Bump version to 0.8.2 (#14789)

## Summary

Ref: https://github.com/astral-sh/ruff/pull/14754#discussion_r1871040646

## Test Plan

Remove the TODO comment and update the mdtest.

.github/workflows/ci.yaml

@@ -32,6 +32,8 @@ 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:
@@ -79,6 +81,11 @@ jobs:
               - python/**
               - .github/workflows/ci.yaml
 
+            fuzz:
+              - fuzz/Cargo.toml
+              - fuzz/Cargo.lock
+              - fuzz/fuzz_targets/**
+
             code:
               - "**/*"
               - "!**/*.md"
@@ -288,7 +295,7 @@ jobs:
     name: "cargo fuzz build"
     runs-on: ubuntu-latest
     needs: determine_changes
-    if: ${{ github.ref == 'refs/heads/main' }}
+    if: ${{ github.ref == 'refs/heads/main' || needs.determine_changes.outputs.fuzz == 'true' }}
     timeout-minutes: 10
     steps:
       - uses: actions/checkout@v4
@@ -383,7 +390,7 @@ jobs:
           name: ruff
           path: target/debug
 
-      - uses: dawidd6/action-download-artifact@v6
+      - uses: dawidd6/action-download-artifact@v7
         name: Download baseline Ruff binary
         with:
           name: ruff
@@ -559,7 +566,7 @@ jobs:
       - name: "Install Rust toolchain"
         run: rustup show
       - name: Install uv
-        uses: astral-sh/setup-uv@v3
+        uses: astral-sh/setup-uv@v4
       - uses: Swatinem/rust-cache@v2
       - name: "Install Insiders dependencies"
         if: ${{ env.MKDOCS_INSIDERS_SSH_KEY_EXISTS == 'true' }}

.github/workflows/pr-comment.yaml

@@ -17,7 +17,7 @@ jobs:
   comment:
     runs-on: ubuntu-latest
     steps:
-      - uses: dawidd6/action-download-artifact@v6
+      - uses: dawidd6/action-download-artifact@v7
         name: Download pull request number
         with:
           name: pr-number
@@ -33,7 +33,7 @@ jobs:
             echo "pr-number=$(<pr-number)" >> $GITHUB_OUTPUT
           fi
 
-      - uses: dawidd6/action-download-artifact@v6
+      - uses: dawidd6/action-download-artifact@v7
         name: "Download ecosystem results"
         id: download-ecosystem-result
         if: steps.pr-number.outputs.pr-number

.github/workflows/publish-playground.yml

@@ -47,7 +47,7 @@ jobs:
         working-directory: playground
       - name: "Deploy to Cloudflare Pages"
         if: ${{ env.CF_API_TOKEN_EXISTS == 'true' }}
-        uses: cloudflare/wrangler-action@v3.12.1
+        uses: cloudflare/wrangler-action@v3.13.0
         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@v3
+        uses: astral-sh/setup-uv@v4
       - uses: actions/download-artifact@v4
         with:
           pattern: wheels-*

.pre-commit-config.yaml

@@ -22,7 +22,7 @@ repos:
       - id: validate-pyproject
 
   - repo: https://github.com/executablebooks/mdformat
-    rev: 0.7.18
+    rev: 0.7.19
     hooks:
       - id: mdformat
         additional_dependencies:
@@ -36,7 +36,7 @@ repos:
           )$
 
   - repo: https://github.com/igorshubovych/markdownlint-cli
-    rev: v0.42.0
+    rev: v0.43.0
     hooks:
       - id: markdownlint-fix
         exclude: |
@@ -59,7 +59,7 @@ repos:
           - black==24.10.0
 
   - repo: https://github.com/crate-ci/typos
-    rev: v1.27.3
+    rev: v1.28.1
     hooks:
       - id: typos
 
@@ -73,7 +73,7 @@ repos:
         pass_filenames: false # This makes it a lot faster
 
   - repo: https://github.com/astral-sh/ruff-pre-commit
-    rev: v0.7.4
+    rev: v0.8.1
     hooks:
       - id: ruff-format
       - id: ruff
@@ -83,7 +83,7 @@ repos:
 
   # Prettier
   - repo: https://github.com/rbubley/mirrors-prettier
-    rev: v3.3.3
+    rev: v3.4.1
     hooks:
       - id: prettier
         types: [yaml]

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

@@ -1,5 +1,42 @@
 # Changelog
 
+## 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
@@ -21,6 +58,7 @@
 - \[`ruff`\] 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
 
@@ -34,6 +72,8 @@
 
 - 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))
@@ -254,7 +294,7 @@ 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))
 
@@ -1269,7 +1309,7 @@ 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))
 
@@ -1644,7 +1684,7 @@ 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

@@ -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.lock

@@ -413,7 +413,7 @@ dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -693,7 +693,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "strsim 0.10.0",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -704,7 +704,7 @@ checksum = "a668eda54683121533a393014d8692171709ff57a7d61f187b6e782719f8933f"
 dependencies = [
  "darling_core",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -774,7 +774,7 @@ dependencies = [
  "glob",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -826,7 +826,7 @@ checksum = "97369cbbc041bc366949bc74d34658d6cda5621039731c6310521892a3a20ae0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -1246,7 +1246,7 @@ checksum = "1ec89e9337638ecdc08744df490b221a7399bf8d164eb52a665454e60e075ad6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -1314,9 +1314,9 @@ dependencies = [
 
 [[package]]
 name = "indexmap"
-version = "2.6.0"
+version = "2.7.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "707907fe3c25f5424cce2cb7e1cbcafee6bdbe735ca90ef77c29e84591e5b9da"
+checksum = "62f822373a4fe84d4bb149bf54e584a7f4abec90e072ed49cda0edea5b95471f"
 dependencies = [
  "equivalent",
  "hashbrown 0.15.2",
@@ -1420,7 +1420,7 @@ dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -1485,10 +1485,11 @@ checksum = "8b23360e99b8717f20aaa4598f5a6541efbe30630039fbc7706cf954a87947ae"
 
 [[package]]
 name = "js-sys"
-version = "0.3.72"
+version = "0.3.74"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6a88f1bda2bd75b0452a14784937d796722fdebfe50df998aeb3f0b7603019a9"
+checksum = "a865e038f7f6ed956f788f0d7d60c541fff74c7bd74272c5d4cf15c63743e705"
 dependencies = [
+ "once_cell",
  "wasm-bindgen",
 ]
 
@@ -1520,9 +1521,9 @@ checksum = "e2abad23fbc42b3700f2f279844dc832adb2b2eb069b2df918f455c4e18cc646"
 
 [[package]]
 name = "libc"
-version = "0.2.164"
+version = "0.2.167"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "433bfe06b8c75da9b2e3fbea6e5329ff87748f0b144ef75306e674c3f6f7c13f"
+checksum = "09d6582e104315a817dff97f75133544b2e094ee22447d2acf4a74e189ba06fc"
 
 [[package]]
 name = "libcst"
@@ -1546,7 +1547,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a2ae40017ac09cd2c6a53504cb3c871c7f2b41466eac5bc66ba63f39073b467b"
 dependencies = [
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -1833,9 +1834,9 @@ checksum = "04744f49eae99ab78e0d5c0b603ab218f515ea8cfe5a456d7629ad883a3b6e7d"
 
 [[package]]
 name = "ordermap"
-version = "0.5.3"
+version = "0.5.4"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "31f2bd7b03bf2c767e1bb7b91505dbe022833776e60480275e6f2fb0db0c7503"
+checksum = "f80a48eb68b6a7da9829b8b0429011708f775af80676a91063d023a66a656106"
 dependencies = [
  "indexmap",
 ]
@@ -1910,9 +1911,9 @@ checksum = "1e91099d4268b0e11973f036e885d652fb0b21fedcf69738c627f94db6a44f42"
 
 [[package]]
 name = "pathdiff"
-version = "0.2.2"
+version = "0.2.3"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d61c5ce1153ab5b689d0c074c4e7fc613e942dfb7dd9eea5ab202d2ad91fe361"
+checksum = "df94ce210e5bc13cb6651479fa48d14f601d9858cfe0467f43ae157023b938d3"
 
 [[package]]
 name = "peg"
@@ -1965,7 +1966,7 @@ dependencies = [
  "once_cell",
  "pep440_rs",
  "regex",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "serde",
  "smallvec",
  "thiserror 1.0.67",
@@ -2012,7 +2013,7 @@ dependencies = [
  "pest_meta",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -2172,6 +2173,26 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "quickcheck"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "588f6378e4dd99458b60ec275b4477add41ce4fa9f64dcba6f15adccb19b50d6"
+dependencies = [
+ "rand",
+]
+
+[[package]]
+name = "quickcheck_macros"
+version = "1.0.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b22a693222d716a9587786f37ac3f6b4faedb5b80c23914e7303ff5a1d8016e9"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn 1.0.109",
+]
+
 [[package]]
 name = "quote"
 version = "1.0.37"
@@ -2272,6 +2293,8 @@ dependencies = [
  "itertools 0.13.0",
  "memchr",
  "ordermap",
+ "quickcheck",
+ "quickcheck_macros",
  "red_knot_test",
  "red_knot_vendored",
  "ruff_db",
@@ -2282,7 +2305,7 @@ dependencies = [
  "ruff_python_stdlib",
  "ruff_source_file",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "salsa",
  "serde",
  "smallvec",
@@ -2309,7 +2332,7 @@ dependencies = [
  "ruff_python_ast",
  "ruff_source_file",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "serde",
  "serde_json",
  "shellexpand",
@@ -2322,6 +2345,7 @@ name = "red_knot_test"
 version = "0.0.0"
 dependencies = [
  "anyhow",
+ "camino",
  "colored",
  "memchr",
  "red_knot_python_semantic",
@@ -2332,7 +2356,7 @@ dependencies = [
  "ruff_python_trivia",
  "ruff_source_file",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "salsa",
  "smallvec",
 ]
@@ -2380,7 +2404,7 @@ dependencies = [
  "ruff_db",
  "ruff_python_ast",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "salsa",
  "serde",
  "thiserror 2.0.3",
@@ -2489,7 +2513,7 @@ dependencies = [
 
 [[package]]
 name = "ruff"
-version = "0.8.1"
+version = "0.8.2"
 dependencies = [
  "anyhow",
  "argfile",
@@ -2529,7 +2553,7 @@ dependencies = [
  "ruff_source_file",
  "ruff_text_size",
  "ruff_workspace",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "serde",
  "serde_json",
  "shellexpand",
@@ -2560,7 +2584,7 @@ dependencies = [
  "ruff_python_formatter",
  "ruff_python_parser",
  "ruff_python_trivia",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "serde",
  "serde_json",
  "tikv-jemallocator",
@@ -2602,7 +2626,7 @@ dependencies = [
  "ruff_python_trivia",
  "ruff_source_file",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "salsa",
  "serde",
  "tempfile",
@@ -2671,7 +2695,7 @@ dependencies = [
  "ruff_cache",
  "ruff_macros",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "schemars",
  "serde",
  "static_assertions",
@@ -2708,7 +2732,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_linter"
-version = "0.8.1"
+version = "0.8.2"
 dependencies = [
  "aho-corasick",
  "annotate-snippets 0.9.2",
@@ -2749,7 +2773,7 @@ dependencies = [
  "ruff_python_trivia",
  "ruff_source_file",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "schemars",
  "serde",
  "serde_json",
@@ -2775,7 +2799,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "ruff_python_trivia",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -2811,7 +2835,7 @@ dependencies = [
  "ruff_python_trivia",
  "ruff_source_file",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "schemars",
  "serde",
 ]
@@ -2857,7 +2881,7 @@ dependencies = [
  "ruff_python_trivia",
  "ruff_source_file",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "schemars",
  "serde",
  "serde_json",
@@ -2904,7 +2928,7 @@ dependencies = [
  "ruff_python_trivia",
  "ruff_source_file",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "static_assertions",
  "unicode-ident",
  "unicode-normalization",
@@ -2935,7 +2959,7 @@ dependencies = [
  "ruff_python_parser",
  "ruff_python_stdlib",
  "ruff_text_size",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "schemars",
  "serde",
 ]
@@ -2993,7 +3017,7 @@ dependencies = [
  "ruff_source_file",
  "ruff_text_size",
  "ruff_workspace",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "serde",
  "serde_json",
  "shellexpand",
@@ -3023,7 +3047,7 @@ dependencies = [
 
 [[package]]
 name = "ruff_wasm"
-version = "0.8.1"
+version = "0.8.2"
 dependencies = [
  "console_error_panic_hook",
  "console_log",
@@ -3074,7 +3098,7 @@ dependencies = [
  "ruff_python_semantic",
  "ruff_python_stdlib",
  "ruff_source_file",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "schemars",
  "serde",
  "shellexpand",
@@ -3101,9 +3125,9 @@ checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
 [[package]]
 name = "rustc-hash"
-version = "2.0.0"
+version = "2.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "583034fd73374156e66797ed8e5b0d5690409c9226b22d87cb7f19821c05d152"
+checksum = "c7fb8039b3032c191086b10f11f319a6e99e1e82889c5cc6046f515c9db1d497"
 
 [[package]]
 name = "rustix"
@@ -3120,9 +3144,9 @@ dependencies = [
 
 [[package]]
 name = "rustls"
-version = "0.23.10"
+version = "0.23.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "05cff451f60db80f490f3c182b77c35260baace73209e9cdbbe526bfe3a4d402"
+checksum = "934b404430bb06b3fae2cba809eb45a1ab1aecd64491213d7c3301b88393f8d1"
 dependencies = [
  "log",
  "once_cell",
@@ -3135,15 +3159,15 @@ dependencies = [
 
 [[package]]
 name = "rustls-pki-types"
-version = "1.7.0"
+version = "1.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "976295e77ce332211c0d24d92c0e83e50f5c5f046d11082cea19f3df13a3562d"
+checksum = "16f1201b3c9a7ee8039bcadc17b7e605e2945b27eee7631788c1bd2b0643674b"
 
 [[package]]
 name = "rustls-webpki"
-version = "0.102.5"
+version = "0.102.8"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f9a6fccd794a42c2c105b513a2f62bc3fd8f3ba57a4593677ceb0bd035164d78"
+checksum = "64ca1bc8749bd4cf37b5ce386cc146580777b4e8572c7b97baf22c83f444bee9"
 dependencies = [
  "ring",
  "rustls-pki-types",
@@ -3175,7 +3199,7 @@ dependencies = [
  "indexmap",
  "lazy_static",
  "parking_lot",
- "rustc-hash 2.0.0",
+ "rustc-hash 2.1.0",
  "salsa-macro-rules",
  "salsa-macros",
  "smallvec",
@@ -3195,7 +3219,7 @@ dependencies = [
  "heck",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
  "synstructure",
 ]
 
@@ -3229,7 +3253,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "serde_derive_internals",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3278,7 +3302,7 @@ checksum = "ad1e866f866923f252f05c889987993144fb74e722403468a4ebd70c3cd756c0"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3289,7 +3313,7 @@ checksum = "330f01ce65a3a5fe59a60c82f3c9a024b573b8a6e875bd233fe5f934e71d54e3"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3312,7 +3336,7 @@ checksum = "6c64451ba24fc7a6a2d60fc75dd9c83c90903b19028d4eff35e88fc1e86564e9"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3353,7 +3377,7 @@ dependencies = [
  "darling",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3387,9 +3411,9 @@ dependencies = [
 
 [[package]]
 name = "similar"
-version = "2.5.0"
+version = "2.6.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "fa42c91313f1d05da9b26f267f931cf178d4aba455b4c4622dd7355eb80c6640"
+checksum = "1de1d4f81173b03af4c0cbed3c898f6bff5b870e4a7f5d6f4057d62a7a4b686e"
 
 [[package]]
 name = "siphasher"
@@ -3461,7 +3485,7 @@ dependencies = [
  "proc-macro2",
  "quote",
  "rustversion",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3472,9 +3496,20 @@ checksum = "81cdd64d312baedb58e21336b31bc043b77e01cc99033ce76ef539f78e965ebc"
 
 [[package]]
 name = "syn"
-version = "2.0.89"
+version = "1.0.109"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "44d46482f1c1c87acd84dea20c1bf5ebff4c757009ed6bf19cfd36fb10e92c4e"
+checksum = "72b64191b275b66ffe2469e8af2c1cfe3bafa67b529ead792a6d0160888b4237"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "unicode-ident",
+]
+
+[[package]]
+name = "syn"
+version = "2.0.90"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "919d3b74a5dd0ccd15aeb8f93e7006bd9e14c295087c9896a110f490752bcf31"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -3489,7 +3524,7 @@ checksum = "c8af7666ab7b6390ab78131fb5b0fce11d6b7a6951602017c35fa82800708971"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3552,7 +3587,7 @@ dependencies = [
  "cfg-if",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3563,7 +3598,7 @@ checksum = "5c89e72a01ed4c579669add59014b9a524d609c0c88c6a585ce37485879f6ffb"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
  "test-case-core",
 ]
 
@@ -3593,7 +3628,7 @@ checksum = "b607164372e89797d78b8e23a6d67d5d1038c1c65efd52e1389ef8b77caba2a6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3604,7 +3639,7 @@ checksum = "f077553d607adc1caf65430528a576c757a71ed73944b66ebb58ef2bbd243568"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -3708,9 +3743,9 @@ dependencies = [
 
 [[package]]
 name = "tracing"
-version = "0.1.40"
+version = "0.1.41"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c3523ab5a71916ccf420eebdf5521fcef02141234bbc0b8a49f2fdc4544364ef"
+checksum = "784e0ac535deb450455cbfa28a6f0df145ea1bb7ae51b821cf5e7927fdcfbdd0"
 dependencies = [
  "log",
  "pin-project-lite",
@@ -3720,20 +3755,20 @@ dependencies = [
 
 [[package]]
 name = "tracing-attributes"
-version = "0.1.27"
+version = "0.1.28"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "34704c8d6ebcbc939824180af020566b01a7c01f80641264eba0999f6c2b6be7"
+checksum = "395ae124c09f9e6918a2310af6038fba074bcf474ac352496d5910dd59a2226d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
 name = "tracing-core"
-version = "0.1.32"
+version = "0.1.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c06d3da6113f116aaee68e4d601191614c9053067f9ab7f6edbcb161237daa54"
+checksum = "e672c95779cf947c5311f83787af4fa8fffd12fb27e4993211a84bdfd9610f9c"
 dependencies = [
  "once_cell",
  "valuable",
@@ -3775,9 +3810,9 @@ dependencies = [
 
 [[package]]
 name = "tracing-subscriber"
-version = "0.3.18"
+version = "0.3.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "ad0f048c97dbd9faa9b7df56362b8ebcaa52adb06b498c050d2f4e32f90a7a8b"
+checksum = "e8189decb5ac0fa7bc8b96b7cb9b2701d60d48805aca84a238004d665fcc4008"
 dependencies = [
  "matchers",
  "nu-ansi-term 0.46.0",
@@ -3926,18 +3961,21 @@ checksum = "8ecb6da28b8a351d773b68d5825ac39017e680750f980f3a1a85cd8dd28a47c1"
 
 [[package]]
 name = "ureq"
-version = "2.10.1"
+version = "2.11.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "b74fc6b57825be3373f7054754755f03ac3a8f5d70015ccad699ba2029956f4a"
+checksum = "b30e6f97efe1fa43535ee241ee76967d3ff6ff3953ebb430d8d55c5393029e7b"
 dependencies = [
  "base64 0.22.0",
  "flate2",
+ "litemap",
  "log",
  "once_cell",
  "rustls",
  "rustls-pki-types",
  "url",
  "webpki-roots",
+ "yoke",
+ "zerofrom",
 ]
 
 [[package]]
@@ -3996,7 +4034,7 @@ checksum = "6b91f57fe13a38d0ce9e28a03463d8d3c2468ed03d75375110ec71d93b449a08"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -4071,9 +4109,9 @@ checksum = "9c8d87e72b64a3b4db28d11ce29237c246188f4f51057d65a7eab63b7987e423"
 
 [[package]]
 name = "wasm-bindgen"
-version = "0.2.95"
+version = "0.2.97"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "128d1e363af62632b8eb57219c8fd7877144af57558fb2ef0368d0087bddeb2e"
+checksum = "d15e63b4482863c109d70a7b8706c1e364eb6ea449b201a76c5b89cedcec2d5c"
 dependencies = [
  "cfg-if",
  "once_cell",
@@ -4082,36 +4120,37 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-backend"
-version = "0.2.95"
+version = "0.2.97"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cb6dd4d3ca0ddffd1dd1c9c04f94b868c37ff5fac97c30b97cff2d74fce3a358"
+checksum = "8d36ef12e3aaca16ddd3f67922bc63e48e953f126de60bd33ccc0101ef9998cd"
 dependencies = [
  "bumpalo",
  "log",
  "once_cell",
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-futures"
-version = "0.4.45"
+version = "0.4.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "cc7ec4f8827a71586374db3e87abdb5a2bb3a15afed140221307c3ec06b1f63b"
+checksum = "9dfaf8f50e5f293737ee323940c7d8b08a66a95a419223d9f41610ca08b0833d"
 dependencies = [
  "cfg-if",
  "js-sys",
+ "once_cell",
  "wasm-bindgen",
  "web-sys",
 ]
 
 [[package]]
 name = "wasm-bindgen-macro"
-version = "0.2.95"
+version = "0.2.97"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e79384be7f8f5a9dd5d7167216f022090cf1f9ec128e6e6a482a2cb5c5422c56"
+checksum = "705440e08b42d3e4b36de7d66c944be628d579796b8090bfa3471478a2260051"
 dependencies = [
  "quote",
  "wasm-bindgen-macro-support",
@@ -4119,32 +4158,32 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-macro-support"
-version = "0.2.95"
+version = "0.2.97"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "26c6ab57572f7a24a4985830b120de1594465e5d500f24afe89e16b4e833ef68"
+checksum = "98c9ae5a76e46f4deecd0f0255cc223cfa18dc9b261213b8aa0c7b36f61b3f1d"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
  "wasm-bindgen-backend",
  "wasm-bindgen-shared",
 ]
 
 [[package]]
 name = "wasm-bindgen-shared"
-version = "0.2.95"
+version = "0.2.97"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "65fc09f10666a9f147042251e0dda9c18f166ff7de300607007e96bdebc1068d"
+checksum = "6ee99da9c5ba11bd675621338ef6fa52296b76b83305e9b6e5c77d4c286d6d49"
 
 [[package]]
 name = "wasm-bindgen-test"
-version = "0.3.45"
+version = "0.3.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d381749acb0943d357dcbd8f0b100640679883fcdeeef04def49daf8d33a5426"
+checksum = "3d919bb60ebcecb9160afee6c71b43a58a4f0517a2de0054cd050d02cec08201"
 dependencies = [
- "console_error_panic_hook",
  "js-sys",
  "minicov",
+ "once_cell",
  "scoped-tls",
  "wasm-bindgen",
  "wasm-bindgen-futures",
@@ -4153,20 +4192,20 @@ dependencies = [
 
 [[package]]
 name = "wasm-bindgen-test-macro"
-version = "0.3.45"
+version = "0.3.47"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c97b2ef2c8d627381e51c071c2ab328eac606d3f69dd82bcbca20a9e389d95f0"
+checksum = "222ebde6ea87fbfa6bdd2e9f1fd8a91d60aee5db68792632176c4e16a74fc7d8"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
 name = "web-sys"
-version = "0.3.69"
+version = "0.3.74"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "77afa9a11836342370f4817622a2f0f418b134426d91a82dfb48f532d2ec13ef"
+checksum = "a98bc3c33f0fe7e59ad7cd041b89034fa82a7c2d4365ca538dda6cdaf513863c"
 dependencies = [
  "js-sys",
  "wasm-bindgen",
@@ -4462,7 +4501,7 @@ checksum = "28cc31741b18cb6f1d5ff12f5b7523e3d6eb0852bbbad19d73905511d9849b95"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
  "synstructure",
 ]
 
@@ -4483,7 +4522,7 @@ checksum = "9ce1b18ccd8e73a9321186f97e46f9f04b778851177567b1975109d26a08d2a6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]
@@ -4503,7 +4542,7 @@ checksum = "0ea7b4a3637ea8669cedf0f1fd5c286a17f3de97b8dd5a70a6c167a1730e63a5"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
  "synstructure",
 ]
 
@@ -4532,7 +4571,7 @@ checksum = "6eafa6dfb17584ea3e2bd6e76e0cc15ad7af12b09abdd1ca55961bed9b1063c6"
 dependencies = [
  "proc-macro2",
  "quote",
- "syn",
+ "syn 2.0.90",
 ]
 
 [[package]]

README.md

@@ -136,8 +136,8 @@ curl -LsSf https://astral.sh/ruff/install.sh | sh
 powershell -c "irm https://astral.sh/ruff/install.ps1 | iex"
 
 # For a specific version.
-curl -LsSf https://astral.sh/ruff/0.8.1/install.sh | sh
-powershell -c "irm https://astral.sh/ruff/0.8.1/install.ps1 | iex"
+curl -LsSf https://astral.sh/ruff/0.8.2/install.sh | sh
+powershell -c "irm https://astral.sh/ruff/0.8.2/install.ps1 | iex"
 ```
 
 You can also install Ruff via [Homebrew](https://formulae.brew.sh/formula/ruff), [Conda](https://anaconda.org/conda-forge/ruff),
@@ -170,7 +170,7 @@ Ruff can also be used as a [pre-commit](https://pre-commit.com/) hook via [`ruff
 ```yaml
 - repo: https://github.com/astral-sh/ruff-pre-commit
   # Ruff version.
-  rev: v0.8.1
+  rev: v0.8.2
   hooks:
     # Run the linter.
     - id: ruff

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/target_version.rs

@@ -5,11 +5,11 @@
 pub enum TargetVersion {
     Py37,
     Py38,
+    #[default]
     Py39,
     Py310,
     Py311,
     Py312,
-    #[default]
     Py313,
 }
 

crates/red_knot/tests/file_watching.rs

@@ -1,25 +1,23 @@
 #![allow(clippy::disallowed_names)]
 
 use std::io::Write;
-use std::time::Duration;
+use std::time::{Duration, Instant};
 
 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;
-use red_knot_workspace::watch::{directory_watcher, WorkspaceWatcher};
+use red_knot_workspace::watch::{directory_watcher, ChangeEvent, 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<watch::ChangeEvent>>,
+    changes_receiver: crossbeam::channel::Receiver<Vec<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,
@@ -40,12 +38,36 @@ impl TestCase {
         &self.db
     }
 
-    fn stop_watch(&mut self) -> Vec<watch::ChangeEvent> {
-        self.try_stop_watch(Duration::from_secs(10))
-            .expect("Expected watch changes but observed none")
+    #[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 try_stop_watch(&mut self, timeout: Duration) -> Option<Vec<watch::ChangeEvent>> {
+    fn try_stop_watch<M>(
+        &mut self,
+        mut matcher: M,
+        timeout: Duration,
+    ) -> Result<Vec<ChangeEvent>, Vec<ChangeEvent>>
+    where
+        M: MatchEvent,
+    {
         tracing::debug!("Try stopping watch with timeout {:?}", timeout);
 
         let watcher = self
@@ -53,36 +75,50 @@ impl TestCase {
             .take()
             .expect("Cannot call `stop_watch` more than once");
 
-        let mut all_events = self
-            .changes_receiver
-            .recv_timeout(timeout)
-            .unwrap_or_default();
+        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);
+            }
+        }
 
         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);
         }
 
-        if all_events.is_empty() {
-            return None;
-        }
-
-        Some(all_events)
+        Ok(all_events)
     }
 
-    fn take_watch_changes(&self) -> Vec<watch::ChangeEvent> {
+    fn take_watch_changes(&self) -> Vec<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<watch::ChangeEvent>> {
-        let Some(watcher) = &self.watcher else {
-            return None;
-        };
+    fn try_take_watch_changes(&self, timeout: Duration) -> Option<Vec<ChangeEvent>> {
+        let watcher = self.watcher.as_ref()?;
 
         let mut all_events = self
             .changes_receiver
@@ -104,7 +140,7 @@ impl TestCase {
         Some(all_events)
     }
 
-    fn apply_changes(&mut self, changes: Vec<watch::ChangeEvent>) {
+    fn apply_changes(&mut self, changes: Vec<ChangeEvent>) {
         self.db.apply_changes(changes, Some(&self.configuration));
     }
 
@@ -140,6 +176,23 @@ 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<()>;
 }
@@ -315,7 +368,7 @@ fn new_file() -> anyhow::Result<()> {
 
     std::fs::write(foo_path.as_std_path(), "print('Hello')")?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("foo.py"));
 
     case.apply_changes(changes);
 
@@ -338,7 +391,7 @@ fn new_ignored_file() -> anyhow::Result<()> {
 
     std::fs::write(foo_path.as_std_path(), "print('Hello')")?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("foo.py"));
 
     case.apply_changes(changes);
 
@@ -360,7 +413,7 @@ fn changed_file() -> anyhow::Result<()> {
 
     update_file(&foo_path, "print('Version 2')")?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("foo.py"));
 
     assert!(!changes.is_empty());
 
@@ -385,7 +438,7 @@ fn deleted_file() -> anyhow::Result<()> {
 
     std::fs::remove_file(foo_path.as_std_path())?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("foo.py"));
 
     case.apply_changes(changes);
 
@@ -417,7 +470,7 @@ fn move_file_to_trash() -> anyhow::Result<()> {
         trash_path.join("foo.py").as_std_path(),
     )?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("foo.py"));
 
     case.apply_changes(changes);
 
@@ -449,7 +502,7 @@ 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();
+    let changes = case.stop_watch(event_for_file("foo.py"));
 
     case.apply_changes(changes);
 
@@ -477,7 +530,7 @@ fn rename_file() -> anyhow::Result<()> {
 
     std::fs::rename(foo_path.as_std_path(), bar_path.as_std_path())?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("bar.py"));
 
     case.apply_changes(changes);
 
@@ -521,7 +574,7 @@ 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();
+    let changes = case.stop_watch(event_for_file("sub"));
 
     case.apply_changes(changes);
 
@@ -580,7 +633,7 @@ 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();
+    let changes = case.stop_watch(event_for_file("sub"));
 
     case.apply_changes(changes);
 
@@ -604,8 +657,6 @@ fn directory_moved_to_trash() -> anyhow::Result<()> {
 
 #[test]
 fn directory_renamed() -> anyhow::Result<()> {
-    let _tracing = setup_logging_with_filter("file_watching=TRACE,red_knot=TRACE");
-
     let mut case = setup([
         ("bar.py", "import sub.a"),
         ("sub/__init__.py", ""),
@@ -644,11 +695,8 @@ 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")?;
 
-    let changes = case.stop_watch();
-
-    for event in &changes {
-        tracing::debug!("Event: {:?}", event);
-    }
+    // 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"));
 
     case.apply_changes(changes);
 
@@ -721,7 +769,7 @@ 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();
+    let changes = case.stop_watch(event_for_file("sub"));
 
     case.apply_changes(changes);
 
@@ -758,7 +806,7 @@ fn search_path() -> anyhow::Result<()> {
 
     std::fs::write(site_packages.join("a.py").as_std_path(), "class A: ...")?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("a.py"));
 
     case.apply_changes(changes);
 
@@ -789,7 +837,7 @@ fn add_search_path() -> anyhow::Result<()> {
 
     std::fs::write(site_packages.join("a.py").as_std_path(), "class A: ...")?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("a.py"));
 
     case.apply_changes(changes);
 
@@ -818,9 +866,9 @@ 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(Duration::from_millis(100));
+    let changes = case.try_stop_watch(|_: &ChangeEvent| true, Duration::from_millis(100));
 
-    assert_eq!(changes, None);
+    assert_eq!(changes, Err(vec![]));
 
     Ok(())
 }
@@ -858,7 +906,7 @@ fn changed_versions_file() -> anyhow::Result<()> {
         "os: 3.0-",
     )?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("VERSIONS"));
 
     case.apply_changes(changes);
 
@@ -911,7 +959,7 @@ 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();
+    let changes = case.stop_watch(event_for_file("foo.py"));
 
     case.apply_changes(changes);
 
@@ -982,7 +1030,7 @@ 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();
+    let changes = case.stop_watch(ChangeEvent::is_changed);
 
     case.apply_changes(changes);
 
@@ -1021,7 +1069,7 @@ mod unix {
         )
         .with_context(|| "Failed to set file permissions.")?;
 
-        let changes = case.stop_watch();
+        let changes = case.stop_watch(event_for_file("foo.py"));
 
         case.apply_changes(changes);
 
@@ -1119,7 +1167,7 @@ mod unix {
         update_file(baz_workspace, "def baz(): print('Version 3')")
             .context("Failed to update bar/baz.py")?;
 
-        let changes = case.stop_watch();
+        let changes = case.stop_watch(event_for_file("baz.py"));
 
         case.apply_changes(changes);
 
@@ -1190,7 +1238,7 @@ mod unix {
         update_file(&patched_bar_baz, "def baz(): print('Version 2')")
             .context("Failed to update bar/baz.py")?;
 
-        let changes = case.stop_watch();
+        let changes = case.stop_watch(event_for_file("baz.py"));
 
         case.apply_changes(changes);
 
@@ -1298,7 +1346,7 @@ mod unix {
         update_file(&baz_original, "def baz(): print('Version 2')")
             .context("Failed to update bar/baz.py")?;
 
-        let changes = case.stop_watch();
+        let changes = case.stop_watch(event_for_file("baz.py"));
 
         case.apply_changes(changes);
 
@@ -1352,7 +1400,7 @@ fn nested_packages_delete_root() -> anyhow::Result<()> {
 
     std::fs::remove_file(case.workspace_path("pyproject.toml").as_std_path())?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(ChangeEvent::is_deleted);
 
     case.apply_changes(changes);
 
@@ -1364,7 +1412,6 @@ fn nested_packages_delete_root() -> anyhow::Result<()> {
 
 #[test]
 fn added_package() -> anyhow::Result<()> {
-    let _ = setup_logging();
     let mut case = setup([
         (
             "pyproject.toml",
@@ -1406,7 +1453,7 @@ fn added_package() -> anyhow::Result<()> {
     )
     .context("failed to write pyproject.toml for package b")?;
 
-    let changes = case.stop_watch();
+    let changes = case.stop_watch(event_for_file("pyproject.toml"));
 
     case.apply_changes(changes);
 
@@ -1449,7 +1496,7 @@ 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();
+    let changes = case.stop_watch(ChangeEvent::is_deleted);
 
     case.apply_changes(changes);
 

crates/red_knot_python_semantic/Cargo.toml

@@ -49,6 +49,8 @@ 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" }
 
 [lints]
 workspace = true

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

@@ -0,0 +1,75 @@
+# 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:
+    pass
+
+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):
+    pass
+
+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 f() -> Subclass:
+    pass
+
+reveal_type(f())  # revealed: Subclass
+```

