Use TypeVar refresh uniformly for class object access (#15945)

Fixes #15934

I think this is a right thing to do, it may even fix some other rare
accidental `TypeVar` clashes not involving self-types. This causes a bit
of churn in tests, but not too much.

Author: ilevkivskyi

mypy/checkmember.py

@@ -1198,12 +1198,12 @@ class B(A[str]): pass
     # (i.e. appear in the return type of the class object on which the method was accessed).
     if isinstance(t, CallableType):
         tvars = original_vars if original_vars is not None else []
+        t = freshen_all_functions_type_vars(t)
         if is_classmethod:
-            t = freshen_all_functions_type_vars(t)
             t = bind_self(t, original_type, is_classmethod=True)
             assert isuper is not None
             t = expand_type_by_instance(t, isuper)
-            freeze_all_type_vars(t)
+        freeze_all_type_vars(t)
         return t.copy_modified(variables=list(tvars) + list(t.variables))
     elif isinstance(t, Overloaded):
         return Overloaded(

test-data/unit/check-classes.test

@@ -1162,7 +1162,7 @@ def test() -> None:
             reveal_type(x)  # N: Revealed type is "T`-1"
             reveal_type(x.returns_int())  # N: Revealed type is "builtins.int"
             return foo
-    reveal_type(Foo.bar)  # N: Revealed type is "def [T <: __main__.Foo@5] (self: __main__.Foo@5, foo: T`-1) -> T`-1"
+    reveal_type(Foo.bar)  # N: Revealed type is "def [T <: __main__.Foo@5] (self: __main__.Foo@5, foo: T`1) -> T`1"
 
 [case testGenericClassWithInvalidTypevarUseWithinFunction]
 from typing import TypeVar

test-data/unit/check-incremental.test

@@ -3035,10 +3035,10 @@ main:15: error: Unsupported left operand type for >= ("NoCmp")
 [case testAttrsIncrementalDunder]
 from a import A
 reveal_type(A)  # N: Revealed type is "def (a: builtins.int) -> a.A"
-reveal_type(A.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-reveal_type(A.__le__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-reveal_type(A.__gt__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-reveal_type(A.__ge__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
+reveal_type(A.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`3, other: _AT`3) -> builtins.bool"
+reveal_type(A.__le__)  # N: Revealed type is "def [_AT] (self: _AT`4, other: _AT`4) -> builtins.bool"
+reveal_type(A.__gt__)  # N: Revealed type is "def [_AT] (self: _AT`5, other: _AT`5) -> builtins.bool"
+reveal_type(A.__ge__)  # N: Revealed type is "def [_AT] (self: _AT`6, other: _AT`6) -> builtins.bool"
 
