[ty] Make special cases for subscript inference exhaustive

## Summary

Closes https://github.com/astral-sh/ty/issues/2267.

crates/ruff_linter/src/rules/flake8_pytest_style/rules/assertion.rs

@@ -106,6 +106,16 @@ impl Violation for PytestCompositeAssertion {
 ///     assert exc_info.value.args
 /// ```
 ///
+/// Or, for pytest 8.4.0 and later:
+/// ```python
+/// import pytest
+///
+///
+/// def test_foo():
+///     with pytest.raises(ZeroDivisionError, check=lambda e: e.args):
+///         1 / 0
+/// ```
+///
 /// ## References
 /// - [`pytest` documentation: `pytest.raises`](https://docs.pytest.org/en/latest/reference/reference.html#pytest-raises)
 #[derive(ViolationMetadata)]

crates/ruff_linter/src/rules/isort/rules/add_required_imports.rs

@@ -140,7 +140,7 @@ pub(crate) fn add_required_imports(
     source_type: PySourceType,
     context: &LintContext,
 ) {
-    for required_import in &settings.isort.required_imports {
+    for required_import in settings.isort.required_imports.iter().rev() {
         add_required_import(
             required_import,
             parsed,

crates/ruff_linter/src/rules/isort/snapshots/ruff_linter__rules__isort__tests__required_imports_docstring.py.snap

@@ -1,14 +1,6 @@
 ---
 source: crates/ruff_linter/src/rules/isort/mod.rs
 ---
-I002 [*] Missing required import: `from __future__ import annotations`
---> docstring.py:1:1
-help: Insert required import: `from __future__ import annotations`
-1 | """Hello, world!"""
-2 + from __future__ import annotations
-3 | 
-4 | x = 1
-
 I002 [*] Missing required import: `from __future__ import generator_stop`
 --> docstring.py:1:1
 help: Insert required import: `from __future__ import generator_stop`
@@ -16,3 +8,11 @@ help: Insert required import: `from __future__ import generator_stop`
 2 + from __future__ import generator_stop
 3 | 
 4 | x = 1
+
+I002 [*] Missing required import: `from __future__ import annotations`
+--> docstring.py:1:1
+help: Insert required import: `from __future__ import annotations`
+1 | """Hello, world!"""
+2 + from __future__ import annotations
+3 | 
+4 | x = 1

crates/ruff_linter/src/rules/isort/snapshots/ruff_linter__rules__isort__tests__required_imports_multiple_strings.py.snap

@@ -1,15 +1,6 @@
 ---
 source: crates/ruff_linter/src/rules/isort/mod.rs
 ---
-I002 [*] Missing required import: `from __future__ import annotations`
---> multiple_strings.py:1:1
-help: Insert required import: `from __future__ import annotations`
-1 | """This is a docstring."""
-2 + from __future__ import annotations
-3 | "This is not a docstring."
-4 | "This is also not a docstring."
-5 | 
-
 I002 [*] Missing required import: `from __future__ import generator_stop`
 --> multiple_strings.py:1:1
 help: Insert required import: `from __future__ import generator_stop`
@@ -17,4 +8,13 @@ help: Insert required import: `from __future__ import generator_stop`
 2 + from __future__ import generator_stop
 3 | "This is not a docstring."
 4 | "This is also not a docstring."
+5 | 
+
+I002 [*] Missing required import: `from __future__ import annotations`
+--> multiple_strings.py:1:1
+help: Insert required import: `from __future__ import annotations`
+1 | """This is a docstring."""
+2 + from __future__ import annotations
+3 | "This is not a docstring."
+4 | "This is also not a docstring."
 5 |

crates/ruff_linter/src/rules/pyupgrade/mod.rs

@@ -398,17 +398,17 @@ mod tests {
         1 + from pipes import Template
         2 + from shlex import quote
 
-        I002 [*] Missing required import: `from __future__ import generator_stop`
-        --> <filename>:1:1
-        help: Insert required import: `from __future__ import generator_stop`
-        1 + from __future__ import generator_stop
-        2 | from pipes import quote, Template
-
         I002 [*] Missing required import: `from collections import Sequence`
         --> <filename>:1:1
         help: Insert required import: `from collections import Sequence`
         1 + from collections import Sequence
         2 | from pipes import quote, Template
+
+        I002 [*] Missing required import: `from __future__ import generator_stop`
+        --> <filename>:1:1
+        help: Insert required import: `from __future__ import generator_stop`
+        1 + from __future__ import generator_stop
+        2 | from pipes import quote, Template
         ");
     }
 

crates/ty/docs/rules.md

@@ -8,7 +8,7 @@
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20ambiguous-protocol-member" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L541" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L542" target="_blank">View source</a>
 </small>
 
 
@@ -80,7 +80,7 @@ def test(): -> "int":
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20call-non-callable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L140" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L141" target="_blank">View source</a>
 </small>
 
 
@@ -104,7 +104,7 @@ Calling a non-callable object will raise a `TypeError` at runtime.
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.7">0.0.7</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20call-top-callable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L158" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L159" target="_blank">View source</a>
 </small>
 
 
@@ -135,7 +135,7 @@ def f(x: object):
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-argument-forms" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L209" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L210" target="_blank">View source</a>
 </small>
 
 
@@ -167,7 +167,7 @@ f(int)  # error
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-declarations" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L235" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L236" target="_blank">View source</a>
 </small>
 
 
@@ -198,7 +198,7 @@ a = 1
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20conflicting-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L260" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L261" target="_blank">View source</a>
 </small>
 
 
@@ -230,7 +230,7 @@ class C(A, B): ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-class-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L286" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L287" target="_blank">View source</a>
 </small>
 
 
@@ -262,7 +262,7 @@ class B(A): ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20cyclic-type-alias-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L312" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L313" target="_blank">View source</a>
 </small>
 
 
@@ -290,7 +290,7 @@ type B = A
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.16">0.0.1-alpha.16</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20deprecated" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L356" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L357" target="_blank">View source</a>
 </small>
 
 
@@ -317,7 +317,7 @@ old_func()  # emits [deprecated] diagnostic
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20division-by-zero" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L334" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L335" target="_blank">View source</a>
 </small>
 
 
@@ -346,7 +346,7 @@ false positives it can produce.
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L377" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L378" target="_blank">View source</a>
 </small>
 
 
@@ -373,7 +373,7 @@ class B(A, A): ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20duplicate-kw-only" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L398" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L399" target="_blank">View source</a>
 </small>
 
 
@@ -529,7 +529,7 @@ def test(): -> "Literal[5]":
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20inconsistent-mro" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L624" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L625" target="_blank">View source</a>
 </small>
 
 
@@ -559,7 +559,7 @@ class C(A, B): ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20index-out-of-bounds" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L648" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L649" target="_blank">View source</a>
 </small>
 
 
@@ -585,7 +585,7 @@ t[3]  # IndexError: tuple index out of range
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.12">0.0.1-alpha.12</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20instance-layout-conflict" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L430" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L431" target="_blank">View source</a>
 </small>
 
 
@@ -674,7 +674,7 @@ an atypical memory layout.
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-argument-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L702" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L703" target="_blank">View source</a>
 </small>
 
 
@@ -701,7 +701,7 @@ func("foo")  # error: [invalid-argument-type]
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-assignment" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L742" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L743" target="_blank">View source</a>
 </small>
 
 
@@ -729,7 +729,7 @@ a: int = ''
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-attribute-access" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2079" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2122" target="_blank">View source</a>
 </small>
 
 
@@ -763,7 +763,7 @@ C.instance_var = 3  # error: Cannot assign to instance variable
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.19">0.0.1-alpha.19</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-await" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L764" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L765" target="_blank">View source</a>
 </small>
 
 
@@ -799,7 +799,7 @@ asyncio.run(main())
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L794" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L795" target="_blank">View source</a>
 </small>
 
 
@@ -823,7 +823,7 @@ class A(42): ...  # error: [invalid-base]
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-context-manager" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L879" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L880" target="_blank">View source</a>
 </small>
 
 
@@ -850,7 +850,7 @@ with 1:
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-declaration" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L900" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L901" target="_blank">View source</a>
 </small>
 
 
@@ -879,7 +879,7 @@ a: str
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-exception-caught" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L923" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L924" target="_blank">View source</a>
 </small>
 
 
@@ -923,7 +923,7 @@ except ZeroDivisionError:
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.28">0.0.1-alpha.28</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-explicit-override" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1749" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1792" target="_blank">View source</a>
 </small>
 
 
@@ -965,7 +965,7 @@ class D(A):
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.35">0.0.1-alpha.35</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-frozen-dataclass-subclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2330" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2373" target="_blank">View source</a>
 </small>
 
 
@@ -1009,7 +1009,7 @@ class NonFrozenChild(FrozenBase):  # Error raised here
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-generic-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L959" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1002" target="_blank">View source</a>
 </small>
 
 
@@ -1041,6 +1041,55 @@ class D(Generic[U, T]): ...
 
 - [Typing spec: Generics](https://typing.python.org/en/latest/spec/generics.html#introduction)
 
+## `invalid-generic-enum`
+
+<small>
+Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
+Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.12">0.0.12</a> ·
+<a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-generic-enum" target="_blank">Related issues</a> ·
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L960" target="_blank">View source</a>
+</small>
+
+
+**What it does**
+
+Checks for enum classes that are also generic.
+
+**Why is this bad?**
+
+Enum classes cannot be generic. Python does not support generic enums:
+attempting to create one will either result in an immediate `TypeError`
+at runtime, or will create a class that cannot be specialized in the way
+that a normal generic class can.
+
+**Examples**
+
+```python
+from enum import Enum
+from typing import Generic, TypeVar
+
+T = TypeVar("T")
+
+# error: enum class cannot be generic (class creation fails with `TypeError`)
+class E[T](Enum):
+    A = 1
+
+# error: enum class cannot be generic (class creation fails with `TypeError`)
+class F(Enum, Generic[T]):
+    A = 1
+
+# error: enum class cannot be generic -- the class creation does not immediately fail...
+class G(Generic[T], Enum):
+    A = 1
+
+# ...but this raises `KeyError`:
+x: G[int]
+```
+
+**References**
+
+- [Python documentation: Enum](https://docs.python.org/3/library/enum.html)
+
 ## `invalid-ignore-comment`
 
 <small>
@@ -1077,7 +1126,7 @@ a = 20 / 0  # type: ignore
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.17">0.0.1-alpha.17</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L669" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L670" target="_blank">View source</a>
 </small>
 
 
@@ -1116,7 +1165,7 @@ carol = Person(name="Carol", age=25)  # typo!
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-legacy-type-variable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L990" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1033" target="_blank">View source</a>
 </small>
 
 
@@ -1151,7 +1200,7 @@ def f(t: TypeVar("U")): ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-metaclass" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1087" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1130" target="_blank">View source</a>
 </small>
 
 
@@ -1185,7 +1234,7 @@ class B(metaclass=f): ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-method-override" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2232" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2275" target="_blank">View source</a>
 </small>
 
 
@@ -1292,7 +1341,7 @@ Correct use of `@override` is enforced by ty's `invalid-explicit-override` rule.
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.19">0.0.1-alpha.19</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-named-tuple" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L576" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L577" target="_blank">View source</a>
 </small>
 
 
@@ -1346,7 +1395,7 @@ AttributeError: Cannot overwrite NamedTuple attribute _asdict
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-newtype" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1063" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1106" target="_blank">View source</a>
 </small>
 
 
@@ -1376,7 +1425,7 @@ Baz = NewType("Baz", int | str)  # error: invalid base for `typing.NewType`
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1114" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1157" target="_blank">View source</a>
 </small>
 
 
@@ -1426,7 +1475,7 @@ def foo(x: int) -> int: ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-parameter-default" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1213" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1256" target="_blank">View source</a>
 </small>
 
 
@@ -1452,7 +1501,7 @@ def f(a: int = ''): ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-paramspec" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1018" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1061" target="_blank">View source</a>
 </small>
 
 
@@ -1483,7 +1532,7 @@ P2 = ParamSpec("S2")  # error: ParamSpec name must match the variable it's assig
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-protocol" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L512" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L513" target="_blank">View source</a>
 </small>
 
 
@@ -1517,7 +1566,7 @@ TypeError: Protocols can only inherit from other protocols, got <class 'int'>
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-raise" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1233" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1276" target="_blank">View source</a>
 </small>
 
 
@@ -1566,7 +1615,7 @@ def g():
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-return-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L723" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L724" target="_blank">View source</a>
 </small>
 
 
@@ -1591,7 +1640,7 @@ def func() -> int:
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-super-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1276" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1319" target="_blank">View source</a>
 </small>
 
 
@@ -1687,7 +1736,7 @@ class C: ...
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.10">0.0.10</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-total-ordering" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2368" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2411" target="_blank">View source</a>
 </small>
 
 
@@ -1733,7 +1782,7 @@ class MyClass:
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.6">0.0.1-alpha.6</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-alias-type" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1042" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1085" target="_blank">View source</a>
 </small>
 
 
@@ -1760,7 +1809,7 @@ NewAlias = TypeAliasType(get_name(), int)        # error: TypeAliasType name mus
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.29">0.0.1-alpha.29</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1508" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1551" target="_blank">View source</a>
 </small>
 
 
@@ -1807,7 +1856,7 @@ Bar[int]  # error: too few arguments
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-checking-constant" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1315" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1358" target="_blank">View source</a>
 </small>
 
 
@@ -1837,7 +1886,7 @@ TYPE_CHECKING = ''
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-form" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1339" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1382" target="_blank">View source</a>
 </small>
 
 
@@ -1867,7 +1916,7 @@ b: Annotated[int]  # `Annotated` expects at least two arguments
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1391" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1434" target="_blank">View source</a>
 </small>
 