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

@@ -0,0 +1,128 @@
+# `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 import LiteralString
+
+x: LiteralString
+
+def f():
+    reveal_type(x)  # revealed: LiteralString
+```
+
+### Within `Literal`
+
+`LiteralString` cannot be used within `Literal`:
+
+```py
+from typing import Literal, LiteralString
+
+bad_union: Literal["hello", LiteralString]  # error: [invalid-literal-parameter]
+bad_nesting: Literal[LiteralString]  # error: [invalid-literal-parameter]
+```
+
+### Parametrized
+
+`LiteralString` cannot be parametrized.
+
+```py
+from typing import LiteralString
+
+a: LiteralString[str]  # error: [invalid-type-parameter]
+b: LiteralString["foo"]  # error: [invalid-type-parameter]
+```
+
+### As a base class
+
+Subclassing `LiteralString` leads to a runtime error.
+
+```py
+from typing import LiteralString
+
+class C(LiteralString): ...  # error: [invalid-base]
+```
+
+## Inference
+
+### Common operations
+
+```py
+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(call todo)
+
+template: LiteralString = "{}, {}"
+reveal_type(template)  # revealed: Literal["{}, {}"]
+# TODO: Infer `LiteralString`
+reveal_type(template.format(foo, bar))  # revealed: @Todo(call todo)
+```
+
+### Assignability
+
+`Literal[""]` is assignable to `LiteralString`, and `LiteralString` is assignable to `str`, but not
+vice versa.
+
+```py
+def coinflip() -> bool:
+    return True
+
+foo_1: Literal["foo"] = "foo"
+bar_1: LiteralString = foo_1  # fine
+
+foo_2 = "foo" if coinflip() 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 coinflip() else 1
+reveal_type(baz_3)  # revealed: Literal["foo"] | Literal[1]
+qux_3: LiteralString = baz_3  # error: [invalid-assignment]
+```
+
+### Narrowing
+
+```py
+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"]
+```
+
+[1]: https://typing.readthedocs.io/en/latest/spec/literal.html#literalstring

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

@@ -38,7 +38,7 @@ if (x := 1) and bool_instance():
 if True or (x := 1):
     # TODO: infer that the second arm is never executed, and raise `unresolved-reference`.
     # error: [possibly-unresolved-reference]
-    reveal_type(x)  # revealed: Never
+    reveal_type(x)  # revealed: Literal[1]
 
 if True and (x := 1):
     # TODO: infer that the second arm is always executed, do not raise a diagnostic

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

@@ -0,0 +1,219 @@
+# 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:
+    pass
+
+# TODO: Emit a diagnostic
+reveal_type(len(NoDunderLen()))  # revealed: int
+```

crates/red_knot_python_semantic/resources/mdtest/invalid_syntax.md

@@ -0,0 +1,64 @@
+# Syntax errors
+
+Test cases to ensure that red knot does not panic if there are syntax errors in the source code.
+
+## 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
+
+```py
+# error: [invalid-syntax]
+pass = 1
+
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+type pass = 1
+
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+def True(for):
+    # error: [invalid-syntax]
+    pass
+
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [invalid-syntax]
+# error: [unresolved-reference] "Name `pass` used when not defined"
+for while in pass:
+    pass
+
+# error: [invalid-syntax]
+# error: [unresolved-reference] "Name `in` used when not defined"
+while in:
+    pass
+
+# 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/narrow/bool-call.md

@@ -0,0 +1,32 @@
+## 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/statically-known-branches.md

@@ -1,303 +0,0 @@
-# Statically-known branches
-
-## Always false
-
-### If
-
-```py
-x = 1
-
-if False:
-    x = 2
-
-reveal_type(x)  # revealed: Literal[1]
-```
-
-### Else
-
-```py
-x = 1
-
-if True:
-    pass
-else:
-    x = 2
-
-reveal_type(x)  # revealed: Literal[1]
-```
-
-## Always true
-
-### If
-
-```py
-x = 1
-
-if True:
-    x = 2
-
-reveal_type(x)  # revealed: Literal[2]
-```
-
-### Else
-
-```py
-x = 1
-
-if False:
-    pass
-else:
-    x = 2
-
-reveal_type(x)  # revealed: Literal[2]
-```
-
-## Combination
-
-```py
-x = 1
-
-if True:
-    x = 2
-else:
-    x = 3
-
-reveal_type(x)  # revealed: Literal[2]
-```
-
-## Nested
-
-```py path=nested_if_true_if_true.py
-x = 1
-
-if True:
-    if True:
-        x = 2
-    else:
-        x = 3
-else:
-    x = 4
-
-reveal_type(x)  # revealed: Literal[2]
-```
-
-```py path=nested_if_true_if_false.py
-x = 1
-
-if True:
-    if False:
-        x = 2
-    else:
-        x = 3
-else:
-    x = 4
-
-reveal_type(x)  # revealed: Literal[3]
-```
-
-```py path=nested_if_true_if_bool.py
-def flag() -> bool: ...
-
-x = 1
-
-if True:
-    if flag():
-        x = 2
-    else:
-        x = 3
-else:
-    x = 4
-
-reveal_type(x)  # revealed: Literal[2, 3]
-```
-
-```py path=nested_if_bool_if_true.py
-def flag() -> bool: ...
-
-x = 1
-
-if flag():
-    if True:
-        x = 2
-    else:
-        x = 3
-else:
-    x = 4
-
-reveal_type(x)  # revealed: Literal[2, 4]
-```
-
-```py path=nested_else_if_true.py
-x = 1
-
-if False:
-    x = 2
-else:
-    if True:
-        x = 3
-    else:
-        x = 4
-
-reveal_type(x)  # revealed: Literal[3]
-```
-
-```py path=nested_else_if_false.py
-x = 1
-
-if False:
-    x = 2
-else:
-    if False:
-        x = 3
-    else:
-        x = 4
-
-reveal_type(x)  # revealed: Literal[4]
-```
-
-```py path=nested_else_if_bool.py
-def flag() -> bool: ...
-
-x = 1
-
-if False:
-    x = 2
-else:
-    if flag():
-        x = 3
-    else:
-        x = 4
-
-reveal_type(x)  # revealed: Literal[3, 4]
-```
-
-## If-expressions
-
-### Always true
-
-```py
-x = 1 if True else 2
-
-reveal_type(x)  # revealed: Literal[1]
-```
-
-### Always false
-
-```py
-x = 1 if False else 2
-
-reveal_type(x)  # revealed: Literal[2]
-```
-
-## Boolean expressions
-
-### Always true
-
-```py
-(x := 1) == 1 or (x := 2)
-
-reveal_type(x)  # revealed: Literal[1]
-```
-
-### Always false
-
-```py
-(x := 1) == 0 or (x := 2)
-
-reveal_type(x)  # revealed: Literal[2]
-```
-
-## Conditional declarations
-
-```py path=if_false.py
-x: str
-
-if False:
-    x: int
-
-def f() -> None:
-    reveal_type(x)  # revealed: str
-```
-
-```py path=if_true_else.py
-x: str
-
-if True:
-    pass
-else:
-    x: int
-
-def f() -> None:
-    reveal_type(x)  # revealed: str
-```
-
-```py path=if_true.py
-x: str
-
-if True:
-    x: int
-
-def f() -> None:
-    reveal_type(x)  # revealed: int
-```
-
-```py path=if_false_else.py
-x: str
-
-if False:
-    pass
-else:
-    x: int
-
-def f() -> None:
-    reveal_type(x)  # revealed: int
-```
-
-```py path=if_bool.py
-def flag() -> bool: ...
-
-x: str
-
-if flag():
-    x: int
-
-def f() -> None:
-    reveal_type(x)  # revealed: str | int
-```
-
-## Conditionally defined functions
-
-```py
-def f() -> int: ...
-def g() -> int: ...
-
-if True:
-    def f() -> str: ...
-
-else:
-    def g() -> str: ...
-
-reveal_type(f())  # revealed: str
-reveal_type(g())  # revealed: int
-```
-
-## Conditionally defined class attributes
-
-```py
-class C:
-    if True:
-        x: int = 1
-    else:
-        x: str = "a"
-
-reveal_type(C.x)  # revealed: int
-```
-
-## TODO
-
-- declarations vs bindings => NoDefault: NoDefaultType
-- conditional imports
-- conditional class definitions
-- compare with tests in if.md=>Statically known branches
-- boundness
-    - TODO in `issubclass.md`

crates/red_knot_python_semantic/resources/mdtest/sys_version_info.md

@@ -49,14 +49,14 @@ sometimes not:
 ```py
 import sys
 
-reveal_type(sys.version_info >= (3, 9, 1))  # revealed: Literal[True]
-reveal_type(sys.version_info >= (3, 9, 1, "final", 0))  # revealed: Literal[True]
+reveal_type(sys.version_info >= (3, 9, 1))  # revealed: bool
+reveal_type(sys.version_info >= (3, 9, 1, "final", 0))  # revealed: bool
 
 # TODO: While this won't fail at runtime, the user has probably made a mistake
 # if they're comparing a tuple of length >5 with `sys.version_info`
 # (`sys.version_info` is a tuple of length 5). It might be worth
 # emitting a lint diagnostic of some kind warning them about the probable error?
-reveal_type(sys.version_info >= (3, 9, 1, "final", 0, 5))  # revealed: Literal[True]
+reveal_type(sys.version_info >= (3, 9, 1, "final", 0, 5))  # revealed: bool
 
 reveal_type(sys.version_info == (3, 8, 1, "finallllll", 0))  # revealed: Literal[False]
 ```
@@ -102,8 +102,8 @@ The fields of `sys.version_info` can be accessed by name:
 import sys
 
 reveal_type(sys.version_info.major >= 3)  # revealed: Literal[True]
-reveal_type(sys.version_info.minor >= 13)  # revealed: Literal[True]
-reveal_type(sys.version_info.minor >= 14)  # revealed: Literal[False]
+reveal_type(sys.version_info.minor >= 9)  # revealed: Literal[True]
+reveal_type(sys.version_info.minor >= 10)  # revealed: Literal[False]
 ```
 
 But the `micro`, `releaselevel` and `serial` fields are inferred as `@Todo` until we support
@@ -125,14 +125,14 @@ The fields of `sys.version_info` can be accessed by index or by slice:
 import sys
 
 reveal_type(sys.version_info[0] < 3)  # revealed: Literal[False]
-reveal_type(sys.version_info[1] > 13)  # revealed: Literal[False]
+reveal_type(sys.version_info[1] > 9)  # revealed: Literal[False]
 
-# revealed: tuple[Literal[3], Literal[13], int, Literal["alpha", "beta", "candidate", "final"], int]
+# revealed: tuple[Literal[3], Literal[9], int, Literal["alpha", "beta", "candidate", "final"], int]
 reveal_type(sys.version_info[:5])
 
-reveal_type(sys.version_info[:2] >= (3, 13))  # revealed: Literal[True]
-reveal_type(sys.version_info[0:2] >= (3, 14))  # revealed: Literal[False]
-reveal_type(sys.version_info[:3] >= (3, 14, 1))  # revealed: Literal[False]
+reveal_type(sys.version_info[:2] >= (3, 9))  # revealed: Literal[True]
+reveal_type(sys.version_info[0:2] >= (3, 10))  # revealed: Literal[False]
+reveal_type(sys.version_info[:3] >= (3, 10, 1))  # revealed: Literal[False]
 reveal_type(sys.version_info[3] == "final")  # revealed: bool
 reveal_type(sys.version_info[3] == "finalllllll")  # revealed: Literal[False]
 ```

