[ty] Fix bug where ty would think all types had an __mro__ attribute (#20995)

Author: AlexWaygood

crates/ty_completion_eval/completion-evaluation-tasks.csv

@@ -20,6 +20,6 @@ scope-existing-over-new-import,main.py,0,474
 scope-prioritize-closer,main.py,0,2
 scope-simple-long-identifier,main.py,0,1
 tstring-completions,main.py,0,1
-ty-extensions-lower-stdlib,main.py,0,7
+ty-extensions-lower-stdlib,main.py,0,8
 type-var-typing-over-ast,main.py,0,3
 type-var-typing-over-ast,main.py,1,270

crates/ty_ide/src/completion.rs

@@ -1864,7 +1864,7 @@ C.<CURSOR>
         __instancecheck__ :: bound method <class 'C'>.__instancecheck__(instance: Any, /) -> bool
         __itemsize__ :: int
         __module__ :: str
-        __mro__ :: tuple[<class 'C'>, <class 'object'>]
+        __mro__ :: tuple[type, ...]
         __name__ :: str
         __ne__ :: def __ne__(self, value: object, /) -> bool
         __new__ :: def __new__(cls) -> Self@__new__
@@ -1933,7 +1933,7 @@ Meta.<CURSOR>
                 __instancecheck__ :: def __instancecheck__(self, instance: Any, /) -> bool
                 __itemsize__ :: int
                 __module__ :: str
-                __mro__ :: tuple[<class 'Meta'>, <class 'type'>, <class 'object'>]
+                __mro__ :: tuple[type, ...]
                 __name__ :: str
                 __ne__ :: def __ne__(self, value: object, /) -> bool
                 __or__ :: def __or__[Self](self: Self@__or__, value: Any, /) -> UnionType | Self@__or__
@@ -2061,7 +2061,7 @@ Quux.<CURSOR>
         __instancecheck__ :: bound method <class 'Quux'>.__instancecheck__(instance: Any, /) -> bool
         __itemsize__ :: int
         __module__ :: str
-        __mro__ :: tuple[<class 'Quux'>, <class 'object'>]
+        __mro__ :: tuple[type, ...]
         __name__ :: str
         __ne__ :: def __ne__(self, value: object, /) -> bool
         __new__ :: def __new__(cls) -> Self@__new__
@@ -2138,7 +2138,7 @@ Answer.<CURSOR>
                 __len__ :: bound method <class 'Answer'>.__len__() -> int
                 __members__ :: MappingProxyType[str, Unknown]
                 __module__ :: str
-                __mro__ :: tuple[<class 'Answer'>, <class 'Enum'>, <class 'object'>]
+                __mro__ :: tuple[type, ...]
                 __name__ :: str
                 __ne__ :: def __ne__(self, value: object, /) -> bool
                 __new__ :: def __new__(cls, value: object) -> Self@__new__

crates/ty_python_semantic/resources/mdtest/annotations/annotated.md

@@ -72,21 +72,23 @@ Inheriting from `Annotated[T, ...]` is equivalent to inheriting from `T` itself.
 
 ```py
 from typing_extensions import Annotated
+from ty_extensions import reveal_mro
 
 class C(Annotated[int, "foo"]): ...
 
-# TODO: Should be `tuple[Literal[C], Literal[int], Literal[object]]`
-reveal_type(C.__mro__)  # revealed: tuple[<class 'C'>, @Todo(Inference of subscript on special form), <class 'object'>]
+# TODO: Should be `(<class 'C'>, <class 'int'>, <class 'object'>)`
+reveal_mro(C)  # revealed: (<class 'C'>, @Todo(Inference of subscript on special form), <class 'object'>)
 ```
 
 ### Not parameterized
 
 ```py
 from typing_extensions import Annotated
+from ty_extensions import reveal_mro
 
 # At runtime, this is an error.
 # error: [invalid-base]
 class C(Annotated): ...
 
-reveal_type(C.__mro__)  # revealed: tuple[<class 'C'>, Unknown, <class 'object'>]
+reveal_mro(C)  # revealed: (<class 'C'>, Unknown, <class 'object'>)
 ```

