[ty] Generic types aliases (implicit and PEP 613)#21553
Merged
Conversation
Diagnostic diff on typing conformance testsChanges were detected when running ty on typing conformance tests--- old-output.txt 2025-11-28 19:17:48.980568399 +0000
+++ new-output.txt 2025-11-28 19:17:52.680561701 +0000
@@ -4,21 +4,26 @@
_directives_deprecated_library.py:41:25: error[invalid-return-type] Function always implicitly returns `None`, which is not assignable to return type `int | float`
_directives_deprecated_library.py:45:24: error[invalid-return-type] Function always implicitly returns `None`, which is not assignable to return type `str`
aliases_explicit.py:41:24: error[invalid-type-form] List literals are not allowed in this context in a type expression: Did you mean `tuple[str, str]`?
-aliases_explicit.py:52:5: error[type-assertion-failure] Type `list[int]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-aliases_explicit.py:53:5: error[type-assertion-failure] Type `tuple[str, ...] | list[str]` does not match asserted type `@Todo(Generic specialization of types.UnionType)`
-aliases_explicit.py:54:5: error[type-assertion-failure] Type `tuple[int, int, int, str]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-aliases_explicit.py:56:5: error[type-assertion-failure] Type `(int, str, /) -> str` does not match asserted type `@Todo(Generic specialization of typing.Callable)`
-aliases_explicit.py:57:5: error[type-assertion-failure] Type `(int, str, str, /) -> None` does not match asserted type `@Todo(Generic specialization of typing.Callable)`
-aliases_explicit.py:59:5: error[type-assertion-failure] Type `int | str | None | list[list[int]]` does not match asserted type `int | str | None | list[@Todo(specialized generic alias in type expression)]`
+aliases_explicit.py:41:36: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_explicit.py:57:5: error[type-assertion-failure] Type `(int, str, str, /) -> None` does not match asserted type `(...) -> Unknown`
+aliases_explicit.py:60:5: error[type-assertion-failure] Type `(...) -> None` does not match asserted type `@Todo(Callable[..] specialized with ParamSpec)`
+aliases_explicit.py:67:24: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+aliases_explicit.py:68:24: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+aliases_explicit.py:69:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_explicit.py:70:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_explicit.py:71:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
aliases_explicit.py:101:6: error[call-non-callable] Object of type `UnionType` is not callable
+aliases_explicit.py:102:20: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
aliases_implicit.py:54:24: error[invalid-type-form] List literals are not allowed in this context in a type expression: Did you mean `tuple[str, str]`?
-aliases_implicit.py:63:5: error[type-assertion-failure] Type `list[int]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-aliases_implicit.py:64:5: error[type-assertion-failure] Type `tuple[str, ...] | list[str]` does not match asserted type `@Todo(Generic specialization of types.UnionType)`
-aliases_implicit.py:65:5: error[type-assertion-failure] Type `tuple[int, int, int, str]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-aliases_implicit.py:67:5: error[type-assertion-failure] Type `(int, str, /) -> str` does not match asserted type `@Todo(Generic specialization of typing.Callable)`
-aliases_implicit.py:68:5: error[type-assertion-failure] Type `(int, str, str, /) -> None` does not match asserted type `@Todo(Generic specialization of typing.Callable)`
-aliases_implicit.py:70:5: error[type-assertion-failure] Type `int | str | None | list[list[int]]` does not match asserted type `int | str | None | list[@Todo(specialized generic alias in type expression)]`
-aliases_implicit.py:71:5: error[type-assertion-failure] Type `list[bool]` does not match asserted type `@Todo(specialized generic alias in type expression)`
+aliases_implicit.py:54:36: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_implicit.py:68:5: error[type-assertion-failure] Type `(int, str, str, /) -> None` does not match asserted type `(...) -> Unknown`
+aliases_implicit.py:72:5: error[type-assertion-failure] Type `(...) -> None` does not match asserted type `@Todo(Callable[..] specialized with ParamSpec)`
