revealed: None
+x is None or reveal_type(x)  # revealed: A
+reveal_type(x)  # revealed: A | None
 ```
 
 ## Narrowing in `and`
 
 ```py
-def _(flag: bool):
-    class A: ...
-    x: A | None = A() if flag else None
+def bool_instance() -> bool:
+    return True
 
-    isinstance(x, A) and reveal_type(x)  # revealed: A
-    x is None and reveal_type(x)  # revealed: None
-    reveal_type(x)  # revealed: A | None
+class A: ...
+
+x: A | None = A() if bool_instance() else None
+
+isinstance(x, A) and reveal_type(x)  # revealed: A
+x is None and reveal_type(x)  # revealed: None
+reveal_type(x)  # revealed: A | None
 ```
 
 ## Multiple `and` arms
 
 ```py
-def _(flag1: bool, flag2: bool, flag3: bool, flag4: bool):
-    class A: ...
-    x: A | None = A() if flag1 else None
+def bool_instance() -> bool:
+    return True
 
-    flag2 and isinstance(x, A) and reveal_type(x)  # revealed: A
-    isinstance(x, A) and flag2 and reveal_type(x)  # revealed: A
-    reveal_type(x) and isinstance(x, A) and flag3  # revealed: A | None
+class A: ...
+
+x: A | None = A() if bool_instance() else None
+
+bool_instance() and isinstance(x, A) and reveal_type(x)  # revealed: A
+isinstance(x, A) and bool_instance() and reveal_type(x)  # revealed: A
+reveal_type(x) and isinstance(x, A) and bool_instance()  # revealed: A | None
 ```
 
 ## Multiple `or` arms
 
 ```py
-def _(flag1: bool, flag2: bool, flag3: bool, flag4: bool):
-    class A: ...
-    x: A | None = A() if flag1 else None
+def bool_instance() -> bool:
+    return True
 
-    flag2 or isinstance(x, A) or reveal_type(x)  # revealed: None
-    isinstance(x, A) or flag3 or reveal_type(x)  # revealed: None
-    reveal_type(x) or isinstance(x, A) or flag4  # revealed: A | None
+class A: ...
+
+x: A | None = A() if bool_instance() else None
+
+bool_instance() or isinstance(x, A) or reveal_type(x)  # revealed: None
+isinstance(x, A) or bool_instance() or reveal_type(x)  # revealed: None
+reveal_type(x) or isinstance(x, A) or bool_instance()  # revealed: A | None
 ```
 
 ## Multiple predicates
 
 ```py
-def _(flag1: bool, flag2: bool):
-    class A: ...
-    x: A | None | Literal[1] = A() if flag1 else None if flag2 else 1
+def bool_instance() -> bool:
+    return True
 
-    x is None or isinstance(x, A) or reveal_type(x)  # revealed: Literal[1]
+class A: ...
+
+x: A | None | Literal[1] = A() if bool_instance() else None if bool_instance() else 1
+
+x is None or isinstance(x, A) or reveal_type(x)  # revealed: Literal[1]
 ```
 
 ## Mix of `and` and `or`
 
 ```py
-def _(flag1: bool, flag2: bool):
-    class A: ...
-    x: A | None | Literal[1] = A() if flag1 else None if flag2 else 1
+def bool_instance() -> bool:
+    return True
 
-    isinstance(x, A) or x is not None and reveal_type(x)  # revealed: Literal[1]
+class A: ...
+
+x: A | None | Literal[1] = A() if bool_instance() else None if bool_instance() else 1
+
+isinstance(x, A) or x is not None and reveal_type(x)  # revealed: Literal[1]
 ```

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

@@ -6,11 +6,15 @@
 class A: ...
 class B: ...
 
-def _(x: A | B):
-    if isinstance(x, A) and isinstance(x, B):
-        reveal_type(x)  # revealed:  A & B
-    else:
-        reveal_type(x)  # revealed:  B & ~A | A & ~B
+def instance() -> A | B:
+    return A()
+
+x = instance()
+
+if isinstance(x, A) and isinstance(x, B):
+    reveal_type(x)  # revealed:  A & B
+else:
+    reveal_type(x)  # revealed:  B & ~A | A & ~B
 ```
 
 ## Arms might not add narrowing constraints
@@ -19,18 +23,25 @@ def _(x: A | B):
 class A: ...
 class B: ...
 
-def _(flag: bool, x: A | B):
-    if isinstance(x, A) and flag:
-        reveal_type(x)  # revealed: A
-    else:
-        reveal_type(x)  # revealed: A | B
+def bool_instance() -> bool:
+    return True
 
-    if flag and isinstance(x, A):
-        reveal_type(x)  # revealed: A
-    else:
-        reveal_type(x)  # revealed: A | B
+def instance() -> A | B:
+    return A()
 
+x = instance()
+
+if isinstance(x, A) and bool_instance():
+    reveal_type(x)  # revealed: A
+else:
     reveal_type(x)  # revealed: A | B
+
+if bool_instance() and isinstance(x, A):
+    reveal_type(x)  # revealed: A
+else:
+    reveal_type(x)  # revealed: A | B
+
+reveal_type(x)  # revealed: A | B
 ```
 
 ## Statically known arms
@@ -39,35 +50,39 @@ def _(flag: bool, x: A | B):
 class A: ...
 class B: ...
 
-def _(x: A | B):
-    if isinstance(x, A) and True:
-        reveal_type(x)  # revealed: A
-    else:
-        reveal_type(x)  # revealed: B & ~A
+def instance() -> A | B:
+    return A()
 
-    if True and isinstance(x, A):
-        reveal_type(x)  # revealed: A
-    else:
-        reveal_type(x)  # revealed: B & ~A
+x = instance()
 
-    if False and isinstance(x, A):
-        # TODO: should emit an `unreachable code` diagnostic
-        reveal_type(x)  # revealed: A
-    else:
-        reveal_type(x)  # revealed: A | B
+if isinstance(x, A) and True:
+    reveal_type(x)  # revealed: A
+else:
+    reveal_type(x)  # revealed: B & ~A
 
-    if False or isinstance(x, A):
-        reveal_type(x)  # revealed: A
-    else:
-        reveal_type(x)  # revealed: B & ~A
-
-    if True or isinstance(x, A):
-        reveal_type(x)  # revealed: A | B
-    else:
-        # TODO: should emit an `unreachable code` diagnostic
-        reveal_type(x)  # revealed: B & ~A
+if True and isinstance(x, A):
+    reveal_type(x)  # revealed: A
+else:
+    reveal_type(x)  # revealed: B & ~A
 
+if False and isinstance(x, A):
+    # TODO: should emit an `unreachable code` diagnostic
+    reveal_type(x)  # revealed: A
+else:
     reveal_type(x)  # revealed: A | B
+
+if False or isinstance(x, A):
+    reveal_type(x)  # revealed: A
+else:
+    reveal_type(x)  # revealed: B & ~A
+
+if True or isinstance(x, A):
+    reveal_type(x)  # revealed: A | B
+else:
+    # TODO: should emit an `unreachable code` diagnostic
+    reveal_type(x)  # revealed: B & ~A
+
+reveal_type(x)  # revealed: A | B
 ```
 
 ## The type of multiple symbols can be narrowed down
@@ -76,17 +91,22 @@ def _(x: A | B):
 class A: ...
 class B: ...
 
-def _(x: A | B, y: A | B):
-    if isinstance(x, A) and isinstance(y, B):
-        reveal_type(x)  # revealed: A
-        reveal_type(y)  # revealed: B
-    else:
-        # No narrowing: Only-one or both checks might have failed
-        reveal_type(x)  # revealed: A | B
-        reveal_type(y)  # revealed: A | B
+def instance() -> A | B:
+    return A()
 