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

@@ -56,10 +56,11 @@ allowed, even when the unknown superclass is `int`. The assignment to `y` should
 
 ```py
 from typing import Any
+from ty_extensions import reveal_mro
 
 class SubclassOfAny(Any): ...
 
-reveal_type(SubclassOfAny.__mro__)  # revealed: tuple[<class 'SubclassOfAny'>, Any, <class 'object'>]
+reveal_mro(SubclassOfAny)  # revealed: (<class 'SubclassOfAny'>, Any, <class 'object'>)
 
 x: SubclassOfAny = 1  # error: [invalid-assignment]
 y: int = SubclassOfAny()

crates/ty_python_semantic/resources/mdtest/annotations/stdlib_typing_aliases.md

@@ -114,57 +114,58 @@ The aliases can be inherited from. Some of these are still partially or wholly T
 
 ```py
 import typing
+from ty_extensions import reveal_mro
 
 ####################
 ### Built-ins
 ####################
 
 class ListSubclass(typing.List): ...
 
-# revealed: tuple[<class 'ListSubclass'>, <class 'list[Unknown]'>, <class 'MutableSequence[Unknown]'>, <class 'Sequence[Unknown]'>, <class 'Reversible[Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>]
-reveal_type(ListSubclass.__mro__)
+# revealed: (<class 'ListSubclass'>, <class 'list[Unknown]'>, <class 'MutableSequence[Unknown]'>, <class 'Sequence[Unknown]'>, <class 'Reversible[Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>)
+reveal_mro(ListSubclass)
 
 class DictSubclass(typing.Dict): ...
 
-# revealed: tuple[<class 'DictSubclass'>, <class 'dict[Unknown, Unknown]'>, <class 'MutableMapping[Unknown, Unknown]'>, <class 'Mapping[Unknown, Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>]
-reveal_type(DictSubclass.__mro__)
+# revealed: (<class 'DictSubclass'>, <class 'dict[Unknown, Unknown]'>, <class 'MutableMapping[Unknown, Unknown]'>, <class 'Mapping[Unknown, Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>)
+reveal_mro(DictSubclass)
 
 class SetSubclass(typing.Set): ...
 
-# revealed: tuple[<class 'SetSubclass'>, <class 'set[Unknown]'>, <class 'MutableSet[Unknown]'>, <class 'AbstractSet[Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>]
-reveal_type(SetSubclass.__mro__)
+# revealed: (<class 'SetSubclass'>, <class 'set[Unknown]'>, <class 'MutableSet[Unknown]'>, <class 'AbstractSet[Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>)
+reveal_mro(SetSubclass)
 
 class FrozenSetSubclass(typing.FrozenSet): ...
 
-# revealed: tuple[<class 'FrozenSetSubclass'>, <class 'frozenset[Unknown]'>, <class 'AbstractSet[Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>]
-reveal_type(FrozenSetSubclass.__mro__)
+# revealed: (<class 'FrozenSetSubclass'>, <class 'frozenset[Unknown]'>, <class 'AbstractSet[Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>)
+reveal_mro(FrozenSetSubclass)
 
 ####################
 ### `collections`
 ####################
 
 class ChainMapSubclass(typing.ChainMap): ...
 
-# revealed: tuple[<class 'ChainMapSubclass'>, <class 'ChainMap[Unknown, Unknown]'>, <class 'MutableMapping[Unknown, Unknown]'>, <class 'Mapping[Unknown, Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>]
-reveal_type(ChainMapSubclass.__mro__)
+# revealed: (<class 'ChainMapSubclass'>, <class 'ChainMap[Unknown, Unknown]'>, <class 'MutableMapping[Unknown, Unknown]'>, <class 'Mapping[Unknown, Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>)
+reveal_mro(ChainMapSubclass)
 
 class CounterSubclass(typing.Counter): ...
 
-# revealed: tuple[<class 'CounterSubclass'>, <class 'Counter[Unknown]'>, <class 'dict[Unknown, int]'>, <class 'MutableMapping[Unknown, int]'>, <class 'Mapping[Unknown, int]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>]
-reveal_type(CounterSubclass.__mro__)
+# revealed: (<class 'CounterSubclass'>, <class 'Counter[Unknown]'>, <class 'dict[Unknown, int]'>, <class 'MutableMapping[Unknown, int]'>, <class 'Mapping[Unknown, int]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>)
+reveal_mro(CounterSubclass)
 
 class DefaultDictSubclass(typing.DefaultDict): ...
 