+aliases_implicit.py:76:24: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+aliases_implicit.py:77:24: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+aliases_implicit.py:78:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_implicit.py:79:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_implicit.py:80:29: error[invalid-type-arguments] Too many type arguments: expected 1, got 2
+aliases_implicit.py:81:25: error[invalid-type-arguments] Type `str` is not assignable to upper bound `int | float` of type variable `TFloat@GoodTypeAlias12`
aliases_implicit.py:107:9: error[invalid-type-form] Variable of type `list[Unknown | <class 'int'> | <class 'str'>]` is not allowed in a type expression
aliases_implicit.py:108:9: error[invalid-type-form] Variable of type `tuple[tuple[<class 'int'>, <class 'str'>]]` is not allowed in a type expression
aliases_implicit.py:109:9: error[invalid-type-form] Variable of type `list[<class 'int'> | Unknown]` is not allowed in a type expression
@@ -29,6 +34,7 @@
aliases_implicit.py:118:10: error[invalid-type-form] Variable of type `Literal["int"]` is not allowed in a type expression
aliases_implicit.py:119:10: error[invalid-type-form] Variable of type `Literal["int | str"]` is not allowed in a type expression
aliases_implicit.py:133:6: error[call-non-callable] Object of type `UnionType` is not callable
+aliases_implicit.py:135:20: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
aliases_newtype.py:11:8: error[invalid-argument-type] Argument is incorrect: Expected `int`, found `Literal["user"]`
aliases_newtype.py:12:14: error[invalid-assignment] Object of type `Literal[42]` is not assignable to `UserId`
aliases_newtype.py:18:11: error[invalid-assignment] Object of type `<NewType pseudo-class 'UserId'>` is not assignable to `type`
@@ -75,7 +81,6 @@
aliases_type_statement.py:88:1: error[cyclic-type-alias-definition] Cyclic definition of `RecursiveTypeAlias6`
aliases_type_statement.py:89:1: error[cyclic-type-alias-definition] Cyclic definition of `RecursiveTypeAlias7`
aliases_typealiastype.py:32:7: error[unresolved-attribute] Object of type `typing.TypeAliasType` has no attribute `other_attrib`
-aliases_typealiastype.py:39:26: error[invalid-type-form] List literals are not allowed in this context in a type expression: Did you mean `tuple[int, str]`?
aliases_typealiastype.py:52:40: error[invalid-type-form] Function calls are not allowed in type expressions
aliases_typealiastype.py:53:40: error[invalid-type-form] List literals are not allowed in this context in a type expression: Did you mean `tuple[int, str]`?
aliases_typealiastype.py:54:42: error[invalid-type-form] Tuple literals are not allowed in this context in a type expression
@@ -92,9 +97,6 @@
aliases_typealiastype.py:63:42: error[invalid-type-form] Boolean operations are not allowed in type expressions
aliases_typealiastype.py:64:42: error[invalid-type-form] F-strings are not allowed in type expressions
aliases_typealiastype.py:66:47: error[unresolved-reference] Name `BadAlias21` used when not defined
-aliases_variance.py:18:24: error[non-subscriptable] Cannot subscript object of type `<class 'ClassA[typing.TypeVar]'>` with no `__class_getitem__` method
-aliases_variance.py:28:16: error[non-subscriptable] Cannot subscript object of type `<class 'ClassA[typing.TypeVar]'>` with no `__class_getitem__` method
-aliases_variance.py:44:16: error[non-subscriptable] Cannot subscript object of type `<class 'ClassB[typing.TypeVar, typing.TypeVar]'>` with no `__class_getitem__` method
annotations_forward_refs.py:47:10: error[invalid-type-form] Invalid subscript of object of type `list[Unknown | <class 'int'>]` in type expression
annotations_forward_refs.py:49:10: error[invalid-type-form] Variable of type `Literal[1]` is not allowed in a type expression
annotations_forward_refs.py:54:11: error[fstring-type-annotation] Type expressions cannot use f-strings
@@ -139,6 +141,10 @@
callables_annotation.py:58:5: error[invalid-type-form] Special form `typing.Callable` expected exactly two arguments (parameter types and return type)
callables_annotation.py:58:14: error[invalid-type-form] The first argument to `Callable` must be either a list of types, ParamSpec, Concatenate, or `...`
callables_annotation.py:157:20: error[invalid-assignment] Object of type `Proto7` is not assignable to `Proto6`
+callables_annotation.py:172:19: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+callables_annotation.py:175:19: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+callables_annotation.py:188:25: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+callables_annotation.py:189:25: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