 A(1) < A(2)
 A(1) <= A(2)
@@ -3072,10 +3072,10 @@ class A:
 [stale]
 [out2]
 main:2: note: Revealed type is "def (a: builtins.int) -> a.A"
-main:3: note: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-main:4: note: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-main:5: note: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-main:6: note: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
+main:3: note: Revealed type is "def [_AT] (self: _AT`1, other: _AT`1) -> builtins.bool"
+main:4: note: Revealed type is "def [_AT] (self: _AT`2, other: _AT`2) -> builtins.bool"
+main:5: note: Revealed type is "def [_AT] (self: _AT`3, other: _AT`3) -> builtins.bool"
+main:6: note: Revealed type is "def [_AT] (self: _AT`4, other: _AT`4) -> builtins.bool"
 main:15: error: Unsupported operand types for < ("A" and "int")
 main:16: error: Unsupported operand types for <= ("A" and "int")
 main:17: error: Unsupported operand types for > ("A" and "int")
@@ -3963,10 +3963,10 @@ class A:
 tmp/b.py:3: note: Revealed type is "def (a: builtins.int) -> a.A"
 tmp/b.py:4: note: Revealed type is "def (builtins.object, builtins.object) -> builtins.bool"
 tmp/b.py:5: note: Revealed type is "def (builtins.object, builtins.object) -> builtins.bool"
-tmp/b.py:6: note: Revealed type is "def [_DT] (self: _DT`-1, other: _DT`-1) -> builtins.bool"
-tmp/b.py:7: note: Revealed type is "def [_DT] (self: _DT`-1, other: _DT`-1) -> builtins.bool"
-tmp/b.py:8: note: Revealed type is "def [_DT] (self: _DT`-1, other: _DT`-1) -> builtins.bool"
-tmp/b.py:9: note: Revealed type is "def [_DT] (self: _DT`-1, other: _DT`-1) -> builtins.bool"
+tmp/b.py:6: note: Revealed type is "def [_DT] (self: _DT`1, other: _DT`1) -> builtins.bool"
+tmp/b.py:7: note: Revealed type is "def [_DT] (self: _DT`2, other: _DT`2) -> builtins.bool"
+tmp/b.py:8: note: Revealed type is "def [_DT] (self: _DT`3, other: _DT`3) -> builtins.bool"
+tmp/b.py:9: note: Revealed type is "def [_DT] (self: _DT`4, other: _DT`4) -> builtins.bool"
 tmp/b.py:18: error: Unsupported operand types for < ("A" and "int")
 tmp/b.py:19: error: Unsupported operand types for <= ("A" and "int")
 tmp/b.py:20: error: Unsupported operand types for > ("A" and "int")
@@ -6325,7 +6325,7 @@ reveal_type(D.meth)
 reveal_type(D().meth)
 [out]
 [out2]
-tmp/m.py:4: note: Revealed type is "def [Self <: lib.C] (self: Self`0, other: Self`0) -> Self`0"
+tmp/m.py:4: note: Revealed type is "def [Self <: lib.C] (self: Self`1, other: Self`1) -> Self`1"
 tmp/m.py:5: note: Revealed type is "def (other: m.D) -> m.D"
 
 [case testIncrementalNestedGenericCallableCrash]

test-data/unit/check-parameter-specification.test

@@ -901,8 +901,8 @@ class A:
     def func(self, action: Callable[_P, _R], *args: _P.args, **kwargs: _P.kwargs) -> _R:
         ...
 
-reveal_type(A.func)  # N: Revealed type is "def [_P, _R] (self: __main__.A, action: def (*_P.args, **_P.kwargs) -> _R`-2, *_P.args, **_P.kwargs) -> _R`-2"
-reveal_type(A().func)  # N: Revealed type is "def [_P, _R] (action: def (*_P.args, **_P.kwargs) -> _R`5, *_P.args, **_P.kwargs) -> _R`5"
+reveal_type(A.func)  # N: Revealed type is "def [_P, _R] (self: __main__.A, action: def (*_P.args, **_P.kwargs) -> _R`3, *_P.args, **_P.kwargs) -> _R`3"
+reveal_type(A().func)  # N: Revealed type is "def [_P, _R] (action: def (*_P.args, **_P.kwargs) -> _R`7, *_P.args, **_P.kwargs) -> _R`7"
 
 def f(x: int) -> int:
     ...
@@ -934,8 +934,8 @@ class A:
     def func(self, action: Job[_P, None]) -> Job[_P, None]:
         ...
 
-reveal_type(A.func)  # N: Revealed type is "def [_P] (self: __main__.A, action: __main__.Job[_P`-1, None]) -> __main__.Job[_P`-1, None]"
-reveal_type(A().func)  # N: Revealed type is "def [_P] (action: __main__.Job[_P`3, None]) -> __main__.Job[_P`3, None]"
+reveal_type(A.func)  # N: Revealed type is "def [_P] (self: __main__.A, action: __main__.Job[_P`2, None]) -> __main__.Job[_P`2, None]"
+reveal_type(A().func)  # N: Revealed type is "def [_P] (action: __main__.Job[_P`4, None]) -> __main__.Job[_P`4, None]"
 reveal_type(A().func(Job(lambda x: x)))  # N: Revealed type is "__main__.Job[[x: Any], None]"
 
 def f(x: int, y: int) -> None: ...