+x = instance()
+y = instance()
+
+if isinstance(x, A) and isinstance(y, B):
+    reveal_type(x)  # revealed: A
+    reveal_type(y)  # revealed: B
+else:
+    # No narrowing: Only-one or both checks might have failed
     reveal_type(x)  # revealed: A | B
     reveal_type(y)  # revealed: A | B
+
+reveal_type(x)  # revealed: A | B
+reveal_type(y)  # revealed: A | B
 ```
 
 ## Narrowing in `or` conditional
@@ -96,11 +116,15 @@ class A: ...
 class B: ...
 class C: ...
 
-def _(x: A | B | C):
-    if isinstance(x, A) or isinstance(x, B):
-        reveal_type(x)  # revealed:  A | B
-    else:
-        reveal_type(x)  # revealed:  C & ~A & ~B
+def instance() -> A | B | C:
+    return A()
+
+x = instance()
+
+if isinstance(x, A) or isinstance(x, B):
+    reveal_type(x)  # revealed:  A | B
+else:
+    reveal_type(x)  # revealed:  C & ~A & ~B
 ```
 
 ## In `or`, all arms should add constraint in order to narrow
@@ -110,11 +134,18 @@ class A: ...
 class B: ...
 class C: ...
 
-def _(flag: bool, x: A | B | C):
-    if isinstance(x, A) or isinstance(x, B) or flag:
-        reveal_type(x)  # revealed:  A | B | C
-    else:
-        reveal_type(x)  # revealed:  C & ~A & ~B
+def instance() -> A | B | C:
+    return A()
+
+def bool_instance() -> bool:
+    return True
+
+x = instance()
+
+if isinstance(x, A) or isinstance(x, B) or bool_instance():
+    reveal_type(x)  # revealed:  A | B | C
+else:
+    reveal_type(x)  # revealed:  C & ~A & ~B
 ```
 
 ## in `or`, all arms should narrow the same set of symbols
@@ -124,23 +155,28 @@ class A: ...
 class B: ...
 class C: ...
 
-def _(x: A | B | C, y: A | B | C):
-    if isinstance(x, A) or isinstance(y, A):
-        # The predicate might be satisfied by the right side, so the type of `x` can’t be narrowed down here.
-        reveal_type(x)  # revealed:  A | B | C
-        # The same for `y`
-        reveal_type(y)  # revealed:  A | B | C
-    else:
-        reveal_type(x)  # revealed:  B & ~A | C & ~A
-        reveal_type(y)  # revealed:  B & ~A | C & ~A
+def instance() -> A | B | C:
+    return A()
 
-    if (isinstance(x, A) and isinstance(y, A)) or (isinstance(x, B) and isinstance(y, B)):
-        # Here, types of `x` and `y` can be narrowd since all `or` arms constraint them.
-        reveal_type(x)  # revealed:  A | B
-        reveal_type(y)  # revealed:  A | B
-    else:
-        reveal_type(x)  # revealed:  A | B | C
-        reveal_type(y)  # revealed:  A | B | C
+x = instance()
+y = instance()
+
+if isinstance(x, A) or isinstance(y, A):
+    # The predicate might be satisfied by the right side, so the type of `x` can’t be narrowed down here.
+    reveal_type(x)  # revealed:  A | B | C
+    # The same for `y`
+    reveal_type(y)  # revealed:  A | B | C
+else:
+    reveal_type(x)  # revealed:  B & ~A | C & ~A
+    reveal_type(y)  # revealed:  B & ~A | C & ~A
+
+if (isinstance(x, A) and isinstance(y, A)) or (isinstance(x, B) and isinstance(y, B)):
+    # Here, types of `x` and `y` can be narrowd since all `or` arms constraint them.
+    reveal_type(x)  # revealed:  A | B
+    reveal_type(y)  # revealed:  A | B
+else:
+    reveal_type(x)  # revealed:  A | B | C
+    reveal_type(y)  # revealed:  A | B | C
 ```
 
 ## mixing `and` and `not`
@@ -150,12 +186,16 @@ class A: ...
 class B: ...
 class C: ...
 
-def _(x: A | B | C):
-    if isinstance(x, B) and not isinstance(x, C):
-        reveal_type(x)  # revealed:  B & ~C
-    else:
-        # ~(B & ~C) -> ~B | C -> (A & ~B) | (C & ~B) | C -> (A & ~B) | C
-        reveal_type(x)  # revealed: A & ~B | C
+def instance() -> A | B | C:
+    return A()
+
+x = instance()
+
+if isinstance(x, B) and not isinstance(x, C):
+    reveal_type(x)  # revealed:  B & ~C
+else:
+    # ~(B & ~C) -> ~B | C -> (A & ~B) | (C & ~B) | C -> (A & ~B) | C
+    reveal_type(x)  # revealed: A & ~B | C
 ```
 
 ## mixing `or` and `not`
@@ -165,11 +205,15 @@ class A: ...
 class B: ...
 class C: ...
 
-def _(x: A | B | C):
-    if isinstance(x, B) or not isinstance(x, C):
-        reveal_type(x)  # revealed: B | A & ~C
-    else:
-        reveal_type(x)  # revealed: C & ~B
+def instance() -> A | B | C:
+    return A()
+
+x = instance()
+
+if isinstance(x, B) or not isinstance(x, C):
+    reveal_type(x)  # revealed: B | A & ~C
+else:
+    reveal_type(x)  # revealed: C & ~B
 ```
 
 ## `or` with nested `and`
@@ -179,12 +223,16 @@ class A: ...
 class B: ...
 class C: ...
 
-def _(x: A | B | C):
-    if isinstance(x, A) or (isinstance(x, B) and not isinstance(x, C)):
-        reveal_type(x)  # revealed:  A | B & ~C
-    else:
-        # ~(A | (B & ~C)) -> ~A & ~(B & ~C) -> ~A & (~B | C) -> (~A & C) | (~A ~ B)
-        reveal_type(x)  # revealed:  C & ~A
+def instance() -> A | B | C:
+    return A()
+
+x = instance()
+
+if isinstance(x, A) or (isinstance(x, B) and not isinstance(x, C)):
+    reveal_type(x)  # revealed:  A | B & ~C
+else:
+    # ~(A | (B & ~C)) -> ~A & ~(B & ~C) -> ~A & (~B | C) -> (~A & C) | (~A ~ B)
+    reveal_type(x)  # revealed:  C & ~A
 ```
 
 ## `and` with nested `or`
@@ -194,32 +242,41 @@ class A: ...
 class B: ...
 class C: ...
 
-def _(x: A | B | C):
-    if isinstance(x, A) and (isinstance(x, B) or not isinstance(x, C)):
-        # A & (B | ~C) -> (A & B) | (A & ~C)
-        reveal_type(x)  # revealed:  A & B | A & ~C
-    else:
-        # ~((A & B) | (A & ~C)) ->
-        # ~(A & B) & ~(A & ~C) ->
-        # (~A | ~B) & (~A | C) ->
-        # [(~A | ~B) & ~A] | [(~A | ~B) & C] ->
-        # ~A | (~A & C) | (~B & C) ->
-        # ~A | (C & ~B) ->
-        # ~A | (C & ~B)  The positive side of ~A is  A | B | C ->
-        reveal_type(x)  # revealed:  B & ~A | C & ~A | C & ~B
+def instance() -> A | B | C:
+    return A()
+
+x = instance()
+
+if isinstance(x, A) and (isinstance(x, B) or not isinstance(x, C)):
+    # A & (B | ~C) -> (A & B) | (A & ~C)
+    reveal_type(x)  # revealed:  A & B | A & ~C
+else:
+    # ~((A & B) | (A & ~C)) ->
+    # ~(A & B) & ~(A & ~C) ->
+    # (~A | ~B) & (~A | C) ->
+    # [(~A | ~B) & ~A] | [(~A | ~B) & C] ->
+    # ~A | (~A & C) | (~B & C) ->
+    # ~A | (C & ~B) ->
+    # ~A | (C & ~B)  The positive side of ~A is  A | B | C ->
+    reveal_type(x)  # revealed:  B & ~A | C & ~A | C & ~B
 ```
 