callables_kwargs.py:24:5: error[type-assertion-failure] Type `int` does not match asserted type `@Todo(`Unpack[]` special form)`
callables_kwargs.py:32:9: error[type-assertion-failure] Type `str` does not match asserted type `@Todo(`Unpack[]` special form)`
callables_kwargs.py:35:5: error[type-assertion-failure] Type `str` does not match asserted type `@Todo(`Unpack[]` special form)`
@@ -467,9 +473,8 @@
generics_defaults_referential.py:37:10: error[invalid-argument-type] Argument to bound method `__init__` is incorrect: Expected `int`, found `Literal[""]`
generics_defaults_referential.py:94:1: error[type-assertion-failure] Type `type[Bar[Any, list[Any]]]` does not match asserted type `<class 'Bar'>`
generics_defaults_referential.py:95:1: error[type-assertion-failure] Type `type[Bar[int, list[int]]]` does not match asserted type `<class 'Bar[int, list[int]]'>`
-generics_defaults_specialization.py:26:5: error[type-assertion-failure] Type `SomethingWithNoDefaults[int, str]` does not match asserted type `SomethingWithNoDefaults[int, typing.TypeVar]`
-generics_defaults_specialization.py:27:5: error[type-assertion-failure] Type `SomethingWithNoDefaults[int, bool]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-generics_defaults_specialization.py:30:1: error[non-subscriptable] Cannot subscript object of type `<class 'SomethingWithNoDefaults[int, typing.TypeVar]'>` with no `__class_getitem__` method
+generics_defaults_specialization.py:26:5: error[type-assertion-failure] Type `SomethingWithNoDefaults[int, str]` does not match asserted type `SomethingWithNoDefaults[int, DefaultStrT]`
+generics_defaults_specialization.py:30:15: error[invalid-type-arguments] Too many type arguments: expected between 0 and 1, got 2
generics_defaults_specialization.py:45:1: error[type-assertion-failure] Type `type[Bar[str]]` does not match asserted type `<class 'Bar'>`
generics_paramspec_basic.py:10:1: error[invalid-paramspec] The name of a `ParamSpec` (`NotIt`) must match the name of the variable it is assigned to (`WrongName`)
generics_paramspec_basic.py:23:20: error[invalid-return-type] Function always implicitly returns `None`, which is not assignable to return type `P@func1`
@@ -617,27 +622,41 @@
generics_typevartuple_concat.py:52:1: error[type-assertion-failure] Type `tuple[int, bool, str]` does not match asserted type `tuple[@Todo(PEP 646), ...]`
generics_typevartuple_overloads.py:16:13: error[invalid-argument-type] `@Todo(starred expression)` is not a valid argument to `Generic`
generics_typevartuple_specialization.py:16:13: error[invalid-argument-type] `@Todo(starred expression)` is not a valid argument to `Generic`
-generics_typevartuple_specialization.py:46:5: error[type-assertion-failure] Type `tuple[int, int | float, bool]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-generics_typevartuple_specialization.py:47:5: error[type-assertion-failure] Type `tuple[str, @Todo(specialized non-generic class)]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-generics_typevartuple_specialization.py:50:23: error[invalid-type-form] Tuple literals are not allowed in this context in a type expression: Did you mean `tuple[()]`?
-generics_typevartuple_specialization.py:50:42: error[invalid-type-form] Tuple literals are not allowed in this context in a type expression: Did you mean `tuple[()]`?
-generics_typevartuple_specialization.py:51:5: error[type-assertion-failure] Type `tuple[int]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-generics_typevartuple_specialization.py:52:5: error[type-assertion-failure] Type `tuple[str, @Todo(specialized non-generic class)]` does not match asserted type `@Todo(specialized generic alias in type expression)`
+generics_typevartuple_specialization.py:45:23: error[invalid-type-arguments] Too many type arguments: expected 0, got 2
+generics_typevartuple_specialization.py:45:51: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+generics_typevartuple_specialization.py:46:5: error[type-assertion-failure] Type `tuple[int, int | float, bool]` does not match asserted type `tuple[@Todo(PEP 646), ...]`
+generics_typevartuple_specialization.py:51:5: error[type-assertion-failure] Type `tuple[int]` does not match asserted type `tuple[@Todo(PEP 646), ...]`
generics_typevartuple_specialization.py:52:37: error[invalid-type-form] Tuple literals are not allowed in this context in a type expression: Did you mean `tuple[()]`?
