update: Type annotations are not allowed for enum members

Co-authored-by: Ali Hamdan <[email protected]>

Author: terencehonles

mypy/semanal.py

@@ -4213,6 +4213,9 @@ def analyze_name_lvalue(
                     lvalue,
                 )
 
+            if explicit_type and has_explicit_value:
+                self.fail("Type annotations are not allowed for enum members", lvalue)
+
         if (not existing or isinstance(existing.node, PlaceholderNode)) and not outer:
             # Define new variable.
             var = self.make_name_lvalue_var(lvalue, kind, not explicit_type, has_explicit_value)

mypyc/test-data/run-classes.test

@@ -254,8 +254,8 @@ from enum import Enum
 
 class TestEnum(Enum):
     _order_ = "a b"
-    a : int = 1
-    b : int = 2
+    a = 1
+    b = 2
 
     @classmethod
     def test(cls) -> int:

test-data/unit/check-enum.test

@@ -1764,7 +1764,7 @@ class B(A):
     x = 1  # E: Cannot override writable attribute "x" with a final one
 
 class A1(Enum):
-    x: int = 1
+    x: int = 1  # E: Type annotations are not allowed for enum members
 class B1(A1):  # E: Cannot extend enum with existing members: "A1"
     pass
 
@@ -2185,3 +2185,24 @@ reveal_type(A.y.value)  # N: Revealed type is "Literal[2]?"
 def some_a(a: A):
     reveal_type(a.value)  # N: Revealed type is "Union[Literal[1]?, Literal[2]?]"
 [builtins fixtures/dict.pyi]
+
+
+[case testErrorOnAnnotatedMember]
+from enum import Enum
+
+class Medal(Enum):
+    gold: int = 1  # E: Type annotations are not allowed for enum members
+    silver: str = 2  # E: Type annotations are not allowed for enum members \
+                     # E: Incompatible types in assignment (expression has type "int", variable has type "str")
+    bronze = 3
+
+
+[case testEnumMemberWithPlaceholder]
+from enum import Enum
+
+class Pet(Enum):
+    CAT = ...
+    DOG: str = ...  # E: Type annotations are not allowed for enum members \
+                    # E: Incompatible types in assignment (expression has type "ellipsis", variable has type "str")
+
+[file test.pyi]

test-data/unit/check-python311.test

@@ -1,39 +1,3 @@
-[case testMatchLiteralPatternEnumWithNonMember-xfail]
-from enum import Enum, nonmember
-from typing import NoReturn
-def assert_never(x: NoReturn) -> None: ...
-
-class int:
-    def __new__(cls, value: int): pass
-
-class Medal(int, Enum):
-    prize: str = nonmember("nothing")
-
-    def __new__(cls, value: int, prize: str | None = None) -> Medal:
-        enum = int.__new__(cls, value)
-        enum._value_ = value
-        if prize is not None:
-            enum.prize = prize
-        return enum
-
-    gold = (1, 'cash prize')
-    silver = (2, 'sponsorship')
-    bronze = (3,)
-
-m: Medal
-
-match m:
-    case Medal.gold:
-        reveal_type(m)  # N: Revealed type is "Literal[__main__.Medal.gold]"
-    case Medal.silver:
-        reveal_type(m)  # N: Revealed type is "Literal[__main__.Medal.silver]"
-    case Medal.bronze:
-        reveal_type(m)  # N: Revealed type is "Literal[__main__.Medal.bronze]"
-    case _ as unreachable:
-        assert_never(unreachable)
-
-[builtins fixtures/tuple.pyi]
-
 [case testTryStarSimple]
 try:
     pass

test-data/unit/pythoneval.test

@@ -1601,14 +1601,24 @@ _testSpecialTypingProtocols.py:8: error: Statement is unreachable
 [case testEnumValueWithPlaceholderNodeType]
 # https://github.com/python/mypy/issues/11971
 from enum import Enum
-from typing import Callable, Dict
+from typing import Any, Callable, Dict
 class Foo(Enum):
     Bar: Foo = Callable[[str], None]
-    Baz: Foo = Callable[[Dict[str, "Missing"]], None]
+    Baz: Any = Callable[[Dict[str, "Missing"]], None]
+
+reveal_type(Foo.Bar)
+reveal_type(Foo.Bar.value)  # this should probably not be "Foo" https://typing.readthedocs.io/en/latest/spec/enums.html#member-values
+reveal_type(Foo.Baz)
+reveal_type(Foo.Baz.value)
 [out]
+_testEnumValueWithPlaceholderNodeType.py:5: error: Type annotations are not allowed for enum members
 _testEnumValueWithPlaceholderNodeType.py:5: error: Incompatible types in assignment (expression has type "<typing special form>", variable has type "Foo")
-_testEnumValueWithPlaceholderNodeType.py:6: error: Incompatible types in assignment (expression has type "<typing special form>", variable has type "Foo")
+_testEnumValueWithPlaceholderNodeType.py:6: error: Type annotations are not allowed for enum members
 _testEnumValueWithPlaceholderNodeType.py:6: error: Name "Missing" is not defined
+_testEnumValueWithPlaceholderNodeType.py:8: note: Revealed type is "Literal[_testEnumValueWithPlaceholderNodeType.Foo.Bar]?"
+_testEnumValueWithPlaceholderNodeType.py:9: note: Revealed type is "_testEnumValueWithPlaceholderNodeType.Foo"
+_testEnumValueWithPlaceholderNodeType.py:10: note: Revealed type is "Literal[_testEnumValueWithPlaceholderNodeType.Foo.Baz]?"
+_testEnumValueWithPlaceholderNodeType.py:11: note: Revealed type is "Any"
 
 [case testTypeshedRecursiveTypesExample]
 from typing import List, Union