Fix CI

Author: sobolevn

mypy/checker.py

@@ -2426,20 +2426,7 @@ def check_assignment(self, lvalue: Lvalue, rvalue: Expression, infer_lvalue_type
 
                 # Special case: only non-abstract non-protocol classes can be assigned to
                 # variables with explicit type Type[A], where A is protocol or abstract.
-                rvalue_type = get_proper_type(rvalue_type)
-                lvalue_type = get_proper_type(lvalue_type)
-                if (isinstance(rvalue_type, CallableType) and rvalue_type.is_type_obj() and
-                        (rvalue_type.type_object().is_abstract or
-                         rvalue_type.type_object().is_protocol) and
-                        ((isinstance(lvalue_type, TypeType) and
-                          isinstance(lvalue_type.item, Instance) and
-                          (lvalue_type.item.type.is_abstract or
-                           lvalue_type.item.type.is_protocol)) or
-                         (isinstance(lvalue_type, CallableType) and
-                          isinstance(lvalue_type.ret_type, Instance) and
-                          (lvalue_type.ret_type.type.is_abstract or
-                           lvalue_type.ret_type.type.is_protocol)))):
-                    self.msg.concrete_only_assign(lvalue_type, rvalue)
+                if not self.check_concrete_only_assign(lvalue_type, rvalue_type, rvalue):
                     return
                 if rvalue_type and infer_lvalue_type and not isinstance(lvalue_type, PartialType):
                     # Don't use type binder for definitions of special forms, like named tuples.
@@ -2457,6 +2444,38 @@ def check_assignment(self, lvalue: Lvalue, rvalue: Expression, infer_lvalue_type
                 self.infer_variable_type(inferred, lvalue, rvalue_type, rvalue)
             self.check_assignment_to_slots(lvalue)
 
+    def check_concrete_only_assign(self, lvalue_type: Optional[Type],
+                                   rvalue_type: Type, rvalue: Expression) -> bool:
+        rvalue_type = get_proper_type(rvalue_type)
+        lvalue_type = get_proper_type(lvalue_type)
+        if not (
+            isinstance(rvalue_type, CallableType) and
+            rvalue_type.is_type_obj() and
+            (rvalue_type.type_object().is_abstract or
+                rvalue_type.type_object().is_protocol)):
+            return True
+
+        lvalue_is_a_type = (
+            isinstance(lvalue_type, TypeType) and
+            isinstance(lvalue_type.item, Instance) and
+            (lvalue_type.item.type.is_abstract or
+                lvalue_type.item.type.is_protocol)
+        )
+
+        lvalue_is_a_callable = False
+        if isinstance(lvalue_type, CallableType):
+            ret_type = get_proper_type(lvalue_type.ret_type)
+            lvalue_is_a_callable = (
+                isinstance(ret_type, Instance) and
+                (ret_type.type.is_abstract or ret_type.type.is_protocol)
+            )
+
+        if lvalue_is_a_type or lvalue_is_a_callable:
+            # `lvalue_type` here is either `TypeType` or `CallableType`:
+            self.msg.concrete_only_assign(cast(Type, lvalue_type), rvalue)
+            return False
+        return True
+
     # (type, operator) tuples for augmented assignments supported with partial types
     partial_type_augmented_ops: Final = {
         ('builtins.list', '+'),

test-data/unit/check-abstract.test

@@ -269,6 +269,14 @@ var = A # E: Can only assign concrete classes to a variable of type "Callable[[]
 var = B # E: Can only assign concrete classes to a variable of type "Callable[[], A]"
 var = C # OK
 
+# Type aliases:
+A1 = A
+B1 = B
+C1 = C
+var = A1 # E: Can only assign concrete classes to a variable of type "Callable[[], A]"
+var = B1 # E: Can only assign concrete classes to a variable of type "Callable[[], A]"
+var = C1 # OK
+
 [case testInstantiationAbstractsInTypeForClassMethods]
 from typing import Type
 from abc import abstractmethod

test-data/unit/check-protocols.test

@@ -1636,6 +1636,14 @@ var = P # E: Can only assign concrete classes to a variable of type "Callable[[]
 var = B # OK
 var = C # OK
 
+# Type aliases:
+P1 = P
+B1 = B
+C1 = C
+var = P1 # E: Can only assign concrete classes to a variable of type "Callable[[], P]"
+var = B1 # OK
+var = C1 # OK
+
 [case testInstantiationProtocolInTypeForClassMethods]
 from typing import Type, Protocol