 ## Boolean expression internal narrowing
 
 ```py
-def _(x: str | None, y: str | None):
-    if x is None and y is not x:
-        reveal_type(y)  # revealed: str
+def optional_string() -> str | None:
+    return None
 
-    # Neither of the conditions alone is sufficient for narrowing y's type:
-    if x is None:
-        reveal_type(y)  # revealed: str | None
+x = optional_string()
+y = optional_string()
 
-    if y is not x:
-        reveal_type(y)  # revealed: str | None
+if x is None and y is not x:
+    reveal_type(y)  # revealed: str
+
+# Neither of the conditions alone is sufficient for narrowing y's type:
+if x is None:
+    reveal_type(y)  # revealed: str | None
+
+if y is not x:
+    reveal_type(y)  # revealed: str | None
 ```

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

@@ -3,47 +3,55 @@
 ## Positive contributions become negative in elif-else blocks
 
 ```py
-def _(x: int):
-    if x == 1:
-        # cannot narrow; could be a subclass of `int`
-        reveal_type(x)  # revealed: int
-    elif x == 2:
-        reveal_type(x)  # revealed: int & ~Literal[1]
-    elif x != 3:
-        reveal_type(x)  # revealed: int & ~Literal[1] & ~Literal[2] & ~Literal[3]
+def int_instance() -> int:
+    return 42
+
+x = int_instance()
+
+if x == 1:
+    # cannot narrow; could be a subclass of `int`
+    reveal_type(x)  # revealed: int
+elif x == 2:
+    reveal_type(x)  # revealed: int & ~Literal[1]
+elif x != 3:
+    reveal_type(x)  # revealed: int & ~Literal[1] & ~Literal[2] & ~Literal[3]
 ```
 
 ## Positive contributions become negative in elif-else blocks, with simplification
 
 ```py
-def _(flag1: bool, flag2: bool):
-    x = 1 if flag1 else 2 if flag2 else 3
+def bool_instance() -> bool:
+    return True
 
-    if x == 1:
-        # TODO should be Literal[1]
-        reveal_type(x)  # revealed: Literal[1, 2, 3]
-    elif x == 2:
-        # TODO should be Literal[2]
-        reveal_type(x)  # revealed: Literal[2, 3]
-    else:
-        reveal_type(x)  # revealed: Literal[3]
+x = 1 if bool_instance() else 2 if bool_instance() else 3
+
+if x == 1:
+    # TODO should be Literal[1]
+    reveal_type(x)  # revealed: Literal[1, 2, 3]
+elif x == 2:
+    # TODO should be Literal[2]
+    reveal_type(x)  # revealed: Literal[2, 3]
+else:
+    reveal_type(x)  # revealed: Literal[3]
 ```
 
 ## Multiple negative contributions using elif, with simplification
 
 ```py
-def _(flag1: bool, flag2: bool):
-    x = 1 if flag1 else 2 if flag2 else 3
+def bool_instance() -> bool:
+    return True
 
-    if x != 1:
-        reveal_type(x)  # revealed: Literal[2, 3]
-    elif x != 2:
-        # TODO should be `Literal[1]`
-        reveal_type(x)  # revealed: Literal[1, 3]
-    elif x == 3:
-        # TODO should be Never
-        reveal_type(x)  # revealed: Literal[1, 2, 3]
-    else:
-        # TODO should be Never
-        reveal_type(x)  # revealed: Literal[1, 2]
+x = 1 if bool_instance() else 2 if bool_instance() else 3
+
+if x != 1:
+    reveal_type(x)  # revealed: Literal[2, 3]
+elif x != 2:
+    # TODO should be `Literal[1]`
+    reveal_type(x)  # revealed: Literal[1, 3]
+elif x == 3:
+    # TODO should be Never
+    reveal_type(x)  # revealed: Literal[1, 2, 3]
+else:
+    # TODO should be Never
+    reveal_type(x)  # revealed: Literal[1, 2]
 ```

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

@@ -3,64 +3,77 @@
 ## `is None`
 
 ```py
-def _(flag: bool):
-    x = None if flag else 1
+def bool_instance() -> bool:
+    return True
 
-    if x is None:
-        reveal_type(x)  # revealed: None
-    else:
-        reveal_type(x)  # revealed: Literal[1]
+flag = bool_instance()
+x = None if flag else 1
 
-    reveal_type(x)  # revealed: None | Literal[1]
+if x is None:
+    reveal_type(x)  # revealed: None
+else:
+    reveal_type(x)  # revealed: Literal[1]
+
+reveal_type(x)  # revealed: None | Literal[1]
 ```
 
 ## `is` for other types
 
 ```py
-def _(flag: bool):
-    class A: ...
-    x = A()
-    y = x if flag else None
+def bool_instance() -> bool:
+    return True
 
-    if y is x:
-        reveal_type(y)  # revealed: A
-    else:
-        reveal_type(y)  # revealed: A | None
+flag = bool_instance()
 
+class A: ...
+
+x = A()
+y = x if flag else None
+
+if y is x:
+    reveal_type(y)  # revealed: A
+else:
     reveal_type(y)  # revealed: A | None
+
+reveal_type(y)  # revealed: A | None
 ```
 
 ## `is` in chained comparisons
 
 ```py
-def _(x_flag: bool, y_flag: bool):
-    x = True if x_flag else False
-    y = True if y_flag else False
+def bool_instance() -> bool:
+    return True
 
+x_flag, y_flag = bool_instance(), bool_instance()
+x = True if x_flag else False
+y = True if y_flag else False
+
+reveal_type(x)  # revealed: bool
+reveal_type(y)  # revealed: bool
+
+if y is x is False:  # Interpreted as `(y is x) and (x is False)`
+    reveal_type(x)  # revealed: Literal[False]
+    reveal_type(y)  # revealed: bool
+else:
+    # The negation of the clause above is (y is not x) or (x is not False)
+    # So we can't narrow the type of x or y here, because each arm of the `or` could be true
     reveal_type(x)  # revealed: bool
     reveal_type(y)  # revealed: bool
-
-    if y is x is False:  # Interpreted as `(y is x) and (x is False)`
-        reveal_type(x)  # revealed: Literal[False]
-        reveal_type(y)  # revealed: bool
-    else:
-        # The negation of the clause above is (y is not x) or (x is not False)
-        # So we can't narrow the type of x or y here, because each arm of the `or` could be true
-        reveal_type(x)  # revealed: bool
-        reveal_type(y)  # revealed: bool
 ```
 
 ## `is` in elif clause
 
 ```py
-def _(flag1: bool, flag2: bool):
-    x = None if flag1 else (1 if flag2 else True)
+def bool_instance() -> bool:
+    return True
 
-    reveal_type(x)  # revealed: None | Literal[1] | Literal[True]
-    if x is None:
-        reveal_type(x)  # revealed: None
-    elif x is True:
-        reveal_type(x)  # revealed: Literal[True]
-    else:
-        reveal_type(x)  # revealed: Literal[1]
+x = None if bool_instance() else (1 if bool_instance() else True)
+
+reveal_type(x)  # revealed: None | Literal[1] | Literal[True]
+if x is None:
+    reveal_type(x)  # revealed: None
+elif x is True:
+    reveal_type(x)  # revealed: Literal[True]
+else:
+    reveal_type(x)  # revealed: Literal[1]
 ```

