Add property support as well

Author: ilevkivskyi

mypy/checker.py

@@ -4400,9 +4400,9 @@ def set_inferred_type(self, var: Var, lvalue: Lvalue, type: Type) -> None:
         refers to the variable (lvalue). If var is None, do nothing.
         """
         if var and not self.current_node_deferred:
-            # TODO: should we also set 'is_ready = True' here?
             var.type = type
             var.is_inferred = True
+            var.is_ready = True
             if var not in self.var_decl_frames:
                 # Used for the hack to improve optional type inference in conditionals
                 self.var_decl_frames[var] = {frame.id for frame in self.binder.frames}
@@ -4424,6 +4424,11 @@ def set_inferred_type(self, var: Var, lvalue: Lvalue, type: Type) -> None:
                     var.is_staticmethod = True
                 elif is_node_class(definition):
                     var.is_classmethod = True
+                elif is_property(definition):
+                    var.is_property = True
+                    if isinstance(p_type, Overloaded):
+                        # TODO: in theory we can have a property with a deleter only.
+                        var.is_settable_property = True
 
     def set_inference_error_fallback_type(self, var: Var, lvalue: Lvalue, type: Type) -> None:
         """Store best known type for variable if type inference failed.
@@ -8801,6 +8806,8 @@ def is_static(func: FuncBase | Decorator) -> bool:
 
 
 def is_property(defn: SymbolNode) -> bool:
+    if isinstance(defn, FuncDef):
+        return defn.is_property
     if isinstance(defn, Decorator):
         return defn.func.is_property
     if isinstance(defn, OverloadedFuncDef):

test-data/unit/check-callable.test

@@ -614,6 +614,26 @@ reveal_type(C.bar2)  # N: Revealed type is "Overload(def (x: builtins.int) -> bu
 reveal_type(C().bar2)  # N: Revealed type is "Overload(def (x: builtins.int) -> builtins.int, def (x: builtins.str) -> builtins.str)"
 [builtins fixtures/classmethod.pyi]
 
+[case testPropertyAliasInClassBody]
+class A:
+    @property
+    def f(self) -> int: ...
+
+    g = f
+
+    @property
+    def f2(self) -> int: ...
+    @f2.setter
+    def f2(self, val: int) -> None: ...
+
+    g2 = f2
+
+reveal_type(A().g)  # N: Revealed type is "builtins.int"
+reveal_type(A().g2)  # N: Revealed type is "builtins.int"
+A().g2 = 1
+A().g2 = "no"  # E: Incompatible types in assignment (expression has type "str", variable has type "int")
+[builtins fixtures/property.pyi]
+
 [case testCallableUnionCallback]
 from typing import Union, Callable, TypeVar