Serialize additional attributes of "Any" objects (#4481)

Author: gvanrossum

mypy/types.py

@@ -327,12 +327,15 @@ def __eq__(self, other: object) -> bool:
         return isinstance(other, AnyType)
 
     def serialize(self) -> JsonDict:
-        return {'.class': 'AnyType'}
+        return {'.class': 'AnyType', 'type_of_any': self.type_of_any.name,
+                'source_any': self.source_any.serialize() if self.source_any is not None else None}
 
     @classmethod
     def deserialize(cls, data: JsonDict) -> 'AnyType':
         assert data['.class'] == 'AnyType'
-        return AnyType(TypeOfAny.special_form)
+        source = data['source_any']
+        return AnyType(TypeOfAny[data['type_of_any']],
+                       AnyType.deserialize(source) if source is not None else None)
 
 
 class UninhabitedType(Type):

test-data/unit/check-incremental.test

@@ -3447,3 +3447,22 @@ import m  # No error here
 tmp/m/a.py:1: error: Unsupported operand types for + ("int" and "str")
 [out2]
 tmp/m/a.py:1: error: Unsupported operand types for + ("int" and "str")
+
+[case testDisallowAnyExprIncremental]
+# cmd: mypy -m main
+# flags:  --disallow-any-expr
+
+[file ns.py]
+class Namespace:
+    def __init__(self):
+        self.user = 0
+
+[file main.py]
+import ns
+user = ns.Namespace.user
+
+[out1]
+tmp/main.py:2: error: Expression has type "Any"
+
+[out2]
+tmp/main.py:2: error: Expression has type "Any"