 
@@ -1901,7 +1950,7 @@ f(10)  # Error
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.11">0.0.1-alpha.11</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-guard-definition" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1363" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1406" target="_blank">View source</a>
 </small>
 
 
@@ -1935,7 +1984,7 @@ class C:
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-type-variable-constraints" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1419" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1462" target="_blank">View source</a>
 </small>
 
 
@@ -1970,7 +2019,7 @@ T = TypeVar('T', bound=str)  # valid bound TypeVar
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.9">0.0.9</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20invalid-typed-dict-statement" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2207" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2250" target="_blank">View source</a>
 </small>
 
 
@@ -2001,7 +2050,7 @@ class Foo(TypedDict):
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1448" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1491" target="_blank">View source</a>
 </small>
 
 
@@ -2026,7 +2075,7 @@ func()  # TypeError: func() missing 1 required positional argument: 'x'
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.20">0.0.1-alpha.20</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20missing-typed-dict-key" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2180" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2223" target="_blank">View source</a>
 </small>
 
 
@@ -2059,7 +2108,7 @@ alice["age"]  # KeyError
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20no-matching-overload" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1467" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1510" target="_blank">View source</a>
 </small>
 
 
@@ -2088,7 +2137,7 @@ func("string")  # error: [no-matching-overload]
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20not-iterable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1549" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1592" target="_blank">View source</a>
 </small>
 
 
@@ -2114,7 +2163,7 @@ for i in 34:  # TypeError: 'int' object is not iterable
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20not-subscriptable" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1490" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1533" target="_blank">View source</a>
 </small>
 
 
@@ -2138,7 +2187,7 @@ Subscripting an object that does not support it will raise a `TypeError` at runt
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.29">0.0.1-alpha.29</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20override-of-final-method" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1722" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1765" target="_blank">View source</a>
 </small>
 
 
@@ -2171,7 +2220,7 @@ class B(A):
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20parameter-already-assigned" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1600" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1643" target="_blank">View source</a>
 </small>
 
 
@@ -2198,7 +2247,7 @@ f(1, x=2)  # Error raised here
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20positional-only-parameter-as-kwarg" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1933" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1976" target="_blank">View source</a>
 </small>
 
 
@@ -2225,7 +2274,7 @@ f(x=1)  # Error raised here
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1621" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1664" target="_blank">View source</a>
 </small>
 
 
@@ -2253,7 +2302,7 @@ A.c  # AttributeError: type object 'A' has no attribute 'c'
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-implicit-call" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L183" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L184" target="_blank">View source</a>
 </small>
 
 
@@ -2285,7 +2334,7 @@ A()[0]  # TypeError: 'A' object is not subscriptable
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-missing-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1643" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1686" target="_blank">View source</a>
 </small>
 
 
@@ -2322,7 +2371,7 @@ from module import a  # ImportError: cannot import name 'a' from 'module'
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1673" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1716" target="_blank">View source</a>
 </small>
 
 
@@ -2386,7 +2435,7 @@ def test(): -> "int":
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20redundant-cast" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2107" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2150" target="_blank">View source</a>
 </small>
 
 
@@ -2413,7 +2462,7 @@ cast(int, f())  # Redundant
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20static-assert-error" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2055" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2098" target="_blank">View source</a>
 </small>
 
 
@@ -2443,7 +2492,7 @@ static_assert(int(2.0 * 3.0) == 6)  # error: does not have a statically known tr
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20subclass-of-final-class" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1699" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1742" target="_blank">View source</a>
 </small>
 
 
@@ -2472,7 +2521,7 @@ class B(A): ...  # Error raised here
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.30">0.0.1-alpha.30</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20super-call-in-named-tuple-method" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1867" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1910" target="_blank">View source</a>
 </small>
 
 
@@ -2506,7 +2555,7 @@ class F(NamedTuple):
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20too-many-positional-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1807" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1850" target="_blank">View source</a>
 </small>
 
 
@@ -2533,7 +2582,7 @@ f("foo")  # Error raised here
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20type-assertion-failure" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1785" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1828" target="_blank">View source</a>
 </small>
 
 
@@ -2561,7 +2610,7 @@ def _(x: int):
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unavailable-implicit-super-arguments" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1828" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1871" target="_blank">View source</a>
 </small>
 
 
@@ -2607,7 +2656,7 @@ class A:
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20undefined-reveal" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1894" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1937" target="_blank">View source</a>
 </small>
 
 
@@ -2631,7 +2680,7 @@ reveal_type(1)  # NameError: name 'reveal_type' is not defined
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unknown-argument" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1912" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1955" target="_blank">View source</a>
 </small>
 
 
@@ -2658,7 +2707,7 @@ f(x=1, y=2)  # Error raised here
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-attribute" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1954" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1997" target="_blank">View source</a>
 </small>
 
 
@@ -2686,7 +2735,7 @@ A().foo  # AttributeError: 'A' object has no attribute 'foo'
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.15">0.0.1-alpha.15</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-global" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2128" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2171" target="_blank">View source</a>
 </small>
 
 
@@ -2744,7 +2793,7 @@ def g():
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-import" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1976" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2019" target="_blank">View source</a>
 </small>
 
 
@@ -2769,7 +2818,7 @@ import foo  # ModuleNotFoundError: No module named 'foo'
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unresolved-reference" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1995" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2038" target="_blank">View source</a>
 </small>
 
 
@@ -2794,7 +2843,7 @@ print(x)  # NameError: name 'x' is not defined
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.7">0.0.1-alpha.7</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L812" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L813" target="_blank">View source</a>
 </small>
 
 
@@ -2833,7 +2882,7 @@ class D(C): ...  # error: [unsupported-base]
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-bool-conversion" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1569" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1612" target="_blank">View source</a>
 </small>
 
 
@@ -2870,7 +2919,7 @@ b1 < b2 < b1  # exception raised here
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'ignore'."><code>ignore</code></a> ·
 Preview (since <a href="https://github.com/astral-sh/ty/releases/tag/1.0.0">1.0.0</a>) ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-dynamic-base" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L845" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L846" target="_blank">View source</a>
 </small>
 
 
@@ -2911,7 +2960,7 @@ def factory(base: type[Base]) -> type:
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20unsupported-operator" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2014" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2057" target="_blank">View source</a>
 </small>
 
 
@@ -2975,7 +3024,7 @@ to `false` to prevent this rule from reporting unused `type: ignore` comments.
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'warn'."><code>warn</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.22">0.0.1-alpha.22</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20useless-overload-body" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1157" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L1200" target="_blank">View source</a>
 </small>
 
 
@@ -3038,7 +3087,7 @@ def foo(x: int | str) -> int | str:
 Default level: <a href="../../rules#rule-levels" title="This lint has a default level of 'error'."><code>error</code></a> ·
 Added in <a href="https://github.com/astral-sh/ty/releases/tag/0.0.1-alpha.1">0.0.1-alpha.1</a> ·
 <a href="https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20zero-stepsize-in-slice" target="_blank">Related issues</a> ·
-<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2036" target="_blank">View source</a>
+<a href="https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L2079" target="_blank">View source</a>
 </small>
 
 

crates/ty_python_semantic/resources/mdtest/bidirectional.md

@@ -42,6 +42,12 @@ def f[T](x: T, cond: bool) -> T | list[T]:
     return x if cond else [x]
 
 l5: int | list[int] = f(1, True)
+
+a: list[int] = [1, 2, *(3, 4, 5)]
+reveal_type(a)  # revealed: list[int]
+
+b: list[list[int]] = [[1], [2], *([3], [4])]
+reveal_type(b)  # revealed: list[list[int]]
 ```
 
 `typed_dict.py`:

crates/ty_python_semantic/resources/mdtest/call/type.md

@@ -834,7 +834,7 @@ class Base: ...
 bases_tuple = (Base,)
 Cls1 = type("Cls1", (*bases_tuple,), {})
 reveal_type(Cls1)  # revealed: <class 'Cls1'>
-reveal_mro(Cls1)  # revealed: (<class 'Cls1'>, @Todo(StarredExpression), <class 'object'>)
+reveal_mro(Cls1)  # revealed: (<class 'Cls1'>, <class 'Base'>, <class 'object'>)
 
 # Unpacking a dict for the namespace - the dict contents are not tracked anyway
 namespace = {"attr": 1}

crates/ty_python_semantic/resources/mdtest/classes.md

@@ -25,3 +25,22 @@ B = bytes
 
 reveal_mro(C)  # revealed: (<class 'C'>, <class 'int'>, <class 'G[bytes]'>, typing.Generic, <class 'object'>)
 ```
+
+## Starred bases
+
+These are currently not supported, but ideally we would support them in some limited situations.
+
+```py
+from ty_extensions import reveal_mro
+
+class A: ...
+class B: ...
+class C: ...
+
+bases = (A, B, C)
+
+class Foo(*bases): ...
+
+# revealed: (<class 'Foo'>, @Todo(StarredExpression), <class 'object'>)
+reveal_mro(Foo)
+```

crates/ty_python_semantic/resources/mdtest/enums.md

@@ -1016,6 +1016,108 @@ class Color(Enum):
 reveal_type(Color.RED != Color.RED)  # revealed: bool
 ```
 
+## Generic enums are invalid
+
+Enum classes cannot be generic. Python does not support generic enums, and attempting to create one
+will result in a `TypeError` at runtime.
+
+### PEP 695 syntax
+
+Using PEP 695 type parameters on an enum is invalid:
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from enum import Enum
+
+# error: [invalid-generic-enum] "Enum class `E` cannot be generic"
+class E[T](Enum):
+    A = 1
+    B = 2
+```
+
+### Legacy `Generic` base class
+
+Inheriting from both `Enum` and `Generic[T]` is also invalid:
+
+```py
+from enum import Enum
+from typing import Generic, TypeVar
+
+T = TypeVar("T")
+
+# error: [invalid-generic-enum] "Enum class `F` cannot be generic"
+class F(Enum, Generic[T]):
+    A = 1
+    B = 2
+```
+
+### Swapped order (`Generic` first)
+
+The order of bases doesn't matter; it's still invalid:
+
+```py
+from enum import Enum
+from typing import Generic, TypeVar
+
+T = TypeVar("T")
+
+# error: [invalid-generic-enum] "Enum class `G` cannot be generic"
+class G(Generic[T], Enum):
+    A = 1
+    B = 2
+```
+
+### Enum subclasses
+
+Subclasses of enum base classes also cannot be generic:
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from enum import Enum, IntEnum
+from typing import Generic, TypeVar
+
+T = TypeVar("T")
+
+# error: [invalid-generic-enum] "Enum class `MyIntEnum` cannot be generic"
+class MyIntEnum[T](IntEnum):
+    A = 1
+
+# error: [invalid-generic-enum] "Enum class `MyFlagEnum` cannot be generic"
+class MyFlagEnum(IntEnum, Generic[T]):
+    A = 1
+```
+
+### Custom enum base class
+
+Even with custom enum subclasses that don't have members, they cannot be made generic:
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from enum import Enum
+from typing import Generic, TypeVar
+
+T = TypeVar("T")
+
+class MyEnumBase(Enum):
+    def some_method(self) -> None: ...
+
+# error: [invalid-generic-enum] "Enum class `MyEnum` cannot be generic"
+class MyEnum[T](MyEnumBase):
+    A = 1
+```
+
 ## References
 
 - Typing spec: <https://typing.python.org/en/latest/spec/enums.html>

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

@@ -43,13 +43,11 @@ reveal_type(len((1,)))  # revealed: Literal[1]
 reveal_type(len((1, 2)))  # revealed: Literal[2]
 reveal_type(len(tuple()))  # revealed: Literal[0]
 
-# TODO: Handle star unpacks; Should be: Literal[0]
-reveal_type(len((*[],)))  # revealed: Literal[1]
+reveal_type(len((*[],)))  # revealed: Literal[0]
 
 # fmt: off
 
-# TODO: Handle star unpacks; Should be: Literal[1]
-reveal_type(len(  # revealed: Literal[2]
+reveal_type(len(  # revealed: Literal[1]
     (
         *[],
         1,
@@ -58,11 +56,8 @@ reveal_type(len(  # revealed: Literal[2]
 
 # fmt: on
 
-# 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]
+reveal_type(len((*[], 1, 2)))  # revealed: Literal[2]
+reveal_type(len((*[], *{})))  # revealed: Literal[0]
 ```
 
 Tuple subclasses:

crates/ty_python_semantic/resources/mdtest/generics/pep695/variance.md

@@ -797,7 +797,7 @@ class B(A):
     pass
 
 class C[T]:
-    def check(x: object) -> TypeIs[T]:
+    def check(self, x: object) -> TypeIs[T]:
         # this is a bad check, but we only care about it type-checking
         return False
 
@@ -835,7 +835,7 @@ class B(A):
     pass
 
 class C[T]:
-    def check(x: object) -> TypeGuard[T]:
+    def check(self, x: object) -> TypeGuard[T]:
         # this is a bad check, but we only care about it type-checking
         return False
 

crates/ty_python_semantic/resources/mdtest/narrow/callable.md

@@ -69,6 +69,30 @@ def call_with_args(y: object, a: int, b: str) -> object:
     return None
 ```
 
+## Narrowing with named expressions (walrus operator)
+
+When `callable()` is used with a named expression, the target of the named expression should be
+narrowed.
+
+```py
+from typing import Any
+
+class Foo:
+    func: Any | None
+
+def f(foo: Foo):
+    first = getattr(foo, "func", None)
+    if callable(first):
+        reveal_type(first)  # revealed: Any & Top[(...) -> object]
+    else:
+        reveal_type(first)  # revealed: (Any & ~Top[(...) -> object]) | None
+
+    if callable(second := getattr(foo, "func", None)):
+        reveal_type(second)  # revealed: Any & Top[(...) -> object]
+    else:
+        reveal_type(second)  # revealed: (Any & ~Top[(...) -> object]) | None
+```
+
 ## Assignability of narrowed callables
 
 A narrowed callable `Top[Callable[..., object]]` should be assignable to `Callable[..., Any]`. This

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

@@ -580,3 +580,19 @@ def test(a: Any, items: list[T]) -> None:
     if isinstance(v, dict):
         cast(T, v)  # no panic
 ```
+
+## Narrowing with named expressions (walrus operator)
+
+When `isinstance()` is used with a named expression, the target of the named expression should be
+narrowed.
+
+```py
+def get_value() -> int | str:
+    return 1
+
+def f():
+    if isinstance(x := get_value(), int):
+        reveal_type(x)  # revealed: int
+    else:
+        reveal_type(x)  # revealed: str
+```