generics_typevartuple_specialization.py:59:14: error[invalid-argument-type] `@Todo(starred expression)` is not a valid argument to `Generic`
-generics_typevartuple_specialization.py:93:5: error[type-assertion-failure] Type `tuple[str, int]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-generics_typevartuple_specialization.py:94:5: error[type-assertion-failure] Type `tuple[int | float]` does not match asserted type `@Todo(specialized generic alias in type expression)`
+generics_typevartuple_specialization.py:92:28: error[invalid-type-arguments] Too many type arguments: expected 0, got 2
+generics_typevartuple_specialization.py:92:56: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+generics_typevartuple_specialization.py:93:5: error[type-assertion-failure] Type `tuple[str, int]` does not match asserted type `tuple[@Todo(PEP 646), ...]`
+generics_typevartuple_specialization.py:94:5: error[type-assertion-failure] Type `tuple[int | float]` does not match asserted type `tuple[@Todo(PEP 646), ...]`
generics_typevartuple_specialization.py:95:5: error[type-assertion-failure] Type `tuple[Any, *tuple[Any, ...]]` does not match asserted type `tuple[@Todo(PEP 646), ...]`
+generics_typevartuple_specialization.py:102:32: error[invalid-type-arguments] Too many type arguments: expected 0, got 2
+generics_typevartuple_specialization.py:103:33: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+generics_typevartuple_specialization.py:127:9: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+generics_typevartuple_specialization.py:130:18: error[invalid-type-arguments] Too many type arguments: expected 0, got 3
generics_typevartuple_specialization.py:130:35: error[invalid-return-type] Function always implicitly returns `None`, which is not assignable to return type `tuple[tuple[@Todo(PEP 646), ...], T1@func7, T2@func7]`
+generics_typevartuple_specialization.py:134:18: error[invalid-type-arguments] Too many type arguments: expected 0, got 2
+generics_typevartuple_specialization.py:134:37: error[invalid-type-arguments] Too many type arguments: expected 0, got 3
+generics_typevartuple_specialization.py:134:63: error[invalid-type-arguments] Too many type arguments: expected 0, got 4
generics_typevartuple_specialization.py:135:5: error[type-assertion-failure] Type `tuple[tuple[()], str, bool]` does not match asserted type `tuple[tuple[@Todo(PEP 646), ...], Unknown, Unknown]`
generics_typevartuple_specialization.py:136:5: error[type-assertion-failure] Type `tuple[tuple[str], bool, int | float]` does not match asserted type `tuple[tuple[@Todo(PEP 646), ...], Unknown, Unknown]`
generics_typevartuple_specialization.py:137:5: error[type-assertion-failure] Type `tuple[tuple[str, bool], int | float, int]` does not match asserted type `tuple[tuple[@Todo(PEP 646), ...], Unknown, Unknown]`
+generics_typevartuple_specialization.py:143:18: error[invalid-type-arguments] Too many type arguments: expected 0, got 4
generics_typevartuple_specialization.py:143:39: error[invalid-return-type] Function always implicitly returns `None`, which is not assignable to return type `tuple[tuple[@Todo(PEP 646), ...], T1@func9, T2@func9, T3@func9]`
+generics_typevartuple_specialization.py:147:19: error[invalid-type-arguments] Too many type arguments: expected 0, got 3
+generics_typevartuple_specialization.py:147:45: error[invalid-type-arguments] Too many type arguments: expected 0, got 4
generics_typevartuple_specialization.py:148:5: error[type-assertion-failure] Type `tuple[tuple[()], str, bool, int | float]` does not match asserted type `tuple[tuple[@Todo(PEP 646), ...], Unknown, Unknown, Unknown]`
generics_typevartuple_specialization.py:149:5: error[type-assertion-failure] Type `tuple[tuple[bool], str, int | float, int]` does not match asserted type `tuple[tuple[@Todo(PEP 646), ...], Unknown, Unknown, Unknown]`
-generics_typevartuple_specialization.py:157:5: error[type-assertion-failure] Type `tuple[*tuple[int, ...], int]` does not match asserted type `@Todo(Support for `typing.GenericAlias` instances in type expressions)`
-generics_typevartuple_specialization.py:158:5: error[type-assertion-failure] Type `tuple[*tuple[int, ...], str]` does not match asserted type `@Todo(specialized generic alias in type expression)`
-generics_typevartuple_specialization.py:159:5: error[type-assertion-failure] Type `tuple[*tuple[int, ...], str]` does not match asserted type `@Todo(specialized generic alias in type expression)`
+generics_typevartuple_specialization.py:153:12: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
+generics_typevartuple_specialization.py:156:28: error[invalid-type-arguments] Too many type arguments: expected 0, got 2
+generics_typevartuple_specialization.py:156:59: error[invalid-type-arguments] Too many type arguments: expected 0, got 2