crates/red_knot_python_semantic/resources/mdtest/unpacking.md

@@ -267,3 +267,42 @@ reveal_type(b)  # revealed: LiteralString
 # TODO: Should be list[int] once support for assigning to starred expression is added
 reveal_type(c)  # revealed: @Todo(starred unpacking)
 ```
+
+### Unicode
+
+```py
+# TODO: Add diagnostic (need more values to unpack)
+(a, b) = "é"
+
+reveal_type(a)  # revealed: LiteralString
+reveal_type(b)  # revealed: Unknown
+```
+
+### Unicode escape (1)
+
+```py
+# TODO: Add diagnostic (need more values to unpack)
+(a, b) = "\u9E6C"
+
+reveal_type(a)  # revealed: LiteralString
+reveal_type(b)  # revealed: Unknown
+```
+
+### Unicode escape (2)
+
+```py
+# TODO: Add diagnostic (need more values to unpack)
+(a, b) = "\U0010FFFF"
+
+reveal_type(a)  # revealed: LiteralString
+reveal_type(b)  # revealed: Unknown
+```
+
+### Surrogates
+
+```py
+(a, b) = "\uD800\uDFFF"
+
+reveal_type(a)  # revealed: LiteralString
+reveal_type(b)  # revealed: LiteralString
+```

crates/red_knot_python_semantic/src/db.rs

@@ -11,8 +11,13 @@ pub trait Db: SourceDb + Upcast<dyn SourceDb> {
 pub(crate) mod tests {
     use std::sync::Arc;
 
+    use crate::program::{Program, SearchPathSettings};
+    use crate::python_version::PythonVersion;
+    use crate::ProgramSettings;
+
+    use anyhow::Context;
     use ruff_db::files::{File, Files};
-    use ruff_db::system::{DbWithTestSystem, System, TestSystem};
+    use ruff_db::system::{DbWithTestSystem, System, SystemPathBuf, TestSystem};
     use ruff_db::vendored::VendoredFileSystem;
     use ruff_db::{Db as SourceDb, Upcast};
 
@@ -108,4 +113,66 @@ pub(crate) mod tests {
             events.push(event);
         }
     }
+
+    pub(crate) struct TestDbBuilder<'a> {
+        /// Target Python version
+        python_version: PythonVersion,
+        /// Path to a custom typeshed directory
+        custom_typeshed: Option<SystemPathBuf>,
+        /// Path and content pairs for files that should be present
+        files: Vec<(&'a str, &'a str)>,
+    }
+
+    impl<'a> TestDbBuilder<'a> {
+        pub(crate) fn new() -> Self {
+            Self {
+                python_version: PythonVersion::default(),
+                custom_typeshed: None,
+                files: vec![],
+            }
+        }
+
+        pub(crate) fn with_python_version(mut self, version: PythonVersion) -> Self {
+            self.python_version = version;
+            self
+        }
+
+        pub(crate) fn with_custom_typeshed(mut self, path: &str) -> Self {
+            self.custom_typeshed = Some(SystemPathBuf::from(path));
+            self
+        }
+
+        pub(crate) fn with_file(mut self, path: &'a str, content: &'a str) -> Self {
+            self.files.push((path, content));
+            self
+        }
+
+        pub(crate) fn build(self) -> anyhow::Result<TestDb> {
+            let mut db = TestDb::new();
+
+            let src_root = SystemPathBuf::from("/src");
+            db.memory_file_system().create_directory_all(&src_root)?;
+
+            db.write_files(self.files)
+                .context("Failed to write test files")?;
+
+            let mut search_paths = SearchPathSettings::new(src_root);
+            search_paths.custom_typeshed = self.custom_typeshed;
+
+            Program::from_settings(
+                &db,
+                &ProgramSettings {
+                    target_version: self.python_version,
+                    search_paths,
+                },
+            )
+            .context("Failed to configure Program settings")?;
+
+            Ok(db)
+        }
+    }
+
+    pub(crate) fn setup_db() -> TestDb {
+        TestDbBuilder::new().build().expect("valid TestDb setup")
+    }
 }

crates/red_knot_python_semantic/src/module_resolver/resolver.rs

@@ -416,7 +416,7 @@ impl<'db> Iterator for SearchPathIterator<'db> {
     }
 }
 
-impl<'db> FusedIterator for SearchPathIterator<'db> {}
+impl FusedIterator for SearchPathIterator<'_> {}
 
 /// Represents a single `.pth` file in a `site-packages` directory.
 /// One or more lines in a `.pth` file may be a (relative or absolute)

crates/red_knot_python_semantic/src/python_version.rs

@@ -39,7 +39,7 @@ impl PythonVersion {
 
 impl Default for PythonVersion {
     fn default() -> Self {
-        Self::PY313 // TODO: temporarily changed to 3.13 to activate all sys.version_info branches
+        Self::PY39
     }
 }
 

crates/red_knot_python_semantic/src/semantic_index.rs

@@ -1229,32 +1229,4 @@ match 1:
 
         assert!(matches!(binding.kind(&db), DefinitionKind::For(_)));
     }
-
-    #[test]
-    #[ignore]
-    fn if_statement() {
-        let TestCase { db, file } = test_case(
-            "
-x = False
-
-if True:
-    x: bool
-",
-        );
-
-        let index = semantic_index(&db, file);
-        // let global_table = index.symbol_table(FileScopeId::global());
-
-        let use_def = index.use_def_map(FileScopeId::global());
-
-        // use_def
-
-        use_def.print(&db);
-
-        assert!(false);
-        // let binding = use_def
-        //     .first_public_binding(global_table.symbol_id_by_name(name).expect("symbol exists"))
-        //     .expect("Expected with item definition for {name}");
-        // assert!(matches!(binding.kind(&db), DefinitionKind::WithItem(_)));
-    }
 }

crates/red_knot_python_semantic/src/semantic_index/builder.rs

@@ -23,7 +23,7 @@ use crate::semantic_index::symbol::{
     FileScopeId, NodeWithScopeKey, NodeWithScopeRef, Scope, ScopeId, ScopedSymbolId,
     SymbolTableBuilder,
 };
-use crate::semantic_index::use_def::{ActiveConstraintsSnapshot, FlowSnapshot, UseDefMapBuilder};
+use crate::semantic_index::use_def::{FlowSnapshot, UseDefMapBuilder};
 use crate::semantic_index::SemanticIndex;
 use crate::unpack::Unpack;
 use crate::Db;
@@ -200,20 +200,12 @@ impl<'db> SemanticIndexBuilder<'db> {
         self.current_use_def_map().snapshot()
     }
 
-    fn constraints_snapshot(&self) -> ActiveConstraintsSnapshot {
-        self.current_use_def_map().constraints_snapshot()
-    }
-
-    fn flow_restore(&mut self, state: FlowSnapshot, active_constraints: ActiveConstraintsSnapshot) {
+    fn flow_restore(&mut self, state: FlowSnapshot) {
         self.current_use_def_map_mut().restore(state);
-        self.current_use_def_map_mut()
-            .restore_constraints(active_constraints);
     }
 
-    fn flow_merge(&mut self, state: FlowSnapshot, active_constraints: ActiveConstraintsSnapshot) {
+    fn flow_merge(&mut self, state: FlowSnapshot) {
         self.current_use_def_map_mut().merge(state);
-        self.current_use_def_map_mut()
-            .restore_constraints(active_constraints);
     }
 
     fn add_symbol(&mut self, name: Name) -> ScopedSymbolId {
@@ -773,7 +765,6 @@ where
             ast::Stmt::If(node) => {
                 self.visit_expr(&node.test);
                 let pre_if = self.flow_snapshot();
-                let pre_if_constraints = self.constraints_snapshot();
                 let constraint = self.record_expression_constraint(&node.test);
                 let mut constraints = vec![constraint];
                 self.visit_body(&node.body);
@@ -799,7 +790,7 @@ where
                     post_clauses.push(self.flow_snapshot());
                     // we can only take an elif/else branch if none of the previous ones were
                     // taken, so the block entry state is always `pre_if`
-                    self.flow_restore(pre_if.clone(), pre_if_constraints.clone());
+                    self.flow_restore(pre_if.clone());
                     for constraint in &constraints {
                         self.record_negated_constraint(*constraint);
                     }
@@ -810,7 +801,7 @@ where
                     self.visit_body(clause_body);
                 }
                 for post_clause_state in post_clauses {
-                    self.flow_merge(post_clause_state, pre_if_constraints.clone());
+                    self.flow_merge(post_clause_state);
                 }
             }
             ast::Stmt::While(ast::StmtWhile {
@@ -822,7 +813,6 @@ where
                 self.visit_expr(test);
 
                 let pre_loop = self.flow_snapshot();
-                let pre_loop_constraints = self.constraints_snapshot();
 
                 // Save aside any break states from an outer loop
                 let saved_break_states = std::mem::take(&mut self.loop_break_states);
@@ -841,13 +831,13 @@ where
 
                 // We may execute the `else` clause without ever executing the body, so merge in
                 // the pre-loop state before visiting `else`.
-                self.flow_merge(pre_loop, pre_loop_constraints.clone());
+                self.flow_merge(pre_loop);
                 self.visit_body(orelse);
 
                 // Breaking out of a while loop bypasses the `else` clause, so merge in the break
                 // states after visiting `else`.
                 for break_state in break_states {
-                    self.flow_merge(break_state, pre_loop_constraints.clone()); // TODO?
+                    self.flow_merge(break_state);
                 }
             }
             ast::Stmt::With(ast::StmtWith {
@@ -890,7 +880,6 @@ where
                 self.visit_expr(iter);
 
                 let pre_loop = self.flow_snapshot();
-                let pre_loop_constraints = self.constraints_snapshot();
                 let saved_break_states = std::mem::take(&mut self.loop_break_states);
 
                 debug_assert_eq!(&self.current_assignments, &[]);
@@ -911,13 +900,13 @@ where
 
                 // We may execute the `else` clause without ever executing the body, so merge in
                 // the pre-loop state before visiting `else`.
-                self.flow_merge(pre_loop, pre_loop_constraints.clone());
+                self.flow_merge(pre_loop);
                 self.visit_body(orelse);
 
                 // Breaking out of a `for` loop bypasses the `else` clause, so merge in the break
                 // states after visiting `else`.
                 for break_state in break_states {
-                    self.flow_merge(break_state, pre_loop_constraints.clone());
+                    self.flow_merge(break_state);
                 }
             }
             ast::Stmt::Match(ast::StmtMatch {
@@ -929,7 +918,6 @@ where
                 self.visit_expr(subject);
 
                 let after_subject = self.flow_snapshot();
-                let after_subject_cs = self.constraints_snapshot();
                 let Some((first, remaining)) = cases.split_first() else {
                     return;
                 };
@@ -939,18 +927,18 @@ where
                 let mut post_case_snapshots = vec![];
                 for case in remaining {
                     post_case_snapshots.push(self.flow_snapshot());
-                    self.flow_restore(after_subject.clone(), after_subject_cs.clone());
+                    self.flow_restore(after_subject.clone());
                     self.add_pattern_constraint(subject, &case.pattern);
                     self.visit_match_case(case);
                 }
                 for post_clause_state in post_case_snapshots {
-                    self.flow_merge(post_clause_state, after_subject_cs.clone());
+                    self.flow_merge(post_clause_state);
                 }
                 if !cases
                     .last()
                     .is_some_and(|case| case.guard.is_none() && case.pattern.is_wildcard())
                 {
-                    self.flow_merge(after_subject, after_subject_cs.clone());
+                    self.flow_merge(after_subject);
                 }
             }
             ast::Stmt::Try(ast::StmtTry {
@@ -968,7 +956,6 @@ where
                 // We will merge this state with all of the intermediate
                 // states during the `try` block before visiting those suites.
                 let pre_try_block_state = self.flow_snapshot();
-                let pre_try_block_constraints = self.constraints_snapshot();
 
                 self.try_node_context_stack_manager.push_context();
 
@@ -989,17 +976,14 @@ where
                     // as there necessarily must have been 0 `except` blocks executed
                     // if we hit the `else` block.
                     let post_try_block_state = self.flow_snapshot();
-                    let post_try_block_constraints = self.constraints_snapshot();
 
                     // Prepare for visiting the `except` block(s)
-                    self.flow_restore(pre_try_block_state, pre_try_block_constraints.clone());
+                    self.flow_restore(pre_try_block_state);
                     for state in try_block_snapshots {
-                        self.flow_merge(state, pre_try_block_constraints.clone());
-                        // TODO?
+                        self.flow_merge(state);
                     }
 
                     let pre_except_state = self.flow_snapshot();
-                    let pre_except_constraints = self.constraints_snapshot();
                     let num_handlers = handlers.len();
 
                     for (i, except_handler) in handlers.iter().enumerate() {
@@ -1038,22 +1022,19 @@ where
                         // as we'll immediately call `self.flow_restore()` to a different state
                         // as soon as this loop over the handlers terminates.
                         if i < (num_handlers - 1) {
-                            self.flow_restore(
-                                pre_except_state.clone(),
-                                pre_except_constraints.clone(),
-                            );
+                            self.flow_restore(pre_except_state.clone());
                         }
                     }
 
                     // If we get to the `else` block, we know that 0 of the `except` blocks can have been executed,
                     // and the entire `try` block must have been executed:
-                    self.flow_restore(post_try_block_state, post_try_block_constraints);
+                    self.flow_restore(post_try_block_state);
                 }
 
                 self.visit_body(orelse);
 
                 for post_except_state in post_except_states {
-                    self.flow_merge(post_except_state, pre_try_block_constraints.clone());
+                    self.flow_merge(post_except_state);
                 }
 
                 // TODO: there's lots of complexity here that isn't yet handled by our model.
@@ -1210,17 +1191,19 @@ where
             ast::Expr::If(ast::ExprIf {
                 body, test, orelse, ..
             }) => {
+                // TODO detect statically known truthy or falsy test (via type inference, not naive
+                // AST inspection, so we can't simplify here, need to record test expression for
+                // later checking)
                 self.visit_expr(test);
                 let pre_if = self.flow_snapshot();
-                let pre_if_constraints = self.constraints_snapshot();
                 let constraint = self.record_expression_constraint(test);
                 self.visit_expr(body);
                 let post_body = self.flow_snapshot();
-                self.flow_restore(pre_if, pre_if_constraints.clone());
+                self.flow_restore(pre_if);
 
                 self.record_negated_constraint(constraint);
                 self.visit_expr(orelse);
-                self.flow_merge(post_body, pre_if_constraints);
+                self.flow_merge(post_body);
             }
             ast::Expr::ListComp(
                 list_comprehension @ ast::ExprListComp {
@@ -1281,7 +1264,7 @@ where
                 // AST inspection, so we can't simplify here, need to record test expression for
                 // later checking)
                 let mut snapshots = vec![];
-                let pre_op_constraints = self.constraints_snapshot();
+
                 for (index, value) in values.iter().enumerate() {
                     self.visit_expr(value);
                     // In the last value we don't need to take a snapshot nor add a constraint
@@ -1296,7 +1279,7 @@ where
                     }
                 }
                 for snapshot in snapshots {
-                    self.flow_merge(snapshot, pre_op_constraints.clone());
+                    self.flow_merge(snapshot);
                 }
             }
             _ => {

crates/red_knot_python_semantic/src/semantic_index/use_def.rs

@@ -221,8 +221,6 @@
 //! snapshot, and merging a snapshot into the current state. The logic using these methods lives in
 //! [`SemanticIndexBuilder`](crate::semantic_index::builder::SemanticIndexBuilder), e.g. where it
 //! visits a `StmtIf` node.
-use std::collections::HashSet;
-
 use self::symbol_state::{
     BindingIdWithConstraintsIterator, ConstraintIdIterator, DeclarationIdIterator,
     ScopedConstraintId, ScopedDefinitionId, SymbolBindings, SymbolDeclarations, SymbolState,
@@ -270,109 +268,6 @@ pub(crate) struct UseDefMap<'db> {
 }
 
 impl<'db> UseDefMap<'db> {
-    #[cfg(test)]
-    pub(crate) fn print(&self, db: &dyn crate::db::Db) {
-        use crate::semantic_index::constraint::ConstraintNode;
-
-        println!("all_definitions:");
-        println!("================");
-
-        for (id, d) in self.all_definitions.iter_enumerated() {
-            println!(
-                "{:?}: {:?} {:?} {:?}",
-                id,
-                d.category(db),
-                d.scope(db),
-                d.symbol(db),
-            );
-            println!("    {:?}", d.kind(db));
-            println!();
-        }
-
-        println!("all_constraints:");
-        println!("================");
-
-        for (id, c) in self.all_constraints.iter_enumerated() {
-            println!("{:?}: {:?}", id, c.node);
-            if let ConstraintNode::Expression(e) = c.node {
-                println!("    {:?}", e.node_ref(db));
-            }
-        }
-
-        println!();
-
-        println!("bindings_by_use:");
-        println!("================");
-
-        for (id, bindings) in self.bindings_by_use.iter_enumerated() {
-            println!("{:?}:", id);
-            for binding in bindings.iter() {
-                let definition = self.all_definitions[binding.definition];
-                let mut constraint_ids = binding.constraint_ids.peekable();
-                let mut active_constraint_ids =
-                    binding.constraints_active_at_binding_ids.peekable();
-
-                println!("  * {:?}", definition);
-
-                if constraint_ids.peek().is_some() {
-                    println!("    Constraints:");
-                    for constraint_id in constraint_ids {
-                        println!("        {:?}", self.all_constraints[constraint_id]);
-                    }
-                } else {
-                    println!("    No constraints");
-                }
-
-                println!();
-
-                if active_constraint_ids.peek().is_some() {
-                    println!("    Active constraints at binding:");
-                    for constraint_id in active_constraint_ids {
-                        println!("        {:?}", self.all_constraints[constraint_id]);
-                    }
-                } else {
-                    println!("    No active constraints at binding");
-                }
-            }
-        }
-
-        println!();
-
-        println!("public_symbols:");
-        println!("================");
-
-        for (id, symbol) in self.public_symbols.iter_enumerated() {
-            println!("{:?}:", id);
-            println!("  * Bindings:");
-            for binding in symbol.bindings().iter() {
-                let definition = self.all_definitions[binding.definition];
-                let mut constraint_ids = binding.constraint_ids.peekable();
-
-                println!("    {:?}", definition);
-
-                if constraint_ids.peek().is_some() {
-                    println!("      Constraints:");
-                    for constraint_id in constraint_ids {
-                        println!("          {:?}", self.all_constraints[constraint_id]);
-                    }
-                } else {
-                    println!("      No constraints");
-                }
-            }
-
-            println!("  * Declarations:");
-            for (declaration, _) in symbol.declarations().iter() {
-                let definition = self.all_definitions[declaration];
-                println!("    {:?}", definition);
-            }
-
-            println!();
-        }
-
-        println!();
-        println!();
-    }
-
     pub(crate) fn bindings_at_use(
         &self,
         use_id: ScopedUseId,
@@ -457,7 +352,6 @@ impl<'db> UseDefMap<'db> {
     ) -> DeclarationsIterator<'a, 'db> {
         DeclarationsIterator {
             all_definitions: &self.all_definitions,
-            all_constraints: &self.all_constraints,
             inner: declarations.iter(),
             may_be_undeclared: declarations.may_be_undeclared(),
         }
@@ -471,7 +365,7 @@ enum SymbolDefinitions {
     Declarations(SymbolDeclarations),
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 pub(crate) struct BindingWithConstraintsIterator<'map, 'db> {
     all_definitions: &'map IndexVec<ScopedDefinitionId, Definition<'db>>,
     all_constraints: &'map IndexVec<ScopedConstraintId, Constraint<'db>>,
@@ -490,10 +384,6 @@ impl<'map, 'db> Iterator for BindingWithConstraintsIterator<'map, 'db> {
                     all_constraints: self.all_constraints,
                     constraint_ids: def_id_with_constraints.constraint_ids,
                 },
-                constraints_active_at_binding: ConstraintsIterator {
-                    all_constraints: self.all_constraints,
-                    constraint_ids: def_id_with_constraints.constraints_active_at_binding_ids,
-                },
             })
     }
 }
@@ -503,16 +393,14 @@ impl std::iter::FusedIterator for BindingWithConstraintsIterator<'_, '_> {}
 pub(crate) struct BindingWithConstraints<'map, 'db> {
     pub(crate) binding: Definition<'db>,
     pub(crate) constraints: ConstraintsIterator<'map, 'db>,
-    pub(crate) constraints_active_at_binding: ConstraintsIterator<'map, 'db>,
 }
 
-#[derive(Debug, Clone)]
 pub(crate) struct ConstraintsIterator<'map, 'db> {
     all_constraints: &'map IndexVec<ScopedConstraintId, Constraint<'db>>,
     constraint_ids: ConstraintIdIterator<'map>,
 }
 
-impl<'map, 'db> Iterator for ConstraintsIterator<'map, 'db> {
+impl<'db> Iterator for ConstraintsIterator<'_, 'db> {
     type Item = Constraint<'db>;
 
     fn next(&mut self) -> Option<Self::Item> {
@@ -526,7 +414,6 @@ impl std::iter::FusedIterator for ConstraintsIterator<'_, '_> {}
 
 pub(crate) struct DeclarationsIterator<'map, 'db> {
     all_definitions: &'map IndexVec<ScopedDefinitionId, Definition<'db>>,
-    all_constraints: &'map IndexVec<ScopedConstraintId, Constraint<'db>>,
     inner: DeclarationIdIterator<'map>,
     may_be_undeclared: bool,
 }
@@ -537,19 +424,11 @@ impl DeclarationsIterator<'_, '_> {
     }
 }
 
-impl<'map, 'db> Iterator for DeclarationsIterator<'map, 'db> {
-    type Item = (Definition<'db>, ConstraintsIterator<'map, 'db>);
+impl<'db> Iterator for DeclarationsIterator<'_, 'db> {
+    type Item = Definition<'db>;
 
     fn next(&mut self) -> Option<Self::Item> {
-        self.inner.next().map(|(def_id, constraints)| {
-            (
-                self.all_definitions[def_id],
-                ConstraintsIterator {
-                    all_constraints: self.all_constraints,
-                    constraint_ids: constraints,
-                },
-            )
-        })
+        self.inner.next().map(|def_id| self.all_definitions[def_id])
     }
 }
 
@@ -561,9 +440,6 @@ pub(super) struct FlowSnapshot {
     symbol_states: IndexVec<ScopedSymbolId, SymbolState>,
 }
 
-#[derive(Clone, Debug)]
-pub(super) struct ActiveConstraintsSnapshot(HashSet<ScopedConstraintId>);
-
 #[derive(Debug, Default)]
 pub(super) struct UseDefMapBuilder<'db> {
     /// Append-only array of [`Definition`].
@@ -572,8 +448,6 @@ pub(super) struct UseDefMapBuilder<'db> {
     /// Append-only array of [`Constraint`].
     all_constraints: IndexVec<ScopedConstraintId, Constraint<'db>>,
 
-    active_constraints: HashSet<ScopedConstraintId>,
-
     /// Live bindings at each so-far-recorded use.
     bindings_by_use: IndexVec<ScopedUseId, SymbolBindings>,
 
@@ -597,7 +471,7 @@ impl<'db> UseDefMapBuilder<'db> {
             binding,
             SymbolDefinitions::Declarations(symbol_state.declarations().clone()),
         );
-        symbol_state.record_binding(def_id, &self.active_constraints);
+        symbol_state.record_binding(def_id);
     }
 
     pub(super) fn record_constraint(&mut self, constraint: Constraint<'db>) {
@@ -605,7 +479,6 @@ impl<'db> UseDefMapBuilder<'db> {
         for state in &mut self.symbol_states {
             state.record_constraint(constraint_id);
         }
-        self.active_constraints.insert(constraint_id);
     }
 
     pub(super) fn record_declaration(
@@ -619,7 +492,7 @@ impl<'db> UseDefMapBuilder<'db> {
             declaration,
             SymbolDefinitions::Bindings(symbol_state.bindings().clone()),
         );
-        symbol_state.record_declaration(def_id, &self.active_constraints);
+        symbol_state.record_declaration(def_id);
     }
 
     pub(super) fn record_declaration_and_binding(
@@ -630,8 +503,8 @@ impl<'db> UseDefMapBuilder<'db> {
         // We don't need to store anything in self.definitions_by_definition.
         let def_id = self.all_definitions.push(definition);
         let symbol_state = &mut self.symbol_states[symbol];
-        symbol_state.record_declaration(def_id, &self.active_constraints);
-        symbol_state.record_binding(def_id, &self.active_constraints);
+        symbol_state.record_declaration(def_id);
+        symbol_state.record_binding(def_id);
     }
 
     pub(super) fn record_use(&mut self, symbol: ScopedSymbolId, use_id: ScopedUseId) {
@@ -650,10 +523,6 @@ impl<'db> UseDefMapBuilder<'db> {
         }
     }
 
-    pub(super) fn constraints_snapshot(&self) -> ActiveConstraintsSnapshot {
-        ActiveConstraintsSnapshot(self.active_constraints.clone())
-    }
-
     /// Restore the current builder symbols state to the given snapshot.
     pub(super) fn restore(&mut self, snapshot: FlowSnapshot) {
         // We never remove symbols from `symbol_states` (it's an IndexVec, and the symbol
@@ -672,10 +541,6 @@ impl<'db> UseDefMapBuilder<'db> {
             .resize(num_symbols, SymbolState::undefined());
     }
 
-    pub(super) fn restore_constraints(&mut self, snapshot: ActiveConstraintsSnapshot) {
-        self.active_constraints = snapshot.0;
-    }
-
     /// Merge the given snapshot into the current state, reflecting that we might have taken either
     /// path to get here. The new state for each symbol should include definitions from both the
     /// prior state and the snapshot.

crates/red_knot_python_semantic/src/semantic_index/use_def/bitset.rs

@@ -122,7 +122,7 @@ impl<const B: usize> BitSet<B> {
 }
 
 /// Iterator over values in a [`BitSet`].
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 pub(super) struct BitSetIterator<'a, const B: usize> {
     /// The blocks we are iterating over.
     blocks: &'a [u64],

crates/red_knot_python_semantic/src/semantic_index/use_def/symbol_state.rs

@@ -43,8 +43,6 @@
 //!
 //! Tracking live declarations is simpler, since constraints are not involved, but otherwise very
 //! similar to tracking live bindings.
-use std::collections::HashSet;
-
 use super::bitset::{BitSet, BitSetIterator};
 use ruff_index::newtype_index;
 use smallvec::SmallVec;
@@ -89,8 +87,6 @@ pub(super) struct SymbolDeclarations {
     /// [`BitSet`]: which declarations (as [`ScopedDefinitionId`]) can reach the current location?
     live_declarations: Declarations,
 
-    constraints_active_at_declaration: Constraints, // TODO: rename to constraints_active_at_declaration
-
     /// Could the symbol be un-declared at this point?
     may_be_undeclared: bool,
 }
@@ -99,27 +95,14 @@ impl SymbolDeclarations {
     fn undeclared() -> Self {
         Self {
             live_declarations: Declarations::default(),
-            constraints_active_at_declaration: Constraints::default(),
             may_be_undeclared: true,
         }
     }
 
     /// Record a newly-encountered declaration for this symbol.
-    fn record_declaration(
-        &mut self,
-        declaration_id: ScopedDefinitionId,
-        active_constraints: &HashSet<ScopedConstraintId>,
-    ) {
+    fn record_declaration(&mut self, declaration_id: ScopedDefinitionId) {
         self.live_declarations = Declarations::with(declaration_id.into());
         self.may_be_undeclared = false;
-
-        // TODO: unify code with below
-        self.constraints_active_at_declaration = Constraints::with_capacity(1);
-        self.constraints_active_at_declaration
-            .push(BitSet::default());
-        for active_constraint_id in active_constraints {
-            self.constraints_active_at_declaration[0].insert(active_constraint_id.as_u32());
-        }
     }
 
     /// Add undeclared as a possibility for this symbol.
@@ -131,7 +114,6 @@ impl SymbolDeclarations {
     pub(super) fn iter(&self) -> DeclarationIdIterator {
         DeclarationIdIterator {
             inner: self.live_declarations.iter(),
-            constraints_active_at_binding: self.constraints_active_at_declaration.iter(),
         }
     }
 
@@ -156,8 +138,6 @@ pub(super) struct SymbolBindings {
     /// binding in `live_bindings`.
     constraints: Constraints,
 
-    constraints_active_at_binding: Constraints,
-
     /// Could the symbol be unbound at this point?
     may_be_unbound: bool,
 }
@@ -167,7 +147,6 @@ impl SymbolBindings {
         Self {
             live_bindings: Bindings::default(),
             constraints: Constraints::default(),
-            constraints_active_at_binding: Constraints::default(),
             may_be_unbound: true,
         }
     }
@@ -178,21 +157,12 @@ impl SymbolBindings {
     }
 
     /// Record a newly-encountered binding for this symbol.
-    pub(super) fn record_binding(
-        &mut self,
-        binding_id: ScopedDefinitionId,
-        active_constraints: &HashSet<ScopedConstraintId>,
-    ) {
+    pub(super) fn record_binding(&mut self, binding_id: ScopedDefinitionId) {
         // The new binding replaces all previous live bindings in this path, and has no
         // constraints.
         self.live_bindings = Bindings::with(binding_id.into());
         self.constraints = Constraints::with_capacity(1);
         self.constraints.push(BitSet::default());
-        self.constraints_active_at_binding = Constraints::with_capacity(1);
-        self.constraints_active_at_binding.push(BitSet::default());
-        for active_constraint_id in active_constraints {
-            self.constraints_active_at_binding[0].insert(active_constraint_id.as_u32());
-        }
         self.may_be_unbound = false;
     }
 
@@ -208,7 +178,6 @@ impl SymbolBindings {
         BindingIdWithConstraintsIterator {
             definitions: self.live_bindings.iter(),
             constraints: self.constraints.iter(),
-            constraints_active_at_binding: self.constraints_active_at_binding.iter(),
         }
     }
 
@@ -238,12 +207,8 @@ impl SymbolState {
     }
 
     /// Record a newly-encountered binding for this symbol.
-    pub(super) fn record_binding(
-        &mut self,
-        binding_id: ScopedDefinitionId,
-        active_constraints: &HashSet<ScopedConstraintId>,
-    ) {
-        self.bindings.record_binding(binding_id, active_constraints);
+    pub(super) fn record_binding(&mut self, binding_id: ScopedDefinitionId) {
+        self.bindings.record_binding(binding_id);
     }
 
     /// Add given constraint to all live bindings.
@@ -257,13 +222,8 @@ impl SymbolState {
     }
 
     /// Record a newly-encountered declaration of this symbol.
-    pub(super) fn record_declaration(
-        &mut self,
-        declaration_id: ScopedDefinitionId,
-        active_constraints: &HashSet<ScopedConstraintId>,
-    ) {
-        self.declarations
-            .record_declaration(declaration_id, active_constraints);
+    pub(super) fn record_declaration(&mut self, declaration_id: ScopedDefinitionId) {
+        self.declarations.record_declaration(declaration_id);
     }
 
     /// Merge another [`SymbolState`] into this one.
@@ -272,93 +232,24 @@ impl SymbolState {
             bindings: SymbolBindings {
                 live_bindings: Bindings::default(),
                 constraints: Constraints::default(),
-                constraints_active_at_binding: Constraints::default(), // TODO
                 may_be_unbound: self.bindings.may_be_unbound || b.bindings.may_be_unbound,
             },
             declarations: SymbolDeclarations {
                 live_declarations: self.declarations.live_declarations.clone(),
-                constraints_active_at_declaration: Constraints::default(), // TODO
                 may_be_undeclared: self.declarations.may_be_undeclared
                     || b.declarations.may_be_undeclared,
             },
         };
 
-        // let mut constraints_active_at_binding = BitSet::default();
-        // for active_constraint_id in active_constraints.0 {
-        //     constraints_active_at_binding.insert(active_constraint_id.as_u32());
-        // }
-
         std::mem::swap(&mut a, self);
-        // self.declarations
-        //     .live_declarations
-        //     .union(&b.declarations.live_declarations);
-
-        let mut a_decls_iter = a.declarations.live_declarations.iter();
-        let mut b_decls_iter = b.declarations.live_declarations.iter();
-        let mut a_constraints_active_at_declaration_iter =
-            a.declarations.constraints_active_at_declaration.into_iter();
-        let mut b_constraints_active_at_declaration_iter =
-            b.declarations.constraints_active_at_declaration.into_iter();
-
-        let mut opt_a_decl: Option<u32> = a_decls_iter.next();
-        let mut opt_b_decl: Option<u32> = b_decls_iter.next();
-
-        let push = |decl,
-                    constraints_active_at_declaration_iter: &mut ConstraintsIntoIterator,
-                    merged: &mut Self| {
-            merged.declarations.live_declarations.insert(decl);
-            let constraints_active_at_binding = constraints_active_at_declaration_iter
-                .next()
-                .expect("declarations and constraints_active_at_binding length mismatch");
-            merged
-                .declarations
-                .constraints_active_at_declaration
-                .push(constraints_active_at_binding);
-        };
-
-        loop {
-            match (opt_a_decl, opt_b_decl) {
-                (Some(a_decl), Some(b_decl)) => match a_decl.cmp(&b_decl) {
-                    std::cmp::Ordering::Less => {
-                        push(a_decl, &mut a_constraints_active_at_declaration_iter, self);
-                        opt_a_decl = a_decls_iter.next();
-                    }
-                    std::cmp::Ordering::Greater => {
-                        push(b_decl, &mut b_constraints_active_at_declaration_iter, self);
-                        opt_b_decl = b_decls_iter.next();
-                    }
-                    std::cmp::Ordering::Equal => {
-                        push(a_decl, &mut b_constraints_active_at_declaration_iter, self);
-                        self.declarations
-                            .constraints_active_at_declaration
-                            .last_mut()
-                            .unwrap()
-                            .intersect(&a_constraints_active_at_declaration_iter.next().unwrap());
-
-                        opt_a_decl = a_decls_iter.next();
-                        opt_b_decl = b_decls_iter.next();
-                    }
-                },
-                (Some(a_decl), None) => {
-                    push(a_decl, &mut a_constraints_active_at_declaration_iter, self);
-                    opt_a_decl = a_decls_iter.next();
-                }
-                (None, Some(b_decl)) => {
-                    push(b_decl, &mut b_constraints_active_at_declaration_iter, self);
-                    opt_b_decl = b_decls_iter.next();
-                }
-                (None, None) => break,
-            }
-        }
+        self.declarations
+            .live_declarations
+            .union(&b.declarations.live_declarations);
 
         let mut a_defs_iter = a.bindings.live_bindings.iter();
         let mut b_defs_iter = b.bindings.live_bindings.iter();
         let mut a_constraints_iter = a.bindings.constraints.into_iter();
         let mut b_constraints_iter = b.bindings.constraints.into_iter();
-        let mut a_constraints_active_at_binding_iter =
-            a.bindings.constraints_active_at_binding.into_iter();
-        let mut b_constraints_active_at_binding_iter =
-            b.bindings.constraints_active_at_binding.into_iter();
 
         let mut opt_a_def: Option<u32> = a_defs_iter.next();
