Fix inference for overloaded __call__ with generic self

mypy/checkmember.py

@@ -330,13 +330,12 @@ def analyze_instance_member_access(
             signature = method.type
         signature = freshen_all_functions_type_vars(signature)
         if not method.is_static:
-            if name != "__call__":
-                # TODO: use proper treatment of special methods on unions instead
-                #       of this hack here and below (i.e. mx.self_type).
-                dispatched_type = meet.meet_types(mx.original_type, typ)
-                signature = check_self_arg(
-                    signature, dispatched_type, method.is_class, mx.context, name, mx.msg
-                )
+            # TODO: use proper treatment of special methods on unions instead
+            #       of this hack here and below (i.e. mx.self_type).
+            dispatched_type = meet.meet_types(mx.original_type, typ)
+            signature = check_self_arg(
+                signature, dispatched_type, method.is_class, mx.context, name, mx.msg
+            )
             signature = bind_self(signature, mx.self_type, is_classmethod=method.is_class)
         # TODO: should we skip these steps for static methods as well?
         # Since generic static methods should not be allowed.

mypy/subtypes.py

@@ -463,10 +463,15 @@ def visit_instance(self, left: Instance) -> bool:
                         assert unpacked.type.fullname == "builtins.tuple"
                         if isinstance(get_proper_type(unpacked.args[0]), AnyType):
                             return not self.proper_subtype
-                if mapped.type.fullname == "builtins.tuple" and isinstance(
-                    get_proper_type(mapped.args[0]), AnyType
-                ):
+                if all(isinstance(get_proper_type(a), AnyType) for a in mapped.args):
                     return not self.proper_subtype
+                if mapped.type.tuple_type:
+                    # similar to logic inside map_instance_to_supertype
+                    tuple_type = expand_type_by_instance(mapped.type.tuple_type, mapped)
+                    assert isinstance(tuple_type, TupleType)
+                    return self._is_subtype(
+                        tuple_type, right.copy_modified(fallback=tuple_type.partial_fallback)
+                    ) and self._is_subtype(left, mypy.typeops.tuple_fallback(right))
             return False
         if isinstance(right, TypeVarTupleType):
             # tuple[Any, ...] is like Any in the world of tuples (see special case above).

test-data/unit/check-overloading.test

@@ -6650,3 +6650,27 @@ def d(x: int) -> int: ...
 def d(f: int, *, x: int) -> str: ...
 def d(*args, **kwargs): ...
 [builtins fixtures/tuple.pyi]
+
+[case testOverloadCallableGenericSelf]
+from typing import Any, TypeVar, Generic, overload, reveal_type
+
+T = TypeVar("T")
+
+class MyCallable(Generic[T]):
+    def __init__(self, t: T):
+        self.t = t
+
+    @overload
+    def __call__(self: "MyCallable[int]") -> str: ...
+    @overload
+    def __call__(self: "MyCallable[str]") -> int: ...
+    def __call__(self): ...
+
+c = MyCallable(5)
+reveal_type(c)  # N: Revealed type is "__main__.MyCallable[builtins.int]"
+reveal_type(c())  # N: Revealed type is "builtins.str"
+
+c2 = MyCallable("test")
+reveal_type(c2)  # N: Revealed type is "__main__.MyCallable[builtins.str]"
+reveal_type(c2()) # should be int  # N: Revealed type is "builtins.int"
+[builtins fixtures/tuple.pyi]

test-data/unit/check-tuples.test

@@ -1434,7 +1434,21 @@ def foo(o: CallableTuple) -> int:
 class CallableTuple(Tuple[str, int]):
     def __call__(self, n: int, m: int) -> int:
         return n
+[builtins fixtures/tuple.pyi]
+
+[case testTypeTupleGenericCall]
+from typing import Generic, Tuple, TypeVar
+
+T = TypeVar('T')
 
+def foo(o: CallableTuple[int]) -> int:
+    reveal_type(o)  # N: Revealed type is "Tuple[builtins.str, builtins.int, fallback=__main__.CallableTuple[builtins.int]]"
+    reveal_type(o.count(3))  # N: Revealed type is "builtins.int"
+    return o(1, 2)
+
+class CallableTuple(Tuple[str, T]):
+    def __call__(self, n: int, m: int) -> int:
+        return n
 [builtins fixtures/tuple.pyi]
 
 [case testTupleCompatibleWithSequence]