-# revealed: tuple[<class 'DefaultDictSubclass'>, <class 'defaultdict[Unknown, Unknown]'>, <class 'dict[Unknown, Unknown]'>, <class 'MutableMapping[Unknown, Unknown]'>, <class 'Mapping[Unknown, Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>]
-reveal_type(DefaultDictSubclass.__mro__)
+# revealed: (<class 'DefaultDictSubclass'>, <class 'defaultdict[Unknown, Unknown]'>, <class 'dict[Unknown, Unknown]'>, <class 'MutableMapping[Unknown, Unknown]'>, <class 'Mapping[Unknown, Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>)
+reveal_mro(DefaultDictSubclass)
 
 class DequeSubclass(typing.Deque): ...
 
-# revealed: tuple[<class 'DequeSubclass'>, <class 'deque[Unknown]'>, <class 'MutableSequence[Unknown]'>, <class 'Sequence[Unknown]'>, <class 'Reversible[Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>]
-reveal_type(DequeSubclass.__mro__)
+# revealed: (<class 'DequeSubclass'>, <class 'deque[Unknown]'>, <class 'MutableSequence[Unknown]'>, <class 'Sequence[Unknown]'>, <class 'Reversible[Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>)
+reveal_mro(DequeSubclass)
 
 class OrderedDictSubclass(typing.OrderedDict): ...
 
-# revealed: tuple[<class 'OrderedDictSubclass'>, <class 'OrderedDict[Unknown, Unknown]'>, <class 'dict[Unknown, Unknown]'>, <class 'MutableMapping[Unknown, Unknown]'>, <class 'Mapping[Unknown, Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>]
-reveal_type(OrderedDictSubclass.__mro__)
+# revealed: (<class 'OrderedDictSubclass'>, <class 'OrderedDict[Unknown, Unknown]'>, <class 'dict[Unknown, Unknown]'>, <class 'MutableMapping[Unknown, Unknown]'>, <class 'Mapping[Unknown, Unknown]'>, <class 'Collection[Unknown]'>, <class 'Iterable[Unknown]'>, <class 'Container[Unknown]'>, typing.Protocol, typing.Generic, <class 'object'>)
+reveal_mro(OrderedDictSubclass)
 ```

crates/ty_python_semantic/resources/mdtest/annotations/unsupported_special_forms.md

@@ -78,6 +78,7 @@ You can't inherit from most of these. `typing.Callable` is an exception.
 ```py
 from typing import Callable
 from typing_extensions import Self, Unpack, TypeGuard, TypeIs, Concatenate, Generic
+from ty_extensions import reveal_mro
 
 class A(Self): ...  # error: [invalid-base]
 class B(Unpack): ...  # error: [invalid-base]
@@ -87,7 +88,7 @@ class E(Concatenate): ...  # error: [invalid-base]
 class F(Callable): ...
 class G(Generic): ...  # error: [invalid-base] "Cannot inherit from plain `Generic`"
 
-reveal_type(F.__mro__)  # revealed: tuple[<class 'F'>, @Todo(Support for Callable as a base class), <class 'object'>]
+reveal_mro(F)  # revealed: (<class 'F'>, @Todo(Support for Callable as a base class), <class 'object'>)
 ```
 
 ## Subscriptability

crates/ty_python_semantic/resources/mdtest/attributes.md

@@ -1468,6 +1468,8 @@ C.X = "bar"
 ### Multiple inheritance
 
 ```py
+from ty_extensions import reveal_mro
+
 class O: ...
 
 class F(O):
@@ -1481,8 +1483,8 @@ class C(D, F): ...
 class B(E, D): ...
 class A(B, C): ...
 