+generics_typevartuple_specialization.py:157:5: error[type-assertion-failure] Type `tuple[*tuple[int, ...], int]` does not match asserted type `tuple[@Todo(PEP 646), ...]`
+generics_typevartuple_specialization.py:158:5: error[type-assertion-failure] Type `tuple[*tuple[int, ...], str]` does not match asserted type `tuple[@Todo(PEP 646), ...]`
+generics_typevartuple_specialization.py:159:5: error[type-assertion-failure] Type `tuple[*tuple[int, ...], str]` does not match asserted type `tuple[@Todo(PEP 646), ...]`
+generics_typevartuple_specialization.py:163:13: error[invalid-type-arguments] Too many type arguments: expected 0, got 1
generics_typevartuple_unpack.py:17:13: error[invalid-argument-type] `@Todo(starred expression)` is not a valid argument to `Generic`
generics_upper_bound.py:37:1: error[type-assertion-failure] Type `list[int]` does not match asserted type `list[Unknown | int]`
generics_upper_bound.py:38:1: error[type-assertion-failure] Type `set[int]` does not match asserted type `set[Unknown | int]`
@@ -648,20 +667,6 @@
generics_variance.py:14:6: error[invalid-legacy-type-variable] A `TypeVar` cannot be both covariant and contravariant
generics_variance.py:26:27: error[invalid-return-type] Function always implicitly returns `None`, which is not assignable to return type `Iterator[T_co@ImmutableList]`
generics_variance.py:57:28: error[invalid-return-type] Function always implicitly returns `None`, which is not assignable to return type `B_co@func`
-generics_variance.py:175:25: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:175:35: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:179:29: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:179:39: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:183:21: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:183:27: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:187:25: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:187:31: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:191:33: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:191:43: error[non-subscriptable] Cannot subscript object of type `<class 'Co[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:191:49: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:196:5: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:196:15: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
-generics_variance.py:196:25: error[non-subscriptable] Cannot subscript object of type `<class 'Contra[typing.TypeVar]'>` with no `__class_getitem__` method
generics_variance_inference.py:19:26: error[invalid-return-type] Function always implicitly returns `None`, which is not assignable to return type `T3@ClassA`
generics_variance_inference.py:24:33: error[invalid-assignment] Object of type `ClassA[int | float, int, int]` is not assignable to `ClassA[int, int, int]`
generics_variance_inference.py:25:37: error[invalid-assignment] Object of type `ClassA[int | float, int, int]` is not assignable to `ClassA[int | float, int | float, int]`
@@ -930,10 +935,6 @@
specialtypes_type.py:139:5: error[type-assertion-failure] Type `type[Any]` does not match asserted type `type`
specialtypes_type.py:143:1: error[unresolved-attribute] Object of type `typing.Type` has no attribute `unknown`
specialtypes_type.py:145:1: error[unresolved-attribute] Class `type` has no attribute `unknown`
-specialtypes_type.py:152:16: error[invalid-type-form] `typing.TypeVar` is not a generic class
-specialtypes_type.py:156:16: error[invalid-type-form] `typing.TypeVar` is not a generic class
-specialtypes_type.py:160:1: error[type-assertion-failure] Type `int` does not match asserted type `Unknown`
-specialtypes_type.py:161:1: error[type-assertion-failure] Type `int` does not match asserted type `Unknown`
specialtypes_type.py:169:21: error[invalid-assignment] Object of type `type` is not assignable to `type[int]`
specialtypes_type.py:175:16: error[invalid-return-type] Return type does not match returned value: expected `type[T@ClassA]`, found `type`
tuples_type_compat.py:15:27: error[invalid-assignment] Object of type `tuple[int | float, int | float | complex]` is not assignable to `tuple[int, int]`
@@ -1038,4 +1039,4 @@
typeddicts_usage.py:28:17: error[missing-typed-dict-key] Missing required key 'name' in TypedDict `Movie` constructor
typeddicts_usage.py:28:18: error[invalid-key] Unknown key "title" for TypedDict `Movie`: Unknown key "title"
typeddicts_usage.py:40:24: error[invalid-type-form] The special form `typing.TypedDict` is not allowed in type expressions
-Found 1040 diagnostics
+Found 1041 diagnostics
|
sharkdp
commented
Nov 21, 2025
Comment on lines
+82
to
+83
| reveal_type(a) # revealed: int | ||
| reveal_type(b) # revealed: int |
Contributor
Author
There was a problem hiding this comment.