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

@@ -5,28 +5,34 @@
 The type guard removes `None` from the union type:
 
 ```py
-def _(flag: bool):
-    x = None if flag else 1
+def bool_instance() -> bool:
+    return True
 
-    if x is not None:
-        reveal_type(x)  # revealed: Literal[1]
-    else:
-        reveal_type(x)  # revealed: None
+flag = bool_instance()
+x = None if flag else 1
 
-    reveal_type(x)  # revealed: None | Literal[1]
+if x is not None:
+    reveal_type(x)  # revealed: Literal[1]
+else:
+    reveal_type(x)  # revealed: None
+
+reveal_type(x)  # revealed: None | Literal[1]
 ```
 
 ## `is not` for other singleton types
 
 ```py
-def _(flag: bool):
-    x = True if flag else False
-    reveal_type(x)  # revealed: bool
+def bool_instance() -> bool:
+    return True
 
-    if x is not False:
-        reveal_type(x)  # revealed: Literal[True]
-    else:
-        reveal_type(x)  # revealed: Literal[False]
+flag = bool_instance()
+x = True if flag else False
+reveal_type(x)  # revealed: bool
+
+if x is not False:
+    reveal_type(x)  # revealed: Literal[True]
+else:
+    reveal_type(x)  # revealed: Literal[False]
 ```
 
 ## `is not` for non-singleton types
@@ -47,17 +53,20 @@ else:
 ## `is not` for other types
 
 ```py
-def _(flag: bool):
-    class A: ...
-    x = A()
-    y = x if flag else None
+def bool_instance() -> bool:
+    return True
 
-    if y is not x:
-        reveal_type(y)  # revealed: A | None
-    else:
-        reveal_type(y)  # revealed: A
+class A: ...
 
+x = A()
+y = x if bool_instance() else None
+
+if y is not x:
     reveal_type(y)  # revealed: A | None
+else:
+    reveal_type(y)  # revealed: A
+
+reveal_type(y)  # revealed: A | None
 ```
 
 ## `is not` in chained comparisons
@@ -65,20 +74,23 @@ def _(flag: bool):
 The type guard removes `False` from the union type of the tested value only.
 
 ```py
-def _(x_flag: bool, y_flag: bool):
-    x = True if x_flag else False
-    y = True if y_flag else False
+def bool_instance() -> bool:
+    return True
+
+x_flag, y_flag = bool_instance(), bool_instance()
+x = True if x_flag else False
+y = True if y_flag else False
+
+reveal_type(x)  # revealed: bool
+reveal_type(y)  # revealed: bool
+
+if y is not x is not False:  # Interpreted as `(y is not x) and (x is not False)`
+    reveal_type(x)  # revealed: Literal[True]
+    reveal_type(y)  # revealed: bool
+else:
+    # The negation of the clause above is (y is x) or (x is False)
+    # So we can't narrow the type of x or y here, because each arm of the `or` could be true
 
     reveal_type(x)  # revealed: bool
     reveal_type(y)  # revealed: bool
-
-    if y is not x is not False:  # Interpreted as `(y is not x) and (x is not False)`
-        reveal_type(x)  # revealed: Literal[True]
-        reveal_type(y)  # revealed: bool
-    else:
-        # The negation of the clause above is (y is x) or (x is False)
-        # So we can't narrow the type of x or y here, because each arm of the `or` could be true
-
-        reveal_type(x)  # revealed: bool
-        reveal_type(y)  # revealed: bool
 ```

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

@@ -3,45 +3,54 @@
 ## Multiple negative contributions
 
 ```py
-def _(x: int):
-    if x != 1:
-        if x != 2:
-            if x != 3:
-                reveal_type(x)  # revealed: int & ~Literal[1] & ~Literal[2] & ~Literal[3]
+def int_instance() -> int:
+    return 42
+
+x = int_instance()
+
+if x != 1:
+    if x != 2:
+        if x != 3:
+            reveal_type(x)  # revealed: int & ~Literal[1] & ~Literal[2] & ~Literal[3]
 ```
 
 ## Multiple negative contributions with simplification
 
 ```py
-def _(flag1: bool, flag2: bool):
-    x = 1 if flag1 else 2 if flag2 else 3
+def bool_instance() -> bool:
+    return True
 
-    if x != 1:
-        reveal_type(x)  # revealed: Literal[2, 3]
-        if x != 2:
-            reveal_type(x)  # revealed: Literal[3]
+flag1, flag2 = bool_instance(), bool_instance()
+x = 1 if flag1 else 2 if flag2 else 3
+
+if x != 1:
+    reveal_type(x)  # revealed: Literal[2, 3]
+    if x != 2:
+        reveal_type(x)  # revealed: Literal[3]
 ```
 
 ## elif-else blocks
 
 ```py
-def _(flag1: bool, flag2: bool):
-    x = 1 if flag1 else 2 if flag2 else 3
+def bool_instance() -> bool:
+    return True
 
-    if x != 1:
+x = 1 if bool_instance() else 2 if bool_instance() else 3
+
+if x != 1:
+    reveal_type(x)  # revealed: Literal[2, 3]
+    if x == 2:
+        # TODO should be `Literal[2]`
         reveal_type(x)  # revealed: Literal[2, 3]
-        if x == 2:
-            # TODO should be `Literal[2]`
-            reveal_type(x)  # revealed: Literal[2, 3]
-        elif x == 3:
-            reveal_type(x)  # revealed: Literal[3]
-        else:
-            reveal_type(x)  # revealed: Never
-
-    elif x != 2:
-        # TODO should be Literal[1]
-        reveal_type(x)  # revealed: Literal[1, 3]
+    elif x == 3:
+        reveal_type(x)  # revealed: Literal[3]
     else:
-        # TODO should be Never
-        reveal_type(x)  # revealed: Literal[1, 2, 3]
+        reveal_type(x)  # revealed: Never
+
+elif x != 2:
+    # TODO should be Literal[1]
+    reveal_type(x)  # revealed: Literal[1, 3]
+else:
+    # TODO should be Never
+    reveal_type(x)  # revealed: Literal[1, 2, 3]
 ```

crates/red_knot_python_semantic/resources/mdtest/narrow/conditionals/not.md

@@ -5,25 +5,29 @@ The `not` operator negates a constraint.
 ## `not is None`
 
 ```py
-def _(flag: bool):
-    x = None if flag else 1
+def bool_instance() -> bool:
+    return True
 
-    if not x is None:
-        reveal_type(x)  # revealed: Literal[1]
-    else:
-        reveal_type(x)  # revealed: None
+x = None if bool_instance() else 1
 
-    reveal_type(x)  # revealed: None | Literal[1]
+if not x is None:
+    reveal_type(x)  # revealed: Literal[1]
+else:
+    reveal_type(x)  # revealed: None
+
+reveal_type(x)  # revealed: None | Literal[1]
 ```
 
 ## `not isinstance`
 
 ```py
-def _(flag: bool):
-    x = 1 if flag else "a"
+def bool_instance() -> bool:
+    return True
 
-    if not isinstance(x, (int)):
-        reveal_type(x)  # revealed: Literal["a"]
-    else:
-        reveal_type(x)  # revealed: Literal[1]
+x = 1 if bool_instance() else "a"
+
+if not isinstance(x, (int)):
+    reveal_type(x)  # revealed: Literal["a"]
+else:
+    reveal_type(x)  # revealed: Literal[1]
 ```

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

@@ -3,66 +3,82 @@
 ## `x != None`
 
 ```py
-def _(flag: bool):
-    x = None if flag else 1
+def bool_instance() -> bool:
+    return True
 
-    if x != None:
-        reveal_type(x)  # revealed: Literal[1]
-    else:
-        # TODO should be None
-        reveal_type(x)  # revealed: None | Literal[1]
+flag = bool_instance()
+x = None if flag else 1
+
+if x != None:
+    reveal_type(x)  # revealed: Literal[1]
+else:
+    # TODO should be None
+    reveal_type(x)  # revealed: None | Literal[1]
 ```
 