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

@@ -347,3 +347,19 @@ def _(x: LiteralString):
     else:
         reveal_type(x)  # revealed: LiteralString & ~Literal[""]
 ```
+
+## Narrowing with named expressions (walrus operator)
+
+When a truthiness check is used with a named expression, the target of the named expression should
+be narrowed.
+
+```py
+def get_value() -> str | None:
+    return "hello"
+
+def f():
+    if x := get_value():
+        reveal_type(x)  # revealed: str & ~AlwaysFalsy
+    else:
+        reveal_type(x)  # revealed: (str & ~AlwaysTruthy) | None
+```

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

@@ -70,6 +70,47 @@ def _(x: A | B, y: A | C):
         reveal_type(y)  # revealed: A
 ```
 
+## The top materialization is used for generic classes
+
+```py
+# list is invariant
+def f(x: list[int] | None):
+    if type(x) is list:
+        reveal_type(x)  # revealed: list[int]
+    else:
+        reveal_type(x)  # revealed: list[int] | None
+
+    if type(x) is not list:
+        reveal_type(x)  # revealed: list[int] | None
+    else:
+        reveal_type(x)  # revealed: list[int]
+
+# frozenset is covariant
+def g(x: frozenset[bytes] | None):
+    if type(x) is frozenset:
+        reveal_type(x)  # revealed: frozenset[bytes]
+    else:
+        reveal_type(x)  # revealed: frozenset[bytes] | None
+
+    if type(x) is not frozenset:
+        reveal_type(x)  # revealed: frozenset[bytes] | None
+    else:
+        reveal_type(x)  # revealed: frozenset[bytes]
+
+def h(x: object):
+    if type(x) is list:
+        reveal_type(x)  # revealed: Top[list[Unknown]]
+    elif type(x) is frozenset:
+        reveal_type(x)  # revealed: frozenset[object]
+    else:
+        reveal_type(x)  # revealed: object
+
+    if type(x) is not list and type(x) is not frozenset:
+        reveal_type(x)  # revealed: object
+    else:
+        reveal_type(x)  # revealed: Top[list[Unknown]] | frozenset[object]
+```
+
 ## No narrowing for `type(x) is C[int]`
 
 At runtime, `type(x)` will never return a generic alias object (only ever a class-literal object),
@@ -234,8 +275,7 @@ An early version of <https://github.com/astral-sh/ruff/pull/19920> caused us to
 ```py
 def _(val):
     if type(val) is tuple:
-        # TODO: better would be `Unknown & tuple[object, ...]`
-        reveal_type(val)  # revealed: Unknown & tuple[Unknown, ...]
+        reveal_type(val)  # revealed: Unknown & tuple[object, ...]
 ```
 
 ## Limitations

crates/ty_python_semantic/resources/mdtest/narrow/type_guards.md

@@ -14,8 +14,8 @@ def _(
     b: TypeIs[str | int],
     c: TypeGuard[bool],
     d: TypeIs[tuple[TypeOf[bytes]]],
-    e: TypeGuard,  # error: [invalid-type-form]
-    f: TypeIs,  # error: [invalid-type-form]
+    e: TypeGuard,  # error: [invalid-type-form] "`typing.TypeGuard` requires exactly one argument when used in a type expression"
+    f: TypeIs,  # error: [invalid-type-form] "`typing.TypeIs` requires exactly one argument when used in a type expression"
 ):
     reveal_type(a)  # revealed: TypeGuard[str]
     reveal_type(b)  # revealed: TypeIs[str | int]
@@ -46,12 +46,23 @@ A user-defined type guard must accept at least one positional argument (in addit
 for non-static methods).
 
 ```pyi
+from typing import Any, TypeVar
 from typing_extensions import TypeGuard, TypeIs
 
-# TODO: error: [invalid-type-guard-definition]
+T = TypeVar("T")
+
+# Multiple parameters are allowed
+def is_str_list(val: list[object], allow_empty: bool) -> TypeGuard[list[str]]: ...
+def is_set_of(val: set[Any], type: type[T]) -> TypeGuard[set[T]]: ...
+def is_two_element_tuple(val: tuple[object, ...], a: str, b: str) -> TypeIs[tuple[str, str]]: ...
+
+# error: [invalid-type-guard-definition] "`TypeGuard` function must have a parameter to narrow"
 def _() -> TypeGuard[str]: ...
 
-# TODO: error: [invalid-type-guard-definition]
+# error: [invalid-type-guard-definition] "`TypeGuard` function must have a parameter to narrow"
+def _(*args) -> TypeGuard[str]: ...
+
+# error: [invalid-type-guard-definition] "`TypeIs` function must have a parameter to narrow"
 def _(**kwargs) -> TypeIs[str]: ...
 
 class _:
@@ -63,14 +74,14 @@ class _:
     def _(a) -> TypeIs[str]: ...
 
     # errors
-    def _(self) -> TypeGuard[str]: ...  # TODO: error: [invalid-type-guard-definition]
-    def _(self, /, *, a) -> TypeGuard[str]: ...  # TODO: error: [invalid-type-guard-definition]
+    def _(self) -> TypeGuard[str]: ...  # error: [invalid-type-guard-definition] "`TypeGuard` function must have a parameter to narrow"
+    def _(self, /, *, a) -> TypeGuard[str]: ...  # error: [invalid-type-guard-definition] "`TypeGuard` function must have a parameter to narrow"
     @classmethod
-    def _(cls) -> TypeIs[str]: ...  # TODO: error: [invalid-type-guard-definition]
+    def _(cls) -> TypeIs[str]: ...  # error: [invalid-type-guard-definition] "`TypeIs` function must have a parameter to narrow"
     @classmethod
-    def _() -> TypeIs[str]: ...  # TODO: error: [invalid-type-guard-definition]
+    def _() -> TypeIs[str]: ...  # error: [invalid-type-guard-definition] "`TypeIs` function must have a parameter to narrow"
     @staticmethod
-    def _(*, a) -> TypeGuard[str]: ...  # TODO: error: [invalid-type-guard-definition]
+    def _(*, a) -> TypeGuard[str]: ...  # error: [invalid-type-guard-definition] "`TypeGuard` function must have a parameter to narrow"
 ```
 
 For `TypeIs` functions, the narrowed type must be assignable to the declared type of that parameter,
@@ -86,10 +97,10 @@ def _(a: tuple[object]) -> TypeIs[tuple[str]]: ...
 def _(a: str | Any) -> TypeIs[str]: ...
 def _(a) -> TypeIs[str]: ...
 
-# TODO: error: [invalid-type-guard-definition]
+# error: [invalid-type-guard-definition] "Narrowed type `str` is not assignable to the declared parameter type `int`"
 def _(a: int) -> TypeIs[str]: ...
 
-# TODO: error: [invalid-type-guard-definition]
+# error: [invalid-type-guard-definition] "Narrowed type `int` is not assignable to the declared parameter type `bool | str`"
 def _(a: bool | str) -> TypeIs[int]: ...
 ```
 
@@ -107,12 +118,14 @@ class C:
     @classmethod
     def g(cls, x: object) -> TypeGuard[int]:
         return True
-    # TODO: this could error at definition time
-    def h(self) -> TypeGuard[str]:
+
+    def h(
+        self,
+    ) -> TypeGuard[str]:  # error: [invalid-type-guard-definition] "`TypeGuard` function must have a parameter to narrow"
         return True
-    # TODO: this could error at definition time
+
     @classmethod
-    def j(cls) -> TypeGuard[int]:
+    def j(cls) -> TypeGuard[int]:  # error: [invalid-type-guard-definition] "`TypeGuard` function must have a parameter to narrow"
         return True
 
 def _(x: object):
@@ -221,7 +234,7 @@ def g(a: object) -> TypeIs[int]:
     return True
 
 def _(d: Any):
-    if f():  # error: [missing-argument]
+    if f():  # error: [missing-argument] "No argument provided for required parameter `a` of function `f`"
         ...
 
     if g(*d):
@@ -230,7 +243,7 @@ def _(d: Any):
     if f("foo"):  # TODO: error: [invalid-type-guard-call]
         ...
 
-    if g(a=d):  # error: [invalid-type-guard-call]
+    if g(a=d):  # error: [invalid-type-guard-call] "Type guard call does not have a target"
         ...
 ```
 
@@ -499,3 +512,32 @@ def _(x: object):
     if f(x) and (g(x) or h(x)):
         reveal_type(x)  # revealed: B | (A & C)
 ```
+
+## Narrowing with named expressions (walrus operator)
+
+When a type guard is used with a named expression, the target of the named expression should be
+narrowed.
+
+```py
+from typing_extensions import TypeGuard, TypeIs
+
+def is_str(x: object) -> TypeIs[str]:
+    return isinstance(x, str)
+
+def guard_str(x: object) -> TypeGuard[str]:
+    return isinstance(x, str)
+
+def get_value() -> int | str:
+    return 1
+
+def f():
+    if is_str(x := get_value()):
+        reveal_type(x)  # revealed: str
+    else:
+        reveal_type(x)  # revealed: int
+
+    if guard_str(y := get_value()):
+        reveal_type(y)  # revealed: str
+    else:
+        reveal_type(y)  # revealed: int | str
+```

crates/ty_python_semantic/resources/mdtest/subscript/alias.md

@@ -0,0 +1,43 @@
+# Subscripts involving type aliases
+
+Aliases are expanded during analysis of subscripts.
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from typing_extensions import TypeAlias, Literal
+
+ImplicitTuple = tuple[str, int, int]
+PEP613Tuple: TypeAlias = tuple[str, int, int]
+type PEP695Tuple = tuple[str, int, int]
+
+ImplicitZero = Literal[0]
+PEP613Zero: TypeAlias = Literal[0]
+type PEP695Zero = Literal[0]
+
+def f(
+    implicit_tuple: ImplicitTuple,
+    pep_613_tuple: PEP613Tuple,
+    pep_695_tuple: PEP695Tuple,
+    implicit_zero: ImplicitZero,
+    pep_613_zero: PEP613Zero,
+    pep_695_zero: PEP695Zero,
+):
+    reveal_type(implicit_tuple[:2])  # revealed: tuple[str, int]
+    reveal_type(implicit_tuple[implicit_zero])  # revealed: str
+    reveal_type(implicit_tuple[pep_613_zero])  # revealed: str
+    reveal_type(implicit_tuple[pep_695_zero])  # revealed: str
+
+    reveal_type(pep_613_tuple[:2])  # revealed: tuple[str, int]
+    reveal_type(pep_613_tuple[implicit_zero])  # revealed: str
+    reveal_type(pep_613_tuple[pep_613_zero])  # revealed: str
+    reveal_type(pep_613_tuple[pep_695_zero])  # revealed: str
+
+    reveal_type(pep_695_tuple[:2])  # revealed: tuple[str, int]
+    reveal_type(pep_695_tuple[implicit_zero])  # revealed: str
+    reveal_type(pep_695_tuple[pep_613_zero])  # revealed: str
+    reveal_type(pep_695_tuple[pep_695_zero])  # revealed: str
+```

crates/ty_python_semantic/resources/mdtest/subscript/class.md

@@ -106,5 +106,5 @@ class Bar:
 def f(x: Foo):
     if isinstance(x, Bar):
         # TODO: should be `int`
-        reveal_type(x["whatever"])  # revealed: @Todo(Subscript expressions on intersections)
+        reveal_type(x["whatever"])  # revealed: @Todo(Subscript expressions with intersections)
 ```

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

@@ -80,6 +80,17 @@ def _(m: int, n: int, s2: str):
     reveal_type(substring2)  # revealed: str
 ```
 
+## LiteralString
+
+```py
+from typing_extensions import LiteralString
+
+def f(x: LiteralString):
+    reveal_type(x[0])  # revealed: LiteralString
+    reveal_type(x[True])  # revealed: LiteralString
+    reveal_type(x[1:42])  # revealed: LiteralString
+```
+
 ## Unsupported slice types
 
 ```py

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

@@ -430,5 +430,5 @@ class Bar: ...
 