We now understand the _FutureLike type alias.
|
| Lint rule | Added | Removed | Changed |
|---|---|---|---|
type-assertion-failure |
416 | 510 | 1,474 |
invalid-argument-type |
818 | 347 | 153 |
invalid-type-arguments |
628 | 55 | 4 |
no-matching-overload |
637 | 13 | 0 |
unsupported-operator |
376 | 10 | 19 |
unused-ignore-comment |
11 | 393 | 0 |
possibly-missing-attribute |
156 | 51 | 96 |
invalid-return-type |
254 | 10 | 13 |
unresolved-attribute |
85 | 90 | 37 |
invalid-assignment |
109 | 12 | 23 |
non-subscriptable |
32 | 29 | 8 |
invalid-type-form |
1 | 35 | 2 |
invalid-context-manager |
0 | 0 | 32 |
not-iterable |
22 | 0 | 6 |
invalid-await |
22 | 2 | 3 |
invalid-method-override |
18 | 0 | 2 |
invalid-parameter-default |
9 | 0 | 3 |
call-non-callable |
1 | 7 | 1 |
redundant-cast |
3 | 0 | 0 |
invalid-raise |
2 | 0 | 0 |
too-many-positional-arguments |
0 | 2 | 0 |
unresolved-reference |
0 | 2 | 0 |
unsupported-base |
0 | 2 | 0 |
parameter-already-assigned |
0 | 1 | 0 |
| Total | 3,600 | 1,571 | 1,876 |
sharkdp
force-pushed
the
david/generic-implicit-aliases
branch
from
8c80d76 to
812d07b
Compare
CodSpeed Performance ReportMerging #21553 will degrade performances by 77.43%Comparing Summary
Benchmarks breakdown
|
sharkdp
changed the title
|
sharkdp
force-pushed
the
david/generic-implicit-aliases
branch
from
0a44b07 to
d85469e
Compare
sharkdp
force-pushed
the
david/generic-implicit-aliases
branch
from
e951039 to
6aaa9d7
Compare
sharkdp
force-pushed
the
david/generic-implicit-aliases
branch
from
6aaa9d7 to
d2456eb
Compare
sharkdp
force-pushed
the
david/generic-implicit-aliases
branch
from
422f31e to
495dfe3
Compare
AlexWaygood
reviewed
Nov 28, 2025
Member
There was a problem hiding this comment.
Just a review of the tests so far. A couple more tests you could add (possibly in a followup). I haven't checked whether or not these pass on your branch, just some pathological cases I thought of while reading your tests:
from typing import TypeAlias, TypeVar
T = TypeVar("T")
U = TypeVar("U")
TotallyStringifiedPEP613: TypeAlias = "dict[T, U]"
TotallyStringifiedPartiallySpecialized: TypeAlias = "TotallyStringifiedPEP613[U, int]"
def f(x: "TotallyStringifiedPartiallySpecialized[str]"):
reveal_type(x) # revealed: dict[str, int](Edit David: Added. This one still resolves to a @Todo type that was introduced for this precise case)
and
from typing import TypeVar
T = TypeVar("T")
U = TypeVar("U")
V = TypeVar("V")
X = tuple[T, *tuple[U, ...], V]
Y = X[T, tuple[int, str, U], bytes]
def g(obj: Y[bool, range]):
reveal_type(obj) # revealed: tuple[bool, *tuple[tuple[int, str, range], ...], bytes](Edit David: Added. This one passes!)
| ListOrTupleLegacy = Union[list[T], tuple[T, ...]] | ||
| MyCallable = Callable[P, T] | ||
| AnnotatedType = Annotated[T, "tag"] | ||
| TransparentAlias = T |
Member
There was a problem hiding this comment.