 ## `!=` for other singleton types
 
 ```py
-def _(flag: bool):
-    x = True if flag else False
+def bool_instance() -> bool:
+    return True
 
-    if x != False:
-        reveal_type(x)  # revealed: Literal[True]
-    else:
-        # TODO should be Literal[False]
-        reveal_type(x)  # revealed: bool
+flag = bool_instance()
+x = True if flag else False
+
+if x != False:
+    reveal_type(x)  # revealed: Literal[True]
+else:
+    # TODO should be Literal[False]
+    reveal_type(x)  # revealed: bool
 ```
 
 ## `x != y` where `y` is of literal type
 
 ```py
-def _(flag: bool):
-    x = 1 if flag else 2
+def bool_instance() -> bool:
+    return True
 
-    if x != 1:
-        reveal_type(x)  # revealed: Literal[2]
+flag = bool_instance()
+x = 1 if flag else 2
+
+if x != 1:
+    reveal_type(x)  # revealed: Literal[2]
 ```
 
 ## `x != y` where `y` is a single-valued type
 
 ```py
-def _(flag: bool):
-    class A: ...
-    class B: ...
-    C = A if flag else B
+def bool_instance() -> bool:
+    return True
 
-    if C != A:
-        reveal_type(C)  # revealed: Literal[B]
-    else:
-        # TODO should be Literal[A]
-        reveal_type(C)  # revealed: Literal[A, B]
+flag = bool_instance()
+
+class A: ...
+class B: ...
+
+C = A if flag else B
+
+if C != A:
+    reveal_type(C)  # revealed: Literal[B]
+else:
+    # TODO should be Literal[A]
+    reveal_type(C)  # revealed: Literal[A, B]
 ```
 
 ## `x != y` where `y` has multiple single-valued options
 
 ```py
-def _(flag1: bool, flag2: bool):
-    x = 1 if flag1 else 2
-    y = 2 if flag2 else 3
+def bool_instance() -> bool:
+    return True
 
-    if x != y:
-        reveal_type(x)  # revealed: Literal[1, 2]
-    else:
-        # TODO should be Literal[2]
-        reveal_type(x)  # revealed: Literal[1, 2]
+x = 1 if bool_instance() else 2
+y = 2 if bool_instance() else 3
+
+if x != y:
+    reveal_type(x)  # revealed: Literal[1, 2]
+else:
+    # TODO should be Literal[2]
+    reveal_type(x)  # revealed: Literal[1, 2]
 ```
 
 ## `!=` for non-single-valued types
@@ -70,22 +86,34 @@ def _(flag1: bool, flag2: bool):
 Only single-valued types should narrow the type:
 
 ```py
-def _(flag: bool, a: int, y: int):
-    x = a if flag else None
+def bool_instance() -> bool:
+    return True
 
-    if x != y:
-        reveal_type(x)  # revealed: int | None
+def int_instance() -> int:
+    return 42
+
+flag = bool_instance()
+x = int_instance() if flag else None
+y = int_instance()
+
+if x != y:
+    reveal_type(x)  # revealed: int | None
 ```
 
 ## Mix of single-valued and non-single-valued types
 
 ```py
-def _(flag1: bool, flag2: bool, a: int):
-    x = 1 if flag1 else 2
-    y = 2 if flag2 else a
+def int_instance() -> int:
+    return 42
 
-    if x != y:
-        reveal_type(x)  # revealed: Literal[1, 2]
-    else:
-        reveal_type(x)  # revealed: Literal[1, 2]
+def bool_instance() -> bool:
+    return True
+
+x = 1 if bool_instance() else 2
+y = 2 if bool_instance() else int_instance()
+
+if x != y:
+    reveal_type(x)  # revealed: Literal[1, 2]
+else:
+    reveal_type(x)  # revealed: Literal[1, 2]
 ```

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

@@ -5,19 +5,23 @@ Narrowing for `isinstance(object, classinfo)` expressions.
 ## `classinfo` is a single type
 
 ```py
-def _(flag: bool):
-    x = 1 if flag else "a"
+def bool_instance() -> bool:
+    return True
 
+flag = bool_instance()
+
+x = 1 if flag else "a"
+
+if isinstance(x, int):
+    reveal_type(x)  # revealed: Literal[1]
+
+if isinstance(x, str):
+    reveal_type(x)  # revealed: Literal["a"]
     if isinstance(x, int):
-        reveal_type(x)  # revealed: Literal[1]
+        reveal_type(x)  # revealed: Never
 
-    if isinstance(x, str):
-        reveal_type(x)  # revealed: Literal["a"]
-        if isinstance(x, int):
-            reveal_type(x)  # revealed: Never
-
-    if isinstance(x, (int, object)):
-        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
+if isinstance(x, (int, object)):
+    reveal_type(x)  # revealed: Literal[1] | Literal["a"]
 ```
 
 ## `classinfo` is a tuple of types
@@ -26,48 +30,56 @@ Note: `isinstance(x, (int, str))` should not be confused with `isinstance(x, tup
 The former is equivalent to `isinstance(x, int | str)`:
 
 ```py
-def _(flag: bool, flag1: bool, flag2: bool):
-    x = 1 if flag else "a"
+def bool_instance() -> bool:
+    return True
 
-    if isinstance(x, (int, str)):
-        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
-    else:
-        reveal_type(x)  # revealed: Never
+flag, flag1, flag2 = bool_instance(), bool_instance(), bool_instance()
 
-    if isinstance(x, (int, bytes)):
-        reveal_type(x)  # revealed: Literal[1]
+x = 1 if flag else "a"
 
-    if isinstance(x, (bytes, str)):
-        reveal_type(x)  # revealed: Literal["a"]
+if isinstance(x, (int, str)):
+    reveal_type(x)  # revealed: Literal[1] | Literal["a"]
+else:
+    reveal_type(x)  # revealed: Never
 
-    # No narrowing should occur if a larger type is also
-    # one of the possibilities:
-    if isinstance(x, (int, object)):
-        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
-    else:
-        reveal_type(x)  # revealed: Never
+if isinstance(x, (int, bytes)):
+    reveal_type(x)  # revealed: Literal[1]
 
-    y = 1 if flag1 else "a" if flag2 else b"b"
-    if isinstance(y, (int, str)):
-        reveal_type(y)  # revealed: Literal[1] | Literal["a"]
+if isinstance(x, (bytes, str)):
+    reveal_type(x)  # revealed: Literal["a"]
 
-    if isinstance(y, (int, bytes)):
-        reveal_type(y)  # revealed: Literal[1] | Literal[b"b"]
+# No narrowing should occur if a larger type is also
+# one of the possibilities:
+if isinstance(x, (int, object)):
+    reveal_type(x)  # revealed: Literal[1] | Literal["a"]
+else:
+    reveal_type(x)  # revealed: Never
 
-    if isinstance(y, (str, bytes)):
-        reveal_type(y)  # revealed: Literal["a"] | Literal[b"b"]
+y = 1 if flag1 else "a" if flag2 else b"b"
+if isinstance(y, (int, str)):
+    reveal_type(y)  # revealed: Literal[1] | Literal["a"]
+
+if isinstance(y, (int, bytes)):
+    reveal_type(y)  # revealed: Literal[1] | Literal[b"b"]
+
+if isinstance(y, (str, bytes)):
+    reveal_type(y)  # revealed: Literal["a"] | Literal[b"b"]
 ```
 