 def test4(val: Intersection[tuple[Foo], tuple[Bar]]):
     # TODO: should be `Foo & Bar`
-    reveal_type(val[0])  # revealed: @Todo(Subscript expressions on intersections)
+    reveal_type(val[0])  # revealed: @Todo(Subscript expressions with intersections)
 ```

crates/ty_python_semantic/resources/mdtest/subscript/typevar.md

@@ -0,0 +1,89 @@
+# Subscripts involving type variables
+
+## TypeVar bound/constrained to a tuple/int-literal/bool-literal
+
+The upper bounds of type variables are considered when analysing subscripts.
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from typing_extensions import TypeAlias, Literal
+
+ImplicitTuple = tuple[str, int, int]
+PEP613Tuple: TypeAlias = tuple[str, int, int]
+type PEP695Tuple = tuple[str, int, int]
+
+ImplicitZero = Literal[0]
+PEP613Zero: TypeAlias = Literal[0]
+type PEP695Zero = Literal[0]
+
+# fmt: off
+
+def f[
+    BoundedTupleT: tuple[str, int, bytes],
+    ConstrainedTupleT: (tuple[str, int, bytes], tuple[int, bytes, str]),
+    BoundedZeroT: Literal[0],
+    ConstrainedIntLiteralT: (Literal[0], Literal[1])
+](
+    tuple_1: BoundedTupleT,
+    tuple_2: ConstrainedTupleT,
+    zero: BoundedZeroT,
+    some_integer: ConstrainedIntLiteralT,
+):
+    # TODO: would ideally be `tuple[str, int]`
+    reveal_type(tuple_1[:2])  # revealed: tuple[str | int | bytes, ...]
+    reveal_type(tuple_1[zero])  # revealed: str
+
+    # TODO: ideally this might be `str | int`,
+    # but it's hard to do that without introducing false positives elsewhere
+    reveal_type(tuple_1[some_integer])  # revealed: str | int | bytes
+
+    # TODO: would ideally be `tuple[str, int] | tuple[int, bytes]`
+    reveal_type(tuple_2[:2])  # revealed: tuple[str | int | bytes, ...]
+    reveal_type(tuple_2[zero])  # revealed: str | int
+    reveal_type(tuple_2[some_integer])  # revealed: str | int | bytes
+
+# fmt: on
+```
+
+## TypeVars
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from typing import Protocol
+
+class SupportsLessThan(Protocol):
+    def __lt__(self, other, /) -> bool: ...
+
+def f[K: SupportsLessThan](dictionary: dict[K, int], key: K):
+    reveal_type(dictionary[key])  # revealed: int
+```
+
+## ParamSpecs
+
+```toml
+[environment]
+python-version = "3.12"
+```
+
+```py
+from typing import Callable
+
+def decorator[**P, T](func: Callable[P, T]) -> Callable[P, T]:
+    def inner(*args: P.args, **kwargs: P.kwargs) -> T:
+        if len(args) > 0:
+            # error: [invalid-assignment]
+            args = args[1:]
+
+        # `func` requires the full `ParamSpec` passed into `decorator`,
+        # but here the first argument is skipped, so we should possibly emit an error here:
+        return func(*args, **kwargs)
+    return inner
+```

crates/ty_python_semantic/resources/mdtest/type_compendium/tuple.md

@@ -534,4 +534,34 @@ x: list[Literal[1, 2, 3]] = list((1, 2, 3))
 reveal_type(x)  # revealed: list[Literal[1, 2, 3]]
 ```
 
+## Tuples with starred elements
+
+```py
+from typing import Literal, Sequence
+
+x = (1, *range(3), 3)
+reveal_type(x)  # revealed: tuple[Literal[1], *tuple[int, ...], Literal[3]]
+
+y = 1, 2
+
+reveal_type(("foo", *y))  # revealed: tuple[Literal["foo"], Literal[1], Literal[2]]
+
+aa: tuple[list[int], ...] = ([42], *{[56], [78]}, [100])
+reveal_type(aa)  # revealed: tuple[list[int], list[int], list[int], list[int]]
+
+bb: tuple[list[Literal[42, 56]], ...] = ([42], *{[56, 42], [42]}, [42, 42, 56])
+reveal_type(bb)  # revealed: tuple[list[Literal[42, 56]], list[Literal[42, 56]], list[Literal[42, 56]], list[Literal[42, 56]]]
+
+reveal_type((*[],))  # revealed: tuple[()]
+reveal_type((42, *[], 56, *[]))  # revealed: tuple[Literal[42], Literal[56]]
+
+tup: Sequence[str] = (*{"foo": 42, "bar": 56},)
+
+# TODO: `tuple[str, str]` would be better, given the type annotation
+reveal_type(tup)  # revealed: tuple[Unknown | str, Unknown | str]
+
+def f(x: list[int]):
+    reveal_type((42, 56, *x, 97))  # revealed: tuple[Literal[42], Literal[56], *tuple[int, ...], Literal[97]]
+```
+
 [not a singleton type]: https://discuss.python.org/t/should-we-specify-in-the-language-reference-that-the-empty-tuple-is-a-singleton/67957

crates/ty_python_semantic/src/semantic_index/place.rs

@@ -38,6 +38,12 @@ impl PlaceExpr {
     pub(crate) fn try_from_expr<'e>(expr: impl Into<ast::ExprRef<'e>>) -> Option<Self> {
         let expr = expr.into();
 
+        // For named expressions (walrus operator), extract the target.
+        let expr = match expr {
+            ast::ExprRef::Named(named) => named.target.as_ref().into(),
+            _ => expr,
+        };
+
         if let ast::ExprRef::Name(name) = expr {
             return Some(PlaceExpr::Symbol(Symbol::new(name.id.clone())));
         }

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

@@ -3256,12 +3256,16 @@ impl<'a, 'db> ArgumentTypeChecker<'a, 'db> {
         // This is one of the few places where we want to check if there's _any_ specialization
         // where assignability holds; normally we want to check that assignability holds for
         // _all_ specializations.
+        //
         // TODO: Soon we will go further, and build the actual specializations from the
         // constraint set that we get from this assignability check, instead of inferring and
         // building them in an earlier separate step.
-        if argument_type
-            .when_assignable_to(self.db, expected_ty, self.inferable_typevars)
-            .is_never_satisfied(self.db)
+        //
+        // TODO: handle starred annotations, e.g. `*args: *Ts` or `*args: *tuple[int, *tuple[str, ...]]`
+        if !parameter.has_starred_annotation()
+            && argument_type
+                .when_assignable_to(self.db, expected_ty, self.inferable_typevars)
+                .is_never_satisfied(self.db)
         {
             let positional = matches!(argument, Argument::Positional | Argument::Synthetic)
                 && !parameter.is_variadic();

crates/ty_python_semantic/src/types/class.rs

@@ -45,10 +45,10 @@ use crate::types::visitor::{TypeCollector, TypeVisitor, walk_type_with_recursion
 use crate::types::{
     ApplyTypeMappingVisitor, Binding, BindingContext, BoundSuperType, CallableType,
     CallableTypeKind, CallableTypes, DATACLASS_FLAGS, DataclassFlags, DataclassParams,
-    DeprecatedInstance, FindLegacyTypeVarsVisitor, IntersectionBuilder, KnownInstanceType,
-    ManualPEP695TypeAliasType, MaterializationKind, NormalizedVisitor, PropertyInstanceType,
-    TypeAliasType, TypeContext, TypeMapping, TypedDictParams, UnionBuilder, VarianceInferable,
-    binding_type, declaration_type, determine_upper_bound,
+    DeprecatedInstance, DynamicType, FindLegacyTypeVarsVisitor, IntersectionBuilder,
+    KnownInstanceType, ManualPEP695TypeAliasType, MaterializationKind, NormalizedVisitor,
+    PropertyInstanceType, TypeAliasType, TypeContext, TypeMapping, TypedDictParams, UnionBuilder,
+    VarianceInferable, binding_type, declaration_type, determine_upper_bound,
 };
 use crate::{
     Db, FxIndexMap, FxIndexSet, FxOrderSet, Program,
@@ -664,14 +664,6 @@ impl<'db> ClassLiteral<'db> {
         }
     }
 
-    /// Returns an unknown specialization for this class.
-    pub(crate) fn unknown_specialization(self, db: &'db dyn Db) -> ClassType<'db> {
-        match self {
-            Self::Static(class) => class.unknown_specialization(db),
-            Self::Dynamic(_) => ClassType::NonGeneric(self),
-        }
-    }
-
     /// Returns the definition of this class.
     pub(crate) fn definition(self, db: &'db dyn Db) -> Definition<'db> {
         match self {
@@ -2379,6 +2371,11 @@ impl<'db> StaticClassLiteral<'db> {
 
         let module = parsed_module(db, self.file(db)).load(db);
         let class_stmt = self.node(db, &module);
+
+        if class_stmt.bases().iter().any(ast::Expr::is_starred_expr) {
+            return Box::new([Type::Dynamic(DynamicType::TodoStarredExpression)]);
+        }
+
         let class_definition =
             semantic_index(db, self.file(db)).expect_single_definition(class_stmt);
 

crates/ty_python_semantic/src/types/diagnostic.rs

@@ -73,6 +73,7 @@ pub(crate) fn register_lints(registry: &mut LintRegistryBuilder) {
     registry.register_lint(&INVALID_CONTEXT_MANAGER);
     registry.register_lint(&INVALID_DECLARATION);
     registry.register_lint(&INVALID_EXCEPTION_CAUGHT);
+    registry.register_lint(&INVALID_GENERIC_ENUM);
     registry.register_lint(&INVALID_GENERIC_CLASS);
     registry.register_lint(&INVALID_LEGACY_TYPE_VARIABLE);
     registry.register_lint(&INVALID_PARAMSPEC);
@@ -956,6 +957,48 @@ declare_lint! {
     }
 }
 
+declare_lint! {
+    /// ## What it does
+    /// Checks for enum classes that are also generic.
+    ///
+    /// ## Why is this bad?
+    /// Enum classes cannot be generic. Python does not support generic enums:
+    /// attempting to create one will either result in an immediate `TypeError`
+    /// at runtime, or will create a class that cannot be specialized in the way
+    /// that a normal generic class can.
+    ///
+    /// ## Examples
+    /// ```python
+    /// from enum import Enum
+    /// from typing import Generic, TypeVar
+    ///
+    /// T = TypeVar("T")
+    ///
+    /// # error: enum class cannot be generic (class creation fails with `TypeError`)
+    /// class E[T](Enum):
+    ///     A = 1
+    ///
+    /// # error: enum class cannot be generic (class creation fails with `TypeError`)
+    /// class F(Enum, Generic[T]):
+    ///     A = 1
+    ///
+    /// # error: enum class cannot be generic -- the class creation does not immediately fail...
+    /// class G(Generic[T], Enum):
+    ///     A = 1
+    ///
+    /// # ...but this raises `KeyError`:
+    /// x: G[int]
+    /// ```
+    ///
+    /// ## References
+    /// - [Python documentation: Enum](https://docs.python.org/3/library/enum.html)
+    pub(crate) static INVALID_GENERIC_ENUM = {
+        summary: "detects generic enum classes",
+        status: LintStatus::stable("0.0.12"),
+        default_level: Level::Error,
+    }
+}
+
 declare_lint! {
     /// ## What it does
     /// Checks for the creation of invalid generic classes

crates/ty_python_semantic/src/types/infer/builder.rs

@@ -65,15 +65,15 @@ use crate::types::diagnostic::{
     CYCLIC_CLASS_DEFINITION, CYCLIC_TYPE_ALIAS_DEFINITION, DIVISION_BY_ZERO, DUPLICATE_BASE,
     DUPLICATE_KW_ONLY, INCONSISTENT_MRO, INVALID_ARGUMENT_TYPE, INVALID_ASSIGNMENT,
     INVALID_ATTRIBUTE_ACCESS, INVALID_BASE, INVALID_DECLARATION, INVALID_GENERIC_CLASS,
-    INVALID_KEY, INVALID_LEGACY_TYPE_VARIABLE, INVALID_METACLASS, INVALID_NAMED_TUPLE,
-    INVALID_NEWTYPE, INVALID_OVERLOAD, INVALID_PARAMETER_DEFAULT, INVALID_PARAMSPEC,
-    INVALID_PROTOCOL, INVALID_TYPE_ARGUMENTS, INVALID_TYPE_FORM, INVALID_TYPE_GUARD_CALL,
-    INVALID_TYPE_VARIABLE_CONSTRAINTS, INVALID_TYPED_DICT_STATEMENT, IncompatibleBases,
-    NOT_SUBSCRIPTABLE, POSSIBLY_MISSING_ATTRIBUTE, POSSIBLY_MISSING_IMPLICIT_CALL,
-    POSSIBLY_MISSING_IMPORT, SUBCLASS_OF_FINAL_CLASS, TypedDictDeleteErrorKind, UNDEFINED_REVEAL,
-    UNRESOLVED_ATTRIBUTE, UNRESOLVED_GLOBAL, UNRESOLVED_IMPORT, UNRESOLVED_REFERENCE,
-    UNSUPPORTED_DYNAMIC_BASE, UNSUPPORTED_OPERATOR, USELESS_OVERLOAD_BODY,
-    hint_if_stdlib_attribute_exists_on_other_versions,
+    INVALID_GENERIC_ENUM, INVALID_KEY, INVALID_LEGACY_TYPE_VARIABLE, INVALID_METACLASS,
+    INVALID_NAMED_TUPLE, INVALID_NEWTYPE, INVALID_OVERLOAD, INVALID_PARAMETER_DEFAULT,
+    INVALID_PARAMSPEC, INVALID_PROTOCOL, INVALID_TYPE_ARGUMENTS, INVALID_TYPE_FORM,
+    INVALID_TYPE_GUARD_CALL, INVALID_TYPE_GUARD_DEFINITION, INVALID_TYPE_VARIABLE_CONSTRAINTS,
+    INVALID_TYPED_DICT_STATEMENT, IncompatibleBases, NOT_SUBSCRIPTABLE, POSSIBLY_MISSING_ATTRIBUTE,
+    POSSIBLY_MISSING_IMPLICIT_CALL, POSSIBLY_MISSING_IMPORT, SUBCLASS_OF_FINAL_CLASS,
+    TypedDictDeleteErrorKind, UNDEFINED_REVEAL, UNRESOLVED_ATTRIBUTE, UNRESOLVED_GLOBAL,
+    UNRESOLVED_IMPORT, UNRESOLVED_REFERENCE, UNSUPPORTED_DYNAMIC_BASE, UNSUPPORTED_OPERATOR,
+    USELESS_OVERLOAD_BODY, hint_if_stdlib_attribute_exists_on_other_versions,
     hint_if_stdlib_submodule_exists_on_other_versions, report_attempted_protocol_instantiation,
     report_bad_dunder_set_call, report_bad_frozen_dataclass_inheritance,
     report_cannot_delete_typed_dict_key, report_cannot_pop_required_field_on_typed_dict,
@@ -92,6 +92,7 @@ use crate::types::diagnostic::{
     report_rebound_typevar, report_slice_step_size_zero, report_unsupported_augmented_assignment,
     report_unsupported_binary_operation, report_unsupported_comparison,
 };
+use crate::types::enums::is_enum_class_by_inheritance;
 use crate::types::function::{
     FunctionDecorators, FunctionLiteral, FunctionType, KnownFunction, OverloadLiteral,
     is_implicit_classmethod, is_implicit_staticmethod,
@@ -105,7 +106,7 @@ use crate::types::instance::SliceLiteral;
 use crate::types::mro::{DynamicMroErrorKind, StaticMroErrorKind};
 use crate::types::newtype::NewType;
 use crate::types::subclass_of::SubclassOfInner;
-use crate::types::tuple::{Tuple, TupleLength, TupleSpec, TupleType};
+use crate::types::tuple::{Tuple, TupleLength, TupleSpec, TupleSpecBuilder, TupleType};
 use crate::types::typed_dict::{
     TypedDictAssignmentKind, validate_typed_dict_constructor, validate_typed_dict_dict_literal,
     validate_typed_dict_key_assignment,
@@ -586,6 +587,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
         if self.db().should_check_file(self.file()) {
             self.check_static_class_definitions();
             self.check_overloaded_functions(node);
+            self.check_type_guard_definitions();
         }
     }
 
