Fix enum attributes are not members

mypy/semanal.py

@@ -4235,6 +4235,9 @@ 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)

mypy/semanal_enum.py

@@ -143,6 +143,12 @@ def build_enum_call_typeinfo(
             var = Var(item)
             var.info = info
             var.is_property = True
+            # When an enum is created by its functional form `Enum(name, values)`
+            # - if it is a string it is first split by commas/whitespace
+            # - if it is an iterable of single items each item is assigned a value starting at `start`
+            # - if it is an iterable of (name, value) then the given values will be used
+            # either way, each item should be treated as if it has an explicit value.
+            var.has_explicit_value = True
             var._fullname = f"{info.fullname}.{item}"
             info.names[item] = SymbolTableNode(MDEF, var)
         return info

mypy/typeops.py

@@ -30,7 +30,6 @@
 )
 from mypy.state import state
 from mypy.types import (
-    ENUM_REMOVED_PROPS,
     AnyType,
     CallableType,
     ExtraAttrs,
@@ -901,18 +900,9 @@ class Status(Enum):
         return make_simplified_union(items, contract_literals=False)
     elif isinstance(typ, Instance) and typ.type.fullname == target_fullname:
         if typ.type.is_enum:
-            new_items = []
-            for name, symbol in typ.type.names.items():
-                if not isinstance(symbol.node, Var):
-                    continue
-                # Skip these since Enum will remove it
-                if name in ENUM_REMOVED_PROPS:
-                    continue
-                # Skip private attributes
-                if name.startswith("__"):
-                    continue
-                new_items.append(LiteralType(name, typ))
-            return make_simplified_union(new_items, contract_literals=False)
+            return make_simplified_union(
+                [LiteralType(name, typ) for name in typ.get_enum_values()], contract_literals=False
+            )
         elif typ.type.fullname == "builtins.bool":
             return make_simplified_union(
                 [LiteralType(True, typ), LiteralType(False, typ)], contract_literals=False

mypy/types.py

@@ -1550,7 +1550,14 @@ def is_singleton_type(self) -> bool:
     def get_enum_values(self) -> list[str]:
         """Return the list of values for an Enum."""
         return [
-            name for name, sym in self.type.names.items() if isinstance(sym.node, mypy.nodes.Var)
+            name
+            for name, sym in self.type.names.items()
+            if (
+                isinstance(sym.node, mypy.nodes.Var)
+                and name not in ENUM_REMOVED_PROPS
+                and not name.startswith("__")
+                and sym.node.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-python310.test

@@ -1499,6 +1499,60 @@ def g(m: Medal) -> int:
             reveal_type(m)  # N: Revealed type is "Literal[__main__.Medal.bronze]"
             return 2
 
+
+[case testMatchLiteralPatternEnumWithTypedAttribute]
+from enum import Enum
+from typing import NoReturn
+def assert_never(x: NoReturn) -> None: ...
+
+class int:
+    def __new__(cls, value: int): pass
+
+class Medal(int, Enum):
+    prize: str
+
+    def __new__(cls, value: int, prize: str) -> Medal:
+        enum = int.__new__(cls, value)
+        enum._value_ = value
+        enum.prize = prize
+        return enum
+
+    gold = (1, 'cash prize')
+    silver = (2, 'sponsorship')
+    bronze = (3, 'nothing')
+
+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 testMatchLiteralPatternFunctionalEnum]
+from enum import Enum
+from typing import NoReturn
+def assert_never(x: NoReturn) -> None: ...
+
+Medal = Enum('Medal', 'gold silver bronze')
+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)
+
 [case testMatchLiteralPatternEnumCustomEquals-skip]
 from enum import Enum
 class Medal(Enum):

test-data/unit/pythoneval.test

@@ -1599,14 +1599,24 @@ _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