-# revealed: tuple[<class 'A'>, <class 'B'>, <class 'E'>, <class 'C'>, <class 'D'>, <class 'F'>, <class 'O'>, <class 'object'>]
-reveal_type(A.__mro__)
+# revealed: (<class 'A'>, <class 'B'>, <class 'E'>, <class 'C'>, <class 'D'>, <class 'F'>, <class 'O'>, <class 'object'>)
+reveal_mro(A)
 
 # `E` is earlier in the MRO than `F`, so we should use the type of `E.X`
 reveal_type(A.X)  # revealed: Unknown | Literal[42]
@@ -1682,14 +1684,15 @@ Similar principles apply if `Any` appears in the middle of an inheritance hierar
 
 ```py
 from typing import ClassVar, Literal
+from ty_extensions import reveal_mro
 
 class A:
     x: ClassVar[Literal[1]] = 1
 
 class B(Any): ...
 class C(B, A): ...
 
-reveal_type(C.__mro__)  # revealed: tuple[<class 'C'>, <class 'B'>, Any, <class 'A'>, <class 'object'>]
+reveal_mro(C)  # revealed: (<class 'C'>, <class 'B'>, Any, <class 'A'>, <class 'object'>)
 reveal_type(C.x)  # revealed: Literal[1] & Any
 ```
 

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

@@ -26,6 +26,7 @@ python-version = "3.12"
 
 ```py
 from __future__ import annotations
+from ty_extensions import reveal_mro
 
 class A:
     def a(self): ...
@@ -39,7 +40,7 @@ class C(B):
     def c(self): ...
     cc: int = 3
 
-reveal_type(C.__mro__)  # revealed: tuple[<class 'C'>, <class 'B'>, <class 'A'>, <class 'object'>]
+reveal_mro(C)  # revealed: (<class 'C'>, <class 'B'>, <class 'A'>, <class 'object'>)
 
 super(C, C()).a
 super(C, C()).b
@@ -420,6 +421,8 @@ When the owner is a union type, `super()` is built separately for each branch, a
 super objects are combined into a union.
 
 ```py
+from ty_extensions import reveal_mro
+
 class A: ...
 
 class B:
@@ -429,8 +432,8 @@ class C(A, B): ...
 class D(B, A): ...
 
 def f(x: C | D):
-    reveal_type(C.__mro__)  # revealed: tuple[<class 'C'>, <class 'A'>, <class 'B'>, <class 'object'>]
-    reveal_type(D.__mro__)  # revealed: tuple[<class 'D'>, <class 'B'>, <class 'A'>, <class 'object'>]
+    reveal_mro(C)  # revealed: (<class 'C'>, <class 'A'>, <class 'B'>, <class 'object'>)
+    reveal_mro(D)  # revealed: (<class 'D'>, <class 'B'>, <class 'A'>, <class 'object'>)
 
     s = super(A, x)
     reveal_type(s)  # revealed: <super: <class 'A'>, C> | <super: <class 'A'>, D>

crates/ty_python_semantic/resources/mdtest/classes.md

@@ -13,6 +13,8 @@ python-version = "3.12"
 ```
 
 ```py
+from ty_extensions import reveal_mro
+
 A = int
 
 class G[T]: ...
@@ -21,5 +23,5 @@ class C(A, G["B"]): ...
 A = str
 B = bytes
 
-reveal_type(C.__mro__)  # revealed: tuple[<class 'C'>, <class 'int'>, <class 'G[bytes]'>, typing.Generic, <class 'object'>]
+reveal_mro(C)  # revealed: (<class 'C'>, <class 'int'>, <class 'G[bytes]'>, typing.Generic, <class 'object'>)
 ```

crates/ty_python_semantic/resources/mdtest/dataclasses/dataclasses.md

@@ -1173,14 +1173,16 @@ and attributes like the MRO are unchanged:
 
 ```py
 from dataclasses import dataclass
+from ty_extensions import reveal_mro
 
 @dataclass
 class Person:
     name: str
     age: int | None = None
 
 reveal_type(type(Person))  # revealed: <class 'type'>
-reveal_type(Person.__mro__)  # revealed: tuple[<class 'Person'>, <class 'object'>]
+reveal_type(Person.__mro__)  # revealed: tuple[type, ...]
+reveal_mro(Person)  # revealed: (<class 'Person'>, <class 'object'>)
 ```
 
 The generated methods have the following signatures: