Fix inference for properties with __call__ (#15926)

Fixes #5858

Author: hauntsaninja

mypy/checkmember.py

@@ -2,7 +2,7 @@
 
 from __future__ import annotations
 
-from typing import TYPE_CHECKING, Callable, Sequence, cast
+from typing import TYPE_CHECKING, Callable, Optional, Sequence, cast
 
 from mypy import meet, message_registry, subtypes
 from mypy.erasetype import erase_typevars
@@ -776,12 +776,17 @@ def analyze_var(
         freeze_all_type_vars(t)
         result: Type = t
         typ = get_proper_type(typ)
-        if (
-            var.is_initialized_in_class
-            and (not is_instance_var(var) or mx.is_operator)
-            and isinstance(typ, FunctionLike)
-            and not typ.is_type_obj()
-        ):
+
+        call_type: Optional[ProperType] = None
+        if var.is_initialized_in_class and (not is_instance_var(var) or mx.is_operator):
+            if isinstance(typ, FunctionLike) and not typ.is_type_obj():
+                call_type = typ
+            elif var.is_property:
+                call_type = get_proper_type(_analyze_member_access("__call__", typ, mx))
+            else:
+                call_type = typ
+
+        if isinstance(call_type, FunctionLike) and not call_type.is_type_obj():
             if mx.is_lvalue:
                 if var.is_property:
                     if not var.is_settable_property:
@@ -792,7 +797,7 @@ def analyze_var(
             if not var.is_staticmethod:
                 # Class-level function objects and classmethods become bound methods:
                 # the former to the instance, the latter to the class.
-                functype = typ
+                functype: FunctionLike = call_type
                 # Use meet to narrow original_type to the dispatched type.
                 # For example, assume
                 # * A.f: Callable[[A1], None] where A1 <: A (maybe A1 == A)

test-data/unit/check-functions.test

@@ -3158,3 +3158,20 @@ class C(A, B):
 class D(A, B):
     def f(self, z: int) -> str: pass  # E: Method "f" is not using @override but is overriding a method in class "__main__.A"
 [typing fixtures/typing-override.pyi]
+
+[case testCallableProperty]
+from typing import Callable
+
+class something_callable:
+    def __call__(self, fn) -> str: ...
+
+def decorator(fn: Callable[..., int]) -> something_callable: ...
+
+class A:
+    @property
+    @decorator
+    def f(self) -> int: ...
+
+reveal_type(A.f)  # N: Revealed type is "__main__.something_callable"
+reveal_type(A().f)  # N: Revealed type is "builtins.str"
+[builtins fixtures/property.pyi]