         let mut opt_b_def: Option<u32> = b_defs_iter.next();
@@ -370,10 +261,7 @@ impl SymbolState {
         // path is irrelevant.
 
         // Helper to push `def`, with constraints in `constraints_iter`, onto `self`.
-        let push = |def,
-                    constraints_iter: &mut ConstraintsIntoIterator,
-                    constraints_active_at_binding_iter: &mut ConstraintsIntoIterator,
-                    merged: &mut Self| {
+        let push = |def, constraints_iter: &mut ConstraintsIntoIterator, merged: &mut Self| {
             merged.bindings.live_bindings.insert(def);
             // SAFETY: we only ever create SymbolState with either no definitions and no constraint
             // bitsets (`::unbound`) or one definition and one constraint bitset (`::with`), and
@@ -383,14 +271,7 @@ impl SymbolState {
             let constraints = constraints_iter
                 .next()
                 .expect("definitions and constraints length mismatch");
-            let constraints_active_at_binding = constraints_active_at_binding_iter
-                .next()
-                .expect("definitions and constraints_active_at_binding length mismatch");
             merged.bindings.constraints.push(constraints);
-            merged
-                .bindings
-                .constraints_active_at_binding
-                .push(constraints_active_at_binding);
         };
 
         loop {
@@ -398,32 +279,17 @@ impl SymbolState {
                 (Some(a_def), Some(b_def)) => match a_def.cmp(&b_def) {
                     std::cmp::Ordering::Less => {
                         // Next definition ID is only in `a`, push it to `self` and advance `a`.
-                        push(
-                            a_def,
-                            &mut a_constraints_iter,
-                            &mut a_constraints_active_at_binding_iter,
-                            self,
-                        );
+                        push(a_def, &mut a_constraints_iter, self);
                         opt_a_def = a_defs_iter.next();
                     }
                     std::cmp::Ordering::Greater => {
                         // Next definition ID is only in `b`, push it to `self` and advance `b`.
-                        push(
-                            b_def,
-                            &mut b_constraints_iter,
-                            &mut b_constraints_active_at_binding_iter,
-                            self,
-                        );
+                        push(b_def, &mut b_constraints_iter, self);
                         opt_b_def = b_defs_iter.next();
                     }
                     std::cmp::Ordering::Equal => {
                         // Next definition is in both; push to `self` and intersect constraints.
-                        push(
-                            a_def,
-                            &mut b_constraints_iter,
-                            &mut b_constraints_active_at_binding_iter,
-                            self,
-                        );
+                        push(a_def, &mut b_constraints_iter, self);
                         // SAFETY: we only ever create SymbolState with either no definitions and
                         // no constraint bitsets (`::unbound`) or one definition and one constraint
                         // bitset (`::with`), and `::merge` always pushes one definition and one
@@ -432,11 +298,6 @@ impl SymbolState {
                         let a_constraints = a_constraints_iter
                             .next()
                             .expect("definitions and constraints length mismatch");
-                        // let _a_constraints_active_at_binding =
-                        //     a_constraints_active_at_binding_iter.next().expect(
-                        //         "definitions and constraints_active_at_binding length mismatch",
-                        //     ); // TODO: perform check that we see the same constraints in both paths
-
                         // If the same definition is visible through both paths, any constraint
                         // that applies on only one path is irrelevant to the resulting type from
                         // unioning the two paths, so we intersect the constraints.
@@ -445,29 +306,18 @@ impl SymbolState {
                             .last_mut()
                             .unwrap()
                             .intersect(&a_constraints);
-
                         opt_a_def = a_defs_iter.next();
                         opt_b_def = b_defs_iter.next();
                     }
                 },
                 (Some(a_def), None) => {
                     // We've exhausted `b`, just push the def from `a` and move on to the next.
-                    push(
-                        a_def,
-                        &mut a_constraints_iter,
-                        &mut a_constraints_active_at_binding_iter,
-                        self,
-                    );
+                    push(a_def, &mut a_constraints_iter, self);
                     opt_a_def = a_defs_iter.next();
                 }
                 (None, Some(b_def)) => {
                     // We've exhausted `a`, just push the def from `b` and move on to the next.
-                    push(
-                        b_def,
-                        &mut b_constraints_iter,
-                        &mut b_constraints_active_at_binding_iter,
-                        self,
-                    );
+                    push(b_def, &mut b_constraints_iter, self);
                     opt_b_def = b_defs_iter.next();
                 }
                 (None, None) => break,
@@ -503,37 +353,26 @@ impl Default for SymbolState {
 pub(super) struct BindingIdWithConstraints<'a> {
     pub(super) definition: ScopedDefinitionId,
     pub(super) constraint_ids: ConstraintIdIterator<'a>,
-    pub(super) constraints_active_at_binding_ids: ConstraintIdIterator<'a>,
 }
 
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 pub(super) struct BindingIdWithConstraintsIterator<'a> {
     definitions: BindingsIterator<'a>,
     constraints: ConstraintsIterator<'a>,
-    constraints_active_at_binding: ConstraintsIterator<'a>,
 }
 
 impl<'a> Iterator for BindingIdWithConstraintsIterator<'a> {
     type Item = BindingIdWithConstraints<'a>;
 
     fn next(&mut self) -> Option<Self::Item> {
-        match (
-            self.definitions.next(),
-            self.constraints.next(),
-            self.constraints_active_at_binding.next(),
-        ) {
-            (None, None, None) => None,
-            (Some(def), Some(constraints), Some(constraints_active_at_binding)) => {
-                Some(BindingIdWithConstraints {
-                    definition: ScopedDefinitionId::from_u32(def),
-                    constraint_ids: ConstraintIdIterator {
-                        wrapped: constraints.iter(),
-                    },
-                    constraints_active_at_binding_ids: ConstraintIdIterator {
-                        wrapped: constraints_active_at_binding.iter(),
-                    },
-                })
-            }
+        match (self.definitions.next(), self.constraints.next()) {
+            (None, None) => None,
+            (Some(def), Some(constraints)) => Some(BindingIdWithConstraints {
+                definition: ScopedDefinitionId::from_u32(def),
+                constraint_ids: ConstraintIdIterator {
+                    wrapped: constraints.iter(),
+                },
+            }),
             // SAFETY: see above.
             _ => unreachable!("definitions and constraints length mismatch"),
         }
@@ -542,7 +381,7 @@ impl<'a> Iterator for BindingIdWithConstraintsIterator<'a> {
 
 impl std::iter::FusedIterator for BindingIdWithConstraintsIterator<'_> {}
 
-#[derive(Debug, Clone)]
+#[derive(Debug)]
 pub(super) struct ConstraintIdIterator<'a> {
     wrapped: BitSetIterator<'a, INLINE_CONSTRAINT_BLOCKS>,
 }
@@ -560,25 +399,13 @@ impl std::iter::FusedIterator for ConstraintIdIterator<'_> {}
 #[derive(Debug)]
 pub(super) struct DeclarationIdIterator<'a> {
     inner: DeclarationsIterator<'a>,
-    constraints_active_at_binding: ConstraintsIterator<'a>,
 }
 
-impl<'a> Iterator for DeclarationIdIterator<'a> {
-    type Item = (ScopedDefinitionId, ConstraintIdIterator<'a>);
+impl Iterator for DeclarationIdIterator<'_> {
+    type Item = ScopedDefinitionId;
 
     fn next(&mut self) -> Option<Self::Item> {
-        // self.inner.next().map(ScopedDefinitionId::from_u32)
-        match (self.inner.next(), self.constraints_active_at_binding.next()) {
-            (None, None) => None,
-            (Some(declaration), Some(constraints_active_at_binding)) => Some((
-                ScopedDefinitionId::from_u32(declaration),
-                ConstraintIdIterator {
-                    wrapped: constraints_active_at_binding.iter(),
-                },
-            )),
-            // SAFETY: see above.
-            _ => unreachable!("declarations and constraints_active_at_binding length mismatch"),
-        }
+        self.inner.next().map(ScopedDefinitionId::from_u32)
     }
 }
 
@@ -586,7 +413,7 @@ impl std::iter::FusedIterator for DeclarationIdIterator<'_> {}
 
 #[cfg(test)]
 mod tests {
-    use super::{ScopedConstraintId, SymbolState};
+    use super::{ScopedConstraintId, ScopedDefinitionId, SymbolState};
 
     fn assert_bindings(symbol: &SymbolState, may_be_unbound: bool, expected: &[&str]) {
         assert_eq!(symbol.may_be_unbound(), may_be_unbound);
@@ -618,7 +445,7 @@ mod tests {
         let actual = symbol
             .declarations()
             .iter()
-            .map(|(d, _)| d.as_u32()) // TODO: constraints
+            .map(ScopedDefinitionId::as_u32)
             .collect::<Vec<_>>();
         assert_eq!(actual, expected);
     }
@@ -630,76 +457,76 @@ mod tests {
         assert_bindings(&sym, true, &[]);
     }
 
-    // #[test]
-    // fn with() {
-    //     let mut sym = SymbolState::undefined();
-    //     sym.record_binding(ScopedDefinitionId::from_u32(0));
+    #[test]
+    fn with() {
+        let mut sym = SymbolState::undefined();
+        sym.record_binding(ScopedDefinitionId::from_u32(0));
 
-    //     assert_bindings(&sym, false, &["0<>"]);
-    // }
+        assert_bindings(&sym, false, &["0<>"]);
+    }
 
-    // #[test]
-    // fn set_may_be_unbound() {
-    //     let mut sym = SymbolState::undefined();
-    //     sym.record_binding(ScopedDefinitionId::from_u32(0));
-    //     sym.set_may_be_unbound();
+    #[test]
+    fn set_may_be_unbound() {
+        let mut sym = SymbolState::undefined();
+        sym.record_binding(ScopedDefinitionId::from_u32(0));
+        sym.set_may_be_unbound();
 
-    //     assert_bindings(&sym, true, &["0<>"]);
-    // }
+        assert_bindings(&sym, true, &["0<>"]);
+    }
 
-    // #[test]
-    // fn record_constraint() {
-    //     let mut sym = SymbolState::undefined();
-    //     sym.record_binding(ScopedDefinitionId::from_u32(0));
-    //     sym.record_constraint(ScopedConstraintId::from_u32(0));
+    #[test]
+    fn record_constraint() {
+        let mut sym = SymbolState::undefined();
+        sym.record_binding(ScopedDefinitionId::from_u32(0));
+        sym.record_constraint(ScopedConstraintId::from_u32(0));
 
-    //     assert_bindings(&sym, false, &["0<0>"]);
-    // }
+        assert_bindings(&sym, false, &["0<0>"]);
+    }
 
-    // #[test]
-    // fn merge() {
-    //     // merging the same definition with the same constraint keeps the constraint
-    //     let mut sym0a = SymbolState::undefined();
-    //     sym0a.record_binding(ScopedDefinitionId::from_u32(0));
-    //     sym0a.record_constraint(ScopedConstraintId::from_u32(0));
+    #[test]
+    fn merge() {
+        // merging the same definition with the same constraint keeps the constraint
+        let mut sym0a = SymbolState::undefined();
+        sym0a.record_binding(ScopedDefinitionId::from_u32(0));
+        sym0a.record_constraint(ScopedConstraintId::from_u32(0));
 
-    //     let mut sym0b = SymbolState::undefined();
-    //     sym0b.record_binding(ScopedDefinitionId::from_u32(0));
-    //     sym0b.record_constraint(ScopedConstraintId::from_u32(0));
+        let mut sym0b = SymbolState::undefined();
+        sym0b.record_binding(ScopedDefinitionId::from_u32(0));
+        sym0b.record_constraint(ScopedConstraintId::from_u32(0));
 
-    //     sym0a.merge(sym0b);
-    //     let mut sym0 = sym0a;
-    //     assert_bindings(&sym0, false, &["0<0>"]);
+        sym0a.merge(sym0b);
+        let mut sym0 = sym0a;
+        assert_bindings(&sym0, false, &["0<0>"]);
 
-    //     // merging the same definition with differing constraints drops all constraints
-    //     let mut sym1a = SymbolState::undefined();
-    //     sym1a.record_binding(ScopedDefinitionId::from_u32(1));
-    //     sym1a.record_constraint(ScopedConstraintId::from_u32(1));
+        // merging the same definition with differing constraints drops all constraints
+        let mut sym1a = SymbolState::undefined();
+        sym1a.record_binding(ScopedDefinitionId::from_u32(1));
+        sym1a.record_constraint(ScopedConstraintId::from_u32(1));
 
-    //     let mut sym1b = SymbolState::undefined();
-    //     sym1b.record_binding(ScopedDefinitionId::from_u32(1));
-    //     sym1b.record_constraint(ScopedConstraintId::from_u32(2));
+        let mut sym1b = SymbolState::undefined();
+        sym1b.record_binding(ScopedDefinitionId::from_u32(1));
+        sym1b.record_constraint(ScopedConstraintId::from_u32(2));
 
-    //     sym1a.merge(sym1b);
-    //     let sym1 = sym1a;
-    //     assert_bindings(&sym1, false, &["1<>"]);
+        sym1a.merge(sym1b);
+        let sym1 = sym1a;
+        assert_bindings(&sym1, false, &["1<>"]);
 
-    //     // merging a constrained definition with unbound keeps both
-    //     let mut sym2a = SymbolState::undefined();
-    //     sym2a.record_binding(ScopedDefinitionId::from_u32(2));
-    //     sym2a.record_constraint(ScopedConstraintId::from_u32(3));
+        // merging a constrained definition with unbound keeps both
+        let mut sym2a = SymbolState::undefined();
+        sym2a.record_binding(ScopedDefinitionId::from_u32(2));
+        sym2a.record_constraint(ScopedConstraintId::from_u32(3));
 
-    //     let sym2b = SymbolState::undefined();
+        let sym2b = SymbolState::undefined();
 
-    //     sym2a.merge(sym2b);
-    //     let sym2 = sym2a;
-    //     assert_bindings(&sym2, true, &["2<3>"]);
+        sym2a.merge(sym2b);
+        let sym2 = sym2a;
+        assert_bindings(&sym2, true, &["2<3>"]);
 
-    //     // merging different definitions keeps them each with their existing constraints
-    //     sym0.merge(sym2);
-    //     let sym = sym0;
-    //     assert_bindings(&sym, true, &["0<0>", "2<3>"]);
-    // }
+        // merging different definitions keeps them each with their existing constraints
+        sym0.merge(sym2);
+        let sym = sym0;
+        assert_bindings(&sym, true, &["0<0>", "2<3>"]);
+    }
 
     #[test]
     fn no_declaration() {
@@ -708,54 +535,54 @@ mod tests {
         assert_declarations(&sym, true, &[]);
     }
 
-    // #[test]
-    // fn record_declaration() {
-    //     let mut sym = SymbolState::undefined();
-    //     sym.record_declaration(ScopedDefinitionId::from_u32(1));
+    #[test]
+    fn record_declaration() {
+        let mut sym = SymbolState::undefined();
+        sym.record_declaration(ScopedDefinitionId::from_u32(1));
 
-    //     assert_declarations(&sym, false, &[1]);
-    // }
+        assert_declarations(&sym, false, &[1]);
+    }
 
-    // #[test]
-    // fn record_declaration_override() {
-    //     let mut sym = SymbolState::undefined();
-    //     sym.record_declaration(ScopedDefinitionId::from_u32(1));
-    //     sym.record_declaration(ScopedDefinitionId::from_u32(2));
+    #[test]
+    fn record_declaration_override() {
+        let mut sym = SymbolState::undefined();
+        sym.record_declaration(ScopedDefinitionId::from_u32(1));
+        sym.record_declaration(ScopedDefinitionId::from_u32(2));
 
-    //     assert_declarations(&sym, false, &[2]);
-    // }
+        assert_declarations(&sym, false, &[2]);
+    }
 
-    // #[test]
-    // fn record_declaration_merge() {
-    //     let mut sym = SymbolState::undefined();
-    //     sym.record_declaration(ScopedDefinitionId::from_u32(1));
+    #[test]
+    fn record_declaration_merge() {
+        let mut sym = SymbolState::undefined();
+        sym.record_declaration(ScopedDefinitionId::from_u32(1));
 
-    //     let mut sym2 = SymbolState::undefined();
-    //     sym2.record_declaration(ScopedDefinitionId::from_u32(2));
+        let mut sym2 = SymbolState::undefined();
+        sym2.record_declaration(ScopedDefinitionId::from_u32(2));
 
-    //     sym.merge(sym2);
+        sym.merge(sym2);
 
-    //     assert_declarations(&sym, false, &[1, 2]);
-    // }
+        assert_declarations(&sym, false, &[1, 2]);
+    }
 
-    // #[test]
-    // fn record_declaration_merge_partial_undeclared() {
-    //     let mut sym = SymbolState::undefined();
-    //     sym.record_declaration(ScopedDefinitionId::from_u32(1));
+    #[test]
+    fn record_declaration_merge_partial_undeclared() {
+        let mut sym = SymbolState::undefined();
+        sym.record_declaration(ScopedDefinitionId::from_u32(1));
 
-    //     let sym2 = SymbolState::undefined();
+        let sym2 = SymbolState::undefined();
 
-    //     sym.merge(sym2);
+        sym.merge(sym2);
 
-    //     assert_declarations(&sym, true, &[1]);
-    // }
+        assert_declarations(&sym, true, &[1]);
+    }
 
-    // #[test]
-    // fn set_may_be_undeclared() {
-    //     let mut sym = SymbolState::undefined();
-    //     sym.record_declaration(ScopedDefinitionId::from_u32(0));
-    //     sym.set_may_be_undeclared();
+    #[test]
+    fn set_may_be_undeclared() {
+        let mut sym = SymbolState::undefined();
+        sym.record_declaration(ScopedDefinitionId::from_u32(0));
+        sym.set_may_be_undeclared();
 
-    //     assert_declarations(&sym, true, &[0]);
-    // }
+        assert_declarations(&sym, true, &[0]);
+    }
 }

crates/red_knot_python_semantic/src/semantic_model.rs

@@ -166,31 +166,15 @@ impl_binding_has_ty!(ast::ParameterWithDefault);
 mod tests {
     use ruff_db::files::system_path_to_file;
     use ruff_db::parsed::parsed_module;
-    use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
 
-    use crate::db::tests::TestDb;
-    use crate::program::{Program, SearchPathSettings};
-    use crate::python_version::PythonVersion;
-    use crate::{HasTy, ProgramSettings, SemanticModel};
-
-    fn setup_db<'a>(files: impl IntoIterator<Item = (&'a str, &'a str)>) -> anyhow::Result<TestDb> {
-        let mut db = TestDb::new();
-        db.write_files(files)?;
-
-        Program::from_settings(
-            &db,
-            &ProgramSettings {
-                target_version: PythonVersion::default(),
-                search_paths: SearchPathSettings::new(SystemPathBuf::from("/src")),
-            },
-        )?;
-
-        Ok(db)
-    }
+    use crate::db::tests::TestDbBuilder;
+    use crate::{HasTy, SemanticModel};
 
     #[test]
     fn function_ty() -> anyhow::Result<()> {
-        let db = setup_db([("/src/foo.py", "def test(): pass")])?;
+        let db = TestDbBuilder::new()
+            .with_file("/src/foo.py", "def test(): pass")
+            .build()?;
 
         let foo = system_path_to_file(&db, "/src/foo.py").unwrap();
 
@@ -207,7 +191,9 @@ mod tests {
 
     #[test]
     fn class_ty() -> anyhow::Result<()> {
-        let db = setup_db([("/src/foo.py", "class Test: pass")])?;
+        let db = TestDbBuilder::new()
+            .with_file("/src/foo.py", "class Test: pass")
+            .build()?;
 
         let foo = system_path_to_file(&db, "/src/foo.py").unwrap();
 
@@ -224,10 +210,10 @@ mod tests {
 
     #[test]
     fn alias_ty() -> anyhow::Result<()> {
-        let db = setup_db([
-            ("/src/foo.py", "class Test: pass"),
-            ("/src/bar.py", "from foo import Test"),
-        ])?;
+        let db = TestDbBuilder::new()
+            .with_file("/src/foo.py", "class Test: pass")
+            .with_file("/src/bar.py", "from foo import Test")
+            .build()?;
 
         let bar = system_path_to_file(&db, "/src/bar.py").unwrap();
 

crates/red_knot_python_semantic/src/symbol.rs

@@ -90,7 +90,7 @@ impl<'db> Symbol<'db> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::types::tests::setup_db;
+    use crate::db::tests::setup_db;
 
     #[test]
     fn test_symbol_or_fall_back_to() {

crates/red_knot_python_semantic/src/types.rs

@@ -15,7 +15,6 @@ pub(crate) use self::infer::{
 pub(crate) use self::signatures::Signature;
 use crate::module_resolver::file_to_module;
 use crate::semantic_index::ast_ids::HasScopedExpressionId;
-use crate::semantic_index::constraint::ConstraintNode;
 use crate::semantic_index::definition::Definition;
 use crate::semantic_index::symbol::{self as symbol, ScopeId, ScopedSymbolId};
 use crate::semantic_index::{
@@ -29,7 +28,7 @@ use crate::symbol::{Boundness, Symbol};
 use crate::types::diagnostic::TypeCheckDiagnosticsBuilder;
 use crate::types::mro::{ClassBase, Mro, MroError, MroIterator};
 use crate::types::narrow::narrowing_constraint;
-use crate::{Db, FxOrderSet, Module, Program};
+use crate::{Db, FxOrderSet, Module, Program, PythonVersion};
 
 mod builder;
 mod diagnostic;
@@ -41,6 +40,9 @@ mod signatures;
 mod string_annotation;
 mod unpacker;
 
+#[cfg(test)]
+mod property_tests;
+
 #[salsa::tracked(return_ref)]
 pub fn check_types(db: &dyn Db, file: File) -> TypeCheckDiagnostics {
     let _span = tracing::trace_span!("check_types", file=?file.path(db)).entered();
@@ -223,12 +225,6 @@ fn definition_expression_ty<'db>(
     }
 }
 
-#[derive(Clone, Copy, Debug, PartialEq, Eq)]
-enum UnconditionallyVisible {
-    Yes,
-    No,
-}
-
 /// Infer the combined type of an iterator of bindings.
 ///
 /// Will return a union if there is more than one binding.
@@ -236,88 +232,29 @@ fn bindings_ty<'db>(
     db: &'db dyn Db,
     bindings_with_constraints: BindingWithConstraintsIterator<'_, 'db>,
 ) -> Option<Type<'db>> {
-    let def_types = bindings_with_constraints.map(
+    let mut def_types = bindings_with_constraints.map(
         |BindingWithConstraints {
              binding,
              constraints,
-             constraints_active_at_binding,
          }| {
-            let test_expr_tys = || {
-                constraints_active_at_binding.clone().map(|c| {
-                    let ty = if let ConstraintNode::Expression(test_expr) = c.node {
-                        let inference = infer_expression_types(db, test_expr);
-                        let scope = test_expr.scope(db);
-                        inference
-                            .expression_ty(test_expr.node_ref(db).scoped_expression_id(db, scope))
-                    } else {
-                        // TODO: handle other constraint nodes
-                        todo_type!()
-                    };
+            let mut constraint_tys = constraints
+                .filter_map(|constraint| narrowing_constraint(db, constraint, binding))
+                .peekable();
 
-                    (c, ty)
-                })
-            };
-
-            if test_expr_tys().any(|(c, test_expr_ty)| {
-                if c.is_positive {
-                    test_expr_ty.bool(db).is_always_false()
-                } else {
-                    test_expr_ty.bool(db).is_always_true()
-                }
-            }) {
-                // TODO: do we need to call binding_ty(…) even if we don't need the result?
-                (Type::Never, UnconditionallyVisible::No)
+            let binding_ty = binding_ty(db, binding);
+            if constraint_tys.peek().is_some() {
+                constraint_tys
+                    .fold(
+                        IntersectionBuilder::new(db).add_positive(binding_ty),
+                        IntersectionBuilder::add_positive,
+                    )
+                    .build()
             } else {
-                let mut test_expr_tys_iter = test_expr_tys().peekable();
-
-                let unconditionally_visible = if test_expr_tys_iter.peek().is_some()
-                    && test_expr_tys_iter.all(|(c, test_expr_ty)| {
-                        if c.is_positive {
-                            test_expr_ty.bool(db).is_always_true()
-                        } else {
-                            test_expr_ty.bool(db).is_always_false()
-                        }
-                    }) {
-                    UnconditionallyVisible::Yes
-                } else {
-                    UnconditionallyVisible::No
-                };
-
-                let mut constraint_tys = constraints
-                    .filter_map(|constraint| narrowing_constraint(db, constraint, binding))
-                    .peekable();
-
-                let binding_ty = binding_ty(db, binding);
-                if constraint_tys.peek().is_some() {
-                    let intersection_ty = constraint_tys
-                        .fold(
-                            IntersectionBuilder::new(db).add_positive(binding_ty),
-                            IntersectionBuilder::add_positive,
-                        )
-                        .build();
-                    (intersection_ty, unconditionally_visible)
-                } else {
-                    (binding_ty, unconditionally_visible)
-                }
+                binding_ty
             }
         },
     );
 
-    // TODO: get rid of all the collects and clean up, obviously
-    let def_types: Vec<_> = def_types.collect();
-
-    // shrink the vector to only include everything from the last unconditionally visible binding
-    let def_types: Vec<_> = def_types
-        .iter()
-        .rev()
-        .take_while_inclusive(|(_, unconditionally_visible)| {
-            *unconditionally_visible != UnconditionallyVisible::Yes
-        })
-        .map(|(ty, _)| *ty)
-        .collect();
-
-    let mut def_types = def_types.into_iter().rev();
-
     if let Some(first) = def_types.next() {
         if let Some(second) = def_types.next() {
             Some(UnionType::from_elements(
@@ -353,63 +290,7 @@ fn declarations_ty<'db>(
     declarations: DeclarationsIterator<'_, 'db>,
     undeclared_ty: Option<Type<'db>>,
 ) -> DeclaredTypeResult<'db> {
-    let decl_types = declarations.map(|(declaration, constraints_active_at_declaration)| {
-        let test_expr_tys = || {
-            constraints_active_at_declaration.clone().map(|c| {
-                let ty = if let ConstraintNode::Expression(test_expr) = c.node {
-                    let inference = infer_expression_types(db, test_expr);
-                    let scope = test_expr.scope(db);
-                    inference.expression_ty(test_expr.node_ref(db).scoped_expression_id(db, scope))
-                } else {
-                    // TODO: handle other constraint nodes
-                    todo_type!()
-                };
-
-                (c, ty)
-            })
-        };
-
-        if test_expr_tys().any(|(c, test_expr_ty)| {
-            if c.is_positive {
-                test_expr_ty.bool(db).is_always_false()
-            } else {
-                test_expr_ty.bool(db).is_always_true()
-            }
-        }) {
-            (Type::Never, UnconditionallyVisible::No)
-        } else {
-            let mut test_expr_tys_iter = test_expr_tys().peekable();
-
-            if test_expr_tys_iter.peek().is_some()
-                && test_expr_tys_iter.all(|(c, test_expr_ty)| {
-                    if c.is_positive {
-                        test_expr_ty.bool(db).is_always_true()
-                    } else {
-                        test_expr_ty.bool(db).is_always_false()
-                    }
-                })
-            {
-                (declaration_ty(db, declaration), UnconditionallyVisible::Yes)
-            } else {
-                (declaration_ty(db, declaration), UnconditionallyVisible::No)
-            }
-        }
-    });
-
-    // TODO: get rid of all the collects and clean up, obviously
-    let decl_types: Vec<_> = decl_types.collect();
-
-    // shrink the vector to only include everything from the last unconditionally visible binding
-    let decl_types: Vec<_> = decl_types
-        .iter()
-        .rev()
-        .take_while_inclusive(|(_, unconditionally_visible)| {
-            *unconditionally_visible != UnconditionallyVisible::Yes
-        })
-        .map(|(ty, _)| *ty)
-        .collect();
-
-    let decl_types = decl_types.into_iter().rev();
+    let decl_types = declarations.map(|declaration| declaration_ty(db, declaration));
 
     let mut all_types = undeclared_ty.into_iter().chain(decl_types);
 
@@ -421,13 +302,7 @@ fn declarations_ty<'db>(
     let declared_ty = if let Some(second) = all_types.next() {
         let mut builder = UnionBuilder::new(db).add(first);
         for other in [second].into_iter().chain(all_types) {
-            // Make sure not to emit spurious errors relating to `Type::Todo`,
-            // since we only infer this type due to a limitation in our current model.
-            //
-            // `Unknown` is different here, since we might infer `Unknown`
-            // for one of these due to a variable being defined in one possible
-            // control-flow branch but not another one.
-            if !first.is_equivalent_to(db, other) && !first.is_todo() && !other.is_todo() {
+            if !first.is_equivalent_to(db, other) {
                 conflicting.push(other);
             }
             builder = builder.add(other);
@@ -696,8 +571,11 @@ impl<'db> Type<'db> {
         Self::BytesLiteral(BytesLiteralType::new(db, bytes))
     }
 
-    pub fn tuple(db: &'db dyn Db, elements: &[Type<'db>]) -> Self {
-        Self::Tuple(TupleType::new(db, elements))
+    pub fn tuple<T: Into<Type<'db>>>(
+        db: &'db dyn Db,
+        elements: impl IntoIterator<Item = T>,
+    ) -> Self {
+        TupleType::from_elements(db, elements)
     }
 
     #[must_use]
@@ -716,11 +594,16 @@ impl<'db> Type<'db> {
 
     /// Return true if this type is a [subtype of] type `target`.
     ///
+    /// This method returns `false` if either `self` or `other` is not fully static.
+    ///
     /// [subtype of]: https://typing.readthedocs.io/en/latest/spec/concepts.html#subtype-supertype-and-type-equivalence
     pub(crate) fn is_subtype_of(self, db: &'db dyn Db, target: Type<'db>) -> bool {
         if self.is_equivalent_to(db, target) {
             return true;
         }
+        if !self.is_fully_static(db) || !target.is_fully_static(db) {
+            return false;
+        }
         match (self, target) {
             (Type::Unknown | Type::Any | Type::Todo(_), _) => false,
             (_, Type::Unknown | Type::Any | Type::Todo(_)) => false,
@@ -841,9 +724,6 @@ impl<'db> Type<'db> {
             (Type::KnownInstance(left), right) => {
                 left.instance_fallback(db).is_subtype_of(db, right)
             }
-            (left, Type::KnownInstance(right)) => {
-                left.is_subtype_of(db, right.instance_fallback(db))
-            }
             (Type::Instance(left), Type::Instance(right)) => left.is_instance_of(db, right.class),
             // TODO
             _ => false,
@@ -883,14 +763,48 @@ impl<'db> Type<'db> {
         }
     }
 
-    /// Return true if this type is equivalent to type `other`.
+    /// Return true if this type is [equivalent to] type `other`.
+    ///
+    /// This method returns `false` if either `self` or `other` is not fully static.
+    ///
+    /// [equivalent to]: https://typing.readthedocs.io/en/latest/spec/glossary.html#term-equivalent
     pub(crate) fn is_equivalent_to(self, db: &'db dyn Db, other: Type<'db>) -> bool {
+        if !(self.is_fully_static(db) && other.is_fully_static(db)) {
+            return false;
+        }
+
         // TODO equivalent but not identical structural types, differently-ordered unions and
         // intersections, other cases?
 
         // TODO: Once we have support for final classes, we can establish that
         // `Type::SubclassOf('FinalClass')` is equivalent to `Type::ClassLiteral('FinalClass')`.
-        self == other || matches!((self, other), (Type::Todo(_), Type::Todo(_)))
+
+        // TODO: The following is a workaround that is required to unify the two different versions
+        // of `NoneType` and `NoDefaultType` in typeshed. This should not be required anymore once
+        // we understand `sys.version_info` branches.
+        self == other
+            || matches!((self, other),
+                (
+                    Type::Instance(InstanceType { class: self_class }),
+                    Type::Instance(InstanceType { class: target_class })
+                )
+                if {
+                    let self_known = self_class.known(db);
+                    matches!(self_known, Some(KnownClass::NoneType | KnownClass::NoDefaultType))
+                        && self_known == target_class.known(db)
+                }
+            )
+    }
+
+    /// Returns true if both `self` and `other` are the same gradual form
+    /// (limited to `Any`, `Unknown`, or `Todo`).
+    pub(crate) fn is_same_gradual_form(self, other: Type<'db>) -> bool {
+        matches!(
+            (self, other),
+            (Type::Unknown, Type::Unknown)
+                | (Type::Any, Type::Any)
+                | (Type::Todo(_), Type::Todo(_))
+        )
     }
 
     /// Return true if this type and `other` have no common elements.
@@ -1099,6 +1013,63 @@ impl<'db> Type<'db> {
         }
     }
 
+    /// Returns true if the type does not contain any gradual forms (as a sub-part).
+    pub(crate) fn is_fully_static(self, db: &'db dyn Db) -> bool {
+        match self {
+            Type::Any | Type::Unknown | Type::Todo(_) => false,
+            Type::Never
+            | Type::FunctionLiteral(..)
+            | Type::ModuleLiteral(..)
+            | Type::IntLiteral(_)
+            | Type::BooleanLiteral(_)
+            | Type::StringLiteral(_)
+            | Type::LiteralString
+            | Type::BytesLiteral(_)
+            | Type::SliceLiteral(_)
+            | Type::KnownInstance(_) => true,
+            Type::ClassLiteral(_) | Type::SubclassOf(_) | Type::Instance(_) => {
+                // TODO: Ideally, we would iterate over the MRO of the class, check if all
+                // bases are fully static, and only return `true` if that is the case.
+                //
+                // This does not work yet, because we currently infer `Unknown` for some
+                // generic base classes that we don't understand yet. For example, `str`
+                // is defined as `class str(Sequence[str])` in typeshed and we currently
+                // compute its MRO as `(str, Unknown, object)`. This would make us think
+                // that `str` is a gradual type, which causes all sorts of downstream
+                // issues because it does not participate in equivalence/subtyping etc.
+                //
+                // Another problem is that we run into problems if we eagerly query the
+                // MRO of class literals here. I have not fully investigated this, but
+                // iterating over the MRO alone, without even acting on it, causes us to
+                // infer `Unknown` for many classes.
+
+                true
+            }
+            Type::Union(union) => union
+                .elements(db)
+                .iter()
+                .all(|elem| elem.is_fully_static(db)),
+            Type::Intersection(intersection) => {
+                intersection
+                    .positive(db)
+                    .iter()
+                    .all(|elem| elem.is_fully_static(db))
+                    && intersection
+                        .negative(db)
+                        .iter()
+                        .all(|elem| elem.is_fully_static(db))
+            }
+            Type::Tuple(tuple) => tuple
+                .elements(db)
+                .iter()
+                .all(|elem| elem.is_fully_static(db)),
+            // TODO: Once we support them, make sure that we return `false` for other types
+            // containing gradual forms such as `tuple[Any, ...]` or `Callable[..., str]`.
+            // Conversely, make sure to return `true` for homogeneous tuples such as
+            // `tuple[int, ...]`, once we add support for them.
+        }
+    }
+
     /// Return true if there is just a single inhabitant for this type.
     ///
     /// Note: This function aims to have no false positives, but might return `false`
@@ -1446,21 +1417,76 @@ impl<'db> Type<'db> {
         }
     }
 
+    /// Return the type of `len()` on a type if it is known more precisely than `int`,
+    /// or `None` otherwise.
+    ///
+    /// In the second case, the return type of `len()` in `typeshed` (`int`)
+    /// is used as a fallback.
+    fn len(&self, db: &'db dyn Db) -> Option<Type<'db>> {
+        fn non_negative_int_literal<'db>(db: &'db dyn Db, ty: Type<'db>) -> Option<Type<'db>> {