 ## `classinfo` is a nested tuple of types
 
 ```py
-def _(flag: bool):
-    x = 1 if flag else "a"
+def bool_instance() -> bool:
+    return True
 
-    if isinstance(x, (bool, (bytes, int))):
-        reveal_type(x)  # revealed: Literal[1]
-    else:
-        reveal_type(x)  # revealed: Literal["a"]
+flag = bool_instance()
+
+x = 1 if flag else "a"
+
+if isinstance(x, (bool, (bytes, int))):
+    reveal_type(x)  # revealed: Literal[1]
+else:
+    reveal_type(x)  # revealed: Literal["a"]
 ```
 
 ## Class types
@@ -77,7 +89,9 @@ class A: ...
 class B: ...
 class C: ...
 
-x = object()
+def get_object() -> object: ...
+
+x = get_object()
 
 if isinstance(x, A):
     reveal_type(x)  # revealed: A
@@ -98,40 +112,50 @@ else:
 ## No narrowing for instances of `builtins.type`
 
 ```py
-def _(flag: bool):
-    t = type("t", (), {})
+def bool_instance() -> bool:
+    return True
 
-    # This isn't testing what we want it to test if we infer anything more precise here:
-    reveal_type(t)  # revealed: type
+flag = bool_instance()
 
-    x = 1 if flag else "foo"
+t = type("t", (), {})
 
-    if isinstance(x, t):
-        reveal_type(x)  # revealed: Literal[1] | Literal["foo"]
+# This isn't testing what we want it to test if we infer anything more precise here:
+reveal_type(t)  # revealed: type
+x = 1 if flag else "foo"
+
+if isinstance(x, t):
+    reveal_type(x)  # revealed: Literal[1] | Literal["foo"]
 ```
 
 ## Do not use custom `isinstance` for narrowing
 
 ```py
-def _(flag: bool):
-    def isinstance(x, t):
-        return True
-    x = 1 if flag else "a"
+def bool_instance() -> bool:
+    return True
 
-    if isinstance(x, int):
-        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
+flag = bool_instance()
+
+def isinstance(x, t):
+    return True
+
+x = 1 if flag else "a"
+if isinstance(x, int):
+    reveal_type(x)  # revealed: Literal[1] | Literal["a"]
 ```
 
 ## Do support narrowing if `isinstance` is aliased
 
 ```py
-def _(flag: bool):
-    isinstance_alias = isinstance
+def bool_instance() -> bool:
+    return True
 
-    x = 1 if flag else "a"
+flag = bool_instance()
 
-    if isinstance_alias(x, int):
-        reveal_type(x)  # revealed: Literal[1]
+isinstance_alias = isinstance
+
+x = 1 if flag else "a"
+if isinstance_alias(x, int):
+    reveal_type(x)  # revealed: Literal[1]
 ```
 
 ## Do support narrowing if `isinstance` is imported
@@ -139,38 +163,46 @@ def _(flag: bool):
 ```py
 from builtins import isinstance as imported_isinstance
 
-def _(flag: bool):
-    x = 1 if flag else "a"
+def bool_instance() -> bool:
+    return True
 
-    if imported_isinstance(x, int):
-        reveal_type(x)  # revealed: Literal[1]
+flag = bool_instance()
+x = 1 if flag else "a"
+if imported_isinstance(x, int):
+    reveal_type(x)  # revealed: Literal[1]
 ```
 
 ## Do not narrow if second argument is not a type
 
 ```py
-def _(flag: bool):
-    x = 1 if flag else "a"
+def bool_instance() -> bool:
+    return True
 
-    # TODO: this should cause us to emit a diagnostic during
-    # type checking
-    if isinstance(x, "a"):
-        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
+flag = bool_instance()
+x = 1 if flag else "a"
 
-    # TODO: this should cause us to emit a diagnostic during
-    # type checking
-    if isinstance(x, "int"):
-        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
+# TODO: this should cause us to emit a diagnostic during
+# type checking
+if isinstance(x, "a"):
+    reveal_type(x)  # revealed: Literal[1] | Literal["a"]
+
+# TODO: this should cause us to emit a diagnostic during
+# type checking
+if isinstance(x, "int"):
+    reveal_type(x)  # revealed: Literal[1] | Literal["a"]
 ```
 
 ## Do not narrow if there are keyword arguments
 
 ```py
-def _(flag: bool):
-    x = 1 if flag else "a"
+def bool_instance() -> bool:
+    return True
 
-    # TODO: this should cause us to emit a diagnostic
-    # (`isinstance` has no `foo` parameter)
-    if isinstance(x, int, foo="bar"):
-        reveal_type(x)  # revealed: Literal[1] | Literal["a"]
+flag = bool_instance()
+x = 1 if flag else "a"
+
+# TODO: this should cause us to emit a diagnostic
+# (`isinstance` has no `foo` parameter)
+if isinstance(x, int, foo="bar"):
+    reveal_type(x)  # revealed: Literal[1] | Literal["a"]
 ```

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

@@ -7,43 +7,45 @@ Narrowing for `issubclass(class, classinfo)` expressions.
 ### Basic example
 
 ```py
-def _(flag: bool):
-    t = int if flag else str
+def flag() -> bool: ...
 
-    if issubclass(t, bytes):
-        reveal_type(t)  # revealed: Never
+t = int if flag() else str
 
-    if issubclass(t, object):
-        reveal_type(t)  # revealed: Literal[int, str]
+if issubclass(t, bytes):
+    reveal_type(t)  # revealed: Never
 
+if issubclass(t, object):
+    reveal_type(t)  # revealed: Literal[int, str]
+
+if issubclass(t, int):
+    reveal_type(t)  # revealed: Literal[int]
+else:
+    reveal_type(t)  # revealed: Literal[str]
+
+if issubclass(t, str):
+    reveal_type(t)  # revealed: Literal[str]
     if issubclass(t, int):
-        reveal_type(t)  # revealed: Literal[int]
-    else:
-        reveal_type(t)  # revealed: Literal[str]
-
-    if issubclass(t, str):
-        reveal_type(t)  # revealed: Literal[str]
-        if issubclass(t, int):
-            reveal_type(t)  # revealed: Never
+        reveal_type(t)  # revealed: Never
 ```
 
 ### Proper narrowing in `elif` and `else` branches
 
 ```py
-def _(flag1: bool, flag2: bool):
-    t = int if flag1 else str if flag2 else bytes
+def flag() -> bool: ...
 
-    if issubclass(t, int):
-        reveal_type(t)  # revealed: Literal[int]
-    else:
-        reveal_type(t)  # revealed: Literal[str, bytes]
+t = int if flag() else str if flag() else bytes
 
-    if issubclass(t, int):
-        reveal_type(t)  # revealed: Literal[int]
-    elif issubclass(t, str):
-        reveal_type(t)  # revealed: Literal[str]
-    else:
-        reveal_type(t)  # revealed: Literal[bytes]
+if issubclass(t, int):
+    reveal_type(t)  # revealed: Literal[int]
+else:
+    reveal_type(t)  # revealed: Literal[str, bytes]
+
+if issubclass(t, int):
+    reveal_type(t)  # revealed: Literal[int]
+elif issubclass(t, str):
+    reveal_type(t)  # revealed: Literal[str]
+else:
+    reveal_type(t)  # revealed: Literal[bytes]
 ```
 
 ### Multiple derived classes
@@ -54,28 +56,29 @@ class Derived1(Base): ...
 class Derived2(Base): ...
 class Unrelated: ...
 
-def _(flag1: bool, flag2: bool, flag3: bool):
-    t1 = Derived1 if flag1 else Derived2
+def flag() -> bool: ...
 
