Douglas Creager aba0bd568e [ty] Diagnostic for generic classes that reference typevars in enclosing scope (#20822) ... Generic classes are not allowed to bind or reference a typevar from an enclosing scope: ```py def f[T](x: T, y: T) -> None: class Ok[S]: ... # error: [invalid-generic-class] class Bad1[T]: ... # error: [invalid-generic-class] class Bad2(Iterable[T]): ... class C[T]: class Ok1[S]: ... # error: [invalid-generic-class] class Bad1[T]: ... # error: [invalid-generic-class] class Bad2(Iterable[T]): ... ``` It does not matter if the class uses PEP 695 or legacy syntax. It does not matter if the enclosing scope is a generic class or function. The generic class cannot even _reference_ an enclosing typevar in its base class list. This PR adds diagnostics for these cases. In addition, the PR adds better fallback behavior for generic classes that violate this rule: any enclosing typevars are not included in the class's generic context. (That ensures that we don't inadvertently try to infer specializations for those typevars in places where we shouldn't.) The `dulwich` ecosystem project has [examples of this](d912eaaffd/dulwich/config.py (L251)) that were causing new false positives on #20677. --------- Co-authored-by: Alex Waygood <Alex.Waygood@Gmail.com>		2025-10-13 19:30:49 -04:00
..
annotations	[ty] Do not bind self to non-positional parameters (#20850)	2025-10-13 20:44:27 +02:00
assignment	[ty] bidirectional type inference using function return type annotations (#20528)	2025-10-11 00:38:35 +00:00
binary	Update default and latest Python versions for 3.14 (#20725)	2025-10-07 12:23:11 -04:00
boolean	Revert "[ty] Better control flow for boolean expressions that are inside if (#18010)" (#18150)	2025-05-17 08:27:32 -04:00
boundness_declaredness	[ty] Reformulation of public symbol inference test suite (#20667)	2025-10-01 14:26:17 +02:00
call	[ty] Treat `Callable`s as bound-method descriptors in special cases (#20802)	2025-10-13 21:17:47 +02:00
class	[ty] Fix false-positive diagnostics on `super()` calls (#20814)	2025-10-13 10:57:46 +00:00
comparison	[ty] detect cycles in binary comparison inference (#20446)	2025-09-17 09:45:25 +02:00
comprehensions	[ty] Async for loops and async iterables (#19634)	2025-07-30 17:40:24 +02:00
conditional	[ty] Support as-patterns in reachability analysis (#19728)	2025-08-04 20:13:50 +02:00
dataclasses	[ty] Treat functions, methods, and dynamic types as function-like `Callable`s (#20842)	2025-10-13 15:21:55 +02:00
declaration	[ty] Format conflicting types as an enumeration (#18956)	2025-06-26 14:29:33 +02:00
diagnostics	[ty] defer inference of legacy TypeVar bound/constraints/defaults (#20598)	2025-10-09 21:08:37 +00:00
directives	[ty] Use annotated parameters as type context (#20635)	2025-10-03 17:14:51 -04:00
doc	ty_python_semantic: add union type context to function call type errors	2025-05-09 13:40:51 -04:00
exception	[ty] Filter out `revealed-type` and `undefined-reveal` diagnostics from mdtest snapshots (#20820)	2025-10-12 18:39:32 +00:00
expression	[ty] Rename "possibly unbound" diagnostics to "possibly missing" (#20492)	2025-09-23 14:26:55 +00:00
function	[ty] Improve disambiguation of types via fully qualified names (#20141)	2025-08-29 08:44:18 +00:00
generics	[ty] Diagnostic for generic classes that reference typevars in enclosing scope (#20822)	2025-10-13 19:30:49 -04:00
ide_support	[ty] Filter out `revealed-type` and `undefined-reveal` diagnostics from mdtest snapshots (#20820)	2025-10-12 18:39:32 +00:00
import	[ty] No union with `Unknown` for module-global symbols (#20664)	2025-10-01 16:40:30 +02:00
literal	[ty] Treat functions, methods, and dynamic types as function-like `Callable`s (#20842)	2025-10-13 15:21:55 +02:00
loops	[ty] Filter out `revealed-type` and `undefined-reveal` diagnostics from mdtest snapshots (#20820)	2025-10-12 18:39:32 +00:00
narrow	[ty] Filter out `revealed-type` and `undefined-reveal` diagnostics from mdtest snapshots (#20820)	2025-10-12 18:39:32 +00:00
regression	Rename Red Knot (#17820)	2025-05-03 19:49:15 +02:00
scopes	Update default and latest Python versions for 3.14 (#20725)	2025-10-07 12:23:11 -04:00
shadowing	Rename Red Knot (#17820)	2025-05-03 19:49:15 +02:00
snapshots	[ty] Diagnostic for generic classes that reference typevars in enclosing scope (#20822)	2025-10-13 19:30:49 -04:00
stubs	Update default and latest Python versions for 3.14 (#20725)	2025-10-07 12:23:11 -04:00
subscript	[ty] Rename "possibly unbound" diagnostics to "possibly missing" (#20492)	2025-09-23 14:26:55 +00:00
suppressions	[ty] Consistent use of American english (in rules) (#19488)	2025-07-22 16:10:38 +02:00