+            match ty {
+                // TODO: Emit diagnostic for non-integers and negative integers
+                Type::IntLiteral(value) => (value >= 0).then_some(ty),
+                Type::BooleanLiteral(value) => Some(Type::IntLiteral(value.into())),
+                Type::Union(union) => {
+                    let mut builder = UnionBuilder::new(db);
+                    for element in union.elements(db) {
+                        builder = builder.add(non_negative_int_literal(db, *element)?);
+                    }
+                    Some(builder.build())
+                }
+                _ => None,
+            }
+        }
+
+        let usize_len = match self {
+            Type::BytesLiteral(bytes) => Some(bytes.python_len(db)),
+            Type::StringLiteral(string) => Some(string.python_len(db)),
+            Type::Tuple(tuple) => Some(tuple.len(db)),
+            _ => None,
+        };
+
+        if let Some(usize_len) = usize_len {
+            return usize_len.try_into().ok().map(Type::IntLiteral);
+        }
+
+        let return_ty = match self.call_dunder(db, "__len__", &[*self]) {
+            // TODO: emit a diagnostic
+            CallDunderResult::MethodNotAvailable => return None,
+
+            CallDunderResult::CallOutcome(outcome) | CallDunderResult::PossiblyUnbound(outcome) => {
+                outcome.return_ty(db)?
+            }
+        };
+
+        non_negative_int_literal(db, return_ty)
+    }
+
     /// Return the outcome of calling an object of this type.
     #[must_use]
     fn call(self, db: &'db dyn Db, arg_types: &[Type<'db>]) -> CallOutcome<'db> {
         match self {
             // TODO validate typed call arguments vs callable signature
-            Type::FunctionLiteral(function_type) => {
-                if function_type.is_known(db, KnownFunction::RevealType) {
-                    CallOutcome::revealed(
-                        function_type.signature(db).return_ty,
-                        *arg_types.first().unwrap_or(&Type::Unknown),
-                    )
-                } else {
-                    CallOutcome::callable(function_type.signature(db).return_ty)
+            Type::FunctionLiteral(function_type) => match function_type.known(db) {
+                Some(KnownFunction::RevealType) => CallOutcome::revealed(
+                    function_type.signature(db).return_ty,
+                    *arg_types.first().unwrap_or(&Type::Unknown),
+                ),
+
+                Some(KnownFunction::Len) => {
+                    let normal_return_ty = function_type.signature(db).return_ty;
+
+                    let [only_arg] = arg_types else {
+                        // TODO: Emit a diagnostic
+                        return CallOutcome::callable(normal_return_ty);
+                    };
+                    let len_ty = only_arg.len(db);
+
+                    CallOutcome::callable(len_ty.unwrap_or(normal_return_ty))
                 }
-            }
+
+                _ => CallOutcome::callable(function_type.signature(db).return_ty),
+            },
 
             // TODO annotated return type on `__new__` or metaclass `__call__`
             Type::ClassLiteral(ClassLiteralType { class }) => {
@@ -1509,7 +1535,7 @@ impl<'db> Type<'db> {
             // `Any` is callable, and its return type is also `Any`.
             Type::Any => CallOutcome::callable(Type::Any),
 
-            Type::Todo(_) => CallOutcome::callable(todo_type!()),
+            Type::Todo(_) => CallOutcome::callable(todo_type!("call todo")),
 
             Type::Unknown => CallOutcome::callable(Type::Unknown),
 
@@ -1662,6 +1688,8 @@ impl<'db> Type<'db> {
             Type::KnownInstance(KnownInstanceType::Never | KnownInstanceType::NoReturn) => {
                 Type::Never
             }
+            Type::KnownInstance(KnownInstanceType::LiteralString) => Type::LiteralString,
+            Type::KnownInstance(KnownInstanceType::Any) => Type::Any,
             _ => todo_type!(),
         }
     }
@@ -1898,8 +1926,8 @@ impl<'db> KnownClass {
 
                 // typing_extensions has a 3.13+ re-export for the `typing.NoDefault`
                 // singleton, but not for `typing._NoDefaultType`. So we need to switch
-                // to `typing.NoDefault` for newer versions:
-                if python_version.major >= 3 && python_version.minor >= 13 {
+                // to `typing._NoDefaultType` for newer versions:
+                if python_version >= PythonVersion::PY313 {
                     CoreStdlibModule::Typing
                 } else {
                     CoreStdlibModule::TypingExtensions
@@ -1968,7 +1996,7 @@ impl<'db> KnownClass {
     }
 
     /// Return `true` if the module of `self` matches `module_name`
-    fn check_module(self, db: &dyn Db, module: &Module) -> bool {
+    fn check_module(self, db: &'db dyn Db, module: &Module) -> bool {
         if !module.search_path().is_standard_library() {
             return false;
         }
@@ -2002,6 +2030,8 @@ impl<'db> KnownClass {
 pub enum KnownInstanceType<'db> {
     /// The symbol `typing.Literal` (which can also be found as `typing_extensions.Literal`)
     Literal,
+    /// The symbol `typing.LiteralString` (which can also be found as `typing_extensions.LiteralString`)
+    LiteralString,
     /// The symbol `typing.Optional` (which can also be found as `typing_extensions.Optional`)
     Optional,
     /// The symbol `typing.Union` (which can also be found as `typing_extensions.Union`)
@@ -2010,6 +2040,8 @@ pub enum KnownInstanceType<'db> {
     NoReturn,
     /// The symbol `typing.Never` available since 3.11 (which can also be found as `typing_extensions.Never`)
     Never,
+    /// The symbol `typing.Any` (which can also be found as `typing_extensions.Any`)
+    Any,
     /// A single instance of `typing.TypeVar`
     TypeVar(TypeVarInstance<'db>),
     /// A single instance of `typing.TypeAliasType` (PEP 695 type alias)
@@ -2021,11 +2053,13 @@ impl<'db> KnownInstanceType<'db> {
     pub const fn as_str(self) -> &'static str {
         match self {
             Self::Literal => "Literal",
+            Self::LiteralString => "LiteralString",
             Self::Optional => "Optional",
             Self::Union => "Union",
             Self::TypeVar(_) => "TypeVar",
             Self::NoReturn => "NoReturn",
             Self::Never => "Never",
+            Self::Any => "Any",
             Self::TypeAliasType(_) => "TypeAliasType",
         }
     }
@@ -2034,11 +2068,13 @@ impl<'db> KnownInstanceType<'db> {
     pub const fn bool(self) -> Truthiness {
         match self {
             Self::Literal
+            | Self::LiteralString
             | Self::Optional
             | Self::TypeVar(_)
             | Self::Union
             | Self::NoReturn
             | Self::Never
+            | Self::Any
             | Self::TypeAliasType(_) => Truthiness::AlwaysTrue,
         }
     }
@@ -2047,10 +2083,12 @@ impl<'db> KnownInstanceType<'db> {
     pub fn repr(self, db: &'db dyn Db) -> &'db str {
         match self {
             Self::Literal => "typing.Literal",
+            Self::LiteralString => "typing.LiteralString",
             Self::Optional => "typing.Optional",
             Self::Union => "typing.Union",
             Self::NoReturn => "typing.NoReturn",
             Self::Never => "typing.Never",
+            Self::Any => "typing.Any",
             Self::TypeVar(typevar) => typevar.name(db),
             Self::TypeAliasType(_) => "typing.TypeAliasType",
         }
@@ -2060,10 +2098,12 @@ impl<'db> KnownInstanceType<'db> {
     pub const fn class(self) -> KnownClass {
         match self {
             Self::Literal => KnownClass::SpecialForm,
+            Self::LiteralString => KnownClass::SpecialForm,
             Self::Optional => KnownClass::SpecialForm,
             Self::Union => KnownClass::SpecialForm,
             Self::NoReturn => KnownClass::SpecialForm,
             Self::Never => KnownClass::SpecialForm,
+            Self::Any => KnownClass::Object,
             Self::TypeVar(_) => KnownClass::TypeVar,
             Self::TypeAliasType(_) => KnownClass::TypeAliasType,
         }
@@ -2083,7 +2123,9 @@ impl<'db> KnownInstanceType<'db> {
             return None;
         }
         match (module.name().as_str(), instance_name) {
+            ("typing", "Any") => Some(Self::Any),
             ("typing" | "typing_extensions", "Literal") => Some(Self::Literal),
+            ("typing" | "typing_extensions", "LiteralString") => Some(Self::LiteralString),
             ("typing" | "typing_extensions", "Optional") => Some(Self::Optional),
             ("typing" | "typing_extensions", "Union") => Some(Self::Union),
             ("typing" | "typing_extensions", "NoReturn") => Some(Self::NoReturn),
@@ -2137,7 +2179,7 @@ impl<'db> TypeVarInstance<'db> {
     }
 
     #[allow(unused)]
-    pub(crate) fn constraints(self, db: &'db dyn Db) -> Option<&[Type<'db>]> {
+    pub(crate) fn constraints(self, db: &'db dyn Db) -> Option<&'db [Type<'db>]> {
         if let Some(TypeVarBoundOrConstraints::Constraints(tuple)) = self.bound_or_constraints(db) {
             Some(tuple.elements(db))
         } else {
@@ -2510,14 +2552,6 @@ impl Truthiness {
         matches!(self, Truthiness::Ambiguous)
     }
 
-    const fn is_always_false(self) -> bool {
-        matches!(self, Truthiness::AlwaysFalse)
-    }
-
-    const fn is_always_true(self) -> bool {
-        matches!(self, Truthiness::AlwaysTrue)
-    }
-
     const fn negate(self) -> Self {
         match self {
             Self::AlwaysTrue => Self::AlwaysFalse,
@@ -2626,13 +2660,15 @@ pub enum KnownFunction {
     ConstraintFunction(KnownConstraintFunction),
     /// `builtins.reveal_type`, `typing.reveal_type` or `typing_extensions.reveal_type`
     RevealType,
+    /// `builtins.len`
+    Len,
 }
 
 impl KnownFunction {
     pub fn constraint_function(self) -> Option<KnownConstraintFunction> {
         match self {
             Self::ConstraintFunction(f) => Some(f),
-            Self::RevealType => None,
+            Self::RevealType | Self::Len => None,
         }
     }
 
@@ -2649,6 +2685,7 @@ impl KnownFunction {
             "issubclass" if definition.is_builtin_definition(db) => Some(
                 KnownFunction::ConstraintFunction(KnownConstraintFunction::IsSubclass),
             ),
+            "len" if definition.is_builtin_definition(db) => Some(KnownFunction::Len),
             _ => None,
         }
     }
@@ -2689,7 +2726,7 @@ impl<'db> Class<'db> {
     ///
     /// Were this not a salsa query, then the calling query
     /// would depend on the class's AST and rerun for every change in that file.
-    fn explicit_bases(self, db: &'db dyn Db) -> &[Type<'db>] {
+    fn explicit_bases(self, db: &'db dyn Db) -> &'db [Type<'db>] {
         self.explicit_bases_query(db)
     }
 
@@ -2758,7 +2795,11 @@ impl<'db> Class<'db> {
     pub fn is_subclass_of(self, db: &'db dyn Db, other: Class) -> bool {
         // `is_subclass_of` is checking the subtype relation, in which gradual types do not
         // participate, so we should not return `True` if we find `Any/Unknown` in the MRO.
-        self.iter_mro(db).contains(&ClassBase::Class(other))
+        self.is_subclass_of_base(db, other)
+    }
+
+    fn is_subclass_of_base(self, db: &'db dyn Db, other: impl Into<ClassBase<'db>>) -> bool {
+        self.iter_mro(db).contains(&other.into())
     }
 
     /// Return the explicit `metaclass` of this class, if one is defined.
@@ -3099,8 +3140,9 @@ pub struct StringLiteralType<'db> {
 }
 
 impl<'db> StringLiteralType<'db> {
-    pub fn len(&self, db: &'db dyn Db) -> usize {
-        self.value(db).len()
+    /// The length of the string, as would be returned by Python's `len()`.
+    pub fn python_len(&self, db: &'db dyn Db) -> usize {
+        self.value(db).chars().count()
     }
 }
 
@@ -3110,6 +3152,12 @@ pub struct BytesLiteralType<'db> {
     value: Box<[u8]>,
 }
 
+impl<'db> BytesLiteralType<'db> {
+    pub fn python_len(&self, db: &'db dyn Db) -> usize {
+        self.value(db).len()
+    }
+}
+
 #[salsa::interned]
 pub struct SliceLiteralType<'db> {
     start: Option<i32>,
@@ -3117,7 +3165,7 @@ pub struct SliceLiteralType<'db> {
     step: Option<i32>,
 }
 
-impl<'db> SliceLiteralType<'db> {
+impl SliceLiteralType<'_> {
     fn as_tuple(self, db: &dyn Db) -> (Option<i32>, Option<i32>, Option<i32>) {
         (self.start(db), self.stop(db), self.step(db))
     }
@@ -3129,6 +3177,23 @@ pub struct TupleType<'db> {
 }
 
 impl<'db> TupleType<'db> {
+    pub fn from_elements<T: Into<Type<'db>>>(
+        db: &'db dyn Db,
+        types: impl IntoIterator<Item = T>,
+    ) -> Type<'db> {
+        let mut elements = vec![];
+
+        for ty in types {
+            let ty = ty.into();
+            if ty.is_never() {
+                return Type::Never;
+            }
+            elements.push(ty);
+        }
+
+        Type::Tuple(Self::new(db, elements.into_boxed_slice()))
+    }
+
     pub fn get(&self, db: &'db dyn Db, index: usize) -> Option<Type<'db>> {
         self.elements(db).get(index).copied()
     }
@@ -3146,46 +3211,20 @@ static_assertions::assert_eq_size!(Type, [u8; 16]);
 #[cfg(test)]
 pub(crate) mod tests {
     use super::*;
-    use crate::db::tests::TestDb;
-    use crate::program::{Program, SearchPathSettings};
-    use crate::python_version::PythonVersion;
+    use crate::db::tests::{setup_db, TestDb, TestDbBuilder};
     use crate::stdlib::typing_symbol;
-    use crate::ProgramSettings;
+    use crate::PythonVersion;
     use ruff_db::files::system_path_to_file;
     use ruff_db::parsed::parsed_module;
-    use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
+    use ruff_db::system::DbWithTestSystem;
     use ruff_db::testing::assert_function_query_was_not_run;
     use ruff_python_ast as ast;
     use test_case::test_case;
 
-    pub(crate) fn setup_db_with_python_version(python_version: PythonVersion) -> TestDb {
-        let db = TestDb::new();
-
-        let src_root = SystemPathBuf::from("/src");
-        db.memory_file_system()
-            .create_directory_all(&src_root)
-            .unwrap();
-
-        Program::from_settings(
-            &db,
-            &ProgramSettings {
-                target_version: python_version,
-                search_paths: SearchPathSettings::new(src_root),
-            },
-        )
-        .expect("Valid search path settings");
-
-        db
-    }
-
-    pub(crate) fn setup_db() -> TestDb {
-        setup_db_with_python_version(PythonVersion::default())
-    }
-
     /// A test representation of a type that can be transformed unambiguously into a real Type,
     /// given a db.
-    #[derive(Debug, Clone)]
-    enum Ty {
+    #[derive(Debug, Clone, PartialEq)]
+    pub(crate) enum Ty {
         Never,
         Unknown,
         None,
@@ -3209,7 +3248,7 @@ pub(crate) mod tests {
     }
 
     impl Ty {
-        fn into_type(self, db: &TestDb) -> Type<'_> {
+        pub(crate) fn into_type(self, db: &TestDb) -> Type<'_> {
             match self {
                 Ty::Never => Type::Never,
                 Ty::Unknown => Type::Unknown,
@@ -3240,13 +3279,21 @@ pub(crate) mod tests {
                     builder.build()
                 }
                 Ty::Tuple(tys) => {
-                    let elements: Vec<Type> = tys.into_iter().map(|ty| ty.into_type(db)).collect();
-                    Type::tuple(db, &elements)
+                    let elements = tys.into_iter().map(|ty| ty.into_type(db));
+                    Type::tuple(db, elements)
                 }
             }
         }
     }
 
+    #[test_case(Ty::Tuple(vec![Ty::Never]))]
+    #[test_case(Ty::Tuple(vec![Ty::BuiltinInstance("str"), Ty::Never, Ty::BuiltinInstance("int")]))]
+    #[test_case(Ty::Tuple(vec![Ty::Tuple(vec![Ty::Never])]))]
+    fn tuple_containing_never_simplifies_to_never(ty: Ty) {
+        let db = setup_db();
+        assert_eq!(ty.into_type(&db), Type::Never);
+    }
+
     #[test_case(Ty::BuiltinInstance("str"), Ty::BuiltinInstance("object"))]
     #[test_case(Ty::BuiltinInstance("int"), Ty::BuiltinInstance("object"))]
     #[test_case(Ty::Unknown, Ty::IntLiteral(1))]
@@ -3339,7 +3386,9 @@ pub(crate) mod tests {
     }
 
     #[test_case(Ty::BuiltinInstance("object"), Ty::BuiltinInstance("int"))]
+    #[test_case(Ty::Unknown, Ty::Unknown)]
     #[test_case(Ty::Unknown, Ty::IntLiteral(1))]
+    #[test_case(Ty::Any, Ty::Any)]
     #[test_case(Ty::Any, Ty::IntLiteral(1))]
     #[test_case(Ty::IntLiteral(1), Ty::Unknown)]
     #[test_case(Ty::IntLiteral(1), Ty::Any)]
@@ -3360,6 +3409,7 @@ pub(crate) mod tests {
     #[test_case(Ty::IntLiteral(1), Ty::Intersection{pos: vec![Ty::BuiltinInstance("int")], neg: vec![Ty::IntLiteral(1)]})]
     #[test_case(Ty::BuiltinClassLiteral("int"), Ty::BuiltinClassLiteral("object"))]
     #[test_case(Ty::BuiltinInstance("int"), Ty::BuiltinClassLiteral("int"))]
+    #[test_case(Ty::TypingInstance("_SpecialForm"), Ty::TypingLiteral)]
     fn is_not_subtype_of(from: Ty, to: Ty) {
         let db = setup_db();
         assert!(!from.into_type(&db).is_subtype_of(&db, to.into_type(&db)));
@@ -3446,6 +3496,18 @@ pub(crate) mod tests {
         assert!(from.into_type(&db).is_equivalent_to(&db, to.into_type(&db)));
     }
 
+    #[test_case(Ty::Any, Ty::Any)]
+    #[test_case(Ty::Any, Ty::None)]
+    #[test_case(Ty::Unknown, Ty::Unknown)]
+    #[test_case(Ty::Todo, Ty::Todo)]
+    #[test_case(Ty::Union(vec![Ty::IntLiteral(1), Ty::IntLiteral(2)]), Ty::Union(vec![Ty::IntLiteral(1), Ty::IntLiteral(0)]))]
+    #[test_case(Ty::Union(vec![Ty::IntLiteral(1), Ty::IntLiteral(2)]), Ty::Union(vec![Ty::IntLiteral(1), Ty::IntLiteral(2), Ty::IntLiteral(3)]))]
+    fn is_not_equivalent_to(from: Ty, to: Ty) {
+        let db = setup_db();
+
+        assert!(!from.into_type(&db).is_equivalent_to(&db, to.into_type(&db)));
+    }
+
     #[test_case(Ty::Never, Ty::Never)]
     #[test_case(Ty::Never, Ty::None)]
     #[test_case(Ty::Never, Ty::BuiltinInstance("int"))]
@@ -3635,11 +3697,16 @@ pub(crate) mod tests {
         assert!(from.into_type(&db).is_singleton(&db));
     }
 
-    /// TODO: test documentation
+    /// Explicitly test for Python version <3.13 and >=3.13, to ensure that
+    /// the fallback to `typing_extensions` is working correctly.
+    /// See [`KnownClass::canonical_module`] for more information.
     #[test_case(PythonVersion::PY312)]
     #[test_case(PythonVersion::PY313)]
     fn no_default_type_is_singleton(python_version: PythonVersion) {
-        let db = setup_db_with_python_version(python_version);
+        let db = TestDbBuilder::new()
+            .with_python_version(python_version)
+            .build()
+            .unwrap();
 
         let no_default = Ty::KnownClassInstance(KnownClass::NoDefaultType).into_type(&db);
 
@@ -3684,6 +3751,41 @@ pub(crate) mod tests {
         assert!(!from.into_type(&db).is_singleton(&db));
     }
 
+    #[test_case(Ty::Never)]
+    #[test_case(Ty::None)]
+    #[test_case(Ty::IntLiteral(1))]
+    #[test_case(Ty::BooleanLiteral(true))]
+    #[test_case(Ty::StringLiteral("abc"))]
+    #[test_case(Ty::LiteralString)]
+    #[test_case(Ty::BytesLiteral("abc"))]
+    #[test_case(Ty::KnownClassInstance(KnownClass::Str))]
+    #[test_case(Ty::KnownClassInstance(KnownClass::Object))]
+    #[test_case(Ty::KnownClassInstance(KnownClass::Type))]
+    #[test_case(Ty::BuiltinClassLiteral("str"))]
+    #[test_case(Ty::TypingLiteral)]
+    #[test_case(Ty::Union(vec![Ty::KnownClassInstance(KnownClass::Str), Ty::None]))]
+    #[test_case(Ty::Intersection{pos: vec![Ty::KnownClassInstance(KnownClass::Str)], neg: vec![Ty::LiteralString]})]
+    #[test_case(Ty::Tuple(vec![]))]
+    #[test_case(Ty::Tuple(vec![Ty::KnownClassInstance(KnownClass::Int), Ty::KnownClassInstance(KnownClass::Object)]))]
+    fn is_fully_static(from: Ty) {
+        let db = setup_db();
+
+        assert!(from.into_type(&db).is_fully_static(&db));
+    }
+
+    #[test_case(Ty::Any)]
+    #[test_case(Ty::Unknown)]
+    #[test_case(Ty::Todo)]
+    #[test_case(Ty::Union(vec![Ty::Any, Ty::KnownClassInstance(KnownClass::Str)]))]
+    #[test_case(Ty::Union(vec![Ty::KnownClassInstance(KnownClass::Str), Ty::Unknown]))]
+    #[test_case(Ty::Intersection{pos: vec![Ty::Any], neg: vec![Ty::LiteralString]})]
+    #[test_case(Ty::Tuple(vec![Ty::KnownClassInstance(KnownClass::Int), Ty::Any]))]
+    fn is_not_fully_static(from: Ty) {
+        let db = setup_db();
+
+        assert!(!from.into_type(&db).is_fully_static(&db));
+    }
+
     #[test_case(Ty::IntLiteral(1); "is_int_literal_truthy")]
     #[test_case(Ty::IntLiteral(-1))]
     #[test_case(Ty::StringLiteral("foo"))]
@@ -3738,7 +3840,10 @@ pub(crate) mod tests {
 
     #[test]
     fn typing_vs_typeshed_no_default() {
-        let db = setup_db();
+        let db = TestDbBuilder::new()
+            .with_python_version(PythonVersion::PY313)
+            .build()
+            .unwrap();
 
         let typing_no_default = typing_symbol(&db, "NoDefault").expect_type();
         let typing_extensions_no_default = typing_extensions_symbol(&db, "NoDefault").expect_type();
@@ -3858,19 +3963,6 @@ pub(crate) mod tests {
         let todo3 = todo_type!();
         let todo4 = todo_type!();
 
-        assert!(todo1.is_equivalent_to(&db, todo2));
-        assert!(todo3.is_equivalent_to(&db, todo4));
-        assert!(todo1.is_equivalent_to(&db, todo3));
-
-        assert!(todo1.is_subtype_of(&db, todo2));
-        assert!(todo2.is_subtype_of(&db, todo1));
-
-        assert!(todo3.is_subtype_of(&db, todo4));
-        assert!(todo4.is_subtype_of(&db, todo3));
-
-        assert!(todo1.is_subtype_of(&db, todo3));
-        assert!(todo3.is_subtype_of(&db, todo1));
-
         let int = KnownClass::Int.to_instance(&db);
 
         assert!(int.is_assignable_to(&db, todo1));

crates/red_knot_python_semantic/src/types/builder.rs

@@ -73,7 +73,8 @@ impl<'db> UnionBuilder<'db> {
                         // supertype of bool. Therefore, we are done.
                         break;
                     }
-                    if ty.is_subtype_of(self.db, *element) {
+
+                    if ty.is_same_gradual_form(*element) || ty.is_subtype_of(self.db, *element) {
                         return self;
                     } else if element.is_subtype_of(self.db, ty) {
                         to_remove.push(index);
@@ -259,7 +260,9 @@ impl<'db> InnerIntersectionBuilder<'db> {
             let mut to_remove = SmallVec::<[usize; 1]>::new();
             for (index, existing_positive) in self.positive.iter().enumerate() {
                 // S & T = S    if S <: T
-                if existing_positive.is_subtype_of(db, new_positive) {
+                if existing_positive.is_subtype_of(db, new_positive)
+                    || existing_positive.is_same_gradual_form(new_positive)
+                {
                     return;
                 }
                 // same rule, reverse order
@@ -375,36 +378,14 @@ impl<'db> InnerIntersectionBuilder<'db> {
 #[cfg(test)]
 mod tests {
     use super::{IntersectionBuilder, IntersectionType, Type, UnionType};
-    use crate::db::tests::TestDb;
-    use crate::program::{Program, SearchPathSettings};
-    use crate::python_version::PythonVersion;
-    use crate::stdlib::typing_symbol;
+
+    use crate::db::tests::{setup_db, TestDb};
     use crate::types::{global_symbol, todo_type, KnownClass, UnionBuilder};
-    use crate::ProgramSettings;
+
     use ruff_db::files::system_path_to_file;
-    use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
+    use ruff_db::system::DbWithTestSystem;
     use test_case::test_case;
 
-    fn setup_db() -> TestDb {
-        let db = TestDb::new();
-
-        let src_root = SystemPathBuf::from("/src");
-        db.memory_file_system()
-            .create_directory_all(&src_root)
-            .unwrap();
-
-        Program::from_settings(
-            &db,
-            &ProgramSettings {
-                target_version: PythonVersion::default(),
-                search_paths: SearchPathSettings::new(src_root),
-            },
-        )
-        .expect("Valid search path settings");
-
-        db
-    }
-
     #[test]
     fn build_union() {
         let db = setup_db();
@@ -497,6 +478,17 @@ mod tests {
         assert_eq!(u1.expect_union().elements(&db), &[t1, t0]);
     }
 
+    #[test]
+    fn build_union_simplify_multiple_unknown() {
+        let db = setup_db();
+        let t0 = KnownClass::Str.to_instance(&db);
+        let t1 = Type::Unknown;
+
+        let u = UnionType::from_elements(&db, [t0, t1, t1]);
+
+        assert_eq!(u.expect_union().elements(&db), &[t0, t1]);
+    }
+
     #[test]
     fn build_union_subsume_multiple() {
         let db = setup_db();
@@ -604,6 +596,42 @@ mod tests {
         assert_eq!(ty, Type::Never);
     }
 
+    #[test]
+    fn build_intersection_simplify_multiple_unknown() {
+        let db = setup_db();
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::Unknown)
+            .add_positive(Type::Unknown)
+            .build();
+        assert_eq!(ty, Type::Unknown);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::Unknown)
+            .add_negative(Type::Unknown)
+            .build();
+        assert_eq!(ty, Type::Unknown);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_negative(Type::Unknown)
+            .add_negative(Type::Unknown)
+            .build();
+        assert_eq!(ty, Type::Unknown);
+
+        let ty = IntersectionBuilder::new(&db)
+            .add_positive(Type::Unknown)
+            .add_positive(Type::IntLiteral(0))
+            .add_negative(Type::Unknown)
+            .build();
+        assert_eq!(
+            ty,
+            IntersectionBuilder::new(&db)
+                .add_positive(Type::Unknown)
+                .add_positive(Type::IntLiteral(0))
+                .build()
+        );
+    }
+
     #[test]
     fn intersection_distributes_over_union() {
         let db = setup_db();
@@ -626,59 +654,85 @@ mod tests {
 
     #[test]
     fn intersection_negation_distributes_over_union() {
-        let db = setup_db();
-        let st = typing_symbol(&db, "Sized").expect_type().to_instance(&db);
-        let ht = typing_symbol(&db, "Hashable")
+        let mut db = setup_db();
+        db.write_dedented(
+            "/src/module.py",
+            r#"
+            class A: ...
+            class B: ...
+            "#,
+        )
+        .unwrap();
+        let module = ruff_db::files::system_path_to_file(&db, "/src/module.py").unwrap();
+
+        let a = global_symbol(&db, module, "A")
             .expect_type()
             .to_instance(&db);
-        // sh_t: Sized & Hashable
-        let sh_t = IntersectionBuilder::new(&db)
-            .add_positive(st)
-            .add_positive(ht)
+        let b = global_symbol(&db, module, "B")
+            .expect_type()
+            .to_instance(&db);
+
+        // intersection: A & B
+        let intersection = IntersectionBuilder::new(&db)
+            .add_positive(a)
+            .add_positive(b)
             .build()
             .expect_intersection();
-        assert_eq!(sh_t.pos_vec(&db), &[st, ht]);
-        assert_eq!(sh_t.neg_vec(&db), &[]);
+        assert_eq!(intersection.pos_vec(&db), &[a, b]);
+        assert_eq!(intersection.neg_vec(&db), &[]);
 
-        // ~sh_t => ~Sized | ~Hashable
-        let not_s_h_t = IntersectionBuilder::new(&db)
-            .add_negative(Type::Intersection(sh_t))
+        // ~intersection => ~A | ~B
+        let negated_intersection = IntersectionBuilder::new(&db)
+            .add_negative(Type::Intersection(intersection))
             .build()
             .expect_union();
 
-        // should have as elements: (~Sized),(~Hashable)
-        let not_st = st.negate(&db);
-        let not_ht = ht.negate(&db);
-        assert_eq!(not_s_h_t.elements(&db), &[not_st, not_ht]);
+        // should have as elements ~A and ~B
+        let not_a = a.negate(&db);
+        let not_b = b.negate(&db);
+        assert_eq!(negated_intersection.elements(&db), &[not_a, not_b]);
     }
 
     #[test]
     fn mixed_intersection_negation_distributes_over_union() {
-        let db = setup_db();
-        let it = KnownClass::Int.to_instance(&db);
-        let st = typing_symbol(&db, "Sized").expect_type().to_instance(&db);
-        let ht = typing_symbol(&db, "Hashable")
+        let mut db = setup_db();
+        db.write_dedented(
+            "/src/module.py",
+            r#"
+            class A: ...
+            class B: ...
+            "#,
+        )
+        .unwrap();
+        let module = ruff_db::files::system_path_to_file(&db, "/src/module.py").unwrap();
+
+        let a = global_symbol(&db, module, "A")
             .expect_type()
             .to_instance(&db);
-        // s_not_h_t: Sized & ~Hashable
-        let s_not_h_t = IntersectionBuilder::new(&db)
-            .add_positive(st)
-            .add_negative(ht)
+        let b = global_symbol(&db, module, "B")
+            .expect_type()
+            .to_instance(&db);
+        let int = KnownClass::Int.to_instance(&db);
+
+        // a_not_b: A & ~B
+        let a_not_b = IntersectionBuilder::new(&db)
+            .add_positive(a)
+            .add_negative(b)
             .build()
             .expect_intersection();
-        assert_eq!(s_not_h_t.pos_vec(&db), &[st]);
-        assert_eq!(s_not_h_t.neg_vec(&db), &[ht]);
+        assert_eq!(a_not_b.pos_vec(&db), &[a]);
+        assert_eq!(a_not_b.neg_vec(&db), &[b]);
 
-        // let's build int & ~(Sized & ~Hashable)
-        let tt = IntersectionBuilder::new(&db)
-            .add_positive(it)
-            .add_negative(Type::Intersection(s_not_h_t))
+        // let's build
+        //         int & ~(A & ~B)
+        //       = int & ~(A & ~B)
+        //       = int & (~A | B)
+        //       = (int & ~A) | (int & B)
+        let t = IntersectionBuilder::new(&db)
+            .add_positive(int)
+            .add_negative(Type::Intersection(a_not_b))
             .build();
-
-        // int & ~(Sized & ~Hashable)
-        // -> int & (~Sized | Hashable)
-        // -> (int & ~Sized) | (int & Hashable)
-        assert_eq!(tt.display(&db).to_string(), "int & ~Sized | int & Hashable");
+        assert_eq!(t.display(&db).to_string(), "int & ~A | int & B");
     }
 
     #[test]

crates/red_knot_python_semantic/src/types/display.rs

@@ -289,7 +289,7 @@ struct DisplayMaybeNegatedType<'db> {
     negated: bool,
 }
 
-impl<'db> Display for DisplayMaybeNegatedType<'db> {
+impl Display for DisplayMaybeNegatedType<'_> {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         if self.negated {
             f.write_str("~")?;
@@ -319,7 +319,7 @@ pub(crate) struct DisplayTypeArray<'b, 'db> {
     db: &'db dyn Db,
 }
 
-impl<'db> Display for DisplayTypeArray<'_, 'db> {
+impl Display for DisplayTypeArray<'_, '_> {
     fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
         f.join(", ")
             .entries(self.types.iter().map(|ty| ty.display(self.db)))
@@ -357,31 +357,10 @@ impl Display for DisplayStringLiteralType<'_> {
 #[cfg(test)]
 mod tests {
     use ruff_db::files::system_path_to_file;
-    use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
+    use ruff_db::system::DbWithTestSystem;
 
-    use crate::db::tests::TestDb;
+    use crate::db::tests::setup_db;
     use crate::types::{global_symbol, SliceLiteralType, StringLiteralType, Type, UnionType};
-    use crate::{Program, ProgramSettings, PythonVersion, SearchPathSettings};
-
-    fn setup_db() -> TestDb {
-        let db = TestDb::new();
-
-        let src_root = SystemPathBuf::from("/src");
-        db.memory_file_system()
-            .create_directory_all(&src_root)
-            .unwrap();
-
-        Program::from_settings(
-            &db,
-            &ProgramSettings {
-                target_version: PythonVersion::default(),
-                search_paths: SearchPathSettings::new(src_root),
-            },
-        )
-        .expect("Valid search path settings");
-
-        db
-    }
 
     #[test]
     fn test_condense_literal_display_by_type() -> anyhow::Result<()> {

crates/red_knot_python_semantic/src/types/infer.rs

@@ -1660,7 +1660,7 @@ impl<'db> TypeInferenceBuilder<'db> {
         let value_ty = self.expression_ty(value);
         let name_ast_id = name.scoped_expression_id(self.db, self.scope());
 
-        let target_ty = match assignment.target() {
+        let mut target_ty = match assignment.target() {
             TargetKind::Sequence(unpack) => {
                 let unpacked = infer_unpack_types(self.db, unpack);
                 // Only copy the diagnostics if this is the first assignment to avoid duplicating the
@@ -1674,6 +1674,13 @@ impl<'db> TypeInferenceBuilder<'db> {
             TargetKind::Name => value_ty,
         };
 
+        if let Some(known_instance) = file_to_module(self.db, definition.file(self.db))
+            .as_ref()
+            .and_then(|module| KnownInstanceType::try_from_module_and_symbol(module, &name.id))
+        {
+            target_ty = Type::KnownInstance(known_instance);
+        }
+
         self.store_expression_type(name, target_ty);
         self.add_binding(name.into(), definition, target_ty);
     }
@@ -1893,12 +1900,11 @@ impl<'db> TypeInferenceBuilder<'db> {
             is_async: _,
         } = for_statement;
 
-        self.infer_standalone_expression(iter);
-
         // TODO more complex assignment targets
         if let ast::Expr::Name(name) = &**target {
             self.infer_definition(name);
         } else {
+            self.infer_standalone_expression(iter);
             self.infer_expression(target);
         }
         self.infer_body(body);
@@ -4537,7 +4543,7 @@ impl<'db> TypeInferenceBuilder<'db> {
                 if element_could_alter_type_of_whole_tuple(single_element, single_element_ty) {
                     todo_type!()
                 } else {
-                    Type::tuple(self.db, &[single_element_ty])
+                    Type::tuple(self.db, [single_element_ty])
                 }
             }
         }
@@ -4642,6 +4648,18 @@ impl<'db> TypeInferenceBuilder<'db> {
                 );
                 Type::Unknown
             }
+            KnownInstanceType::LiteralString => {
+                self.diagnostics.add(
+                    subscript.into(),
+                    "invalid-type-parameter",
+                    format_args!(
+                        "Type `{}` expected no type parameter. Did you mean to use `Literal[...]` instead?",
+                        known_instance.repr(self.db)
+                    ),
+                );
+                Type::Unknown
+            }
+            KnownInstanceType::Any => Type::Any,
         }
     }
 
@@ -5027,73 +5045,19 @@ fn perform_membership_test_comparison<'db>(
 
 #[cfg(test)]
 mod tests {
-    use anyhow::Context;
-
-    use crate::db::tests::TestDb;
-    use crate::program::{Program, SearchPathSettings};
-    use crate::python_version::{self, PythonVersion};
+    use crate::db::tests::{setup_db, TestDb, TestDbBuilder};
     use crate::semantic_index::definition::Definition;
     use crate::semantic_index::symbol::FileScopeId;
     use crate::semantic_index::{global_scope, semantic_index, symbol_table, use_def_map};
     use crate::types::check_types;
-    use crate::{HasTy, ProgramSettings, SemanticModel};
+    use crate::{HasTy, SemanticModel};
     use ruff_db::files::{system_path_to_file, File};
     use ruff_db::parsed::parsed_module;
-    use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
+    use ruff_db::system::DbWithTestSystem;
     use ruff_db::testing::assert_function_query_was_not_run;
-    use test_case::test_case;
 
     use super::*;
 
-    fn setup_db_with_python_version(python_version: PythonVersion) -> TestDb {
-        let db = TestDb::new();
-
-        let src_root = SystemPathBuf::from("/src");
-        db.memory_file_system()
-            .create_directory_all(&src_root)
-            .unwrap();
-
-        Program::from_settings(
-            &db,
-            &ProgramSettings {
-                target_version: python_version,
-                search_paths: SearchPathSettings::new(src_root),
-            },
-        )
-        .expect("Valid search path settings");
-
-        db
-    }
-
-    fn setup_db() -> TestDb {
-        setup_db_with_python_version(PythonVersion::default())
-    }
-
-    fn setup_db_with_custom_typeshed<'a>(
-        typeshed: &str,
-        files: impl IntoIterator<Item = (&'a str, &'a str)>,
-    ) -> anyhow::Result<TestDb> {
-        let mut db = TestDb::new();
-        let src_root = SystemPathBuf::from("/src");
-
-        db.write_files(files)
-            .context("Failed to write test files")?;
-
-        Program::from_settings(
-            &db,
-            &ProgramSettings {
-                target_version: PythonVersion::default(),
-                search_paths: SearchPathSettings {
-                    custom_typeshed: Some(SystemPathBuf::from(typeshed)),
-                    ..SearchPathSettings::new(src_root)
-                },
-            },
-        )
-        .context("Failed to create Program")?;
-
-        Ok(db)
-    }
-
     #[track_caller]
     fn assert_public_ty(db: &TestDb, file_name: &str, symbol_name: &str, expected: &str) {
         let file = system_path_to_file(db, file_name).expect("file to exist");
@@ -5340,10 +5304,9 @@ mod tests {
         Ok(())
     }
 
-    #[test_case(PythonVersion::PY39, "ellipsis")]
-    #[test_case(PythonVersion::PY310, "EllipsisType")]
-    fn ellipsis_type(version: PythonVersion, expected_type: &str) -> anyhow::Result<()> {
-        let mut db = setup_db_with_python_version(version);
+    #[test]
+    fn ellipsis_type() -> anyhow::Result<()> {
+        let mut db = setup_db();
 
         db.write_dedented(
             "src/a.py",
@@ -5352,7 +5315,8 @@ mod tests {
             ",
         )?;
 
-        assert_public_ty(&db, "src/a.py", "x", expected_type);
+        // TODO: sys.version_info
+        assert_public_ty(&db, "src/a.py", "x", "EllipsisType | ellipsis");
 
         Ok(())
     }
@@ -5488,17 +5452,15 @@ mod tests {
 
     #[test]
     fn builtin_symbol_custom_stdlib() -> anyhow::Result<()> {
-        let db = setup_db_with_custom_typeshed(
-            "/typeshed",
-            [
-                ("/src/a.py", "c = copyright"),
-                (
-                    "/typeshed/stdlib/builtins.pyi",
-                    "def copyright() -> None: ...",
-                ),
-                ("/typeshed/stdlib/VERSIONS", "builtins: 3.8-"),
-            ],
-        )?;
+        let db = TestDbBuilder::new()
+            .with_custom_typeshed("/typeshed")
+            .with_file("/src/a.py", "c = copyright")
+            .with_file(
+                "/typeshed/stdlib/builtins.pyi",
+                "def copyright() -> None: ...",
+            )
+            .with_file("/typeshed/stdlib/VERSIONS", "builtins: 3.8-")
+            .build()?;
 
         assert_public_ty(&db, "/src/a.py", "c", "Literal[copyright]");
 
@@ -5507,14 +5469,12 @@ mod tests {
 
     #[test]
     fn unknown_builtin_later_defined() -> anyhow::Result<()> {
-        let db = setup_db_with_custom_typeshed(
-            "/typeshed",
-            [
-                ("/src/a.py", "x = foo"),
-                ("/typeshed/stdlib/builtins.pyi", "foo = bar; bar = 1"),
-                ("/typeshed/stdlib/VERSIONS", "builtins: 3.8-"),
-            ],
-        )?;
+        let db = TestDbBuilder::new()
+            .with_custom_typeshed("/typeshed")
+            .with_file("/src/a.py", "x = foo")
+            .with_file("/typeshed/stdlib/builtins.pyi", "foo = bar; bar = 1")
+            .with_file("/typeshed/stdlib/VERSIONS", "builtins: 3.8-")
+            .build()?;
 
         assert_public_ty(&db, "/src/a.py", "x", "Unknown");
 

crates/red_knot_python_semantic/src/types/mro.rs

@@ -374,10 +374,12 @@ impl<'db> ClassBase<'db> {
                 KnownInstanceType::TypeVar(_)
                 | KnownInstanceType::TypeAliasType(_)
                 | KnownInstanceType::Literal
+                | KnownInstanceType::LiteralString
                 | KnownInstanceType::Union
                 | KnownInstanceType::NoReturn
                 | KnownInstanceType::Never
                 | KnownInstanceType::Optional => None,
+                KnownInstanceType::Any => Some(Self::Any),
             },
         }
     }
@@ -405,6 +407,12 @@ impl<'db> ClassBase<'db> {
     }
 }
 
+impl<'db> From<Class<'db>> for ClassBase<'db> {
+    fn from(value: Class<'db>) -> Self {
+        ClassBase::Class(value)
+    }
+}
+
 impl<'db> From<ClassBase<'db>> for Type<'db> {
     fn from(value: ClassBase<'db>) -> Self {
         match value {

crates/red_knot_python_semantic/src/types/narrow.rs

@@ -54,6 +54,7 @@ pub(crate) fn narrowing_constraint<'db>(
     }
 }
 
+#[allow(clippy::ref_option)]
 #[salsa::tracked(return_ref)]
 fn all_narrowing_constraints_for_pattern<'db>(
     db: &'db dyn Db,
@@ -62,6 +63,7 @@ fn all_narrowing_constraints_for_pattern<'db>(
     NarrowingConstraintsBuilder::new(db, ConstraintNode::Pattern(pattern), true).finish()
 }
 
+#[allow(clippy::ref_option)]
 #[salsa::tracked(return_ref)]
 fn all_narrowing_constraints_for_expression<'db>(
     db: &'db dyn Db,
@@ -70,6 +72,7 @@ fn all_narrowing_constraints_for_expression<'db>(
     NarrowingConstraintsBuilder::new(db, ConstraintNode::Expression(expression), true).finish()
 }
 
+#[allow(clippy::ref_option)]
 #[salsa::tracked(return_ref)]
 fn all_negative_narrowing_constraints_for_expression<'db>(
     db: &'db dyn Db,
@@ -291,8 +294,15 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
             .chain(comparators)
             .tuple_windows::<(&ruff_python_ast::Expr, &ruff_python_ast::Expr)>();
         let mut constraints = NarrowingConstraints::default();
+
+        let mut last_rhs_ty: Option<Type> = None;
+
         for (op, (left, right)) in std::iter::zip(&**ops, comparator_tuples) {
+            let lhs_ty = last_rhs_ty.unwrap_or_else(|| {
+                inference.expression_ty(left.scoped_expression_id(self.db, scope))
+            });
             let rhs_ty = inference.expression_ty(right.scoped_expression_id(self.db, scope));
+            last_rhs_ty = Some(rhs_ty);
 
             match left {
                 ast::Expr::Name(ast::ExprName {
@@ -327,6 +337,9 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
                                 constraints.insert(symbol, ty);
                             }
                         }
+                        ast::CmpOp::Eq if lhs_ty.is_literal_string() => {
+                            constraints.insert(symbol, rhs_ty);
+                        }
                         _ => {
                             // TODO other comparison types
                         }
@@ -385,46 +398,58 @@ impl<'db> NarrowingConstraintsBuilder<'db> {
         let scope = self.scope();
         let inference = infer_expression_types(self.db, expression);
 
+        let callable_ty =
+            inference.expression_ty(expr_call.func.scoped_expression_id(self.db, scope));
+
         // TODO: add support for PEP 604 union types on the right hand side of `isinstance`
         // and `issubclass`, for example `isinstance(x, str | (int | float))`.
-        match inference
-            .expression_ty(expr_call.func.scoped_expression_id(self.db, scope))
-            .into_function_literal()
-            .and_then(|f| f.known(self.db))
-            .and_then(KnownFunction::constraint_function)
-        {
-            Some(function) if expr_call.arguments.keywords.is_empty() => {
-                if let [ast::Expr::Name(ast::ExprName { id, .. }), class_info] =
+        match callable_ty {
+            Type::FunctionLiteral(function_type) if expr_call.arguments.keywords.is_empty() => {
+                let function = function_type
+                    .known(self.db)
+                    .and_then(KnownFunction::constraint_function)?;
+
+                let [ast::Expr::Name(ast::ExprName { id, .. }), class_info] =
                     &*expr_call.arguments.args
-                {
-                    let symbol = self.symbols().symbol_id_by_name(id).unwrap();
+                else {
+                    return None;
+                };
 
-                    let class_info_ty =
-                        inference.expression_ty(class_info.scoped_expression_id(self.db, scope));
+                let symbol = self.symbols().symbol_id_by_name(id).unwrap();
 
-                    let to_constraint = match function {
-                        KnownConstraintFunction::IsInstance => {
-                            |class_literal: ClassLiteralType<'db>| {
-                                Type::instance(class_literal.class)
-                            }
+                let class_info_ty =
+                    inference.expression_ty(class_info.scoped_expression_id(self.db, scope));
+
+                let to_constraint = match function {
+                    KnownConstraintFunction::IsInstance => {
+                        |class_literal: ClassLiteralType<'db>| Type::instance(class_literal.class)
+                    }
+                    KnownConstraintFunction::IsSubclass => {
+                        |class_literal: ClassLiteralType<'db>| {
+                            Type::subclass_of(class_literal.class)
                         }
-                        KnownConstraintFunction::IsSubclass => {
-                            |class_literal: ClassLiteralType<'db>| {
-                                Type::subclass_of(class_literal.class)
-                            }
-                        }
-                    };
+                    }
+                };
 
-                    generate_classinfo_constraint(self.db, &class_info_ty, to_constraint).map(
-                        |constraint| {
-                            let mut constraints = NarrowingConstraints::default();
-                            constraints.insert(symbol, constraint.negate_if(self.db, !is_positive));
-                            constraints
-                        },
-                    )
-                } else {
-                    None
-                }
+                generate_classinfo_constraint(self.db, &class_info_ty, to_constraint).map(
+                    |constraint| {
+                        let mut constraints = NarrowingConstraints::default();
+                        constraints.insert(symbol, constraint.negate_if(self.db, !is_positive));
+                        constraints
+                    },
+                )
+            }
+            // for the expression `bool(E)`, we further narrow the type based on `E`
+            Type::ClassLiteral(class_type)
+                if expr_call.arguments.args.len() == 1
+                    && expr_call.arguments.keywords.is_empty()
+                    && class_type.class.is_known(self.db, KnownClass::Bool) =>
+            {
+                self.evaluate_expression_node_constraint(
+                    &expr_call.arguments.args[0],
+                    expression,
+                    is_positive,
+                )
             }
             _ => None,
         }

crates/red_knot_python_semantic/src/types/property_tests.rs

@@ -0,0 +1,243 @@
+//! This module contains quickcheck-based property tests for `Type`s.
+//!
+//! These tests are disabled by default, as they are non-deterministic and slow. You can
+//! run them explicitly using:
+//!
+//! ```sh
+//! cargo test -p red_knot_python_semantic -- --ignored types::property_tests::stable
+//! ```
+//!
+//! The number of tests (default: 100) can be controlled by setting the `QUICKCHECK_TESTS`
+//! environment variable. For example:
+//!
+//! ```sh
+//! QUICKCHECK_TESTS=10000 cargo test …
+//! ```
+//!
+//! If you want to run these tests for a longer period of time, it's advisable to run them
+//! in release mode. As some tests are slower than others, it's advisable to run them in a
+//! loop until they fail:
+//!
+//! ```sh
+//! export QUICKCHECK_TESTS=100000
+//! while cargo test --release -p red_knot_python_semantic -- \
+//!   --ignored types::property_tests::stable; do :; done
+//! ```
+
+use std::sync::{Arc, Mutex, MutexGuard, OnceLock};
+
+use super::tests::Ty;
+use crate::db::tests::{setup_db, TestDb};
+use crate::types::KnownClass;
+use quickcheck::{Arbitrary, Gen};
+
+fn arbitrary_core_type(g: &mut Gen) -> Ty {
+    // We could select a random integer here, but this would make it much less
+    // likely to explore interesting edge cases:
+    let int_lit = Ty::IntLiteral(*g.choose(&[-2, -1, 0, 1, 2]).unwrap());
+    let bool_lit = Ty::BooleanLiteral(bool::arbitrary(g));
+    g.choose(&[
+        Ty::Never,
+        Ty::Unknown,
+        Ty::None,
+        Ty::Any,
+        int_lit,
+        bool_lit,
+        Ty::StringLiteral(""),
+        Ty::StringLiteral("a"),
+        Ty::LiteralString,
+        Ty::BytesLiteral(""),
+        Ty::BytesLiteral("\x00"),
+        Ty::KnownClassInstance(KnownClass::Object),
+        Ty::KnownClassInstance(KnownClass::Str),
+        Ty::KnownClassInstance(KnownClass::Int),
+        Ty::KnownClassInstance(KnownClass::Bool),
+        Ty::KnownClassInstance(KnownClass::List),
+        Ty::KnownClassInstance(KnownClass::Tuple),
+        Ty::KnownClassInstance(KnownClass::FunctionType),
+        Ty::KnownClassInstance(KnownClass::SpecialForm),
+        Ty::KnownClassInstance(KnownClass::TypeVar),
+        Ty::KnownClassInstance(KnownClass::TypeAliasType),
+        Ty::KnownClassInstance(KnownClass::NoDefaultType),
+        Ty::TypingLiteral,
+        Ty::BuiltinClassLiteral("str"),
+        Ty::BuiltinClassLiteral("int"),
+        Ty::BuiltinClassLiteral("bool"),
+        Ty::BuiltinClassLiteral("object"),
+    ])
+    .unwrap()
+    .clone()
+}
+
+/// Constructs an arbitrary type.
+///
+/// The `size` parameter controls the depth of the type tree. For example,
+/// a simple type like `int` has a size of 0, `Union[int, str]` has a size
+/// of 1, `tuple[int, Union[str, bytes]]` has a size of 2, etc.
+fn arbitrary_type(g: &mut Gen, size: u32) -> Ty {
+    if size == 0 {
+        arbitrary_core_type(g)
+    } else {
+        match u32::arbitrary(g) % 4 {
+            0 => arbitrary_core_type(g),
+            1 => Ty::Union(
+                (0..*g.choose(&[2, 3]).unwrap())
+                    .map(|_| arbitrary_type(g, size - 1))
+                    .collect(),
+            ),
+            2 => Ty::Tuple(
+                (0..*g.choose(&[0, 1, 2]).unwrap())
+                    .map(|_| arbitrary_type(g, size - 1))
+                    .collect(),
+            ),
+            3 => Ty::Intersection {
+                pos: (0..*g.choose(&[0, 1, 2]).unwrap())
+                    .map(|_| arbitrary_type(g, size - 1))
+                    .collect(),
+                neg: (0..*g.choose(&[0, 1, 2]).unwrap())
+                    .map(|_| arbitrary_type(g, size - 1))
+                    .collect(),
+            },
+            _ => unreachable!(),
+        }
+    }
+}
+
+impl Arbitrary for Ty {
+    fn arbitrary(g: &mut Gen) -> Ty {
+        const MAX_SIZE: u32 = 2;
+        arbitrary_type(g, MAX_SIZE)
+    }
+
+    fn shrink(&self) -> Box<dyn Iterator<Item = Self>> {
+        // This is incredibly naive. We can do much better here by
+        // trying various subsets of the elements in unions, tuples,
+        // and intersections. For now, we only try to shrink by
+        // reducing unions/tuples/intersections to a single element.
+        match self.clone() {
+            Ty::Union(types) => Box::new(types.into_iter()),
+            Ty::Tuple(types) => Box::new(types.into_iter()),
+            Ty::Intersection { pos, neg } => Box::new(pos.into_iter().chain(neg)),
+            _ => Box::new(std::iter::empty()),
+        }
+    }
+}
+
+static CACHED_DB: OnceLock<Arc<Mutex<TestDb>>> = OnceLock::new();
+
+fn get_cached_db() -> MutexGuard<'static, TestDb> {
+    let db = CACHED_DB.get_or_init(|| Arc::new(Mutex::new(setup_db())));
+    db.lock().unwrap()
+}
+
+/// A macro to define a property test for types.
+///
+/// The `$test_name` identifier specifies the name of the test function. The `$db` identifier
+/// is used to refer to the salsa database in the property to be tested. The actual property is
+/// specified using the syntax:
+///
+///     forall types t1, t2, ..., tn . <property>`
+///
+/// where `t1`, `t2`, ..., `tn` are identifiers that represent arbitrary types, and `<property>`
+/// is an expression using these identifiers.
+///
+macro_rules! type_property_test {
+    ($test_name:ident, $db:ident, forall types $($types:ident),+ . $property:expr) => {
+        #[quickcheck_macros::quickcheck]
+        #[ignore]
+        fn $test_name($($types: crate::types::tests::Ty),+) -> bool {
+            let db_cached = super::get_cached_db();
+            let $db = &*db_cached;
+            $(let $types = $types.into_type($db);)+
+
+            $property
+        }
+    };
+    // A property test with a logical implication.
+    ($name:ident, $db:ident, forall types $($types:ident),+ . $premise:expr => $conclusion:expr) => {
+        type_property_test!($name, $db, forall types $($types),+ . !($premise) || ($conclusion));
+    };
+}
+
+mod stable {
+    // `T` is equivalent to itself.
+    type_property_test!(
+        equivalent_to_is_reflexive, db,
+        forall types t. t.is_equivalent_to(db, t)
+    );
+
+    // `T` is a subtype of itself.
+    type_property_test!(
+        subtype_of_is_reflexive, db,
+        forall types t. t.is_subtype_of(db, t)
+    );
+
+    // `S <: T` and `T <: U` implies that `S <: U`.
+    type_property_test!(
+        subtype_of_is_transitive, db,
+        forall types s, t, u. s.is_subtype_of(db, t) && t.is_subtype_of(db, u) => s.is_subtype_of(db, u)
+    );
+
+    // `T` is not disjoint from itself, unless `T` is `Never`.
+    type_property_test!(
+        disjoint_from_is_irreflexive, db,
+        forall types t. t.is_disjoint_from(db, t) => t.is_never()
+    );
+
+    // `S` is disjoint from `T` implies that `T` is disjoint from `S`.
+    type_property_test!(
+        disjoint_from_is_symmetric, db,
+        forall types s, t. s.is_disjoint_from(db, t) == t.is_disjoint_from(db, s)
+    );
+
+    // `S <: T` implies that `S` is not disjoint from `T`, unless `S` is `Never`.
+    type_property_test!(
+        subtype_of_implies_not_disjoint_from, db,
+        forall types s, t. s.is_subtype_of(db, t) => !s.is_disjoint_from(db, t) || s.is_never()
+    );
+
+    // `T` can be assigned to itself.
+    type_property_test!(
+        assignable_to_is_reflexive, db,
+        forall types t. t.is_assignable_to(db, t)
+    );
+
+    // `S <: T` implies that `S` can be assigned to `T`.
+    type_property_test!(
+        subtype_of_implies_assignable_to, db,
+        forall types s, t. s.is_subtype_of(db, t) => s.is_assignable_to(db, t)
+    );
+
+    // If `T` is a singleton, it is also single-valued.
+    type_property_test!(
+        singleton_implies_single_valued, db,
+        forall types t. t.is_singleton(db) => t.is_single_valued(db)
+    );
+
+    // If `T` contains a gradual form, it should not participate in subtyping
+    type_property_test!(
+        non_fully_static_types_do_not_participate_in_subtyping, db,
+        forall types s, t. !s.is_fully_static(db) => !s.is_subtype_of(db, t) && !t.is_subtype_of(db, s)
+    );
+}
+
+/// This module contains property tests that currently lead to many false positives.
+///
+/// The reason for this is our insufficient understanding of equivalence of types. For
+/// example, we currently consider `int | str` and `str | int` to be different types.
+/// Similar issues exist for intersection types. Once this is resolved, we can move these
+/// tests to the `stable` section. In the meantime, it can still be useful to run these
+/// tests (using [`types::property_tests::flaky`]), to see if there are any new obvious bugs.
+mod flaky {
+    // `S <: T` and `T <: S` implies that `S` is equivalent to `T`.
+    type_property_test!(
+        subtype_of_is_antisymmetric, db,
+        forall types s, t. s.is_subtype_of(db, t) && t.is_subtype_of(db, s) => s.is_equivalent_to(db, t)
+    );
+
+    // Negating `T` twice is equivalent to `T`.
+    type_property_test!(
+        double_negation_is_identity, db,
+        forall types t. t.negate(db).negate(db).is_equivalent_to(db, t)
+    );
+}

crates/red_knot_python_semantic/src/types/signatures.rs

@@ -189,32 +189,9 @@ impl<'db> Parameter<'db> {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::db::tests::TestDb;
-    use crate::program::{Program, SearchPathSettings};
-    use crate::python_version::PythonVersion;
+    use crate::db::tests::{setup_db, TestDb};
     use crate::types::{global_symbol, FunctionType};
-    use crate::ProgramSettings;
-    use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
-
-    pub(crate) fn setup_db() -> TestDb {
-        let db = TestDb::new();
-
-        let src_root = SystemPathBuf::from("/src");
-        db.memory_file_system()
-            .create_directory_all(&src_root)
-            .unwrap();
-
-        Program::from_settings(
-            &db,
-            &ProgramSettings {
-                target_version: PythonVersion::default(),
-                search_paths: SearchPathSettings::new(src_root),
-            },
-        )
-        .expect("Valid search path settings");
-
-        db
-    }
+    use ruff_db::system::DbWithTestSystem;
 
     #[track_caller]
     fn get_function_f<'db>(db: &'db TestDb, file: &'static str) -> FunctionType<'db> {

crates/red_knot_python_semantic/src/types/unpacker.rs

@@ -95,7 +95,8 @@ impl<'db> Unpacker<'db> {
                     // there would be a cost and it's not clear that it's worth it.
                     let value_ty = Type::tuple(
                         self.db,
-                        &vec![Type::LiteralString; string_literal_ty.len(self.db)],
+                        std::iter::repeat(Type::LiteralString)
+                            .take(string_literal_ty.python_len(self.db)),
                     );
                     self.unpack(target, value_ty, scope);
                 }

crates/red_knot_python_semantic/tests/mdtest.rs

@@ -1,7 +1,6 @@
-use std::ffi::OsStr;
-use std::path::Path;
-
+use camino::Utf8Path;
 use dir_test::{dir_test, Fixture};
+use std::path::Path;
 
 /// See `crates/red_knot_test/README.md` for documentation on these tests.
 #[dir_test(
@@ -10,16 +9,46 @@ use dir_test::{dir_test, Fixture};
 )]
 #[allow(clippy::needless_pass_by_value)]
 fn mdtest(fixture: Fixture<&str>) {
-    let fixture_path = Path::new(fixture.path());
+    let fixture_path = Utf8Path::new(fixture.path());
     let crate_dir = Path::new(env!("CARGO_MANIFEST_DIR"));
-    let workspace_root = crate_dir.parent().and_then(Path::parent).unwrap();
+    let workspace_root = crate_dir.ancestors().nth(2).unwrap();
 
-    let long_title = fixture_path
-        .strip_prefix(workspace_root)
-        .unwrap()
-        .to_str()
-        .unwrap();
-    let short_title = fixture_path.file_name().and_then(OsStr::to_str).unwrap();
+    let long_title = fixture_path.strip_prefix(workspace_root).unwrap();
+    let short_title = fixture_path.file_name().unwrap();
 
-    red_knot_test::run(fixture_path, long_title, short_title);
+    let test_name = test_name("mdtest", fixture_path);
+
+    red_knot_test::run(fixture_path, long_title.as_str(), short_title, &test_name);
+}
+
+/// Constructs the test name used for individual markdown files
+///
+/// This code is copied from <https://github.com/fe-lang/dir-test/blob/1c0f41c480a3490bc2653a043ff6e3f8085a1f47/macros/src/lib.rs#L104-L138>
+/// and should be updated if they diverge
+fn test_name(test_func_name: &str, fixture_path: &Utf8Path) -> String {
+    assert!(fixture_path.is_file());
+
+    let dir_path = format!("{}/resources/mdtest", std::env!("CARGO_MANIFEST_DIR"));
+    let rel_path = fixture_path.strip_prefix(dir_path).unwrap();
+    assert!(rel_path.is_relative());
+
+    let mut test_name = test_func_name.to_owned();
+    test_name.push_str("__");
+
+    for component in rel_path.parent().unwrap().components() {
+        let component = component
+            .as_str()
+            .replace(|c: char| c.is_ascii_punctuation(), "_");
+        test_name.push_str(&component);
+        test_name.push('_');
+    }
+
+    test_name.push_str(
+        &rel_path
+            .file_stem()
+            .unwrap()
+            .replace(|c: char| c.is_ascii_punctuation(), "_"),
+    );
+
+    test_name
 }

crates/red_knot_server/src/server/client.rs

@@ -26,7 +26,7 @@ pub(crate) struct Requester<'s> {
     response_handlers: FxHashMap<lsp_server::RequestId, ResponseBuilder<'s>>,
 }
 
-impl<'s> Client<'s> {
+impl Client<'_> {
     pub(super) fn new(sender: ClientSender) -> Self {
         Self {
             notifier: Notifier(sender.clone()),

crates/red_knot_test/Cargo.toml

@@ -20,6 +20,7 @@ ruff_source_file = { workspace = true }
 ruff_text_size = { workspace = true }
 
 anyhow = { workspace = true }
+camino = { workspace = true }
 colored = { workspace = true }
 memchr = { workspace = true }
 regex = { workspace = true }

crates/red_knot_test/README.md

@@ -184,8 +184,11 @@ The tests are run independently, in independent in-memory file systems and with
 [Salsa](https://github.com/salsa-rs/salsa) databases. This means that each is a from-scratch run of
 the type checker, with no data persisting from any previous test.
 
-Due to `cargo test` limitations, an entire test suite (Markdown file) is run as a single Rust test,
-so it's not possible to select individual tests within it to run.
+It is possible to filter to individual tests within a single markdown file using the
+`MDTEST_TEST_FILTER` environment variable. This variable will match any tests which contain the
+value as a case-sensitive substring in its name. An example test name is
+`unpacking.md - Unpacking - Tuple - Multiple assignment`, which contains the name of the markdown
+file and its parent headers joined together with hyphens.
 
 ## Structured test suites
 

crates/red_knot_test/src/lib.rs

@@ -1,3 +1,4 @@
+use camino::Utf8Path;
 use colored::Colorize;
 use parser as test_parser;
 use red_knot_python_semantic::types::check_types;
@@ -7,7 +8,6 @@ use ruff_db::parsed::parsed_module;
 use ruff_db::system::{DbWithTestSystem, SystemPathBuf};
 use ruff_source_file::LineIndex;
 use ruff_text_size::TextSize;
-use std::path::Path;
 
 mod assertion;
 mod db;
@@ -15,23 +15,30 @@ mod diagnostic;
 mod matcher;
 mod parser;
 
+const MDTEST_TEST_FILTER: &str = "MDTEST_TEST_FILTER";
+
 /// Run `path` as a markdown test suite with given `title`.
 ///
 /// Panic on test failure, and print failure details.
 #[allow(clippy::print_stdout)]
-pub fn run(path: &Path, long_title: &str, short_title: &str) {
+pub fn run(path: &Utf8Path, long_title: &str, short_title: &str, test_name: &str) {
     let source = std::fs::read_to_string(path).unwrap();
     let suite = match test_parser::parse(short_title, &source) {
         Ok(suite) => suite,
         Err(err) => {
-            panic!("Error parsing `{}`: {err}", path.to_str().unwrap())
+            panic!("Error parsing `{path}`: {err}")
         }
     };
 
     let mut db = db::Db::setup(SystemPathBuf::from("/src"));
 
+    let filter = std::env::var(MDTEST_TEST_FILTER).ok();
     let mut any_failures = false;
     for test in suite.tests() {
+        if filter.as_ref().is_some_and(|f| !test.name().contains(f)) {
+            continue;
+        }
+
         // Remove all files so that the db is in a "fresh" state.
         db.memory_file_system().remove_all();
         Files::sync_all(&mut db);
@@ -54,6 +61,15 @@ pub fn run(path: &Path, long_title: &str, short_title: &str) {
                     }
                 }
             }
+
+            println!(
+                "\nTo rerun this specific test, set the environment variable: {MDTEST_TEST_FILTER}=\"{}\"",
+                test.name()
+            );
+            println!(
+                "{MDTEST_TEST_FILTER}=\"{}\" cargo test -p red_knot_python_semantic --test mdtest -- {test_name}",
+                test.name()
+            );
         }
     }
 

crates/red_knot_vendored/vendor/typeshed/source_commit.txt

@@ -1 +1 @@
-5052fa2f18db4493892e0f2775030683c9d06531
+0a2da01946a406ede42e9c66f416a7e7758991d6

crates/red_knot_vendored/vendor/typeshed/stdlib/VERSIONS

@@ -33,6 +33,7 @@ _contextvars: 3.7-
 _csv: 3.0-
 _ctypes: 3.0-
 _curses: 3.0-
+_curses_panel: 3.0-
 _dbm: 3.0-
 _decimal: 3.3-
 _dummy_thread: 3.0-3.8
@@ -40,6 +41,7 @@ _dummy_threading: 3.0-3.8
 _frozen_importlib: 3.0-
 _frozen_importlib_external: 3.5-
 _gdbm: 3.0-
+_hashlib: 3.0-
 _heapq: 3.0-
 _imp: 3.0-
 _interpchannels: 3.13-
@@ -52,6 +54,7 @@ _lsprof: 3.0-
 _lzma: 3.3-
 _markupbase: 3.0-
 _msi: 3.0-3.12
+_multibytecodec: 3.0-
 _operator: 3.4-
 _osx_support: 3.0-
 _posixsubprocess: 3.2-
@@ -139,6 +142,12 @@ doctest: 3.0-
 dummy_threading: 3.0-3.8
 email: 3.0-
 encodings: 3.0-
+encodings.cp1125: 3.4-
+encodings.cp273: 3.4-
+encodings.cp858: 3.2-
+encodings.koi8_t: 3.5-
+encodings.kz1048: 3.5-
+encodings.mac_centeuro: 3.0-3.8
 ensurepip: 3.0-
 enum: 3.4-
 errno: 3.0-

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

@@ -2,10 +2,13 @@ import codecs
 import sys
 from _typeshed import ReadableBuffer
 from collections.abc import Callable
-from typing import Literal, overload
+from typing import Literal, final, overload, type_check_only
 from typing_extensions import TypeAlias
 
 # This type is not exposed; it is defined in unicodeobject.c
+# At runtime it calls itself builtins.EncodingMap
+@final
+@type_check_only
 class _EncodingMap:
     def size(self) -> int: ...
 

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

@@ -73,6 +73,7 @@ _VT_co = TypeVar("_VT_co", covariant=True)  # Value type covariant containers.
 @final
 class dict_keys(KeysView[_KT_co], Generic[_KT_co, _VT_co]):  # undocumented
     def __eq__(self, value: object, /) -> bool: ...
+    def __reversed__(self) -> Iterator[_KT_co]: ...
     if sys.version_info >= (3, 13):
         def isdisjoint(self, other: Iterable[_KT_co], /) -> bool: ...
     if sys.version_info >= (3, 10):
@@ -81,6 +82,7 @@ class dict_keys(KeysView[_KT_co], Generic[_KT_co, _VT_co]):  # undocumented
 
 @final
 class dict_values(ValuesView[_VT_co], Generic[_KT_co, _VT_co]):  # undocumented
+    def __reversed__(self) -> Iterator[_VT_co]: ...
     if sys.version_info >= (3, 10):
         @property
         def mapping(self) -> MappingProxyType[_KT_co, _VT_co]: ...
@@ -88,6 +90,7 @@ class dict_values(ValuesView[_VT_co], Generic[_KT_co, _VT_co]):  # undocumented
 @final
 class dict_items(ItemsView[_KT_co, _VT_co]):  # undocumented
     def __eq__(self, value: object, /) -> bool: ...
+    def __reversed__(self) -> Iterator[tuple[_KT_co, _VT_co]]: ...
     if sys.version_info >= (3, 13):
         def isdisjoint(self, other: Iterable[tuple[_KT_co, _VT_co]], /) -> bool: ...
     if sys.version_info >= (3, 10):

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

@@ -1,9 +1,9 @@
 import csv
 import sys
 from _typeshed import SupportsWrite
-from collections.abc import Iterable, Iterator
-from typing import Any, Final
-from typing_extensions import TypeAlias
+from collections.abc import Iterable
+from typing import Any, Final, type_check_only
+from typing_extensions import Self, TypeAlias
 
 __version__: Final[str]
 
@@ -45,17 +45,47 @@ class Dialect:
         strict: bool = False,
     ) -> None: ...
 
-class _reader(Iterator[list[str]]):
-    @property
-    def dialect(self) -> Dialect: ...
-    line_num: int
-    def __next__(self) -> list[str]: ...
+if sys.version_info >= (3, 10):
+    # This class calls itself _csv.reader.
+    class Reader:
+        @property
+        def dialect(self) -> Dialect: ...
+        line_num: int
+        def __iter__(self) -> Self: ...
+        def __next__(self) -> list[str]: ...
 
-class _writer:
-    @property
-    def dialect(self) -> Dialect: ...
-    def writerow(self, row: Iterable[Any]) -> Any: ...
-    def writerows(self, rows: Iterable[Iterable[Any]]) -> None: ...
+    # This class calls itself _csv.writer.
+    class Writer:
+        @property
+        def dialect(self) -> Dialect: ...
+        if sys.version_info >= (3, 13):
+            def writerow(self, row: Iterable[Any], /) -> Any: ...
+            def writerows(self, rows: Iterable[Iterable[Any]], /) -> None: ...
+        else:
+            def writerow(self, row: Iterable[Any]) -> Any: ...
+            def writerows(self, rows: Iterable[Iterable[Any]]) -> None: ...
+
+    # For the return types below.
+    # These aliases can be removed when typeshed drops support for 3.9.
+    _reader = Reader
+    _writer = Writer
+else:
+    # This class is not exposed. It calls itself _csv.reader.
+    @type_check_only
+    class _reader:
+        @property
+        def dialect(self) -> Dialect: ...
+        line_num: int
+        def __iter__(self) -> Self: ...
+        def __next__(self) -> list[str]: ...
+
+    # This class is not exposed. It calls itself _csv.writer.
+    @type_check_only
+    class _writer:
+        @property
+        def dialect(self) -> Dialect: ...
+        def writerow(self, row: Iterable[Any]) -> Any: ...
+        def writerows(self, rows: Iterable[Iterable[Any]]) -> None: ...
 
 def writer(
     csvfile: SupportsWrite[str],

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

@@ -1,9 +1,10 @@
+import _typeshed
 import sys
-from _typeshed import ReadableBuffer, WriteableBuffer
+from _typeshed import ReadableBuffer, StrOrBytesPath, WriteableBuffer
 from abc import abstractmethod
 from collections.abc import Callable, Iterable, Iterator, Mapping, Sequence
 from ctypes import CDLL, ArgumentError as ArgumentError, c_void_p
-from typing import Any, ClassVar, Generic, TypeVar, overload
+from typing import Any, ClassVar, Generic, TypeVar, final, overload, type_check_only
 from typing_extensions import Self, TypeAlias
 
 if sys.version_info >= (3, 9):
@@ -47,46 +48,79 @@ if sys.platform == "win32":
     def LoadLibrary(name: str, load_flags: int = 0, /) -> int: ...
     def FreeLibrary(handle: int, /) -> None: ...
 
-class _CDataMeta(type):
-    # By default mypy complains about the following two methods, because strictly speaking cls
-    # might not be a Type[_CT]. However this can never actually happen, because the only class that
-    # uses _CDataMeta as its metaclass is _CData. So it's safe to ignore the errors here.
-    def __mul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc]  # pyright: ignore[reportGeneralTypeIssues]
-    def __rmul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc]  # pyright: ignore[reportGeneralTypeIssues]
+else:
+    def dlclose(handle: int, /) -> None: ...
+    # The default for flag is RTLD_GLOBAL|RTLD_LOCAL, which is platform dependent.
+    def dlopen(name: StrOrBytesPath, flag: int = ..., /) -> int: ...
+    def dlsym(handle: int, name: str, /) -> int: ...
 
-class _CData(metaclass=_CDataMeta):
+if sys.version_info >= (3, 13):
+    # This class is not exposed. It calls itself _ctypes.CType_Type.
+    @type_check_only
+    class _CType_Type(type):
+        # By default mypy complains about the following two methods, because strictly speaking cls
+        # might not be a Type[_CT]. However this doesn't happen because this is only a
+        # metaclass for subclasses of _CData.
+        def __mul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+        def __rmul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+
+    _CTypeBaseType = _CType_Type
+
+else:
+    _CTypeBaseType = type
+
+# This class is not exposed.
+@type_check_only
+class _CData:
     _b_base_: int
     _b_needsfree_: bool
     _objects: Mapping[Any, int] | None
-    # At runtime the following classmethods are available only on classes, not
-    # on instances. This can't be reflected properly in the type system:
-    #
-    # Structure.from_buffer(...)  # valid at runtime
-    # Structure(...).from_buffer(...)  # invalid at runtime
-    #
-    @classmethod
-    def from_buffer(cls, source: WriteableBuffer, offset: int = ...) -> Self: ...
-    @classmethod
-    def from_buffer_copy(cls, source: ReadableBuffer, offset: int = ...) -> Self: ...
-    @classmethod
-    def from_address(cls, address: int) -> Self: ...
-    @classmethod
-    def from_param(cls, value: Any, /) -> Self | _CArgObject: ...
-    @classmethod
-    def in_dll(cls, library: CDLL, name: str) -> Self: ...
     def __buffer__(self, flags: int, /) -> memoryview: ...
-    def __release_buffer__(self, buffer: memoryview, /) -> None: ...
+    def __ctypes_from_outparam__(self, /) -> Self: ...
 
-class _SimpleCData(_CData, Generic[_T]):
+# this is a union of all the subclasses of _CData, which is useful because of
+# the methods that are present on each of those subclasses which are not present
+# on _CData itself.
+_CDataType: TypeAlias = _SimpleCData[Any] | _Pointer[Any] | CFuncPtr | Union | Structure | Array[Any]
+
+# This class is not exposed. It calls itself _ctypes.PyCSimpleType.
+@type_check_only
+class _PyCSimpleType(_CTypeBaseType):
+    def from_address(self: type[_typeshed.Self], value: int, /) -> _typeshed.Self: ...
+    def from_buffer(self: type[_typeshed.Self], obj: WriteableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_buffer_copy(self: type[_typeshed.Self], buffer: ReadableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_param(self: type[_typeshed.Self], value: Any, /) -> _typeshed.Self | _CArgObject: ...
+    def in_dll(self: type[_typeshed.Self], dll: CDLL, name: str, /) -> _typeshed.Self: ...
+    if sys.version_info < (3, 13):
+        # Inherited from CType_Type starting on 3.13
+        def __mul__(self: type[_CT], value: int, /) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+        def __rmul__(self: type[_CT], value: int, /) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+
+class _SimpleCData(_CData, Generic[_T], metaclass=_PyCSimpleType):
     value: _T
     # The TypeVar can be unsolved here,
     # but we can't use overloads without creating many, many mypy false-positive errors
     def __init__(self, value: _T = ...) -> None: ...  # pyright: ignore[reportInvalidTypeVarUse]
+    def __ctypes_from_outparam__(self, /) -> _T: ...  # type: ignore[override]
 
 class _CanCastTo(_CData): ...