-    if issubclass(t1, Base):
-        reveal_type(t1)  # revealed: Literal[Derived1, Derived2]
+t1 = Derived1 if flag() else Derived2
 
-    if issubclass(t1, Derived1):
-        reveal_type(t1)  # revealed: Literal[Derived1]
-    else:
-        reveal_type(t1)  # revealed: Literal[Derived2]
+if issubclass(t1, Base):
+    reveal_type(t1)  # revealed: Literal[Derived1, Derived2]
 
-    t2 = Derived1 if flag2 else Base
+if issubclass(t1, Derived1):
+    reveal_type(t1)  # revealed: Literal[Derived1]
+else:
+    reveal_type(t1)  # revealed: Literal[Derived2]
 
-    if issubclass(t2, Base):
-        reveal_type(t2)  # revealed: Literal[Derived1, Base]
+t2 = Derived1 if flag() else Base
 
-    t3 = Derived1 if flag3 else Unrelated
+if issubclass(t2, Base):
+    reveal_type(t2)  # revealed: Literal[Derived1, Base]
 
-    if issubclass(t3, Base):
-        reveal_type(t3)  # revealed: Literal[Derived1]
-    else:
-        reveal_type(t3)  # revealed: Literal[Unrelated]
+t3 = Derived1 if flag() else Unrelated
+
+if issubclass(t3, Base):
+    reveal_type(t3)  # revealed: Literal[Derived1]
+else:
+    reveal_type(t3)  # revealed: Literal[Unrelated]
 ```
 
 ### Narrowing for non-literals
@@ -84,36 +87,36 @@ def _(flag1: bool, flag2: bool, flag3: bool):
 class A: ...
 class B: ...
 
-def _(t: type[object]):
-    if issubclass(t, A):
-        reveal_type(t)  # revealed: type[A]
-        if issubclass(t, B):
-            reveal_type(t)  # revealed: type[A] & type[B]
-    else:
-        reveal_type(t)  # revealed: type[object] & ~type[A]
+def get_class() -> type[object]: ...
+
+t = get_class()
+
+if issubclass(t, A):
+    reveal_type(t)  # revealed: type[A]
+    if issubclass(t, B):
+        reveal_type(t)  # revealed: type[A] & type[B]
+else:
+    reveal_type(t)  # revealed: type[object] & ~type[A]
 ```
 
 ### Handling of `None`
 
-`types.NoneType` is only available in Python 3.10 and later:
-
-```toml
-[environment]
-python-version = "3.10"
-```
-
 ```py
+# TODO: this error should ideally go away once we (1) understand `sys.version_info` branches,
+# and (2) set the target Python version for this test to 3.10.
+# error: [possibly-unbound-import] "Member `NoneType` of module `types` is possibly unbound"
 from types import NoneType
 
-def _(flag: bool):
-    t = int if flag else NoneType
+def flag() -> bool: ...
 
-    if issubclass(t, NoneType):
-        reveal_type(t)  # revealed: Literal[NoneType]
+t = int if flag() else NoneType
 
-    if issubclass(t, type(None)):
-        # TODO: this should be just `Literal[NoneType]`
-        reveal_type(t)  # revealed: Literal[int, NoneType]
+if issubclass(t, NoneType):
+    reveal_type(t)  # revealed: Literal[NoneType]
+
+if issubclass(t, type(None)):
+    # TODO: this should be just `Literal[NoneType]`
+    reveal_type(t)  # revealed: Literal[int, NoneType]
 ```
 
 ## `classinfo` contains multiple types
@@ -123,13 +126,14 @@ def _(flag: bool):
 ```py
 class Unrelated: ...
 
-def _(flag1: bool, flag2: bool):
-    t = int if flag1 else str if flag2 else bytes
+def flag() -> bool: ...
 
-    if issubclass(t, (int, (Unrelated, (bytes,)))):
-        reveal_type(t)  # revealed: Literal[int, bytes]
-    else:
-        reveal_type(t)  # revealed: Literal[str]
+t = int if flag() else str if flag() else bytes
+
+if issubclass(t, (int, (Unrelated, (bytes,)))):
+    reveal_type(t)  # revealed: Literal[int, bytes]
+else:
+    reveal_type(t)  # revealed: Literal[str]
 ```
 
 ## Special cases
@@ -144,7 +148,9 @@ to `issubclass`:
 ```py
 class A: ...
 
-t = object()
+def get_object() -> object: ...
+
+t = get_object()
 
 # TODO: we should emit a diagnostic here
 if issubclass(t, A):

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

@@ -3,16 +3,19 @@
 ## Single `match` pattern
 
 ```py
-def _(flag: bool):
-    x = None if flag else 1
+def bool_instance() -> bool:
+    return True
 
-    reveal_type(x)  # revealed: None | Literal[1]
+flag = bool_instance()
 
-    y = 0
+x = None if flag else 1
+reveal_type(x)  # revealed: None | Literal[1]
 
-    match x:
-        case None:
-            y = x
+y = 0
 
-    reveal_type(y)  # revealed: Literal[0] | None
+match x:
+    case None:
+        y = x
+
+reveal_type(y)  # revealed: Literal[0] | None
 ```

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

@@ -3,49 +3,62 @@
 ## After if-else statements, narrowing has no effect if the variable is not mutated in any branch
 
 ```py
-def _(x: int | None):
-    if x is None:
-        pass
-    else:
-        pass
+def optional_int() -> int | None: ...
 
-    reveal_type(x)  # revealed: int | None
+x = optional_int()
+
+if x is None:
+    pass
+else:
+    pass
+
+reveal_type(x)  # revealed: int | None
 ```
 
 ## Narrowing can have a persistent effect if the variable is mutated in one branch
 
 ```py
-def _(x: int | None):
-    if x is None:
-        x = 10
-    else:
-        pass
+def optional_int() -> int | None: ...
 
-    reveal_type(x)  # revealed: int
+x = optional_int()
+
+if x is None:
+    x = 10
+else:
+    pass
+
+reveal_type(x)  # revealed: int
 ```
 
 ## An if statement without an explicit `else` branch is equivalent to one with a no-op `else` branch
 
 ```py
-def _(x: int | None, y: int | None):
-    if x is None:
-        x = 0
+def optional_int() -> int | None: ...
 
-    if y is None:
-        pass
+x = optional_int()
+y = optional_int()
 
-    reveal_type(x)  # revealed: int
-    reveal_type(y)  # revealed: int | None
+if x is None:
+    x = 0
+
+if y is None:
+    pass
+
+reveal_type(x)  # revealed: int
+reveal_type(y)  # revealed: int | None
 ```
 
 ## An if-elif without an explicit else branch is equivalent to one with an empty else branch
 
 ```py
-def _(x: int | None):
-    if x is None:
-        x = 0
-    elif x > 50:
-        x = 50
+def optional_int() -> int | None: ...
 
-    reveal_type(x)  # revealed: int
+x = optional_int()
+
+if x is None:
+    x = 0
+elif x > 50:
+    x = 50
+
+reveal_type(x)  # revealed: int
 ```

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

@@ -1,315 +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
-```
-
-## Truthiness of classes
-
-```py
-class MetaAmbiguous(type):
-    def __bool__(self) -> bool: ...
-
-class MetaFalsy(type):
-    def __bool__(self) -> Literal[False]: ...
-
-class MetaTruthy(type):
-    def __bool__(self) -> Literal[True]: ...
-
-class MetaDeferred(type):
-    def __bool__(self) -> MetaAmbiguous: ...
-
-class AmbiguousClass(metaclass=MetaAmbiguous): ...
-class FalsyClass(metaclass=MetaFalsy): ...
-class TruthyClass(metaclass=MetaTruthy): ...
-class DeferredClass(metaclass=MetaDeferred): ...
-
-def _(
-    a: type[AmbiguousClass],
-    t: type[TruthyClass],
-    f: type[FalsyClass],
-    d: type[DeferredClass],
-    ta: type[TruthyClass | AmbiguousClass],
-    af: type[AmbiguousClass] | type[FalsyClass],
-    flag: bool,
-):
-    reveal_type(ta)  # revealed: type[TruthyClass] | type[AmbiguousClass]
-    if ta:
-        reveal_type(ta)  # revealed: type[TruthyClass] | type[AmbiguousClass] & ~AlwaysFalsy
-
-    reveal_type(af)  # revealed: type[AmbiguousClass] | type[FalsyClass]
-    if af:
-        reveal_type(af)  # revealed: type[AmbiguousClass] & ~AlwaysFalsy
-
-    # TODO: Emit a diagnostic (`d` is not valid in boolean context)
-    if d:
-        # TODO: Should be `Unknown`
-        reveal_type(d)  # revealed: type[DeferredClass] & ~AlwaysFalsy
-
-    tf = TruthyClass if flag else FalsyClass
-    reveal_type(tf)  # revealed: Literal[TruthyClass, FalsyClass]
-
-    if tf:
-        reveal_type(tf)  # revealed: Literal[TruthyClass]
-    else:
-        reveal_type(tf)  # revealed: Literal[FalsyClass]
-```
-
-## Narrowing in chained boolean expressions
-
-```py
-from typing import Literal
-
-class A: ...
-
-def _(x: Literal[0, 1]):
-    reveal_type(x or A())  # revealed: Literal[1] | A
-    reveal_type(x and A())  # revealed: Literal[0] | A
-
-def _(x: str):
-    reveal_type(x or A())  # revealed: str & ~AlwaysFalsy | A
-    reveal_type(x and A())  # revealed: str & ~AlwaysTruthy | A
-
-def _(x: bool | str):
-    reveal_type(x or A())  # revealed: Literal[True] | str & ~AlwaysFalsy | A
-    reveal_type(x and A())  # revealed: Literal[False] | str & ~AlwaysTruthy | A
-
-class Falsy:
-    def __bool__(self) -> Literal[False]: ...
-
-class Truthy:
-    def __bool__(self) -> Literal[True]: ...
-
-def _(x: Falsy | Truthy):
-    reveal_type(x or A())  # revealed: Truthy | A
-    reveal_type(x and A())  # revealed: Falsy | A
-
-class MetaFalsy(type):
-    def __bool__(self) -> Literal[False]: ...
-
-class MetaTruthy(type):
-    def __bool__(self) -> Literal[True]: ...
-
-class FalsyClass(metaclass=MetaFalsy): ...
-class TruthyClass(metaclass=MetaTruthy): ...
-
-def _(x: type[FalsyClass] | type[TruthyClass]):
-    reveal_type(x or A())  # revealed: type[TruthyClass] | A
-    reveal_type(x and A())  # revealed: type[FalsyClass] | A
-```

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

@@ -6,14 +6,18 @@
 class A: ...
 class B: ...
 
-def _(x: A | B):
-    if type(x) is A:
-        reveal_type(x)  # revealed: A
-    else:
-        # It would be wrong to infer `B` here. The type
-        # of `x` could be a subclass of `A`, so we need
-        # to infer the full union type:
-        reveal_type(x)  # revealed: A | B
+def get_a_or_b() -> A | B:
+    return A()
+
+x = get_a_or_b()
+
+if type(x) is A:
+    reveal_type(x)  # revealed: A
+else:
+    # It would be wrong to infer `B` here. The type
+    # of `x` could be a subclass of `A`, so we need
+    # to infer the full union type:
+    reveal_type(x)  # revealed: A | B
 ```
 
 ## `type(x) is not C`
@@ -22,12 +26,16 @@ def _(x: A | B):
 class A: ...
 class B: ...
 
-def _(x: A | B):
-    if type(x) is not A:
-        # Same reasoning as above: no narrowing should occur here.
-        reveal_type(x)  # revealed: A | B
-    else:
-        reveal_type(x)  # revealed: A
+def get_a_or_b() -> A | B:
+    return A()
+
+x = get_a_or_b()
+
+if type(x) is not A:
+    # Same reasoning as above: no narrowing should occur here.
+    reveal_type(x)  # revealed: A | B
+else:
+    reveal_type(x)  # revealed: A
 ```
 
 ## `type(x) == C`, `type(x) != C`
@@ -46,12 +54,16 @@ class IsEqualToEverything(type):
 class A(metaclass=IsEqualToEverything): ...
 class B(metaclass=IsEqualToEverything): ...
 
-def _(x: A | B):
-    if type(x) == A:
-        reveal_type(x)  # revealed: A | B
+def get_a_or_b() -> A | B:
+    return B()
 
-    if type(x) != A:
-        reveal_type(x)  # revealed: A | B
+x = get_a_or_b()
+
+if type(x) == A:
+    reveal_type(x)  # revealed: A | B
+
+if type(x) != A:
+    reveal_type(x)  # revealed: A | B
 ```
 
 ## No narrowing for custom `type` callable
@@ -63,11 +75,15 @@ class B: ...
 def type(x):
     return int
 
-def _(x: A | B):
-    if type(x) is A:
-        reveal_type(x)  # revealed: A | B
-    else:
-        reveal_type(x)  # revealed: A | B
+def get_a_or_b() -> A | B:
+    return A()
+
+x = get_a_or_b()
+
+if type(x) is A:
+    reveal_type(x)  # revealed: A | B
+else:
+    reveal_type(x)  # revealed: A | B
 ```
 
 ## No narrowing for multiple arguments
@@ -75,11 +91,15 @@ def _(x: A | B):
 No narrowing should occur if `type` is used to dynamically create a class:
 
 ```py
-def _(x: str | int):
-    if type(x, (), {}) is str:
-        reveal_type(x)  # revealed: str | int
-    else:
-        reveal_type(x)  # revealed: str | int
+def get_str_or_int() -> str | int:
+    return "test"
+
+x = get_str_or_int()
+
+if type(x, (), {}) is str:
+    reveal_type(x)  # revealed: str | int
+else:
+    reveal_type(x)  # revealed: str | int
 ```
 
 ## No narrowing for keyword arguments
@@ -87,10 +107,14 @@ def _(x: str | int):
 `type` can't be used with a keyword argument:
 
 ```py
-def _(x: str | int):
-    # TODO: we could issue a diagnostic here
-    if type(object=x) is str:
-        reveal_type(x)  # revealed: str | int
+def get_str_or_int() -> str | int:
+    return "test"
+
+x = get_str_or_int()
+
+# TODO: we could issue a diagnostic here
+if type(object=x) is str:
+    reveal_type(x)  # revealed: str | int
 ```
 
 ## Narrowing if `type` is aliased
@@ -101,9 +125,13 @@ class B: ...
 
 alias_for_type = type
 
-def _(x: A | B):
-    if alias_for_type(x) is A:
-        reveal_type(x)  # revealed: A
+def get_a_or_b() -> A | B:
+    return A()
+
+x = get_a_or_b()
+
+if alias_for_type(x) is A:
+    reveal_type(x)  # revealed: A
 ```
 
 ## Limitations
@@ -112,9 +140,13 @@ def _(x: A | B):
 class Base: ...
 class Derived(Base): ...
 
-def _(x: Base):
-    if type(x) is Base:
-        # Ideally, this could be narrower, but there is now way to
-        # express a constraint like `Base & ~ProperSubtypeOf[Base]`.
-        reveal_type(x)  # revealed: Base
+def get_base() -> Base:
+    return Base()
+
+x = get_base()
+
+if type(x) is Base:
+    # Ideally, this could be narrower, but there is now way to
+    # express a constraint like `Base & ~ProperSubtypeOf[Base]`.
+    reveal_type(x)  # revealed: Base
 ```

crates/red_knot_python_semantic/resources/mdtest/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()
-```