type_compendium	[ty] Type-context aware literal promotion (#20776)	2025-10-09 16:53:53 -04:00
type_of	[ty] Improve the `Display` for generic `type[]` types (#19667)	2025-07-31 19:45:01 +01:00
type_properties	[ty] Treat functions, methods, and dynamic types as function-like `Callable`s (#20842)	2025-10-13 15:21:55 +02:00
type_qualifiers	[ty] Allow annotation expressions to be `ast::Attribute` nodes (#20413)	2025-09-15 12:06:48 +01:00
unary	Update class literal display to use `<class 'Foo'>` style (#17889)	2025-05-06 20:11:25 -04:00
with	[ty] Use `typing.Self` for the first parameter of instance methods (#20517)	2025-09-29 21:08:08 +02:00
.mdformat.toml	Rename Red Knot (#17820)	2025-05-03 19:49:15 +02:00
async.md	[ty] Support `async`/`await`, `async with` and `yield from` (#19595)	2025-07-30 11:51:21 +02:00
attributes.md	[ty] Prefer declared base class attribute over inferred attribute on subclass (#20764)	2025-10-13 09:28:57 +02:00
bidirectional.md	[ty] bidirectional type inference using function return type annotations (#20528)	2025-10-11 00:38:35 +00:00
classes.md	[ty] don't assume that deferred type inference means deferred name resolution (#20160)	2025-08-29 16:19:45 -07:00
cycle.md	[ty] Add cycle handling for unpacking targets (#18078)	2025-05-13 21:27:48 +00:00
decorators.md	ty_python_semantic: add union type context to function call type errors	2025-05-09 13:40:51 -04:00
del.md	[ty] No union with `Unknown` for module-global symbols (#20664)	2025-10-01 16:40:30 +02:00
deprecated.md	[ty] Consistent use of American english (in rules) (#19488)	2025-07-22 16:10:38 +02:00
descriptor_protocol.md	[ty] Use `typing.Self` for the first parameter of instance methods (#20517)	2025-09-29 21:08:08 +02:00
enums.md	[ty] Enums: allow multiple aliases to point to the same member (#20669)	2025-10-01 15:51:53 +02:00
exhaustiveness_checking.md	[ty] Fix subtyping for dynamic specializations (#20592)	2025-09-26 15:05:03 +02:00
final.md	Rename Red Knot (#17820)	2025-05-03 19:49:15 +02:00
implicit_type_aliases.md	[ty] no more diverging query cycles in type expressions (#20359)	2025-09-16 16:44:11 -07:00
instance_layout_conflict.md	[ty] initial support for `slots=True` in dataclasses (#20278)	2025-09-07 18:25:35 +01:00
intersection_types.md	[ty] Expansion of enums into unions of literals (#19382)	2025-07-21 19:37:55 +02:00
invalid_syntax.md	Rename Red Knot (#17820)	2025-05-03 19:49:15 +02:00
known_constants.md	Rename Red Knot (#17820)	2025-05-03 19:49:15 +02:00
mdtest_config.md	Rename Red Knot (#17820)	2025-05-03 19:49:15 +02:00
mdtest_custom_typeshed.md	[ty] Remove `Type::Tuple` (#19669)	2025-08-11 22:03:32 +01:00
metaclass.md	Update class literal display to use `<class 'Foo'>` style (#17889)	2025-05-06 20:11:25 -04:00
mro.md	[ty] Filter out `revealed-type` and `undefined-reveal` diagnostics from mdtest snapshots (#20820)	2025-10-12 18:39:32 +00:00
named_tuple.md	[ty] Use `typing.Self` for the first parameter of instance methods (#20517)	2025-09-29 21:08:08 +02:00
overloads.md	[ty] Improve diagnostics for bad `@overload` definitions (#20745)	2025-10-07 21:52:57 +00:00
pep695_type_aliases.md	[ty] defer inference of legacy TypeVar bound/constraints/defaults (#20598)	2025-10-09 21:08:37 +00:00
properties.md	[ty] `"foo".startswith` is not an instance of `types.MethodWrapperType` (#20317)	2025-09-10 11:14:26 +00:00
protocols.md	[ty] Filter out `revealed-type` and `undefined-reveal` diagnostics from mdtest snapshots (#20820)	2025-10-12 18:39:32 +00:00
public_types.md	[ty] Disambiguate classes that live in different modules but have the same fully qualified names (#20756)	2025-10-08 18:27:40 +01:00
statically_known_branches.md	[ty] Rename "possibly unbound" diagnostics to "possibly missing" (#20492)	2025-09-23 14:26:55 +00:00
sys_platform.md	Rename Red Knot (#17820)	2025-05-03 19:49:15 +02:00
sys_version_info.md	Rename Red Knot (#17820)	2025-05-03 19:49:15 +02:00
t_strings.md	[ty] Add support for PEP 750 t-strings (#20085)	2025-08-25 18:49:49 +00:00
terminal_statements.md	[ty] improve lazy scope place lookup (#19321)	2025-07-25 07:11:11 +00:00
ty_extensions.md	[ty] Simplify and fix `CallableTypeOf[..]` implementation (#20797)	2025-10-10 12:04:37 +02:00
typed_dict.md	[ty] bidirectional type inference using function return type annotations (#20528)	2025-10-11 00:38:35 +00:00
union_types.md	[ty] Introduce `TypeRelation::Redundancy` (#20602)	2025-10-03 18:35:30 +01:00
unpacking.md	[ty] Infer more precise types for collection literals (#20360)	2025-09-17 18:51:50 -04:00
unreachable.md	[ty] Rename "possibly unbound" diagnostics to "possibly missing" (#20492)	2025-09-23 14:26:55 +00:00