 class _PointerLike(_CanCastTo): ...
 
-class _Pointer(_PointerLike, _CData, Generic[_CT]):
+# This type is not exposed. It calls itself _ctypes.PyCPointerType.
+@type_check_only
+class _PyCPointerType(_CTypeBaseType):
+    def from_address(self: type[_typeshed.Self], value: int, /) -> _typeshed.Self: ...
+    def from_buffer(self: type[_typeshed.Self], obj: WriteableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_buffer_copy(self: type[_typeshed.Self], buffer: ReadableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_param(self: type[_typeshed.Self], value: Any, /) -> _typeshed.Self | _CArgObject: ...
+    def in_dll(self: type[_typeshed.Self], dll: CDLL, name: str, /) -> _typeshed.Self: ...
+    def set_type(self, type: Any, /) -> None: ...
+    if sys.version_info < (3, 13):
+        # Inherited from CType_Type starting on 3.13
+        def __mul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+        def __rmul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+
+class _Pointer(_PointerLike, _CData, Generic[_CT], metaclass=_PyCPointerType):
     _type_: type[_CT]
     contents: _CT
     @overload
@@ -105,16 +139,32 @@ def POINTER(type: None, /) -> type[c_void_p]: ...
 def POINTER(type: type[_CT], /) -> type[_Pointer[_CT]]: ...
 def pointer(obj: _CT, /) -> _Pointer[_CT]: ...
 
+# This class is not exposed. It calls itself _ctypes.CArgObject.
+@final
+@type_check_only
 class _CArgObject: ...
 
-def byref(obj: _CData, offset: int = ...) -> _CArgObject: ...
+def byref(obj: _CData | _CDataType, offset: int = ...) -> _CArgObject: ...
 
-_ECT: TypeAlias = Callable[[_CData | None, CFuncPtr, tuple[_CData, ...]], _CData]
+_ECT: TypeAlias = Callable[[_CData | _CDataType | None, CFuncPtr, tuple[_CData | _CDataType, ...]], _CDataType]
 _PF: TypeAlias = tuple[int] | tuple[int, str | None] | tuple[int, str | None, Any]
 
-class CFuncPtr(_PointerLike, _CData):
-    restype: type[_CData] | Callable[[int], Any] | None
-    argtypes: Sequence[type[_CData]]
+# This class is not exposed. It calls itself _ctypes.PyCFuncPtrType.
+@type_check_only
+class _PyCFuncPtrType(_CTypeBaseType):
+    def from_address(self: type[_typeshed.Self], value: int, /) -> _typeshed.Self: ...
+    def from_buffer(self: type[_typeshed.Self], obj: WriteableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_buffer_copy(self: type[_typeshed.Self], buffer: ReadableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_param(self: type[_typeshed.Self], value: Any, /) -> _typeshed.Self | _CArgObject: ...
+    def in_dll(self: type[_typeshed.Self], dll: CDLL, name: str, /) -> _typeshed.Self: ...
+    if sys.version_info < (3, 13):
+        # Inherited from CType_Type starting on 3.13
+        def __mul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+        def __rmul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+
+class CFuncPtr(_PointerLike, _CData, metaclass=_PyCFuncPtrType):
+    restype: type[_CDataType] | Callable[[int], Any] | None
+    argtypes: Sequence[type[_CDataType]]
     errcheck: _ECT
     # Abstract attribute that must be defined on subclasses
     _flags_: ClassVar[int]
@@ -129,7 +179,7 @@ class CFuncPtr(_PointerLike, _CData):
     if sys.platform == "win32":
         @overload
         def __init__(
-            self, vtbl_index: int, name: str, paramflags: tuple[_PF, ...] | None = ..., iid: _CData | None = ..., /
+            self, vtbl_index: int, name: str, paramflags: tuple[_PF, ...] | None = ..., iid: _CData | _CDataType | None = ..., /
         ) -> None: ...
 
     def __call__(self, *args: Any, **kwargs: Any) -> Any: ...
@@ -137,30 +187,95 @@ class CFuncPtr(_PointerLike, _CData):
 _GetT = TypeVar("_GetT")
 _SetT = TypeVar("_SetT")
 
+# This class is not exposed. It calls itself _ctypes.CField.
+@final
+@type_check_only
 class _CField(Generic[_CT, _GetT, _SetT]):
     offset: int
     size: int
-    @overload
-    def __get__(self, instance: None, owner: type[Any] | None, /) -> Self: ...
-    @overload
-    def __get__(self, instance: Any, owner: type[Any] | None, /) -> _GetT: ...
+    if sys.version_info >= (3, 10):
+        @overload
+        def __get__(self, instance: None, owner: type[Any] | None = None, /) -> Self: ...
+        @overload
+        def __get__(self, instance: Any, owner: type[Any] | None = None, /) -> _GetT: ...
+    else:
+        @overload
+        def __get__(self, instance: None, owner: type[Any] | None, /) -> Self: ...
+        @overload
+        def __get__(self, instance: Any, owner: type[Any] | None, /) -> _GetT: ...
+
     def __set__(self, instance: Any, value: _SetT, /) -> None: ...
 
-class _StructUnionMeta(_CDataMeta):
-    _fields_: Sequence[tuple[str, type[_CData]] | tuple[str, type[_CData], int]]
-    _pack_: int
-    _anonymous_: Sequence[str]
+# This class is not exposed. It calls itself _ctypes.UnionType.
+@type_check_only
+class _UnionType(_CTypeBaseType):
+    def from_address(self: type[_typeshed.Self], value: int, /) -> _typeshed.Self: ...
+    def from_buffer(self: type[_typeshed.Self], obj: WriteableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_buffer_copy(self: type[_typeshed.Self], buffer: ReadableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_param(self: type[_typeshed.Self], value: Any, /) -> _typeshed.Self | _CArgObject: ...
+    def in_dll(self: type[_typeshed.Self], dll: CDLL, name: str, /) -> _typeshed.Self: ...
+    # At runtime, various attributes are created on a Union subclass based
+    # on its _fields_. This method doesn't exist, but represents those
+    # dynamically created attributes.
     def __getattr__(self, name: str) -> _CField[Any, Any, Any]: ...
+    if sys.version_info < (3, 13):
+        # Inherited from CType_Type starting on 3.13
+        def __mul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+        def __rmul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+
+class Union(_CData, metaclass=_UnionType):
+    _fields_: ClassVar[Sequence[tuple[str, type[_CDataType]] | tuple[str, type[_CDataType], int]]]
+    _pack_: ClassVar[int]
+    _anonymous_: ClassVar[Sequence[str]]
+    if sys.version_info >= (3, 13):
+        _align_: ClassVar[int]
 
-class _StructUnionBase(_CData, metaclass=_StructUnionMeta):
     def __init__(self, *args: Any, **kw: Any) -> None: ...
     def __getattr__(self, name: str) -> Any: ...
     def __setattr__(self, name: str, value: Any) -> None: ...
 
-class Union(_StructUnionBase): ...
-class Structure(_StructUnionBase): ...
+# This class is not exposed. It calls itself _ctypes.PyCStructType.
+@type_check_only
+class _PyCStructType(_CTypeBaseType):
+    def from_address(self: type[_typeshed.Self], value: int, /) -> _typeshed.Self: ...
+    def from_buffer(self: type[_typeshed.Self], obj: WriteableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_buffer_copy(self: type[_typeshed.Self], buffer: ReadableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_param(self: type[_typeshed.Self], value: Any, /) -> _typeshed.Self | _CArgObject: ...
+    def in_dll(self: type[_typeshed.Self], dll: CDLL, name: str, /) -> _typeshed.Self: ...
+    # At runtime, various attributes are created on a Structure subclass based
+    # on its _fields_. This method doesn't exist, but represents those
+    # dynamically created attributes.
+    def __getattr__(self, name: str) -> _CField[Any, Any, Any]: ...
+    if sys.version_info < (3, 13):
+        # Inherited from CType_Type starting on 3.13
+        def __mul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+        def __rmul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
 
-class Array(_CData, Generic[_CT]):
+class Structure(_CData, metaclass=_PyCStructType):
+    _fields_: ClassVar[Sequence[tuple[str, type[_CDataType]] | tuple[str, type[_CDataType], int]]]
+    _pack_: ClassVar[int]
+    _anonymous_: ClassVar[Sequence[str]]
+    if sys.version_info >= (3, 13):
+        _align_: ClassVar[int]
+
+    def __init__(self, *args: Any, **kw: Any) -> None: ...
+    def __getattr__(self, name: str) -> Any: ...
+    def __setattr__(self, name: str, value: Any) -> None: ...
+
+# This class is not exposed. It calls itself _ctypes.PyCArrayType.
+@type_check_only
+class _PyCArrayType(_CTypeBaseType):
+    def from_address(self: type[_typeshed.Self], value: int, /) -> _typeshed.Self: ...
+    def from_buffer(self: type[_typeshed.Self], obj: WriteableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_buffer_copy(self: type[_typeshed.Self], buffer: ReadableBuffer, offset: int = 0, /) -> _typeshed.Self: ...
+    def from_param(self: type[_typeshed.Self], value: Any, /) -> _typeshed.Self | _CArgObject: ...
+    def in_dll(self: type[_typeshed.Self], dll: CDLL, name: str, /) -> _typeshed.Self: ...
+    if sys.version_info < (3, 13):
+        # Inherited from CType_Type starting on 3.13
+        def __mul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+        def __rmul__(cls: type[_CT], other: int) -> type[Array[_CT]]: ...  # type: ignore[misc] # pyright: ignore[reportGeneralTypeIssues]
+
+class Array(_CData, Generic[_CT], metaclass=_PyCArrayType):
     @property
     @abstractmethod
     def _length_(self) -> int: ...
@@ -205,9 +320,15 @@ class Array(_CData, Generic[_CT]):
     if sys.version_info >= (3, 9):
         def __class_getitem__(cls, item: Any, /) -> GenericAlias: ...
 
-def addressof(obj: _CData, /) -> int: ...
-def alignment(obj_or_type: _CData | type[_CData], /) -> int: ...
+def addressof(obj: _CData | _CDataType, /) -> int: ...
+def alignment(obj_or_type: _CData | _CDataType | type[_CData | _CDataType], /) -> int: ...
 def get_errno() -> int: ...
-def resize(obj: _CData, size: int, /) -> None: ...
+def resize(obj: _CData | _CDataType, size: int, /) -> None: ...
 def set_errno(value: int, /) -> int: ...
-def sizeof(obj_or_type: _CData | type[_CData], /) -> int: ...
+def sizeof(obj_or_type: _CData | _CDataType | type[_CData | _CDataType], /) -> int: ...
+def PyObj_FromPtr(address: int, /) -> Any: ...
+def Py_DECREF(o: _T, /) -> _T: ...
+def Py_INCREF(o: _T, /) -> _T: ...
+def buffer_info(o: _CData | _CDataType | type[_CData | _CDataType], /) -> tuple[str, int, tuple[int, ...]]: ...
+def call_cdeclfunction(address: int, arguments: tuple[Any, ...], /) -> Any: ...
+def call_function(address: int, arguments: tuple[Any, ...], /) -> Any: ...

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

@@ -1,6 +1,7 @@
 import sys
 from _typeshed import ReadOnlyBuffer, SupportsRead
-from typing import IO, Any, NamedTuple, final, overload
+from curses import _ncurses_version
+from typing import IO, Any, final, overload
 from typing_extensions import TypeAlias
 
 # NOTE: This module is ordinarily only available on Unix, but the windows-curses
@@ -549,9 +550,4 @@ class window:  # undocumented
     @overload
     def vline(self, y: int, x: int, ch: _ChType, n: int) -> None: ...
 
-class _ncurses_version(NamedTuple):
-    major: int
-    minor: int
-    patch: int
-
 ncurses_version: _ncurses_version

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

@@ -0,0 +1,27 @@
+from _curses import window
+from typing import final
+
+__version__: str
+version: str
+
+class error(Exception): ...
+
+@final
+class panel:
+    def above(self) -> panel: ...
+    def below(self) -> panel: ...
+    def bottom(self) -> None: ...
+    def hidden(self) -> bool: ...
+    def hide(self) -> None: ...
+    def move(self, y: int, x: int, /) -> None: ...
+    def replace(self, win: window, /) -> None: ...
+    def set_userptr(self, obj: object, /) -> None: ...
+    def show(self) -> None: ...
+    def top(self) -> None: ...
+    def userptr(self) -> object: ...
+    def window(self) -> window: ...
+
+def bottom_panel() -> panel: ...
+def new_panel(win: window, /) -> panel: ...
+def top_panel() -> panel: ...
+def update_panels() -> panel: ...

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

@@ -1,7 +1,7 @@
 import sys
 from _typeshed import ReadOnlyBuffer, StrOrBytesPath
 from types import TracebackType
-from typing import TypeVar, overload
+from typing import TypeVar, final, overload, type_check_only
 from typing_extensions import Self, TypeAlias
 
 if sys.platform != "win32":
@@ -13,6 +13,8 @@ if sys.platform != "win32":
     library: str
 
     # Actual typename dbm, not exposed by the implementation
+    @final
+    @type_check_only
     class _dbm:
         def close(self) -> None: ...
         if sys.version_info >= (3, 13):
@@ -22,18 +24,17 @@ if sys.platform != "win32":
         def __setitem__(self, key: _KeyType, value: _ValueType) -> None: ...
         def __delitem__(self, key: _KeyType) -> None: ...
         def __len__(self) -> int: ...
-        def __del__(self) -> None: ...
         def __enter__(self) -> Self: ...
         def __exit__(
             self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
         ) -> None: ...
         @overload
-        def get(self, k: _KeyType) -> bytes | None: ...
+        def get(self, k: _KeyType, /) -> bytes | None: ...
         @overload
-        def get(self, k: _KeyType, default: _T) -> bytes | _T: ...
+        def get(self, k: _KeyType, default: _T, /) -> bytes | _T: ...
         def keys(self) -> list[bytes]: ...
-        def setdefault(self, k: _KeyType, default: _ValueType = ...) -> bytes: ...
-        # Don't exist at runtime
+        def setdefault(self, k: _KeyType, default: _ValueType = ..., /) -> bytes: ...
+        # This isn't true, but the class can't be instantiated. See #13024
         __new__: None  # type: ignore[assignment]
         __init__: None  # type: ignore[assignment]
 

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

@@ -17,20 +17,13 @@ from decimal import (
     Rounded as Rounded,
     Subnormal as Subnormal,
     Underflow as Underflow,
+    _ContextManager,
 )
-from types import TracebackType
 from typing import Final
 from typing_extensions import TypeAlias
 
 _TrapType: TypeAlias = type[DecimalException]
 
-class _ContextManager:
-    new_context: Context
-    saved_context: Context
-    def __init__(self, new_context: Context) -> None: ...
-    def __enter__(self) -> Context: ...
-    def __exit__(self, t: type[BaseException] | None, v: BaseException | None, tb: TracebackType | None) -> None: ...
-
 __version__: Final[str]
 __libmpdec_version__: Final[str]
 

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

@@ -0,0 +1,80 @@
+import sys
+from _typeshed import ReadableBuffer
+from collections.abc import Callable
+from types import ModuleType
+from typing import AnyStr, final, overload
+from typing_extensions import Self, TypeAlias
+
+_DigestMod: TypeAlias = str | Callable[[], HASH] | ModuleType | None
+
+openssl_md_meth_names: frozenset[str]
+
+class HASH:
+    @property
+    def digest_size(self) -> int: ...
+    @property
+    def block_size(self) -> int: ...
+    @property
+    def name(self) -> str: ...
+    def copy(self) -> Self: ...
+    def digest(self) -> bytes: ...
+    def hexdigest(self) -> str: ...
+    def update(self, obj: ReadableBuffer, /) -> None: ...
+
+if sys.version_info >= (3, 10):
+    class UnsupportedDigestmodError(ValueError): ...
+
+if sys.version_info >= (3, 9):
+    class HASHXOF(HASH):
+        def digest(self, length: int) -> bytes: ...  # type: ignore[override]
+        def hexdigest(self, length: int) -> str: ...  # type: ignore[override]
+
+    @final
+    class HMAC:
+        @property
+        def digest_size(self) -> int: ...
+        @property
+        def block_size(self) -> int: ...
+        @property
+        def name(self) -> str: ...
+        def copy(self) -> Self: ...
+        def digest(self) -> bytes: ...
+        def hexdigest(self) -> str: ...
+        def update(self, msg: ReadableBuffer) -> None: ...
+
+    @overload
+    def compare_digest(a: ReadableBuffer, b: ReadableBuffer, /) -> bool: ...
+    @overload
+    def compare_digest(a: AnyStr, b: AnyStr, /) -> bool: ...
+    def get_fips_mode() -> int: ...
+    def hmac_new(key: bytes | bytearray, msg: ReadableBuffer = b"", digestmod: _DigestMod = None) -> HMAC: ...
+    def new(name: str, string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_md5(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_sha1(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_sha224(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_sha256(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_sha384(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_sha512(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_sha3_224(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_sha3_256(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_sha3_384(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_sha3_512(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASH: ...
+    def openssl_shake_128(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASHXOF: ...
+    def openssl_shake_256(string: ReadableBuffer = b"", *, usedforsecurity: bool = True) -> HASHXOF: ...
+
+else:
+    def new(name: str, string: ReadableBuffer = b"") -> HASH: ...
+    def openssl_md5(string: ReadableBuffer = b"") -> HASH: ...
+    def openssl_sha1(string: ReadableBuffer = b"") -> HASH: ...
+    def openssl_sha224(string: ReadableBuffer = b"") -> HASH: ...
+    def openssl_sha256(string: ReadableBuffer = b"") -> HASH: ...
+    def openssl_sha384(string: ReadableBuffer = b"") -> HASH: ...
+    def openssl_sha512(string: ReadableBuffer = b"") -> HASH: ...
+
+def hmac_digest(key: bytes | bytearray, msg: ReadableBuffer, digest: str) -> bytes: ...
+def pbkdf2_hmac(
+    hash_name: str, password: ReadableBuffer, salt: ReadableBuffer, iterations: int, dklen: int | None = None
+) -> bytes: ...
+def scrypt(
+    password: ReadableBuffer, *, salt: ReadableBuffer, n: int, r: int, p: int, maxmem: int = 0, dklen: int = 64
+) -> bytes: ...

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

@@ -45,5 +45,6 @@ class make_scanner:
     def __init__(self, context: make_scanner) -> None: ...
     def __call__(self, string: str, index: int) -> tuple[Any, int]: ...
 
+def encode_basestring(s: str, /) -> str: ...
 def encode_basestring_ascii(s: str, /) -> str: ...
 def scanstring(string: str, end: int, strict: bool = ...) -> tuple[str, int]: ...

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

@@ -0,0 +1,44 @@
+from _typeshed import ReadableBuffer
+from codecs import _ReadableStream, _WritableStream
+from collections.abc import Iterable
+from typing import final, type_check_only
+
+# This class is not exposed. It calls itself _multibytecodec.MultibyteCodec.
+@final
+@type_check_only
+class _MultibyteCodec:
+    def decode(self, input: ReadableBuffer, errors: str | None = None) -> str: ...
+    def encode(self, input: str, errors: str | None = None) -> bytes: ...
+
+class MultibyteIncrementalDecoder:
+    errors: str
+    def __init__(self, errors: str = "strict") -> None: ...
+    def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
+    def getstate(self) -> tuple[bytes, int]: ...
+    def reset(self) -> None: ...
+    def setstate(self, state: tuple[bytes, int], /) -> None: ...
+
+class MultibyteIncrementalEncoder:
+    errors: str
+    def __init__(self, errors: str = "strict") -> None: ...
+    def encode(self, input: str, final: bool = False) -> bytes: ...
+    def getstate(self) -> int: ...
+    def reset(self) -> None: ...
+    def setstate(self, state: int, /) -> None: ...
+
+class MultibyteStreamReader:
+    errors: str
+    stream: _ReadableStream
+    def __init__(self, stream: _ReadableStream, errors: str = "strict") -> None: ...
+    def read(self, sizeobj: int | None = None, /) -> str: ...
+    def readline(self, sizeobj: int | None = None, /) -> str: ...
+    def readlines(self, sizehintobj: int | None = None, /) -> list[str]: ...
+    def reset(self) -> None: ...
+
+class MultibyteStreamWriter:
+    errors: str
+    stream: _WritableStream
+    def __init__(self, stream: _WritableStream, errors: str = "strict") -> None: ...
+    def reset(self) -> None: ...
+    def write(self, strobj: str, /) -> None: ...
+    def writelines(self, lines: Iterable[str], /) -> None: ...

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

@@ -4,7 +4,6 @@ from collections.abc import Callable, Sequence
 from typing import SupportsIndex
 
 if sys.platform != "win32":
-    def cloexec_pipe() -> tuple[int, int]: ...
     def fork_exec(
         args: Sequence[StrOrBytesPath] | None,
         executable_list: Sequence[bytes],

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

@@ -3,7 +3,7 @@ from _typeshed import ReadableBuffer, WriteableBuffer
 from collections.abc import Iterable
 from socket import error as error, gaierror as gaierror, herror as herror, timeout as timeout
 from typing import Any, SupportsIndex, overload
-from typing_extensions import TypeAlias
+from typing_extensions import CapsuleType, TypeAlias
 
 _CMSG: TypeAlias = tuple[int, int, bytes]
 _CMSGArg: TypeAlias = tuple[int, int, ReadableBuffer]
@@ -72,7 +72,8 @@ SO_SNDBUF: int
 SO_SNDLOWAT: int
 SO_SNDTIMEO: int
 SO_TYPE: int
-SO_USELOOPBACK: int
+if sys.platform != "linux":
+    SO_USELOOPBACK: int
 if sys.platform == "win32":
     SO_EXCLUSIVEADDRUSE: int
 if sys.platform != "win32":
@@ -87,7 +88,10 @@ if sys.platform != "win32" and sys.platform != "darwin":
     SO_PEERSEC: int
     SO_PRIORITY: int
     SO_PROTOCOL: int
+if sys.platform != "win32" and sys.platform != "darwin" and sys.platform != "linux":
     SO_SETFIB: int
+if sys.platform == "linux" and sys.version_info >= (3, 13):
+    SO_BINDTOIFINDEX: int
 
 SOMAXCONN: int
 
@@ -99,27 +103,32 @@ MSG_TRUNC: int
 MSG_WAITALL: int
 if sys.platform != "win32":
     MSG_DONTWAIT: int
-    MSG_EOF: int
     MSG_EOR: int
     MSG_NOSIGNAL: int  # Sometimes this exists on darwin, sometimes not
 if sys.platform != "darwin":
-    MSG_BCAST: int
     MSG_ERRQUEUE: int
+if sys.platform == "win32":
+    MSG_BCAST: int
     MSG_MCAST: int
 if sys.platform != "win32" and sys.platform != "darwin":
-    MSG_BTAG: int
     MSG_CMSG_CLOEXEC: int
     MSG_CONFIRM: int
-    MSG_ETAG: int
     MSG_FASTOPEN: int
     MSG_MORE: int
+if sys.platform != "win32" and sys.platform != "linux":
+    MSG_EOF: int
+if sys.platform != "win32" and sys.platform != "linux" and sys.platform != "darwin":
     MSG_NOTIFICATION: int
+    MSG_BTAG: int  # Not FreeBSD either
+    MSG_ETAG: int  # Not FreeBSD either
 
 SOL_IP: int
 SOL_SOCKET: int
 SOL_TCP: int
 SOL_UDP: int
 if sys.platform != "win32" and sys.platform != "darwin":
+    # Defined in socket.h for Linux, but these aren't always present for
+    # some reason.
     SOL_ATALK: int
     SOL_AX25: int
     SOL_HCI: int
@@ -128,10 +137,11 @@ if sys.platform != "win32" and sys.platform != "darwin":
     SOL_ROSE: int
 
 if sys.platform != "win32":
-    SCM_CREDS: int
     SCM_RIGHTS: int
 if sys.platform != "win32" and sys.platform != "darwin":
     SCM_CREDENTIALS: int
+if sys.platform != "win32" and sys.platform != "linux":
+    SCM_CREDS: int
 
 IPPROTO_ICMP: int
 IPPROTO_IP: int
@@ -143,21 +153,22 @@ IPPROTO_DSTOPTS: int
 IPPROTO_EGP: int
 IPPROTO_ESP: int
 IPPROTO_FRAGMENT: int
-IPPROTO_GGP: int
 IPPROTO_HOPOPTS: int
 IPPROTO_ICMPV6: int
 IPPROTO_IDP: int
 IPPROTO_IGMP: int
-IPPROTO_IPV4: int
 IPPROTO_IPV6: int
-IPPROTO_MAX: int
-IPPROTO_ND: int
 IPPROTO_NONE: int
 IPPROTO_PIM: int
 IPPROTO_PUP: int
 IPPROTO_ROUTING: int
 IPPROTO_SCTP: int
-if sys.platform != "darwin":
+if sys.platform != "linux":
+    IPPROTO_GGP: int
+    IPPROTO_IPV4: int
+    IPPROTO_MAX: int
+    IPPROTO_ND: int
+if sys.platform == "win32":
     IPPROTO_CBT: int
     IPPROTO_ICLFXBM: int
     IPPROTO_IGP: int
@@ -166,18 +177,19 @@ if sys.platform != "darwin":
     IPPROTO_RDP: int
     IPPROTO_ST: int
 if sys.platform != "win32":
-    IPPROTO_EON: int
     IPPROTO_GRE: int
-    IPPROTO_HELLO: int
-    IPPROTO_IPCOMP: int
     IPPROTO_IPIP: int
     IPPROTO_RSVP: int
     IPPROTO_TP: int
+if sys.platform != "win32" and sys.platform != "linux":
+    IPPROTO_EON: int
+    IPPROTO_HELLO: int
+    IPPROTO_IPCOMP: int
     IPPROTO_XTP: int
-if sys.platform != "win32" and sys.platform != "darwin":
-    IPPROTO_BIP: int
-    IPPROTO_MOBILE: int
-    IPPROTO_VRRP: int
+if sys.platform != "win32" and sys.platform != "darwin" and sys.platform != "linux":
+    IPPROTO_BIP: int  # Not FreeBSD either
+    IPPROTO_MOBILE: int  # Not FreeBSD either
+    IPPROTO_VRRP: int  # Not FreeBSD either
 if sys.version_info >= (3, 9) and sys.platform == "linux":
     # Availability: Linux >= 2.6.20, FreeBSD >= 10.1
     IPPROTO_UDPLITE: int
@@ -202,11 +214,10 @@ IP_MULTICAST_IF: int
 IP_MULTICAST_LOOP: int
 IP_MULTICAST_TTL: int
 IP_OPTIONS: int
-IP_RECVDSTADDR: int
+if sys.platform != "linux":
+    IP_RECVDSTADDR: int
 if sys.version_info >= (3, 10):
     IP_RECVTOS: int
-elif sys.platform != "win32" and sys.platform != "darwin":
-    IP_RECVTOS: int
 IP_TOS: int
 IP_TTL: int
 if sys.platform != "win32":
@@ -218,6 +229,7 @@ if sys.platform != "win32":
     IP_RETOPTS: int
 if sys.platform != "win32" and sys.platform != "darwin":
     IP_TRANSPARENT: int
+if sys.platform != "win32" and sys.platform != "darwin" and sys.version_info >= (3, 11):
     IP_BIND_ADDRESS_NO_PORT: int
 if sys.version_info >= (3, 12):
     IP_ADD_SOURCE_MEMBERSHIP: int
@@ -255,6 +267,9 @@ if sys.platform != "win32":
         IPV6_RECVPATHMTU: int
         IPV6_RECVPKTINFO: int
         IPV6_RTHDRDSTOPTS: int
+
+if sys.platform != "win32" and sys.platform != "linux":
+    if sys.version_info >= (3, 9) or sys.platform != "darwin":
         IPV6_USE_MIN_MTU: int
 
 EAI_AGAIN: int
@@ -268,11 +283,12 @@ EAI_SERVICE: int
 EAI_SOCKTYPE: int
 if sys.platform != "win32":
     EAI_ADDRFAMILY: int
+    EAI_OVERFLOW: int
+    EAI_SYSTEM: int
+if sys.platform != "win32" and sys.platform != "linux":
     EAI_BADHINTS: int
     EAI_MAX: int
-    EAI_OVERFLOW: int
     EAI_PROTOCOL: int
-    EAI_SYSTEM: int
 
 AI_ADDRCONFIG: int
 AI_ALL: int
@@ -281,7 +297,7 @@ AI_NUMERICHOST: int
 AI_NUMERICSERV: int
 AI_PASSIVE: int
 AI_V4MAPPED: int
-if sys.platform != "win32":
+if sys.platform != "win32" and sys.platform != "linux":
     AI_DEFAULT: int
     AI_MASK: int
     AI_V4MAPPED_CFG: int
@@ -293,6 +309,8 @@ NI_NAMEREQD: int
 NI_NOFQDN: int
 NI_NUMERICHOST: int
 NI_NUMERICSERV: int
+if sys.platform == "linux" and sys.version_info >= (3, 13):
+    NI_IDN: int
 
 TCP_FASTOPEN: int
 TCP_KEEPCNT: int
@@ -318,6 +336,27 @@ if sys.platform != "win32" and sys.platform != "darwin":
     TCP_SYNCNT: int
     TCP_USER_TIMEOUT: int
     TCP_WINDOW_CLAMP: int
+if sys.platform == "linux" and sys.version_info >= (3, 12):
+    TCP_CC_INFO: int
+    TCP_FASTOPEN_CONNECT: int
+    TCP_FASTOPEN_KEY: int
+    TCP_FASTOPEN_NO_COOKIE: int
+    TCP_INQ: int
+    TCP_MD5SIG: int
+    TCP_MD5SIG_EXT: int
+    TCP_QUEUE_SEQ: int
+    TCP_REPAIR: int
+    TCP_REPAIR_OPTIONS: int
+    TCP_REPAIR_QUEUE: int
+    TCP_REPAIR_WINDOW: int
+    TCP_SAVED_SYN: int
+    TCP_SAVE_SYN: int
+    TCP_THIN_DUPACK: int
+    TCP_THIN_LINEAR_TIMEOUTS: int
+    TCP_TIMESTAMP: int
+    TCP_TX_DELAY: int
+    TCP_ULP: int
+    TCP_ZEROCOPY_RECEIVE: int
 
 # --------------------
 # Specifically documented constants
@@ -334,12 +373,13 @@ if sys.platform == "linux":
     CAN_ERR_FLAG: int
     CAN_ERR_MASK: int
     CAN_RAW: int
-    CAN_RAW_ERR_FILTER: int
     CAN_RAW_FILTER: int
     CAN_RAW_LOOPBACK: int
     CAN_RAW_RECV_OWN_MSGS: int
     CAN_RTR_FLAG: int
     CAN_SFF_MASK: int
+    if sys.version_info < (3, 11):
+        CAN_RAW_ERR_FILTER: int
 
 if sys.platform == "linux":
     # Availability: Linux >= 2.6.25
@@ -437,12 +477,13 @@ if sys.platform == "linux":
     AF_RDS: int
     PF_RDS: int
     SOL_RDS: int
+    # These are present in include/linux/rds.h but don't always show up
+    # here.
     RDS_CANCEL_SENT_TO: int
     RDS_CMSG_RDMA_ARGS: int
     RDS_CMSG_RDMA_DEST: int
     RDS_CMSG_RDMA_MAP: int
     RDS_CMSG_RDMA_STATUS: int
-    RDS_CMSG_RDMA_UPDATE: int
     RDS_CONG_MONITOR: int
     RDS_FREE_MR: int
     RDS_GET_MR: int
@@ -456,6 +497,10 @@ if sys.platform == "linux":
     RDS_RDMA_USE_ONCE: int
     RDS_RECVERR: int
 
+    # This is supported by CPython but doesn't seem to be a real thing.
+    # The closest existing constant in rds.h is RDS_CMSG_CONG_UPDATE
+    # RDS_CMSG_RDMA_UPDATE: int
+
 if sys.platform == "win32":
     SIO_RCVALL: int
     SIO_KEEPALIVE_VALS: int
@@ -522,16 +567,17 @@ if sys.platform == "linux":
 if sys.platform != "win32" or sys.version_info >= (3, 9):
     # Documented as only available on BSD, macOS, but empirically sometimes
     # available on Windows
-    AF_LINK: int
+    if sys.platform != "linux":
+        AF_LINK: int
 
 has_ipv6: bool
 
-if sys.platform != "darwin":
+if sys.platform != "darwin" and sys.platform != "linux":
     if sys.platform != "win32" or sys.version_info >= (3, 9):
         BDADDR_ANY: str
         BDADDR_LOCAL: str
 
-if sys.platform != "win32" and sys.platform != "darwin":
+if sys.platform != "win32" and sys.platform != "darwin" and sys.platform != "linux":
     HCI_FILTER: int  # not in NetBSD or DragonFlyBSD
     HCI_TIME_STAMP: int  # not in FreeBSD, NetBSD, or DragonFlyBSD
     HCI_DATA_DIR: int  # not in FreeBSD, NetBSD, or DragonFlyBSD
@@ -580,36 +626,37 @@ if sys.version_info >= (3, 12):
 if sys.platform == "linux":
     # Netlink is defined by Linux
     AF_NETLINK: int
-    NETLINK_ARPD: int
     NETLINK_CRYPTO: int
     NETLINK_DNRTMSG: int
     NETLINK_FIREWALL: int
     NETLINK_IP6_FW: int
     NETLINK_NFLOG: int
-    NETLINK_ROUTE6: int
     NETLINK_ROUTE: int
-    NETLINK_SKIP: int
-    NETLINK_TAPBASE: int
-    NETLINK_TCPDIAG: int
     NETLINK_USERSOCK: int
-    NETLINK_W1: int
     NETLINK_XFRM: int
+    # Technically still supported by CPython
+    # NETLINK_ARPD: int  # linux 2.0 to 2.6.12 (EOL August 2005)
+    # NETLINK_ROUTE6: int  # linux 2.2 to 2.6.12 (EOL August 2005)
+    # NETLINK_SKIP: int  # linux 2.0 to 2.6.12 (EOL August 2005)
+    # NETLINK_TAPBASE: int  # linux 2.2 to 2.6.12 (EOL August 2005)
+    # NETLINK_TCPDIAG: int  # linux 2.6.0 to 2.6.13 (EOL December 2005)
+    # NETLINK_W1: int  # linux 2.6.13 to 2.6.17 (EOL October 2006)
 
 if sys.platform == "darwin":
     PF_SYSTEM: int
     SYSPROTO_CONTROL: int
 
-if sys.platform != "darwin":
+if sys.platform != "darwin" and sys.platform != "linux":
     if sys.version_info >= (3, 9) or sys.platform != "win32":
         AF_BLUETOOTH: int
 
-if sys.platform != "win32" and sys.platform != "darwin":
+if sys.platform != "win32" and sys.platform != "darwin" and sys.platform != "linux":
     # Linux and some BSD support is explicit in the docs
     # Windows and macOS do not support in practice
     BTPROTO_HCI: int
     BTPROTO_L2CAP: int
     BTPROTO_SCO: int  # not in FreeBSD
-if sys.platform != "darwin":
+if sys.platform != "darwin" and sys.platform != "linux":
     if sys.version_info >= (3, 9) or sys.platform != "win32":
         BTPROTO_RFCOMM: int
 
@@ -636,13 +683,14 @@ AF_SNA: int
 
 if sys.platform != "win32":
     AF_ROUTE: int
+
+if sys.platform == "darwin":
     AF_SYSTEM: int
 
 if sys.platform != "darwin":
     AF_IRDA: int
 
 if sys.platform != "win32" and sys.platform != "darwin":
-    AF_AAL5: int
     AF_ASH: int
     AF_ATMPVC: int
     AF_ATMSVC: int
@@ -661,10 +709,12 @@ if sys.platform != "win32" and sys.platform != "darwin":
 
 # Miscellaneous undocumented
 
-if sys.platform != "win32":
+if sys.platform != "win32" and sys.platform != "linux":
     LOCAL_PEERCRED: int
 
 if sys.platform != "win32" and sys.platform != "darwin":
+    # Defined in linux socket.h, but this isn't always present for
+    # some reason.
     IPX_TYPE: int
 
 # ===== Classes =====
@@ -792,4 +842,4 @@ def if_nameindex() -> list[tuple[int, str]]: ...
 def if_nametoindex(oname: str, /) -> int: ...
 def if_indextoname(index: int, /) -> str: ...
 
-CAPI: object
+CAPI: CapsuleType

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

@@ -44,6 +44,12 @@ def start_new_thread(function: Callable[[Unpack[_Ts]], object], args: tuple[Unpa
 @overload
 def start_new_thread(function: Callable[..., object], args: tuple[Any, ...], kwargs: dict[str, Any], /) -> int: ...
 
+# Obsolete synonym for start_new_thread()
+@overload
+def start_new(function: Callable[[Unpack[_Ts]], object], args: tuple[Unpack[_Ts]], /) -> int: ...
+@overload
+def start_new(function: Callable[..., object], args: tuple[Any, ...], kwargs: dict[str, Any], /) -> int: ...
+
 if sys.version_info >= (3, 10):
     def interrupt_main(signum: signal.Signals = ..., /) -> None: ...
 
@@ -51,7 +57,9 @@ else:
     def interrupt_main() -> None: ...
 
 def exit() -> NoReturn: ...
+def exit_thread() -> NoReturn: ...  # Obsolete synonym for exit()
 def allocate_lock() -> LockType: ...
+def allocate() -> LockType: ...  # Obsolete synonym for allocate_lock()
 def get_ident() -> int: ...
 def stack_size(size: int = 0, /) -> int: ...
 

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

@@ -1,3 +1,4 @@
+from threading import RLock
 from typing import Any
 from typing_extensions import Self, TypeAlias
 from weakref import ReferenceType
@@ -8,6 +9,9 @@ _LocalDict: TypeAlias = dict[Any, Any]
 class _localimpl:
     key: str
     dicts: dict[int, tuple[ReferenceType[Any], _LocalDict]]
+    # Keep localargs in sync with the *args, **kwargs annotation on local.__new__
+    localargs: tuple[list[Any], dict[str, Any]]
+    locallock: RLock
     def get_dict(self) -> _LocalDict: ...
     def create_dict(self) -> _LocalDict: ...
 

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

@@ -107,7 +107,7 @@ class object:
     @property
     def __class__(self) -> type[Self]: ...
     @__class__.setter
-    def __class__(self, type: type[object], /) -> None: ...
+    def __class__(self, type: type[Self], /) -> None: ...
     def __init__(self) -> None: ...
     def __new__(cls) -> Self: ...
     # N.B. `object.__setattr__` and `object.__delattr__` are heavily special-cased by type checkers.
@@ -1963,14 +1963,33 @@ class StopAsyncIteration(Exception):
 
 class SyntaxError(Exception):
     msg: str
+    filename: str | None
     lineno: int | None
     offset: int | None
     text: str | None
-    filename: str | None
+    # Errors are displayed differently if this attribute exists on the exception.
+    # The value is always None.
+    print_file_and_line: None
     if sys.version_info >= (3, 10):
         end_lineno: int | None
         end_offset: int | None
 
+    @overload
+    def __init__(self) -> None: ...
+    @overload
+    def __init__(self, msg: object, /) -> None: ...
+    # Second argument is the tuple (filename, lineno, offset, text)
+    @overload
+    def __init__(self, msg: str, info: tuple[str | None, int | None, int | None, str | None], /) -> None: ...
+    if sys.version_info >= (3, 10):
+        # end_lineno and end_offset must both be provided if one is.
+        @overload
+        def __init__(
+            self, msg: str, info: tuple[str | None, int | None, int | None, str | None, int | None, int | None], /
+        ) -> None: ...
+    # If you provide more than two arguments, it still creates the SyntaxError, but
+    # the arguments from the info tuple are not parsed. This form is omitted.
+
 class SystemError(Exception): ...
 class TypeError(Exception): ...
 class ValueError(Exception): ...

crates/red_knot_vendored/vendor/typeshed/stdlib/bz2.pyi

@@ -126,6 +126,7 @@ class BZ2File(BaseStream, IO[bytes]):
     def readline(self, size: SupportsIndex = -1) -> bytes: ...  # type: ignore[override]
     def readinto(self, b: WriteableBuffer) -> int: ...
     def readlines(self, size: SupportsIndex = -1) -> list[bytes]: ...
+    def peek(self, n: int = 0) -> bytes: ...
     def seek(self, offset: int, whence: int = 0) -> int: ...
     def write(self, data: ReadableBuffer) -> int: ...
     def writelines(self, seq: Iterable[ReadableBuffer]) -> None: ...

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

@@ -3,7 +3,7 @@ from _codecs import *
 from _typeshed import ReadableBuffer
 from abc import abstractmethod
 from collections.abc import Callable, Generator, Iterable
-from typing import Any, BinaryIO, Final, Literal, Protocol, TextIO
+from typing import Any, BinaryIO, ClassVar, Final, Literal, Protocol, TextIO
 from typing_extensions import Self
 
 __all__ = [
@@ -202,6 +202,7 @@ class StreamWriter(Codec):
     def write(self, object: str) -> None: ...
     def writelines(self, list: Iterable[str]) -> None: ...
     def reset(self) -> None: ...
+    def seek(self, offset: int, whence: int = 0) -> None: ...
     def __enter__(self) -> Self: ...
     def __exit__(self, type: type[BaseException] | None, value: BaseException | None, tb: types.TracebackType | None) -> None: ...
     def __getattr__(self, name: str, getattr: Callable[[Any, str], Any] = ...) -> Any: ...
@@ -209,11 +210,14 @@ class StreamWriter(Codec):
 class StreamReader(Codec):
     stream: _ReadableStream
     errors: str
+    # This is set to str, but some subclasses set to bytes instead.
+    charbuffertype: ClassVar[type] = ...
     def __init__(self, stream: _ReadableStream, errors: str = "strict") -> None: ...
     def read(self, size: int = -1, chars: int = -1, firstline: bool = False) -> str: ...
     def readline(self, size: int | None = None, keepends: bool = True) -> str: ...