test-data/unit/check-plugin-attrs.test

@@ -185,10 +185,10 @@ from attr import attrib, attrs
 class A:
     a: int
 reveal_type(A)  # N: Revealed type is "def (a: builtins.int) -> __main__.A"
-reveal_type(A.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-reveal_type(A.__le__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-reveal_type(A.__gt__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-reveal_type(A.__ge__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
+reveal_type(A.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`3, other: _AT`3) -> builtins.bool"
+reveal_type(A.__le__)  # N: Revealed type is "def [_AT] (self: _AT`4, other: _AT`4) -> builtins.bool"
+reveal_type(A.__gt__)  # N: Revealed type is "def [_AT] (self: _AT`5, other: _AT`5) -> builtins.bool"
+reveal_type(A.__ge__)  # N: Revealed type is "def [_AT] (self: _AT`6, other: _AT`6) -> builtins.bool"
 
 A(1) < A(2)
 A(1) <= A(2)
@@ -989,10 +989,10 @@ class C(A, B): pass
 @attr.s
 class D(A): pass
 
-reveal_type(A.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-reveal_type(B.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-reveal_type(C.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
-reveal_type(D.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`-1, other: _AT`-1) -> builtins.bool"
+reveal_type(A.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`5, other: _AT`5) -> builtins.bool"
+reveal_type(B.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`6, other: _AT`6) -> builtins.bool"
+reveal_type(C.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`7, other: _AT`7) -> builtins.bool"
+reveal_type(D.__lt__)  # N: Revealed type is "def [_AT] (self: _AT`8, other: _AT`8) -> builtins.bool"
 
 A() < A()
 B() < B()

test-data/unit/check-selftype.test

@@ -1484,7 +1484,7 @@ class C:
             return self
 class D(C): ...
 
-reveal_type(C.meth)  # N: Revealed type is "def [Self <: __main__.C] (self: Self`0) -> builtins.list[Self`0]"
+reveal_type(C.meth)  # N: Revealed type is "def [Self <: __main__.C] (self: Self`1) -> builtins.list[Self`1]"
 C.attr  # E: Access to generic instance variables via class is ambiguous
 reveal_type(D().meth())  # N: Revealed type is "builtins.list[__main__.D]"
 reveal_type(D().attr)  # N: Revealed type is "builtins.list[__main__.D]"
@@ -1793,7 +1793,7 @@ class C:
     def bar(self) -> Self: ...
     def foo(self, x: S) -> Tuple[Self, S]: ...
 
-reveal_type(C.foo)  # N: Revealed type is "def [Self <: __main__.C, S] (self: Self`0, x: S`-1) -> Tuple[Self`0, S`-1]"
+reveal_type(C.foo)  # N: Revealed type is "def [Self <: __main__.C, S] (self: Self`1, x: S`2) -> Tuple[Self`1, S`2]"
 reveal_type(C().foo(42))  # N: Revealed type is "Tuple[__main__.C, builtins.int]"
 [builtins fixtures/tuple.pyi]
 
@@ -1903,7 +1903,7 @@ class C:
 
 class D(C): ...
 
-reveal_type(D.f)  # N: Revealed type is "def [T] (T`-1) -> T`-1"
+reveal_type(D.f)  # N: Revealed type is "def [T] (T`1) -> T`1"
 reveal_type(D().f)  # N: Revealed type is "def () -> __main__.D"
 
 [case testTypingSelfOnSuperTypeVarValues]
@@ -2015,3 +2015,24 @@ class Add(Async):
 reveal_type(Add.async_func())  # N: Revealed type is "def (x: builtins.int, y: builtins.int) -> builtins.int"
 reveal_type(Add().async_func())  # N: Revealed type is "def (x: builtins.int, y: builtins.int) -> builtins.int"
 [builtins fixtures/classmethod.pyi]
+
+[case testSelfTypeMethodOnClassObject]
+from typing import Self
+
+class Object:  # Needed to mimic object in typeshed
+    ref: Self
+
+class Foo:
+    def foo(self) -> Self:
+        return self
+
+class Ben(Object):
+    MY_MAP = {
+        "foo": Foo.foo,
+    }
+    @classmethod
+    def doit(cls) -> Foo:
+        reveal_type(cls.MY_MAP)  # N: Revealed type is "builtins.dict[builtins.str, def [Self <: __main__.Foo] (self: Self`4) -> Self`4]"
+        foo_method = cls.MY_MAP["foo"]
+        return foo_method(Foo())
+[builtins fixtures/isinstancelist.pyi]