@@ -636,10 +638,22 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 continue;
             }
 
+            // (2) Check that the class is not an enum and generic
+            if is_enum_class_by_inheritance(self.db(), class)
+                && class.generic_context(self.db()).is_some()
+            {
+                if let Some(builder) = self.context.report_lint(&INVALID_GENERIC_ENUM, class_node) {
+                    builder.into_diagnostic(format_args!(
+                        "Enum class `{}` cannot be generic",
+                        class.name(self.db())
+                    ));
+                }
+            }
+
             let is_named_tuple =
                 CodeGeneratorKind::NamedTuple.matches(self.db(), class.into(), None);
 
-            // (2) If it's a `NamedTuple` class, check that no field without a default value
+            // (3) If it's a `NamedTuple` class, check that no field without a default value
             // appears after a field with a default value.
             if is_named_tuple {
                 let mut field_with_default_encountered = None;
@@ -680,7 +694,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
 
             let mut disjoint_bases = IncompatibleBases::default();
 
-            // (3) Iterate through the class's explicit bases to check for various possible errors:
+            // (4) Iterate through the class's explicit bases to check for various possible errors:
             //     - Check for inheritance from plain `Generic`,
             //     - Check for inheritance from a `@final` classes
             //     - If the class is a protocol class: check for inheritance from a non-protocol class
@@ -794,7 +808,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 }
             }
 
-            // (4) Check that the class's MRO is resolvable
+            // (5) Check that the class's MRO is resolvable
             match class.try_mro(self.db(), None) {
                 Err(mro_error) => match mro_error.reason() {
                     StaticMroErrorKind::DuplicateBases(duplicates) => {
@@ -865,7 +879,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 }
             }
 
-            // (5) Check that @total_ordering has a valid ordering method in the MRO
+            // (6) Check that @total_ordering has a valid ordering method in the MRO
             if class.total_ordering(self.db()) && !class.has_ordering_method_in_mro(self.db(), None)
             {
                 // Find the @total_ordering decorator to report the diagnostic at its location
@@ -884,7 +898,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 }
             }
 
-            // (6) Check that the class's metaclass can be determined without error.
+            // (7) Check that the class's metaclass can be determined without error.
             if let Err(metaclass_error) = class.try_metaclass(self.db()) {
                 match metaclass_error.reason() {
                     MetaclassErrorKind::Cycle => {
@@ -960,7 +974,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 }
             }
 
-            // (7) Check that the class arguments matches the arguments of the
+            // (8) Check that the class arguments matches the arguments of the
             // base class `__init_subclass__` method.
             if let Some(args) = class_node.arguments.as_deref() {
                 let call_args: CallArguments = args
@@ -1000,7 +1014,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 }
             }
 
-            // (8) If the class is generic, verify that its generic context does not violate any of
+            // (9) If the class is generic, verify that its generic context does not violate any of
             // the typevar scoping rules.
             if let (Some(legacy), Some(inherited)) = (
                 class.legacy_generic_context(self.db()),
@@ -1079,7 +1093,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 }
             }
 
-            // (9) Check that a dataclass does not have more than one `KW_ONLY`.
+            // (10) Check that a dataclass does not have more than one `KW_ONLY`.
             if let Some(field_policy @ CodeGeneratorKind::DataclassLike(_)) =
                 CodeGeneratorKind::from_class(self.db(), class.into(), None)
             {
@@ -1114,7 +1128,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 }
             }
 
-            // (10) Check for violations of the Liskov Substitution Principle,
+            // (11) Check for violations of the Liskov Substitution Principle,
             // and for violations of other rules relating to invalid overrides of some sort.
             overrides::check_class(&self.context, class);
 
@@ -1122,7 +1136,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 protocol.validate_members(&self.context);
             }
 
-            // (11) If it's a `TypedDict` class, check that it doesn't include any invalid
+            // (12) If it's a `TypedDict` class, check that it doesn't include any invalid
             // statements: https://typing.python.org/en/latest/spec/typeddict.html#class-based-syntax
             //
             //     The body of the class definition defines the items of the `TypedDict` type. It
@@ -1439,6 +1453,85 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
         }
     }
 
+    /// Check that all type guard function definitions have at least one positional parameter
+    /// (in addition to `self`/`cls` for methods), and for `TypeIs`, that the narrowed type is
+    /// assignable to the declared type of that parameter.
+    fn check_type_guard_definitions(&mut self) {
+        for (definition, ty) in self.declarations.iter() {
+            // Only check actual function definitions, not imports.
+            let DefinitionKind::Function(function_ref) = definition.kind(self.db()) else {
+                continue;
+            };
+
+            let Some(function) = ty.inner_type().as_function_literal() else {
+                continue;
+            };
+
+            for overload in function.iter_overloads_and_implementation(self.db()) {
+                let signature = overload.signature(self.db());
+                let return_ty = signature.return_ty;
+
+                // Check if this is a `TypeIs` or `TypeGuard` return type.
+                let (type_guard_form_name, narrowed_type) = match return_ty {
+                    Type::TypeIs(type_is) => ("TypeIs", Some(type_is.return_type(self.db()))),
+                    Type::TypeGuard(_) => ("TypeGuard", None),
+                    _ => continue,
+                };
+
+                let function_node = function_ref.node(self.module());
+
+                // The return type annotation must exist since we matched `TypeIs`/`TypeGuard`.
+                let Some(returns_expr) = function_node.returns.as_deref() else {
+                    continue;
+                };
+
+                // Check if this is a non-static method (first parameter is implicit `self`/`cls`).
+                let is_method = self
+                    .index
+                    .class_definition_of_method(
+                        overload.body_scope(self.db()).file_scope_id(self.db()),
+                    )
+                    .is_some();
+                let has_implicit_receiver = is_method && !overload.is_staticmethod(self.db());
+
+                // Find the first positional parameter to narrow (skip implicit `self`/`cls`).
+                let positional_params: Vec<_> = signature.parameters().positional().collect();
+                let first_narrowed_param_index = usize::from(has_implicit_receiver);
+                let first_narrowed_param = positional_params.get(first_narrowed_param_index);
+
+                let Some(first_narrowed_param) = first_narrowed_param else {
+                    if let Some(builder) = self
+                        .context
+                        .report_lint(&INVALID_TYPE_GUARD_DEFINITION, returns_expr)
+                    {
+                        builder.into_diagnostic(format_args!(
+                            "`{type_guard_form_name}` function must have a parameter to narrow"
+                        ));
+                    }
+                    continue;
+                };
+
+                // For `TypeIs`, check that the narrowed type is assignable to the parameter type.
+                if let Some(narrowed_ty) = narrowed_type {
+                    let param_ty = first_narrowed_param.annotated_type();
+                    if !narrowed_ty.is_assignable_to(self.db(), param_ty) {
+                        if let Some(builder) = self
+                            .context
+                            .report_lint(&INVALID_TYPE_GUARD_DEFINITION, returns_expr)
+                        {
+                            builder.into_diagnostic(format_args!(
+                                "Narrowed type `{narrowed}` is not assignable \
+                                to the declared parameter type `{param}`",
+                                narrowed = narrowed_ty.display(self.db()),
+                                param = param_ty.display(self.db())
+                            ));
+                        }
+                    }
+                }
+            }
+        }
+    }
+
     fn infer_region_definition(&mut self, definition: Definition<'db>) {
         match definition.kind(self.db()) {
             DefinitionKind::Function(function) => {
@@ -8154,7 +8247,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
             ast::Expr::If(if_expression) => self.infer_if_expression(if_expression, tcx),
             ast::Expr::Lambda(lambda_expression) => self.infer_lambda_expression(lambda_expression),
             ast::Expr::Call(call_expression) => self.infer_call_expression(call_expression, tcx),
-            ast::Expr::Starred(starred) => self.infer_starred_expression(starred),
+            ast::Expr::Starred(starred) => self.infer_starred_expression(starred, tcx),
             ast::Expr::Yield(yield_expression) => self.infer_yield_expression(yield_expression),
             ast::Expr::YieldFrom(yield_from) => self.infer_yield_from_expression(yield_from),
             ast::Expr::Await(await_expression) => self.infer_await_expression(await_expression),
@@ -8399,7 +8492,7 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
             parenthesized: _,
         } = tuple;
 
-        // Remove any union elements of that are unrelated to the tuple type.
+        // Remove any union elements of the annotation that are unrelated to the tuple type.
         let tcx = tcx.map(|annotation| {
             let inferable = KnownClass::Tuple
                 .try_to_class_literal(self.db())
@@ -8413,16 +8506,33 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
             )
         });
 
+        let mut is_homogeneous_tuple_annotation = false;
+
         let annotated_tuple = tcx
             .known_specialization(self.db(), KnownClass::Tuple)
             .and_then(|specialization| {
-                specialization
+                let spec = specialization
                     .tuple(self.db())
-                    .expect("the specialization of `KnownClass::Tuple` must have a tuple spec")
-                    .resize(self.db(), TupleLength::Fixed(elts.len()))
-                    .ok()
+                    .expect("the specialization of `KnownClass::Tuple` must have a tuple spec");
+
+                if let Tuple::Variable(tuple) = spec
+                    && tuple.prefix_elements().is_empty()
+                    && tuple.suffix_elements().is_empty()
+                {
+                    is_homogeneous_tuple_annotation = true;
+                }
+
+                spec.resize(self.db(), TupleLength::Fixed(elts.len())).ok()
             });
 
+        // TODO: this is a simplification for now.
+        //
+        // It might be possible to use the type context where the annotation is not a pure-homogeneous
+        // tuple and the actual tuple has starred elements in it. It seems complex to reason about,
+        // though, and unlikely to come up much.
+        let can_use_type_context =
+            is_homogeneous_tuple_annotation || elts.iter().all(|elt| !elt.is_starred_expr());
+
         let mut annotated_elt_tys = annotated_tuple
             .as_ref()
             .map(Tuple::all_elements)
@@ -8431,12 +8541,59 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
             .copied();
 
         let db = self.db();
-        let element_types = elts.iter().map(|element| {
-            let annotated_elt_ty = annotated_elt_tys.next();
-            self.infer_expression(element, TypeContext::new(annotated_elt_ty))
-        });
 
-        Type::heterogeneous_tuple(db, element_types)
+        let mut infer_element = |elt: &ast::Expr| {
+            let ctx = if can_use_type_context {
+                let annotated_elt_ty = annotated_elt_tys.by_ref().next();
+                let expected = if elt.is_starred_expr() {
+                    let expected_element = annotated_elt_ty.unwrap_or_else(Type::object);
+                    Some(KnownClass::Iterable.to_specialized_instance(db, &[expected_element]))
+                } else {
+                    annotated_elt_ty
+                };
+                TypeContext::new(expected)
+            } else {
+                TypeContext::default()
+            };
+            self.infer_expression(elt, ctx)
+        };
+
+        let mut builder = TupleSpecBuilder::with_capacity(elts.len());
+
+        for element in elts {
+            if let ast::Expr::Starred(starred) = element {
+                let element_type = infer_element(element);
+                // Fine to use `iterate` rather than `try_iterate` here:
+                // errors from iterating over something not iterable will have been
+                // emitted in the `infer_element` call above.
+                let mut spec = element_type.iterate(db).into_owned();
+
+                let known_length = match &*starred.value {
+                    ast::Expr::List(ast::ExprList { elts, .. })
+                    | ast::Expr::Set(ast::ExprSet { elts, .. }) => elts
+                        .iter()
+                        .all(|elt| !elt.is_starred_expr())
+                        .then_some(elts.len()),
+                    ast::Expr::Dict(ast::ExprDict { items, .. }) => items
+                        .iter()
+                        .all(|item| item.key.is_some())
+                        .then_some(items.len()),
+                    _ => None,
+                };
+
+                if let Some(known_length) = known_length {
+                    spec = spec
+                        .resize(db, TupleLength::Fixed(known_length))
+                        .unwrap_or(spec);
+                }
+
+                builder = builder.concat(db, &spec);
+            } else {
+                builder.push(infer_element(element));
+            }
+        }
+
+        Type::tuple(TupleType::new(db, &builder.build()))
     }
 
     fn infer_list_expression(&mut self, list: &ast::ExprList, tcx: TypeContext<'db>) -> Type<'db> {
@@ -8762,7 +8919,20 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 // assignments from the type context to potentially _narrow_ the inferred type,
                 // by avoiding literal promotion.
                 let elt_ty_identity = elt_ty.identity(self.db());
-                let elt_tcx = elt_tcx_constraints.get(&elt_ty_identity).copied();
+
+                // If the element is a starred expression, we want to apply the type context to each element
+                // in the unpacked expression (which we will store as a tuple when inferring it). We
+                // therefore wrap the type context in an `tuple[T, ...]` specialization.
+                let elt_tcx = elt_tcx_constraints
+                    .get(&elt_ty_identity)
+                    .copied()
+                    .map(|tcx| {
+                        if elt.is_starred_expr() && collection_class != KnownClass::Dict {
+                            Type::homogeneous_tuple(self.db(), tcx)
+                        } else {
+                            tcx
+                        }
+                    });
 
                 let inferred_elt_ty =
                     infer_elt_expression(self, (i, elt, TypeContext::new(elt_tcx)));
@@ -8781,7 +8951,18 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 let inferred_elt_ty =
                     inferred_elt_ty.promote_literals(self.db(), TypeContext::new(elt_tcx));
 
-                builder.infer(Type::TypeVar(elt_ty), inferred_elt_ty).ok()?;
+                builder
+                    .infer(
+                        Type::TypeVar(elt_ty),
+                        if elt.is_starred_expr() {
+                            inferred_elt_ty
+                                .iterate(self.db())
+                                .homogeneous_element_type(self.db())
+                        } else {
+                            inferred_elt_ty
+                        },
+                    )
+                    .ok()?;
             }
         }
 
@@ -9668,7 +9849,11 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
         }
     }
 
-    fn infer_starred_expression(&mut self, starred: &ast::ExprStarred) -> Type<'db> {
+    fn infer_starred_expression(
+        &mut self,
+        starred: &ast::ExprStarred,
+        tcx: TypeContext<'db>,
+    ) -> Type<'db> {
         let ast::ExprStarred {
             range: _,
             node_index: _,
@@ -9676,17 +9861,15 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
             ctx: _,
         } = starred;
 
-        let iterable_type = self.infer_expression(value, TypeContext::default());
+        let db = self.db();
+        let iterable_type = self.infer_expression(value, tcx);
         iterable_type
-            .try_iterate(self.db())
-            .map(|tuple| tuple.homogeneous_element_type(self.db()))
+            .try_iterate(db)
+            .map(|spec| Type::tuple(TupleType::new(db, &spec)))
             .unwrap_or_else(|err| {
                 err.report_diagnostic(&self.context, iterable_type, value.as_ref().into());
-                err.fallback_element_type(self.db())
-            });
-
-        // TODO
-        Type::Dynamic(DynamicType::TodoStarredExpression)
+                Type::homogeneous_tuple(db, err.fallback_element_type(db))
+            })
     }
 
     fn infer_yield_expression(&mut self, yield_expression: &ast::ExprYield) -> Type<'db> {
@@ -13138,16 +13321,36 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
         let value_node = subscript.value.as_ref();
 
         let inferred = match (value_ty, slice_ty) {
+            (Type::Dynamic(_) | Type::Never, _) => Some(value_ty),
+
+            (Type::TypeAlias(alias), _) => Some(self.infer_subscript_expression_types(
+                subscript,
+                alias.value_type(self.db()),
+                slice_ty,
+                expr_context,
+            )),
+
+            (_, Type::TypeAlias(alias)) => Some(self.infer_subscript_expression_types(
+                subscript,
+                value_ty,
+                alias.value_type(self.db()),
+                expr_context,
+            )),
+
             (Type::Union(union), _) => Some(union.map(db, |element| {
                 self.infer_subscript_expression_types(subscript, *element, slice_ty, expr_context)
             })),
 
+            (_, Type::Union(union)) => Some(union.map(db, |element| {
+                self.infer_subscript_expression_types(subscript, value_ty, *element, expr_context)
+            })),
+
             // TODO: we can map over the intersection and fold the results back into an intersection,
             // but we need to make sure we avoid emitting a diagnostic if one positive element has a `__getitem__`
             // method but another does not. This means `infer_subscript_expression_types`
             // needs to return a `Result` rather than eagerly emitting diagnostics.
-            (Type::Intersection(_), _) => {
-                Some(todo_type!("Subscript expressions on intersections"))
+            (Type::Intersection(_), _) | (_, Type::Intersection(_)) => {
+                Some(todo_type!("Subscript expressions with intersections"))
             }
 
             // Ex) Given `("a", "b", "c", "d")[1]`, return `"b"`
@@ -13227,6 +13430,16 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                     }
                 }),
 
+            (Type::LiteralString, Type::IntLiteral(_) | Type::BooleanLiteral(_)) => {
+                Some(Type::LiteralString)
+            }
+
+            (Type::LiteralString, Type::NominalInstance(nominal))
+                if nominal.slice_literal(db).is_some() =>
+            {
+                Some(Type::LiteralString)
+            }
+
             // Ex) Given `b"value"[1]`, return `97` (i.e., `ord(b"a")`)
             (Type::BytesLiteral(literal_ty), Type::IntLiteral(i64_int)) => {
                 i32::try_from(i64_int).ok().map(|i32_int| {
@@ -13358,7 +13571,39 @@ impl<'db, 'ast> TypeInferenceBuilder<'db, 'ast> {
                 Some(todo_type!("Inference of subscript on special form"))
             }
 
-            _ => None,
+            (
+                Type::FunctionLiteral(_)
+                | Type::WrapperDescriptor(_)
+                | Type::BoundMethod(_)
+                | Type::DataclassDecorator(_)
+                | Type::DataclassTransformer(_)
+                | Type::Callable(_)
+                | Type::ModuleLiteral(_)
+                | Type::ClassLiteral(_)
+                | Type::GenericAlias(_)
+                | Type::SubclassOf(_)
+                | Type::AlwaysFalsy
+                | Type::AlwaysTruthy
+                | Type::IntLiteral(_)
+                | Type::BooleanLiteral(_)
+                | Type::ProtocolInstance(_)
+                | Type::PropertyInstance(_)
+                | Type::EnumLiteral(_)
+                | Type::BoundSuper(_)
+                | Type::TypeIs(_)
+                | Type::TypeGuard(_)
+                | Type::TypedDict(_)
+                | Type::NewTypeInstance(_)
+                | Type::NominalInstance(_)
+                | Type::SpecialForm(_)
+                | Type::KnownInstance(_)
+                | Type::StringLiteral(_)
+                | Type::BytesLiteral(_)
+                | Type::LiteralString
+                | Type::TypeVar(_)  // TODO: more complex logic required here!
+                | Type::KnownBoundMethod(_),
+                _,
+            ) => None,
         };
 
         if let Some(inferred) = inferred {

crates/ty_python_semantic/src/types/infer/builder/annotation_expression.rs

@@ -167,9 +167,9 @@ impl<'db> TypeInferenceBuilder<'db, '_> {
             ast::Expr::StringLiteral(string) => self.infer_string_annotation_expression(string),
 
             // Annotation expressions also get special handling for `*args` and `**kwargs`.
-            ast::Expr::Starred(starred) => {
-                TypeAndQualifiers::declared(self.infer_starred_expression(starred))
-            }
+            ast::Expr::Starred(starred) => TypeAndQualifiers::declared(
+                self.infer_starred_expression(starred, TypeContext::default()),
+            ),
 
             ast::Expr::BytesLiteral(bytes) => {
                 if let Some(builder) = self

crates/ty_python_semantic/src/types/narrow.rs

@@ -454,13 +454,6 @@ fn merge_constraints_or<'db>(
     }
 }
 
-fn place_expr(expr: &ast::Expr) -> Option<PlaceExpr> {
-    match expr {
-        ast::Expr::Named(named) => PlaceExpr::try_from_expr(named.target.as_ref()),
-        _ => PlaceExpr::try_from_expr(expr),
-    }
-}
-
 /// Return `true` if it is possible for any two inhabitants of the given types to
 /// compare equal to each other; otherwise return `false`.
 fn could_compare_equal<'db>(db: &'db dyn Db, left_ty: Type<'db>, right_ty: Type<'db>) -> bool {
@@ -721,7 +714,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
         expr: &ast::Expr,
         is_positive: bool,
     ) -> Option<NarrowingConstraints<'db>> {
-        let target = place_expr(expr)?;
+        let target = PlaceExpr::try_from_expr(expr)?;
         let place = self.expect_place(&target);
 
         let ty = if is_positive {
@@ -1030,15 +1023,15 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
         if matches!(&**ops, [ast::CmpOp::Is | ast::CmpOp::IsNot])
             && let ast::Expr::Subscript(subscript) = &**left
             && let Type::Union(union) = inference.expression_type(&*subscript.value)
-            && let Some(subscript_place_expr) = place_expr(&subscript.value)
+            && let Some(subscript_place_expr) = PlaceExpr::try_from_expr(&subscript.value)
             && let Type::IntLiteral(index) = inference.expression_type(&*subscript.slice)
             && let Ok(index) = i32::try_from(index)
             && let rhs_ty = inference.expression_type(&comparators[0])
             && rhs_ty.is_singleton(self.db)
         {
             let is_positive_check = is_positive == (ops[0] == ast::CmpOp::Is);
-            let filtered: Vec<_> = union
-                .elements(self.db)
+            let union_elements = union.elements(self.db);
+            let filtered: Vec<_> = union_elements
                 .iter()
                 .filter(|elem| {
                     elem.as_nominal_instance()
@@ -1056,11 +1049,11 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
                 })
                 .copied()
                 .collect();
-            if filtered.len() < union.elements(self.db).len() {
+            if filtered.len() < union_elements.len() {
                 let place = self.expect_place(&subscript_place_expr);
                 constraints.insert(
                     place,
-                    NarrowingConstraint::regular(UnionType::from_elements(self.db, filtered)),
+                    NarrowingConstraint::typeguard(UnionType::from_elements(self.db, filtered)),
                 );
             }
         }
@@ -1122,7 +1115,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
         //         reveal_type(u)  # revealed: Bar
         if matches!(&**ops, [ast::CmpOp::In | ast::CmpOp::NotIn])
             && let Type::StringLiteral(key) = inference.expression_type(&**left)
-            && let Some(rhs_place_expr) = place_expr(&comparators[0])
+            && let Some(rhs_place_expr) = PlaceExpr::try_from_expr(&comparators[0])
             && let rhs_type = inference.expression_type(&comparators[0])
             && is_typeddict_or_union_with_typeddicts(self.db, rhs_type)
         {
@@ -1190,7 +1183,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
                 | ast::Expr::Attribute(_)
                 | ast::Expr::Subscript(_)
                 | ast::Expr::Named(_) => {
-                    if let Some(left) = place_expr(left)
+                    if let Some(left) = PlaceExpr::try_from_expr(left)
                         && let Some(ty) =
                             self.evaluate_expr_compare_op(lhs_ty, rhs_ty, *op, is_positive)
                     {
@@ -1215,7 +1208,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
                     };
 
                     let target = match &**args {
-                        [first] => match place_expr(first) {
+                        [first] => match PlaceExpr::try_from_expr(first) {
                             Some(target) => target,
                             None => continue,
                         },
@@ -1244,7 +1237,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
                         constraints.insert(
                             place,
                             NarrowingConstraint::regular(
-                                Type::instance(self.db, rhs_class.unknown_specialization(self.db))
+                                Type::instance(self.db, rhs_class.top_materialization(self.db))
                                     .negate_if(self.db, !is_positive),
                             ),
                         );
@@ -1264,7 +1257,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
                         | ast::Expr::Named(_)
                 ) =>
                 {
-                    if let Some(right_place) = place_expr(right)
+                    if let Some(right_place) = PlaceExpr::try_from_expr(right)
                         // Swap lhs_ty and rhs_ty since we're narrowing the right operand
                         && let Some(ty) =
                             self.evaluate_expr_compare_op(rhs_ty, lhs_ty, *op, is_positive)
@@ -1315,7 +1308,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
 
                 // Narrow only the parts of the type that are safe to narrow based on len().
                 if let Some(narrowed_ty) = Self::narrow_type_by_len(self.db, arg_ty, is_positive) {
-                    let target = place_expr(arg)?;
+                    let target = PlaceExpr::try_from_expr(arg)?;
                     let place = self.expect_place(&target);
                     Some(NarrowingConstraints::from_iter([(
                         place,
@@ -1329,7 +1322,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
                 let [first_arg, second_arg] = &*expr_call.arguments.args else {
                     return None;
                 };
-                let first_arg = place_expr(first_arg)?;
+                let first_arg = PlaceExpr::try_from_expr(first_arg)?;
                 let function = function_type.known(self.db)?;
                 let place = self.expect_place(&first_arg);
 
@@ -1427,7 +1420,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
         singleton: ast::Singleton,
         is_positive: bool,
     ) -> Option<NarrowingConstraints<'db>> {
-        let subject = place_expr(subject.node_ref(self.db, self.module))?;
+        let subject = PlaceExpr::try_from_expr(subject.node_ref(self.db, self.module))?;
         let place = self.expect_place(&subject);
 
         let ty = match singleton {
@@ -1456,7 +1449,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
             return None;
         }
 
-        let subject = place_expr(subject.node_ref(self.db, self.module))?;
+        let subject = PlaceExpr::try_from_expr(subject.node_ref(self.db, self.module))?;
         let place = self.expect_place(&subject);
 
         let class_type =
@@ -1486,7 +1479,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
     ) -> Option<NarrowingConstraints<'db>> {
         let subject_node = subject.node_ref(self.db, self.module);
         let place = {
-            let subject = place_expr(subject_node)?;
+            let subject = PlaceExpr::try_from_expr(subject_node)?;
             self.expect_place(&subject)
         };
         let subject_ty =
@@ -1638,7 +1631,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
         if !is_typeddict_or_union_with_typeddicts(self.db, subscript_value_type) {
             return None;
         }
-        let subscript_place_expr = place_expr(subscript_value_expr)?;
+        let subscript_place_expr = PlaceExpr::try_from_expr(subscript_value_expr)?;
         let Type::StringLiteral(key_literal) = subscript_key_type else {
             return None;
         };
@@ -1724,7 +1717,7 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
             return None;
         }
 
-        let subscript_place_expr = place_expr(subscript_value_expr)?;
+        let subscript_place_expr = PlaceExpr::try_from_expr(subscript_value_expr)?;
 
         // Skip narrowing if any tuple in the union has an out-of-bounds index.
         // A diagnostic will be emitted elsewhere for the out-of-bounds access.
@@ -1741,8 +1734,8 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
         }
 
         // Filter the union based on whether each tuple element at the index could match the rhs.
-        let filtered: Vec<_> = union
-            .elements(self.db)
+        let union_elements = union.elements(self.db);
+        let filtered: Vec<_> = union_elements
             .iter()
             .filter(|elem| {
                 elem.as_nominal_instance()
@@ -1762,11 +1755,11 @@ impl<'db, 'ast> NarrowingConstraintsBuilder<'db, 'ast> {
             .collect();
 
         // Only create a constraint if we actually narrowed something.
-        if filtered.len() < union.elements(self.db).len() {
+        if filtered.len() < union_elements.len() {
             let place = self.expect_place(&subscript_place_expr);
             Some((
                 place,
-                NarrowingConstraint::regular(UnionType::from_elements(self.db, filtered)),
+                NarrowingConstraint::typeguard(UnionType::from_elements(self.db, filtered)),
             ))
         } else {
             None

crates/ty_python_semantic/src/types/signatures.rs

@@ -2204,6 +2204,15 @@ pub(crate) struct Parameter<'db> {
     /// type semantics of the parameter.
     pub(crate) inferred_annotation: bool,
 
+    /// Variadic parameters can have starred annotations, e.g.
+    /// - `*args: *Ts`
+    /// - `*args: *tuple[int, ...]`
+    /// - `*args: *tuple[int, *tuple[str, ...], bytes]`
+    ///
+    /// The `*` prior to the type gives the annotation a different meaning,
+    /// so this must be propagated upwards.
+    has_starred_annotation: bool,
+
     kind: ParameterKind<'db>,
     pub(crate) form: ParameterForm,
 }
@@ -2213,6 +2222,7 @@ impl<'db> Parameter<'db> {
         Self {
             annotated_type: Type::unknown(),
             inferred_annotation: true,
+            has_starred_annotation: false,
             kind: ParameterKind::PositionalOnly {
                 name,
                 default_type: None,
@@ -2225,6 +2235,7 @@ impl<'db> Parameter<'db> {
         Self {
             annotated_type: Type::unknown(),
             inferred_annotation: true,
+            has_starred_annotation: false,
             kind: ParameterKind::PositionalOrKeyword {
                 name,
                 default_type: None,
@@ -2237,6 +2248,7 @@ impl<'db> Parameter<'db> {
         Self {
             annotated_type: Type::unknown(),
             inferred_annotation: true,
+            has_starred_annotation: false,
             kind: ParameterKind::Variadic { name },
             form: ParameterForm::Value,
         }
@@ -2246,6 +2258,7 @@ impl<'db> Parameter<'db> {
         Self {
             annotated_type: Type::unknown(),
             inferred_annotation: true,
+            has_starred_annotation: false,
             kind: ParameterKind::KeywordOnly {
                 name,
                 default_type: None,
@@ -2258,6 +2271,7 @@ impl<'db> Parameter<'db> {
         Self {
             annotated_type: Type::unknown(),
             inferred_annotation: true,
+            has_starred_annotation: false,
             kind: ParameterKind::KeywordVariadic { name },
             form: ParameterForm::Value,
         }
@@ -2306,6 +2320,7 @@ impl<'db> Parameter<'db> {
                 .kind
                 .apply_type_mapping_impl(db, type_mapping, tcx, visitor),
             inferred_annotation: self.inferred_annotation,
+            has_starred_annotation: self.has_starred_annotation,
             form: self.form,
         }
     }
@@ -2323,7 +2338,8 @@ impl<'db> Parameter<'db> {
             annotated_type,
             kind,
             form,
-            ..
+            has_starred_annotation,
+            inferred_annotation: _,
         } = self;
 
         // Ensure unions and intersections are ordered in the annotated type.
@@ -2364,6 +2380,7 @@ impl<'db> Parameter<'db> {
             // Normalize `inferred_annotation` to `false` since it's a display-only field
             // that doesn't affect type semantics.
             inferred_annotation: false,
+            has_starred_annotation: *has_starred_annotation,
             kind,
             form: *form,
         }
@@ -2377,6 +2394,7 @@ impl<'db> Parameter<'db> {
     ) -> Option<Self> {
         let Parameter {
             annotated_type,
+            has_starred_annotation,
             inferred_annotation,
             kind,
             form,
@@ -2437,6 +2455,7 @@ impl<'db> Parameter<'db> {
         Some(Self {
             annotated_type,
             inferred_annotation: *inferred_annotation,
+            has_starred_annotation: *has_starred_annotation,
             kind,
             form: *form,
         })
@@ -2448,18 +2467,20 @@ impl<'db> Parameter<'db> {
         parameter: &ast::Parameter,
         kind: ParameterKind<'db>,
     ) -> Self {
-        let (annotated_type, inferred_annotation) = if let Some(annotation) = parameter.annotation()
-        {
-            (
-                function_signature_expression_type(db, definition, annotation),
-                false,
-            )
-        } else {
-            (Type::unknown(), true)
-        };
+        let (annotated_type, inferred_annotation, has_starred_annotation) =
+            if let Some(annotation) = parameter.annotation() {
+                (
+                    function_signature_expression_type(db, definition, annotation),
+                    false,
+                    annotation.is_starred_expr(),
+                )
+            } else {
+                (Type::unknown(), true, false)
+            };
         Self {
             annotated_type,
             kind,
+            has_starred_annotation,
             form: ParameterForm::Value,
             inferred_annotation,
         }
@@ -2511,6 +2532,12 @@ impl<'db> Parameter<'db> {
         self.annotated_type
     }
 
+    /// Return `true` if this parameter has a starred annotation,
+    /// e.g. `*args: *Ts` or `*args: *tuple[int, *tuple[str, ...], bytes]`
+    pub(crate) fn has_starred_annotation(&self) -> bool {
+        self.has_starred_annotation
+    }
+
     /// Kind of the parameter.
     pub(crate) fn kind(&self) -> &ParameterKind<'db> {
         &self.kind

scripts/conformance.py

@@ -0,0 +1,607 @@
+"""
+Run typing conformance tests and compare results between two ty versions.
+
+By default, this script will use `uv` to run the latest version of ty
+as the new version with `uvx ty@latest`. This requires `uv` to be installed
+and available in the system PATH.
+
+If CONFORMANCE_SUITE_COMMIT is set, the hash will be used to create
+links to the corresponding line in the conformance repository for each
+diagnostic. Otherwise, it will default to `main'.
+
+Examples:
+    # Compare two specific ty versions
+    %(prog)s --old-ty uvx ty@0.0.1a35 --new-ty uvx ty@0.0.7
+
+    # Use local ty builds
+    %(prog)s --old-ty ./target/debug/ty-old --new-ty ./target/debug/ty-new
+
+    # Custom test directory
+    %(prog)s --target-path custom/tests --old-ty uvx ty@0.0.1a35 --new-ty uvx ty@0.0.7
+
+    # Show all diagnostics (not just changed ones)
+    %(prog)s --all --old-ty uvx ty@0.0.1a35 --new-ty uvx ty@0.0.7
+
+    # Show a diff with local paths to the test directory instead of table of links
+    %(prog)s --old-ty uvx ty@0.0.1a35 --new-ty uvx ty@0.0.7 --format diff
+"""
+
+from __future__ import annotations
+
+import argparse
+import json
+import os
+import re
+import subprocess
+import sys
+from dataclasses import dataclass
+from enum import Flag, StrEnum, auto
+from functools import reduce
+from itertools import groupby
+from operator import attrgetter, or_
+from pathlib import Path
+from textwrap import dedent
+from typing import Any, Literal, Self
+
+# The conformance tests include 4 types of errors:
+# 1. Required errors (E): The type checker must raise an error on this line
+# 2. Optional errors (E?): The type checker may raise an error on this line
+# 3. Tagged errors (E[tag]): The type checker must raise at most one error on any of the lines in a file with matching tags
+# 4. Tagged multi-errors (E[tag+]): The type checker should raise one or more errors on any of the tagged lines
+# This regex pattern parses the error lines in the conformance tests, but the following
+# implementation treats all errors as required errors.
+CONFORMANCE_ERROR_PATTERN = re.compile(
+    r"""
+    \#\s*E                  # "# E" begins each error
+    (?P<optional>\?)?       # Optional '?' (E?) indicates that an error is optional
+    (?:                     # An optional tag for errors that may appear on multiple lines at most once
+        \[
+            (?P<tag>[^+\]]+)    # identifier
+            (?P<multi>\+)?      # '+' indicates that an error may occur more than once on tagged lines
+        \]
+    )?
+    (?:
+        \s*:\s*(?P<description>.*) # optional description
+    )?
+    """,
+    re.VERBOSE,
+)
+
+CONFORMANCE_URL = "https://github.com/python/typing/blob/{conformance_suite_commit}/conformance/tests/{filename}#L{line}"
+CONFORMANCE_SUITE_COMMIT = os.environ.get("CONFORMANCE_SUITE_COMMIT", "main")
+
+
+class Source(Flag):
+    OLD = auto()
+    NEW = auto()
+    EXPECTED = auto()
+
+
+class Classification(StrEnum):
+    TRUE_POSITIVE = auto()
+    FALSE_POSITIVE = auto()
+    TRUE_NEGATIVE = auto()
+    FALSE_NEGATIVE = auto()
+
+    def into_title(self) -> str:
+        match self:
+            case Classification.TRUE_POSITIVE:
+                return "True positives added 🎉"
+            case Classification.FALSE_POSITIVE:
+                return "False positives added 🫤"
+            case Classification.TRUE_NEGATIVE:
+                return "False positives removed 🎉"
+            case Classification.FALSE_NEGATIVE:
+                return "True positives removed 🫤"
+
+
+@dataclass(kw_only=True, slots=True)
+class Position:
+    line: int
+    column: int
+
+
+@dataclass(kw_only=True, slots=True)
+class Positions:
+    begin: Position
+    end: Position
+
+
+@dataclass(kw_only=True, slots=True)
+class Location:
+    path: str
+    positions: Positions
+
+    def as_link(self) -> str:
+        file = os.path.basename(self.path)
+        link = CONFORMANCE_URL.format(
+            conformance_suite_commit=CONFORMANCE_SUITE_COMMIT,
+            filename=file,
+            line=self.positions.begin.line,
+        )
+        return f"[{file}:{self.positions.begin.line}:{self.positions.begin.column}]({link})"
+
+
+@dataclass(kw_only=True, slots=True)
+class Diagnostic:
+    check_name: str
+    description: str
+    severity: str
+    fingerprint: str | None
+    location: Location
+    source: Source
+
+    def __str__(self) -> str:
+        return (
+            f"{self.location.path}:{self.location.positions.begin.line}:"
+            f"{self.location.positions.begin.column}: "
+            f"{self.severity_for_display}[{self.check_name}] {self.description}"
+        )
+
+    @classmethod
+    def from_gitlab_output(
+        cls,
+        dct: dict[str, Any],
+        source: Source,
+    ) -> Self:
+        return cls(
+            check_name=dct["check_name"],
+            description=dct["description"],
+            severity=dct["severity"],
+            fingerprint=dct["fingerprint"],
+            location=Location(
+                path=dct["location"]["path"],
+                positions=Positions(
+                    begin=Position(
+                        line=dct["location"]["positions"]["begin"]["line"],
+                        column=dct["location"]["positions"]["begin"]["column"],
+                    ),
+                    end=Position(
+                        line=dct["location"]["positions"]["end"]["line"],
+                        column=dct["location"]["positions"]["end"]["column"],
+                    ),
+                ),
+            ),
+            source=source,
+        )
+
+    @property
+    def key(self) -> str:
+        """Key to group diagnostics by path and beginning line."""
+        return f"{self.location.path}:{self.location.positions.begin.line}"
+
+    @property
+    def severity_for_display(self) -> str:
+        return {
+            "major": "error",
+            "minor": "warning",
+        }.get(self.severity, "unknown")
+
+
+@dataclass(kw_only=True, slots=True)
+class GroupedDiagnostics:
+    key: str
+    sources: Source
+    old: Diagnostic | None
+    new: Diagnostic | None
+    expected: Diagnostic | None
+
+    @property
+    def changed(self) -> bool:
+        return (Source.OLD in self.sources or Source.NEW in self.sources) and not (
+            Source.OLD in self.sources and Source.NEW in self.sources
+        )
+
+    @property
+    def classification(self) -> Classification:
+        if Source.NEW in self.sources and Source.EXPECTED in self.sources:
+            return Classification.TRUE_POSITIVE
+        elif Source.NEW in self.sources and Source.EXPECTED not in self.sources:
+            return Classification.FALSE_POSITIVE
+        elif Source.EXPECTED in self.sources:
+            return Classification.FALSE_NEGATIVE
+        else:
+            return Classification.TRUE_NEGATIVE
+
+    def _render_row(self, diagnostic: Diagnostic):
+        return f"| {diagnostic.location.as_link()} | {diagnostic.check_name} | {diagnostic.description} |"
+
+    def _render_diff(self, diagnostic: Diagnostic, *, removed: bool = False):
+        sign = "-" if removed else "+"
+        return f"{sign} {diagnostic}"
+
+    def display(self, format: Literal["diff", "github"]) -> str:
+        match self.classification:
+            case Classification.TRUE_POSITIVE | Classification.FALSE_POSITIVE:
+                assert self.new is not None
+                return (
+                    self._render_diff(self.new)
+                    if format == "diff"
+                    else self._render_row(self.new)
+                )
+
+            case Classification.FALSE_NEGATIVE | Classification.TRUE_NEGATIVE:
+                diagnostic = self.old or self.expected
+                assert diagnostic is not None
+                return (
+                    self._render_diff(diagnostic, removed=True)
+                    if format == "diff"
+                    else self._render_row(diagnostic)
+                )
+
+            case _:
+                raise ValueError(f"Unexpected classification: {self.classification}")
+
+
+@dataclass(kw_only=True, slots=True)
+class Statistics:
+    true_positives: int = 0
+    false_positives: int = 0
+    false_negatives: int = 0
+
+    @property
+    def precision(self) -> float:
+        if self.true_positives + self.false_positives > 0:
+            return self.true_positives / (self.true_positives + self.false_positives)
+        return 0.0
+
+    @property
+    def recall(self) -> float:
+        if self.true_positives + self.false_negatives > 0:
+            return self.true_positives / (self.true_positives + self.false_negatives)
+        else:
+            return 0.0
+
+    @property
+    def total(self) -> int:
+        return self.true_positives + self.false_positives
+
+
+def collect_expected_diagnostics(path: Path) -> list[Diagnostic]:
+    diagnostics: list[Diagnostic] = []
+    for file in path.resolve().rglob("*.py"):
+        for idx, line in enumerate(file.read_text().splitlines(), 1):
+            if error := re.search(CONFORMANCE_ERROR_PATTERN, line):
+                diagnostics.append(
+                    Diagnostic(
+                        check_name="conformance",
+                        description=error.group("description")
+                        or error.group("tag")
+                        or "Missing",
+                        severity="major",
+                        fingerprint=None,
+                        location=Location(
+                            path=file.as_posix(),
+                            positions=Positions(
+                                begin=Position(
+                                    line=idx,
+                                    column=error.start(),
+                                ),
+                                end=Position(
+                                    line=idx,
+                                    column=error.end(),
+                                ),
+                            ),
+                        ),
+                        source=Source.EXPECTED,
+                    )
+                )
+
+    assert diagnostics, "Failed to discover any expected diagnostics!"
+    return diagnostics
+
+
+def collect_ty_diagnostics(
+    ty_path: list[str],
+    source: Source,
+    tests_path: str = ".",
+    python_version: str = "3.12",
+) -> list[Diagnostic]:
+    process = subprocess.run(
+        [
+            *ty_path,
+            "check",
+            f"--python-version={python_version}",
+            "--output-format=gitlab",
+            "--exit-zero",
+            tests_path,
+        ],
+        capture_output=True,
+        text=True,
+        check=True,
+        timeout=15,
+    )
+
+    if process.returncode != 0:
+        print(process.stderr)
+        raise RuntimeError(f"ty check failed with exit code {process.returncode}")
+
+    return [
+        Diagnostic.from_gitlab_output(dct, source=source)
+        for dct in json.loads(process.stdout)
+    ]
+
+
+def group_diagnostics_by_key(
+    old: list[Diagnostic], new: list[Diagnostic], expected: list[Diagnostic]
+) -> list[GroupedDiagnostics]:
+    diagnostics = [
+        *old,
+        *new,
+        *expected,
+    ]
+    sorted_diagnostics = sorted(diagnostics, key=attrgetter("key"))
+
+    grouped = []
+    for key, group in groupby(sorted_diagnostics, key=attrgetter("key")):
+        group = list(group)
+        sources: Source = reduce(or_, (diag.source for diag in group))
+        grouped.append(
+            GroupedDiagnostics(
+                key=key,
+                sources=sources,
+                old=next(filter(lambda diag: diag.source == Source.OLD, group), None),
+                new=next(filter(lambda diag: diag.source == Source.NEW, group), None),
+                expected=next(
+                    filter(lambda diag: diag.source == Source.EXPECTED, group), None
+                ),
+            )
+        )
+
+    return grouped
+
+
+def compute_stats(
+    grouped_diagnostics: list[GroupedDiagnostics], source: Source
+) -> Statistics:
+    if source == source.EXPECTED:
+        # ty currently raises a false positive here due to incomplete enum.Flag support
+        # see https://github.com/astral-sh/ty/issues/876
+        num_errors = sum(
+            1
+            for g in grouped_diagnostics
+            if source.EXPECTED in g.sources  # ty:ignore[unsupported-operator]
+        )
+        return Statistics(
+            true_positives=num_errors, false_positives=0, false_negatives=0
+        )
+
+    def increment(statistics: Statistics, grouped: GroupedDiagnostics) -> Statistics:
+        if (source in grouped.sources) and (Source.EXPECTED in grouped.sources):
+            statistics.true_positives += 1
+        elif source in grouped.sources:
+            statistics.false_positives += 1
+        elif Source.EXPECTED in grouped.sources:
+            statistics.false_negatives += 1
+        return statistics
+
+    return reduce(increment, grouped_diagnostics, Statistics())
+
+
+def render_grouped_diagnostics(
+    grouped: list[GroupedDiagnostics],
+    *,
+    changed_only: bool = True,
+    format: Literal["diff", "github"] = "diff",
+) -> str:
+    if changed_only:
+        grouped = [diag for diag in grouped if diag.changed]
+
+    sorted_by_class = sorted(
+        grouped,
+        key=attrgetter("classification"),
+        reverse=True,
+    )
+
+    match format:
+        case "diff":
+            header = ["```diff"]
+            footer = "```"
+        case "github":
+            header = [
+                "| Location | Name | Message |",
+                "|----------|------|---------|",
+            ]
+            footer = ""
+        case _:
+            raise ValueError("format must be one of 'diff' or 'github'")
+
+    lines = []
+    for classification, group in groupby(
+        sorted_by_class, key=attrgetter("classification")
+    ):
+        group = list(group)
+
+        lines.append(f"## {classification.into_title()}")
+        lines.extend(["", "<details>", ""])
+
+        lines.extend(header)
+
+        for diag in group:
+            lines.append(diag.display(format=format))
+
+        lines.append(footer)
+        lines.extend(["", "</details>", ""])
+
+    return "\n".join(lines)
+
+
+def diff_format(
+    diff: float,
+    *,
+    greater_is_better: bool = True,
+    neutral: bool = False,
+    is_percentage: bool = False,
+):
+    increased = diff > 0
+    good = " (✅)" if not neutral else ""
+    bad = " (❌)" if not neutral else ""
+    up = "⏫"
+    down = "⏬"
+
+    match (greater_is_better, increased):
+        case (True, True):
+            return f"{up}{good}"
+        case (False, True):
+            return f"{up}{bad}"
+        case (True, False):
+            return f"{down}{bad}"
+        case (False, False):
+            return f"{down}{good}"
+
+
+def render_summary(grouped_diagnostics: list[GroupedDiagnostics]):
+    def format_metric(diff: float, old: float, new: float):
+        if diff > 0:
+            return f"increased from {old:.2%} to {new:.2%}"
+        if diff < 0:
+            return f"decreased from {old:.2%} to {new:.2%}"
+        return f"held steady at {old:.2%}"
+
+    old = compute_stats(grouped_diagnostics, source=Source.OLD)
+    new = compute_stats(grouped_diagnostics, source=Source.NEW)
+
+    precision_change = new.precision - old.precision
+    recall_change = new.recall - old.recall
+    true_pos_change = new.true_positives - old.true_positives
+    false_pos_change = new.false_positives - old.false_positives
+    false_neg_change = new.false_negatives - old.false_negatives
+    total_change = new.total - old.total
+
+    true_pos_diff = diff_format(true_pos_change, greater_is_better=True)
+    false_pos_diff = diff_format(false_pos_change, greater_is_better=False)
+    false_neg_diff = diff_format(false_neg_change, greater_is_better=False)
+    precision_diff = diff_format(
+        precision_change, greater_is_better=True, is_percentage=True
+    )
+    recall_diff = diff_format(recall_change, greater_is_better=True, is_percentage=True)
+    total_diff = diff_format(total_change, neutral=True)
+
+    table = dedent(
+        f"""
+        ## Typing Conformance
+
+        ### Summary
+
+        | Metric | Old | New | Diff | Outcome |
+        |--------|-----|-----|------|---------|
+        | True Positives  | {old.true_positives} | {new.true_positives} | {true_pos_change:+} | {true_pos_diff} |
+        | False Positives | {old.false_positives} | {new.false_positives} | {false_pos_change:+} | {false_pos_diff} |
+        | False Negatives | {old.false_negatives} | {new.false_negatives} | {false_neg_change:+} | {false_neg_diff} |
+        | Total Diagnostics | {old.total} | {new.total} | {total_change} | {total_diff} |
+        | Precision | {old.precision:.2%} | {new.precision:.2%} | {precision_change:+.2%} | {precision_diff} |
+        | Recall | {old.recall:.2%} | {new.recall:.2%} | {recall_change:+.2%} | {recall_diff} |
+
+        """
+    )
+
+    summary = (
+        f"The percentage of diagnostics emitted that were expected errors"
+        f" {format_metric(precision_change, old.precision, new.precision)},"
+        " and the percentage of expected errors that received a diagnostic"
+        f" {format_metric(recall_change, old.recall, new.recall)}."
+    )
+
+    return "\n".join([table, summary])
+
+
+def parse_args():
+    parser = argparse.ArgumentParser(
+        description=__doc__,
+        formatter_class=argparse.RawDescriptionHelpFormatter,
+    )
+
+    parser.add_argument(
+        "--old-ty",
+        nargs="+",
+        help="Command to run old version of ty (default: uvx ty@0.0.1a35)",
+    )
+
+    parser.add_argument(
+        "--new-ty",
+        nargs="+",
+        default=["uvx", "ty@latest"],
+        help="Command to run new version of ty (default: uvx ty@0.0.7)",
+    )
+
+    parser.add_argument(
+        "--tests-path",
+        type=Path,
+        default=Path("typing/conformance/tests"),
+        help="Path to conformance tests directory (default: typing/conformance/tests)",
+    )
+
+    parser.add_argument(
+        "--python-version",
+        type=str,
+        default="3.12",
+        help="Python version to assume when running ty (default: 3.12)",
+    )
+
+    parser.add_argument(
+        "--all",
+        action="store_true",
+        help="Show all diagnostics, not just changed ones",
+    )
+
+    parser.add_argument(
+        "--format", type=str, choices=["diff", "github"], default="github"
+    )
+
+    parser.add_argument(
+        "--output",
+        type=Path,
+        help="Write output to file instead of stdout",
+    )
+
+    args = parser.parse_args()
+
+    if args.old_ty is None:
+        raise ValueError("old_ty is required")
+
+    return args
+
+
+def main():
+    args = parse_args()
+
+    expected = collect_expected_diagnostics(args.tests_path)
+
+    old = collect_ty_diagnostics(
+        ty_path=args.old_ty,
+        tests_path=str(args.tests_path),
+        source=Source.OLD,
+        python_version=args.python_version,
+    )
+
+    new = collect_ty_diagnostics(
+        ty_path=args.new_ty,
+        tests_path=str(args.tests_path),
+        source=Source.NEW,
+        python_version=args.python_version,
+    )
+
+    grouped = group_diagnostics_by_key(
+        old=old,
+        new=new,
+        expected=expected,
+    )
+
+    rendered = "\n\n".join(
+        [
+            render_summary(grouped),
+            render_grouped_diagnostics(
+                grouped, changed_only=not args.all, format=args.format
+            ),
+        ]
+    )
+
+    if args.output:
+        args.output.write_text(rendered, encoding="utf-8")
+        print(f"Output written to {args.output}", file=sys.stderr)
+    else:
+        print(rendered)
+
+
+if __name__ == "__main__":
+    main()

ty.schema.json

@@ -640,6 +640,16 @@
             }
           ]
         },
+        "invalid-generic-enum": {
+          "title": "detects generic enum classes",
+          "description": "## What it does\nChecks for enum classes that are also generic.\n\n## Why is this bad?\nEnum classes cannot be generic. Python does not support generic enums:\nattempting to create one will either result in an immediate `TypeError`\nat runtime, or will create a class that cannot be specialized in the way\nthat a normal generic class can.\n\n## Examples\n```python\nfrom enum import Enum\nfrom typing import Generic, TypeVar\n\nT = TypeVar(\"T\")\n\n# error: enum class cannot be generic (class creation fails with `TypeError`)\nclass E[T](Enum):\n    A = 1\n\n# error: enum class cannot be generic (class creation fails with `TypeError`)\nclass F(Enum, Generic[T]):\n    A = 1\n\n# error: enum class cannot be generic -- the class creation does not immediately fail...\nclass G(Generic[T], Enum):\n    A = 1\n\n# ...but this raises `KeyError`:\nx: G[int]\n```\n\n## References\n- [Python documentation: Enum](https://docs.python.org/3/library/enum.html)",
+          "default": "error",
+          "oneOf": [
+            {
+              "$ref": "#/definitions/Level"
+            }
+          ]
+        },
         "invalid-ignore-comment": {
           "title": "detects ignore comments that use invalid syntax",
           "description": "## What it does\nChecks for `type: ignore` and `ty: ignore` comments that are syntactically incorrect.\n\n## Why is this bad?\nA syntactically incorrect ignore comment is probably a mistake and is useless.\n\n## Examples\n```py\na = 20 / 0  # type: ignoree\n```\n\nUse instead:\n\n```py\na = 20 / 0  # type: ignore\n```",