Pyrefly and pyright accept TransparentAlias as a valid type alias, but mypy does not. I think we could consider adding a TODO here for us to reject it too when it appears in a type expression. TransparentAlias[int] fails at runtime, just like T[int] fails at runtime. And there's no reason to use TransparentAlias[int] rather than just int.
Contributor
Author
There was a problem hiding this comment.
TransparentAlias[int]fails at runtime, just likeT[int]fails at runtime
Ok, but it's sort-of reasonable to have it in a type annotation? I spent extra effort to support it after Carl mentioned it, but we can also remove that special handling again, I guess.
Member
There was a problem hiding this comment.
I'd personally lean towards rejecting it because i can't see any use case for it — it probably indicates that the user is confused about Python typing in some way?
But i don't have a strong opinion; don't let this slow you down when it comes to getting the PR in, if you and/or Carl disagree
Contributor
Author
There was a problem hiding this comment.
I'd personally lean towards rejecting it because i can't see any use case for it — it probably indicates that the user is confused about Python typing in some way?
Maybe. But it seems like an artificial restriction to me? If MyAlias = T | None and MyAlias = Annotated[T, "bla"] are fine, then why should MyAlias = T be forbidden? A PEP 695 type alias type MyAlias[T] = T is (hopefully) also allowed.
Comment on lines
447
to
+448
| DictStrTo = MyDict[str, U] | ||
|
|
||
| reveal_type(DictStrTo) # revealed: GenericAlias | ||
| reveal_type(DictStrTo) # revealed: <class 'dict[str, U@DictStrTo]'> | ||
|
|
||
| def _( | ||
| # TODO: No error here | ||
| # error: [invalid-type-form] "Invalid subscript of object of type `GenericAlias` in type expression" | ||
| dict_str_to_int: DictStrTo[int], | ||
| ): | ||
| # TODO: This should be `dict[str, int]` | ||
| reveal_type(dict_str_to_int) # revealed: Unknown | ||
| reveal_type(dict_str_to_int) # revealed: dict[str, int] |
Member
There was a problem hiding this comment.
great work, this is fantastic!
AlexWaygood
approved these changes
Nov 28, 2025
Comment on lines
+980
to
+983
| // Infer slice as a value expression to avoid false-positive | ||
| // `invalid-type-form` diagnostics, when we have e.g. | ||
| // `MyCallable[[int, str], None]` but `MyCallable` is dynamic. | ||
| self.infer_expression(slice, TypeContext::default()); |
Member
There was a problem hiding this comment.
I think there are probably lots more error cases in type-expression parsing where we should do similarly
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
Add support for generic PEP 613 type aliases and generic implicit type aliases:
closes astral-sh/ty#1643
closes astral-sh/ty#1629
closes astral-sh/ty#1596
closes astral-sh/ty#573
closes astral-sh/ty#221
Typing conformance
New true negatives ✔️
These require
ParamSpecNew true positives ✔️
New true negatives ✔️
These require
ParamSpecNew true positives ✔️
These require
ParamSpecandConcatenate.Favorable diagnostic change ✔️
-generics_defaults_specialization.py:27:5: error[type-assertion-failure] Type `SomethingWithNoDefaults[int, bool]` does not match asserted type `@Todo(specialized generic alias in type expression)`New true negative ✔️
Correct new diagnostic ✔️
One of these should apparently be an error, but not of this kind, so this is good ✔️
Good, those were false positives. ✔️
I skipped the analysis for everything involving
TypeVarTuple.Ecosystem impact
Full report with detailed diff
Previous iterations of this PR showed all kinds of problems. In it's current state, I do not see any large systematic problems, but it is hard to tell with 5k diagnostic changes.
Performance
colour-science/colour, related to this large file with many assignments of hard-coded arrays (lists of lists) tonp.NDArraytypes that we now understand. We now take ~2 seconds to check this file, so definitely not great, but maybe acceptable for now.Test Plan
Updated and new Markdown tests