     def readlines(self, sizehint: int | None = None, keepends: bool = True) -> list[str]: ...
     def reset(self) -> None: ...
+    def seek(self, offset: int, whence: int = 0) -> None: ...
     def __enter__(self) -> Self: ...
     def __exit__(self, type: type[BaseException] | None, value: BaseException | None, tb: types.TracebackType | None) -> None: ...
     def __iter__(self) -> Self: ...

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

@@ -1,5 +1,5 @@
 import sys
-from _typeshed import StrOrBytesPath, SupportsWrite
+from _typeshed import MaybeNone, StrOrBytesPath, SupportsWrite
 from collections.abc import Callable, ItemsView, Iterable, Iterator, Mapping, MutableMapping, Sequence
 from re import Pattern
 from typing import Any, ClassVar, Final, Literal, TypeVar, overload
@@ -263,11 +263,11 @@ class RawConfigParser(_Parser):
     ) -> _T: ...
     # This is incompatible with MutableMapping so we ignore the type
     @overload  # type: ignore[override]
-    def get(self, section: str, option: str, *, raw: bool = False, vars: _Section | None = None) -> str | Any: ...
+    def get(self, section: str, option: str, *, raw: bool = False, vars: _Section | None = None) -> str | MaybeNone: ...
     @overload
     def get(
         self, section: str, option: str, *, raw: bool = False, vars: _Section | None = None, fallback: _T
-    ) -> str | _T | Any: ...
+    ) -> str | _T | MaybeNone: ...
     @overload
     def items(self, *, raw: bool = False, vars: _Section | None = None) -> ItemsView[str, SectionProxy]: ...
     @overload
@@ -277,6 +277,8 @@ class RawConfigParser(_Parser):
     def remove_option(self, section: str, option: str) -> bool: ...
     def remove_section(self, section: str) -> bool: ...
     def optionxform(self, optionstr: str) -> str: ...
+    @property
+    def converters(self) -> ConverterMapping: ...
 
 class ConfigParser(RawConfigParser):
     # This is incompatible with MutableMapping so we ignore the type
@@ -300,28 +302,34 @@ class SectionProxy(MutableMapping[str, str]):
     def parser(self) -> RawConfigParser: ...
     @property
     def name(self) -> str: ...
-    def get(  # type: ignore[override]
+    # This is incompatible with MutableMapping so we ignore the type
+    @overload  # type: ignore[override]
+    def get(
+        self, option: str, *, raw: bool = False, vars: _Section | None = None, _impl: Any | None = None, **kwargs: Any
+    ) -> str | None: ...
+    @overload
+    def get(
         self,
         option: str,
-        fallback: str | None = None,
+        fallback: _T,
         *,
         raw: bool = False,
         vars: _Section | None = None,
         _impl: Any | None = None,
         **kwargs: Any,
-    ) -> str | Any: ...  # can be None in RawConfigParser's sections
+    ) -> str | _T: ...
     # These are partially-applied version of the methods with the same names in
     # RawConfigParser; the stubs should be kept updated together
     @overload
-    def getint(self, option: str, *, raw: bool = ..., vars: _Section | None = ...) -> int: ...
+    def getint(self, option: str, *, raw: bool = ..., vars: _Section | None = ...) -> int | None: ...
     @overload
     def getint(self, option: str, fallback: _T = ..., *, raw: bool = ..., vars: _Section | None = ...) -> int | _T: ...
     @overload
-    def getfloat(self, option: str, *, raw: bool = ..., vars: _Section | None = ...) -> float: ...
+    def getfloat(self, option: str, *, raw: bool = ..., vars: _Section | None = ...) -> float | None: ...
     @overload
     def getfloat(self, option: str, fallback: _T = ..., *, raw: bool = ..., vars: _Section | None = ...) -> float | _T: ...
     @overload
-    def getboolean(self, option: str, *, raw: bool = ..., vars: _Section | None = ...) -> bool: ...
+    def getboolean(self, option: str, *, raw: bool = ..., vars: _Section | None = ...) -> bool | None: ...
     @overload
     def getboolean(self, option: str, fallback: _T = ..., *, raw: bool = ..., vars: _Section | None = ...) -> bool | _T: ...
     # SectionProxy can have arbitrary attributes when custom converters are used

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

@@ -1,7 +1,7 @@
 import abc
 import sys
 from _typeshed import FileDescriptorOrPath, Unused
-from abc import abstractmethod
+from abc import ABC, abstractmethod
 from collections.abc import AsyncGenerator, AsyncIterator, Awaitable, Callable, Generator, Iterator
 from types import TracebackType
 from typing import IO, Any, Generic, Protocol, TypeVar, overload, runtime_checkable
@@ -38,16 +38,22 @@ _P = ParamSpec("_P")
 _ExitFunc: TypeAlias = Callable[[type[BaseException] | None, BaseException | None, TracebackType | None], bool | None]
 _CM_EF = TypeVar("_CM_EF", bound=AbstractContextManager[Any, Any] | _ExitFunc)
 
+# mypy and pyright object to this being both ABC and Protocol.
+# At runtime it inherits from ABC and is not a Protocol, but it is on the
+# allowlist for use as a Protocol.
 @runtime_checkable
-class AbstractContextManager(Protocol[_T_co, _ExitT_co]):
+class AbstractContextManager(ABC, Protocol[_T_co, _ExitT_co]):  # type: ignore[misc]  # pyright: ignore[reportGeneralTypeIssues]
     def __enter__(self) -> _T_co: ...
     @abstractmethod
     def __exit__(
         self, exc_type: type[BaseException] | None, exc_value: BaseException | None, traceback: TracebackType | None, /
     ) -> _ExitT_co: ...
 
+# mypy and pyright object to this being both ABC and Protocol.
+# At runtime it inherits from ABC and is not a Protocol, but it is on the
+# allowlist for use as a Protocol.
 @runtime_checkable
-class AbstractAsyncContextManager(Protocol[_T_co, _ExitT_co]):
+class AbstractAsyncContextManager(ABC, Protocol[_T_co, _ExitT_co]):  # type: ignore[misc]  # pyright: ignore[reportGeneralTypeIssues]
     async def __aenter__(self) -> _T_co: ...
     @abstractmethod
     async def __aexit__(

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

@@ -1,8 +1,15 @@
 import sys
-from typing import Final
+from typing import Final, NamedTuple, type_check_only
 
 if sys.platform != "win32":
-    class _Method: ...
+    @type_check_only
+    class _MethodBase(NamedTuple):
+        name: str
+        ident: str | None
+        salt_chars: int
+        total_size: int
+
+    class _Method(_MethodBase): ...
     METHOD_CRYPT: Final[_Method]
     METHOD_MD5: Final[_Method]
     METHOD_SHA256: Final[_Method]

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

@@ -8,8 +8,6 @@ from _csv import (
     __version__ as __version__,
     _DialectLike,
     _QuotingType,
-    _reader,
-    _writer,
     field_size_limit as field_size_limit,
     get_dialect as get_dialect,
     list_dialects as list_dialects,
@@ -21,6 +19,10 @@ from _csv import (
 
 if sys.version_info >= (3, 12):
     from _csv import QUOTE_NOTNULL as QUOTE_NOTNULL, QUOTE_STRINGS as QUOTE_STRINGS
+if sys.version_info >= (3, 10):
+    from _csv import Reader, Writer
+else:
+    from _csv import _reader as Reader, _writer as Writer
 
 from _typeshed import SupportsWrite
 from collections.abc import Collection, Iterable, Mapping, Sequence
@@ -77,7 +79,7 @@ class DictReader(Generic[_T]):
     fieldnames: Sequence[_T] | None
     restkey: _T | None
     restval: str | Any | None
-    reader: _reader
+    reader: Reader
     dialect: _DialectLike
     line_num: int
     @overload
@@ -125,7 +127,7 @@ class DictWriter(Generic[_T]):
     fieldnames: Collection[_T]
     restval: Any | None
     extrasaction: Literal["raise", "ignore"]
-    writer: _writer
+    writer: Writer
     def __init__(
         self,
         f: SupportsWrite[str],

crates/red_knot_vendored/vendor/typeshed/stdlib/ctypes/__init__.pyi

@@ -10,13 +10,11 @@ from _ctypes import (
     _CanCastTo as _CanCastTo,
     _CArgObject as _CArgObject,
     _CData as _CData,
-    _CDataMeta as _CDataMeta,
+    _CDataType as _CDataType,
     _CField as _CField,
     _Pointer as _Pointer,
     _PointerLike as _PointerLike,
     _SimpleCData as _SimpleCData,
-    _StructUnionBase as _StructUnionBase,
-    _StructUnionMeta as _StructUnionMeta,
     addressof as addressof,
     alignment as alignment,
     byref as byref,
@@ -28,7 +26,7 @@ from _ctypes import (
 )
 from ctypes._endian import BigEndianStructure as BigEndianStructure, LittleEndianStructure as LittleEndianStructure
 from typing import Any, ClassVar, Generic, TypeVar
-from typing_extensions import TypeAlias
+from typing_extensions import Self, TypeAlias, deprecated
 
 if sys.platform == "win32":
     from _ctypes import FormatError as FormatError, get_last_error as get_last_error, set_last_error as set_last_error
@@ -41,6 +39,7 @@ if sys.version_info >= (3, 9):
 
 _T = TypeVar("_T")
 _DLLT = TypeVar("_DLLT", bound=CDLL)
+_CT = TypeVar("_CT", bound=_CData)
 
 DEFAULT_MODE: int
 
@@ -48,7 +47,7 @@ class ArgumentError(Exception): ...
 
 class CDLL:
     _func_flags_: ClassVar[int]
-    _func_restype_: ClassVar[_CData]
+    _func_restype_: ClassVar[_CDataType]
     _name: str
     _handle: int
     _FuncPtr: type[_FuncPointer]
@@ -91,15 +90,21 @@ class _NamedFuncPointer(_FuncPointer):
     __name__: str
 
 def CFUNCTYPE(
-    restype: type[_CData] | None, *argtypes: type[_CData], use_errno: bool = ..., use_last_error: bool = ...
+    restype: type[_CData | _CDataType] | None,
+    *argtypes: type[_CData | _CDataType],
+    use_errno: bool = ...,
+    use_last_error: bool = ...,
 ) -> type[_FuncPointer]: ...
 
 if sys.platform == "win32":
     def WINFUNCTYPE(
-        restype: type[_CData] | None, *argtypes: type[_CData], use_errno: bool = ..., use_last_error: bool = ...
+        restype: type[_CData | _CDataType] | None,
+        *argtypes: type[_CData | _CDataType],
+        use_errno: bool = ...,
+        use_last_error: bool = ...,
     ) -> type[_FuncPointer]: ...
 
-def PYFUNCTYPE(restype: type[_CData] | None, *argtypes: type[_CData]) -> type[_FuncPointer]: ...
+def PYFUNCTYPE(restype: type[_CData | _CDataType] | None, *argtypes: type[_CData | _CDataType]) -> type[_FuncPointer]: ...
 
 # Any type that can be implicitly converted to c_void_p when passed as a C function argument.
 # (bytes is not included here, see below.)
@@ -112,12 +117,17 @@ _CVoidConstPLike: TypeAlias = _CVoidPLike | bytes
 
 _CastT = TypeVar("_CastT", bound=_CanCastTo)
 
-def cast(obj: _CData | _CArgObject | int, typ: type[_CastT]) -> _CastT: ...
+def cast(obj: _CData | _CDataType | _CArgObject | int, typ: type[_CastT]) -> _CastT: ...
 def create_string_buffer(init: int | bytes, size: int | None = None) -> Array[c_char]: ...
 
 c_buffer = create_string_buffer
 
 def create_unicode_buffer(init: int | str, size: int | None = None) -> Array[c_wchar]: ...
+@deprecated("Deprecated in Python 3.13; removal scheduled for Python 3.15")
+def SetPointerType(
+    pointer: type[_Pointer[Any]], cls: Any  # noqa: F811  # Redefinition of unused `pointer` from line 22
+) -> None: ...
+def ARRAY(typ: _CT, len: int) -> Array[_CT]: ...  # Soft Deprecated, no plans to remove
 
 if sys.platform == "win32":
     def DllCanUnloadNow() -> int: ...
@@ -126,12 +136,12 @@ if sys.platform == "win32":
 
 def memmove(dst: _CVoidPLike, src: _CVoidConstPLike, count: int) -> int: ...
 def memset(dst: _CVoidPLike, c: int, count: int) -> int: ...
-def string_at(address: _CVoidConstPLike, size: int = -1) -> bytes: ...
+def string_at(ptr: _CVoidConstPLike, size: int = -1) -> bytes: ...
 
 if sys.platform == "win32":
     def WinError(code: int | None = None, descr: str | None = None) -> OSError: ...
 
-def wstring_at(address: _CVoidConstPLike, size: int = -1) -> str: ...
+def wstring_at(ptr: _CVoidConstPLike, size: int = -1) -> str: ...
 
 class c_byte(_SimpleCData[int]): ...
 
@@ -140,6 +150,8 @@ class c_char(_SimpleCData[bytes]):
 
 class c_char_p(_PointerLike, _SimpleCData[bytes | None]):
     def __init__(self, value: int | bytes | None = ...) -> None: ...
+    @classmethod
+    def from_param(cls, value: Any, /) -> Self | _CArgObject: ...
 
 class c_double(_SimpleCData[float]): ...
 class c_longdouble(_SimpleCData[float]): ...  # can be an alias for c_double
@@ -155,7 +167,13 @@ class c_uint(_SimpleCData[int]): ...  # can be an alias for c_ulong
 class c_ulong(_SimpleCData[int]): ...
 class c_ulonglong(_SimpleCData[int]): ...  # can be an alias for c_ulong
 class c_ushort(_SimpleCData[int]): ...
-class c_void_p(_PointerLike, _SimpleCData[int | None]): ...
+
+class c_void_p(_PointerLike, _SimpleCData[int | None]):
+    @classmethod
+    def from_param(cls, value: Any, /) -> Self | _CArgObject: ...
+
+c_voidp = c_void_p  # backwards compatibility (to a bug)
+
 class c_wchar(_SimpleCData[str]): ...
 
 c_int8 = c_byte
@@ -174,6 +192,8 @@ class c_uint64(_SimpleCData[int]): ...
 
 class c_wchar_p(_PointerLike, _SimpleCData[str | None]):
     def __init__(self, value: int | str | None = ...) -> None: ...
+    @classmethod
+    def from_param(cls, value: Any, /) -> Self | _CArgObject: ...
 
 class c_bool(_SimpleCData[bool]):
     def __init__(self, value: bool = ...) -> None: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/ctypes/macholib/__init__.pyi

@@ -0,0 +1 @@
+__version__: str

crates/red_knot_vendored/vendor/typeshed/stdlib/ctypes/macholib/dyld.pyi

@@ -0,0 +1,8 @@
+from collections.abc import Mapping
+from ctypes.macholib.dylib import dylib_info as dylib_info
+from ctypes.macholib.framework import framework_info as framework_info
+
+__all__ = ["dyld_find", "framework_find", "framework_info", "dylib_info"]
+
+def dyld_find(name: str, executable_path: str | None = None, env: Mapping[str, str] | None = None) -> str: ...
+def framework_find(fn: str, executable_path: str | None = None, env: Mapping[str, str] | None = None) -> str: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/ctypes/macholib/dylib.pyi

@@ -0,0 +1,14 @@
+from typing import TypedDict, type_check_only
+
+__all__ = ["dylib_info"]
+
+# Actual result is produced by re.match.groupdict()
+@type_check_only
+class _DylibInfo(TypedDict):
+    location: str
+    name: str
+    shortname: str
+    version: str | None
+    suffix: str | None
+
+def dylib_info(filename: str) -> _DylibInfo | None: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/ctypes/macholib/framework.pyi

@@ -0,0 +1,14 @@
+from typing import TypedDict, type_check_only
+
+__all__ = ["framework_info"]
+
+# Actual result is produced by re.match.groupdict()
+@type_check_only
+class _FrameworkInfo(TypedDict):
+    location: str
+    name: str
+    shortname: str
+    version: str | None
+    suffix: str | None
+
+def framework_info(filename: str) -> _FrameworkInfo | None: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/ctypes/util.pyi

@@ -4,3 +4,5 @@ def find_library(name: str) -> str | None: ...
 
 if sys.platform == "win32":
     def find_msvcrt() -> str | None: ...
+
+def test() -> None: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/ctypes/wintypes.pyi

@@ -1,7 +1,7 @@
+from _ctypes import _CArgObject, _CField
 from ctypes import (
     Array,
     Structure,
-    _CField,
     _Pointer,
     _SimpleCData,
     c_byte,
@@ -21,8 +21,8 @@ from ctypes import (
     c_wchar,
     c_wchar_p,
 )
-from typing import TypeVar
-from typing_extensions import TypeAlias
+from typing import Any, TypeVar
+from typing_extensions import Self, TypeAlias
 
 BYTE = c_byte
 WORD = c_ushort
@@ -241,10 +241,16 @@ LPBYTE = PBYTE
 PBOOLEAN = PBYTE
 
 # LP_c_char
-class PCHAR(_Pointer[CHAR]): ...
+class PCHAR(_Pointer[CHAR]):
+    # this is inherited from ctypes.c_char_p, kind of.
+    @classmethod
+    def from_param(cls, value: Any, /) -> Self | _CArgObject: ...
 
 # LP_c_wchar
-class PWCHAR(_Pointer[WCHAR]): ...
+class PWCHAR(_Pointer[WCHAR]):
+    # inherited from ctypes.c_wchar_p, kind of
+    @classmethod
+    def from_param(cls, value: Any, /) -> Self | _CArgObject: ...
 
 # LP_c_void_p
 class PHANDLE(_Pointer[HANDLE]): ...

crates/red_knot_vendored/vendor/typeshed/stdlib/curses/__init__.pyi

@@ -1,7 +1,9 @@
+import sys
 from _curses import *
 from _curses import window as window
+from _typeshed import structseq
 from collections.abc import Callable
-from typing import TypeVar
+from typing import Final, TypeVar, final, type_check_only
 from typing_extensions import Concatenate, ParamSpec
 
 # NOTE: The _curses module is ordinarily only available on Unix, but the
@@ -25,3 +27,19 @@ def wrapper(func: Callable[Concatenate[window, _P], _T], /, *arg: _P.args, **kwd
 # it was mapped to the name 'window' in 3.8.
 # Kept here as a legacy alias in case any third-party code is relying on it.
 _CursesWindow = window
+
+# At runtime this class is unexposed and calls itself curses.ncurses_version.
+# That name would conflict with the actual curses.ncurses_version, which is
+# an instance of this class.
+@final
+@type_check_only
+class _ncurses_version(structseq[int], tuple[int, int, int]):
+    if sys.version_info >= (3, 10):
+        __match_args__: Final = ("major", "minor", "patch")
+
+    @property
+    def major(self) -> int: ...
+    @property
+    def minor(self) -> int: ...
+    @property
+    def patch(self) -> int: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/curses/panel.pyi

@@ -1,22 +1 @@
-from _curses import window
-
-version: str
-
-class _Curses_Panel:  # type is <class '_curses_panel.curses panel'> (note the space in the class name)
-    def above(self) -> _Curses_Panel: ...
-    def below(self) -> _Curses_Panel: ...
-    def bottom(self) -> None: ...
-    def hidden(self) -> bool: ...
-    def hide(self) -> None: ...
-    def move(self, y: int, x: int) -> None: ...
-    def replace(self, win: window) -> None: ...
-    def set_userptr(self, obj: object) -> None: ...
-    def show(self) -> None: ...
-    def top(self) -> None: ...
-    def userptr(self) -> object: ...
-    def window(self) -> window: ...
-
-def bottom_panel() -> _Curses_Panel: ...
-def new_panel(win: window, /) -> _Curses_Panel: ...
-def top_panel() -> _Curses_Panel: ...
-def update_panels() -> _Curses_Panel: ...
+from _curses_panel import *

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

@@ -1,8 +1,8 @@
 import sys
 from abc import abstractmethod
 from time import struct_time
-from typing import ClassVar, Final, NamedTuple, NoReturn, SupportsIndex, final, overload
-from typing_extensions import Self, TypeAlias, deprecated
+from typing import ClassVar, Final, NoReturn, SupportsIndex, final, overload, type_check_only
+from typing_extensions import CapsuleType, Self, TypeAlias, deprecated
 
 if sys.version_info >= (3, 11):
     __all__ = ("date", "datetime", "time", "timedelta", "timezone", "tzinfo", "MINYEAR", "MAXYEAR", "UTC")
@@ -40,10 +40,17 @@ if sys.version_info >= (3, 11):
     UTC: timezone
 
 if sys.version_info >= (3, 9):
-    class _IsoCalendarDate(NamedTuple):
-        year: int
-        week: int
-        weekday: int
+    # This class calls itself datetime.IsoCalendarDate. It's neither
+    # NamedTuple nor structseq.
+    @final
+    @type_check_only
+    class _IsoCalendarDate(tuple[int, int, int]):
+        @property
+        def year(self) -> int: ...
+        @property
+        def week(self) -> int: ...
+        @property
+        def weekday(self) -> int: ...
 
 class date:
     min: ClassVar[date]
@@ -325,3 +332,5 @@ class datetime(date):
     def __sub__(self, value: Self, /) -> timedelta: ...
     @overload
     def __sub__(self, value: timedelta, /) -> Self: ...
+
+datetime_CAPI: CapsuleType

crates/red_knot_vendored/vendor/typeshed/stdlib/dbm/__init__.pyi

@@ -2,7 +2,7 @@ import sys
 from _typeshed import StrOrBytesPath
 from collections.abc import Iterator, MutableMapping
 from types import TracebackType
-from typing import Literal
+from typing import Literal, type_check_only
 from typing_extensions import Self, TypeAlias
 
 __all__ = ["open", "whichdb", "error"]
@@ -89,6 +89,8 @@ class _Database(MutableMapping[_KeyType, bytes]):
         self, exc_type: type[BaseException] | None, exc_val: BaseException | None, exc_tb: TracebackType | None
     ) -> None: ...
 
+# This class is not exposed. It calls itself dbm.error.
+@type_check_only
 class _error(Exception): ...
 
 error: tuple[type[_error], type[OSError]]

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

@@ -24,7 +24,8 @@ from _decimal import (
     setcontext as setcontext,
 )
 from collections.abc import Container, Sequence
-from typing import Any, ClassVar, Literal, NamedTuple, overload
+from types import TracebackType
+from typing import Any, ClassVar, Literal, NamedTuple, final, overload, type_check_only
 from typing_extensions import Self, TypeAlias
 
 _Decimal: TypeAlias = Decimal | int
@@ -35,6 +36,14 @@ _TrapType: TypeAlias = type[DecimalException]
 # At runtime, these classes are implemented in C as part of "_decimal".
 # However, they consider themselves to live in "decimal", so we'll put them here.
 
+# This type isn't exposed at runtime. It calls itself decimal.ContextManager
+@final
+@type_check_only
+class _ContextManager:
+    def __init__(self, new_context: Context) -> None: ...
+    def __enter__(self) -> Context: ...
+    def __exit__(self, t: type[BaseException] | None, v: BaseException | None, tb: TracebackType | None) -> None: ...
+
 class DecimalTuple(NamedTuple):
     sign: int
     digits: tuple[int, ...]

crates/red_knot_vendored/vendor/typeshed/stdlib/distutils/ccompiler.pyi

@@ -165,7 +165,7 @@ class CCompiler:
     def execute(
         self, func: Callable[[Unpack[_Ts]], Unused], args: tuple[Unpack[_Ts]], msg: str | None = None, level: int = 1
     ) -> None: ...
-    def spawn(self, cmd: list[str]) -> None: ...
+    def spawn(self, cmd: Iterable[str]) -> None: ...
     def mkpath(self, name: str, mode: int = 0o777) -> None: ...
     @overload
     def move_file(self, src: StrPath, dst: _StrPathT) -> _StrPathT | str: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/distutils/spawn.pyi

@@ -1,6 +1,10 @@
+from collections.abc import Iterable
 from typing import Literal
 
 def spawn(
-    cmd: list[str], search_path: bool | Literal[0, 1] = 1, verbose: bool | Literal[0, 1] = 0, dry_run: bool | Literal[0, 1] = 0
+    cmd: Iterable[str],
+    search_path: bool | Literal[0, 1] = 1,
+    verbose: bool | Literal[0, 1] = 0,
+    dry_run: bool | Literal[0, 1] = 0,
 ) -> None: ...
 def find_executable(executable: str, path: str | None = None) -> str | None: ...

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

@@ -3,7 +3,7 @@ import types
 import unittest
 from _typeshed import ExcInfo
 from collections.abc import Callable
-from typing import Any, ClassVar, NamedTuple
+from typing import Any, NamedTuple, type_check_only
 from typing_extensions import Self, TypeAlias
 
 __all__ = [
@@ -42,17 +42,15 @@ __all__ = [
     "debug",
 ]
 
-# MyPy errors on conditionals within named tuples.
-
 if sys.version_info >= (3, 13):
-    class TestResults(NamedTuple):
-        def __new__(cls, failed: int, attempted: int, *, skipped: int = 0) -> Self: ...  # type: ignore[misc]
-        skipped: int
+    @type_check_only
+    class _TestResultsBase(NamedTuple):
         failed: int
         attempted: int
-        _fields: ClassVar = ("failed", "attempted")  # type: ignore[misc]
-        __match_args__ = ("failed", "attempted")  # type: ignore[misc]
-        __doc__: None  # type: ignore[misc]
+
+    class TestResults(_TestResultsBase):
+        def __new__(cls, failed: int, attempted: int, *, skipped: int = 0) -> Self: ...
+        skipped: int
 
 else:
     class TestResults(NamedTuple):

crates/red_knot_vendored/vendor/typeshed/stdlib/email/__init__.pyi

@@ -4,6 +4,29 @@ from email.policy import Policy
 from typing import IO
 from typing_extensions import TypeAlias
 
+# At runtime, listing submodules in __all__ without them being imported is
+# valid, and causes them to be included in a star import. See #6523
+
+__all__ = [  # noqa: F822  # Undefined names in __all__
+    "base64mime",  # pyright: ignore[reportUnsupportedDunderAll]
+    "charset",  # pyright: ignore[reportUnsupportedDunderAll]
+    "encoders",  # pyright: ignore[reportUnsupportedDunderAll]
+    "errors",  # pyright: ignore[reportUnsupportedDunderAll]
+    "feedparser",  # pyright: ignore[reportUnsupportedDunderAll]
+    "generator",  # pyright: ignore[reportUnsupportedDunderAll]
+    "header",  # pyright: ignore[reportUnsupportedDunderAll]
+    "iterators",  # pyright: ignore[reportUnsupportedDunderAll]
+    "message",  # pyright: ignore[reportUnsupportedDunderAll]
+    "message_from_file",
+    "message_from_binary_file",
+    "message_from_string",
+    "message_from_bytes",
+    "mime",  # pyright: ignore[reportUnsupportedDunderAll]
+    "parser",  # pyright: ignore[reportUnsupportedDunderAll]
+    "quoprimime",  # pyright: ignore[reportUnsupportedDunderAll]
+    "utils",  # pyright: ignore[reportUnsupportedDunderAll]
+]
+
 # Definitions imported by multiple submodules in typeshed
 _ParamType: TypeAlias = str | tuple[str | None, str | None, str]  # noqa: Y047
 _ParamsType: TypeAlias = str | None | tuple[str, str | None, str]  # noqa: Y047
@@ -12,18 +35,3 @@ def message_from_string(s: str, _class: Callable[[], Message] = ..., *, policy:
 def message_from_bytes(s: bytes | bytearray, _class: Callable[[], Message] = ..., *, policy: Policy = ...) -> Message: ...
 def message_from_file(fp: IO[str], _class: Callable[[], Message] = ..., *, policy: Policy = ...) -> Message: ...
 def message_from_binary_file(fp: IO[bytes], _class: Callable[[], Message] = ..., *, policy: Policy = ...) -> Message: ...
-
-# Names in __all__ with no definition:
-#   base64mime
-#   charset
-#   encoders
-#   errors
-#   feedparser
-#   generator
-#   header
-#   iterators
-#   message
-#   mime
-#   parser
-#   quoprimime
-#   utils

crates/red_knot_vendored/vendor/typeshed/stdlib/email/_policybase.pyi

@@ -5,6 +5,8 @@ from email.message import Message
 from typing import Generic, Protocol, TypeVar, type_check_only
 from typing_extensions import Self
 
+__all__ = ["Policy", "Compat32", "compat32"]
+
 _MessageT = TypeVar("_MessageT", bound=Message, default=Message)
 
 @type_check_only

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/aliases.pyi

@@ -0,0 +1 @@
+aliases: dict[str, str]

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/ascii.pyi

@@ -0,0 +1,30 @@
+import codecs
+from _typeshed import ReadableBuffer
+
+class Codec(codecs.Codec):
+    # At runtime, this is codecs.ascii_encode
+    @staticmethod
+    def encode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...
+    # At runtime, this is codecs.ascii_decode
+    @staticmethod
+    def decode(data: ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input: str, final: bool = False) -> bytes: ...
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
+
+class StreamWriter(Codec, codecs.StreamWriter): ...
+class StreamReader(Codec, codecs.StreamReader): ...
+
+# Note: encode being a decode function and decode being an encode function is accurate to runtime.
+class StreamConverter(StreamWriter, StreamReader):  # type: ignore[misc]  # incompatible methods in base classes
+    # At runtime, this is codecs.ascii_decode
+    @staticmethod
+    def encode(data: ReadableBuffer, errors: str | None = None, /) -> tuple[str, int]: ...  # type: ignore[override]
+    # At runtime, this is codecs.ascii_encode
+    @staticmethod
+    def decode(str: str, errors: str | None = None, /) -> tuple[bytes, int]: ...  # type: ignore[override]
+
+def getregentry() -> codecs.CodecInfo: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/base64_codec.pyi

@@ -0,0 +1,26 @@
+import codecs
+from _typeshed import ReadableBuffer
+from typing import ClassVar
+
+# This codec is bytes to bytes.
+
+def base64_encode(input: ReadableBuffer, errors: str = "strict") -> tuple[bytes, int]: ...
+def base64_decode(input: ReadableBuffer, errors: str = "strict") -> tuple[bytes, int]: ...
+
+class Codec(codecs.Codec):
+    def encode(self, input: ReadableBuffer, errors: str = "strict") -> tuple[bytes, int]: ...  # type: ignore[override]
+    def decode(self, input: ReadableBuffer, errors: str = "strict") -> tuple[bytes, int]: ...  # type: ignore[override]
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input: ReadableBuffer, final: bool = False) -> bytes: ...  # type: ignore[override]
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input: ReadableBuffer, final: bool = False) -> bytes: ...  # type: ignore[override]
+
+class StreamWriter(Codec, codecs.StreamWriter):
+    charbuffertype: ClassVar[type] = ...
+
+class StreamReader(Codec, codecs.StreamReader):
+    charbuffertype: ClassVar[type] = ...
+
+def getregentry() -> codecs.CodecInfo: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/big5.pyi

@@ -0,0 +1,23 @@
+import _multibytecodec as mbc
+import codecs
+from typing import ClassVar
+
+codec: mbc._MultibyteCodec
+
+class Codec(codecs.Codec):
+    encode = codec.encode  # type: ignore[assignment]  # pyright: ignore[reportAssignmentType]
+    decode = codec.decode  # type: ignore[assignment]  # pyright: ignore[reportAssignmentType]
+
+class IncrementalEncoder(mbc.MultibyteIncrementalEncoder, codecs.IncrementalEncoder):  # type: ignore[misc]
+    codec: ClassVar[mbc._MultibyteCodec] = ...
+
+class IncrementalDecoder(mbc.MultibyteIncrementalDecoder, codecs.IncrementalDecoder):
+    codec: ClassVar[mbc._MultibyteCodec] = ...
+
+class StreamReader(Codec, mbc.MultibyteStreamReader, codecs.StreamReader):  # type: ignore[misc]
+    codec: ClassVar[mbc._MultibyteCodec] = ...
+
+class StreamWriter(Codec, mbc.MultibyteStreamWriter, codecs.StreamWriter):
+    codec: ClassVar[mbc._MultibyteCodec] = ...
+
+def getregentry() -> codecs.CodecInfo: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/big5hkscs.pyi

@@ -0,0 +1,23 @@
+import _multibytecodec as mbc
+import codecs
+from typing import ClassVar
+
+codec: mbc._MultibyteCodec
+
+class Codec(codecs.Codec):
+    encode = codec.encode  # type: ignore[assignment]  # pyright: ignore[reportAssignmentType]
+    decode = codec.decode  # type: ignore[assignment]  # pyright: ignore[reportAssignmentType]
+
+class IncrementalEncoder(mbc.MultibyteIncrementalEncoder, codecs.IncrementalEncoder):  # type: ignore[misc]
+    codec: ClassVar[mbc._MultibyteCodec] = ...
+
+class IncrementalDecoder(mbc.MultibyteIncrementalDecoder, codecs.IncrementalDecoder):
+    codec: ClassVar[mbc._MultibyteCodec] = ...
+
+class StreamReader(Codec, mbc.MultibyteStreamReader, codecs.StreamReader):  # type: ignore[misc]
+    codec: ClassVar[mbc._MultibyteCodec] = ...
+
+class StreamWriter(Codec, mbc.MultibyteStreamWriter, codecs.StreamWriter):
+    codec: ClassVar[mbc._MultibyteCodec] = ...
+
+def getregentry() -> codecs.CodecInfo: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/bz2_codec.pyi

@@ -0,0 +1,26 @@
+import codecs
+from _typeshed import ReadableBuffer
+from typing import ClassVar
+
+# This codec is bytes to bytes.
+
+def bz2_encode(input: ReadableBuffer, errors: str = "strict") -> tuple[bytes, int]: ...
+def bz2_decode(input: ReadableBuffer, errors: str = "strict") -> tuple[bytes, int]: ...
+
+class Codec(codecs.Codec):
+    def encode(self, input: ReadableBuffer, errors: str = "strict") -> tuple[bytes, int]: ...  # type: ignore[override]
+    def decode(self, input: ReadableBuffer, errors: str = "strict") -> tuple[bytes, int]: ...  # type: ignore[override]
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input: ReadableBuffer, final: bool = False) -> bytes: ...  # type: ignore[override]
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input: ReadableBuffer, final: bool = False) -> bytes: ...  # type: ignore[override]
+
+class StreamWriter(Codec, codecs.StreamWriter):
+    charbuffertype: ClassVar[type] = ...
+
+class StreamReader(Codec, codecs.StreamReader):
+    charbuffertype: ClassVar[type] = ...
+
+def getregentry() -> codecs.CodecInfo: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/charmap.pyi

@@ -0,0 +1,33 @@
+import codecs
+from _codecs import _CharMap
+from _typeshed import ReadableBuffer
+
+class Codec(codecs.Codec):
+    # At runtime, this is codecs.charmap_encode
+    @staticmethod
+    def encode(str: str, errors: str | None = None, mapping: _CharMap | None = None, /) -> tuple[bytes, int]: ...
+    # At runtime, this is codecs.charmap_decode
+    @staticmethod
+    def decode(data: ReadableBuffer, errors: str | None = None, mapping: _CharMap | None = None, /) -> tuple[str, int]: ...
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    mapping: _CharMap | None
+    def __init__(self, errors: str = "strict", mapping: _CharMap | None = None) -> None: ...
+    def encode(self, input: str, final: bool = False) -> bytes: ...
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    mapping: _CharMap | None
+    def __init__(self, errors: str = "strict", mapping: _CharMap | None = None) -> None: ...
+    def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
+
+class StreamWriter(Codec, codecs.StreamWriter):
+    mapping: _CharMap | None
+    def __init__(self, stream: codecs._WritableStream, errors: str = "strict", mapping: _CharMap | None = None) -> None: ...
+    def encode(self, input: str, errors: str = "strict") -> tuple[bytes, int]: ...  # type: ignore[override]
+
+class StreamReader(Codec, codecs.StreamReader):
+    mapping: _CharMap | None
+    def __init__(self, stream: codecs._ReadableStream, errors: str = "strict", mapping: _CharMap | None = None) -> None: ...
+    def decode(self, input: ReadableBuffer, errors: str = "strict") -> tuple[str, int]: ...  # type: ignore[override]
+
+def getregentry() -> codecs.CodecInfo: ...

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/cp037.pyi

@@ -0,0 +1,21 @@
+import codecs
+from _codecs import _EncodingMap
+from _typeshed import ReadableBuffer
+
+class Codec(codecs.Codec):
+    def encode(self, input: str, errors: str = "strict") -> tuple[bytes, int]: ...
+    def decode(self, input: bytes, errors: str = "strict") -> tuple[str, int]: ...
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input: str, final: bool = False) -> bytes: ...
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
+
+class StreamWriter(Codec, codecs.StreamWriter): ...
+class StreamReader(Codec, codecs.StreamReader): ...
+
+def getregentry() -> codecs.CodecInfo: ...
+
+decoding_table: str
+encoding_table: _EncodingMap

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/cp1006.pyi

@@ -0,0 +1,21 @@
+import codecs
+from _codecs import _EncodingMap
+from _typeshed import ReadableBuffer
+
+class Codec(codecs.Codec):
+    def encode(self, input: str, errors: str = "strict") -> tuple[bytes, int]: ...
+    def decode(self, input: bytes, errors: str = "strict") -> tuple[str, int]: ...
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input: str, final: bool = False) -> bytes: ...
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
+
+class StreamWriter(Codec, codecs.StreamWriter): ...
+class StreamReader(Codec, codecs.StreamReader): ...
+
+def getregentry() -> codecs.CodecInfo: ...
+
+decoding_table: str
+encoding_table: _EncodingMap

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/cp1026.pyi

@@ -0,0 +1,21 @@
+import codecs
+from _codecs import _EncodingMap
+from _typeshed import ReadableBuffer
+
+class Codec(codecs.Codec):
+    def encode(self, input: str, errors: str = "strict") -> tuple[bytes, int]: ...
+    def decode(self, input: bytes, errors: str = "strict") -> tuple[str, int]: ...
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input: str, final: bool = False) -> bytes: ...
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
+
+class StreamWriter(Codec, codecs.StreamWriter): ...
+class StreamReader(Codec, codecs.StreamReader): ...
+
+def getregentry() -> codecs.CodecInfo: ...
+
+decoding_table: str
+encoding_table: _EncodingMap

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/cp1125.pyi

@@ -0,0 +1,21 @@
+import codecs
+from _typeshed import ReadableBuffer
+
+class Codec(codecs.Codec):
+    def encode(self, input: str, errors: str = "strict") -> tuple[bytes, int]: ...
+    def decode(self, input: bytes, errors: str = "strict") -> tuple[str, int]: ...
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input: str, final: bool = False) -> bytes: ...
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
+
+class StreamWriter(Codec, codecs.StreamWriter): ...
+class StreamReader(Codec, codecs.StreamReader): ...
+
+def getregentry() -> codecs.CodecInfo: ...
+
+decoding_map: dict[int, int | None]
+decoding_table: str
+encoding_map: dict[int, int]

crates/red_knot_vendored/vendor/typeshed/stdlib/encodings/cp1140.pyi

@@ -0,0 +1,21 @@
+import codecs
+from _codecs import _EncodingMap
+from _typeshed import ReadableBuffer
+
+class Codec(codecs.Codec):
+    def encode(self, input: str, errors: str = "strict") -> tuple[bytes, int]: ...
+    def decode(self, input: bytes, errors: str = "strict") -> tuple[str, int]: ...
+
+class IncrementalEncoder(codecs.IncrementalEncoder):
+    def encode(self, input: str, final: bool = False) -> bytes: ...
+
+class IncrementalDecoder(codecs.IncrementalDecoder):
+    def decode(self, input: ReadableBuffer, final: bool = False) -> str: ...
+
+class StreamWriter(Codec, codecs.StreamWriter): ...
+class StreamReader(Codec, codecs.StreamReader): ...
+
+def getregentry() -> codecs.CodecInfo: ...
+
+decoding_table: str
+encoding_table: _EncodingMap