Class property Choices.values returns list of Members (#232)

For any subclass `E` of `Choices`, `IntegerChoices` or `TextChoices` `E.values` now has type `Sequence[E]` instead of `list[str]` (or `list[int]`). Similarly for `E.choices`. The implementation is borrowed from the typeshed implementation of `enum.EnumMeta`.

I’m not sure about the tests, i.e. just putting a subclass of `Choices` into the models module. Happy to change that.

django-stubs/db/models/enums.pyi

@@ -1,12 +1,16 @@
 import enum
-from typing import Any
+from typing import Any, Sequence, TypeVar
+
+_EnumMemberT = TypeVar("_EnumMemberT")
 
 class ChoicesMeta(enum.EnumMeta):
     names: list[str] = ...
-    choices: list[tuple[Any, str]] = ...
     labels: list[str] = ...
-    values: list[Any] = ...
     def __contains__(self, item: Any) -> bool: ...
+    @property
+    def values(self: type[_EnumMemberT]) -> Sequence[_EnumMemberT]: ...
+    @property
+    def choices(self: type[_EnumMemberT]) -> Sequence[tuple[_EnumMemberT, str]]: ...
 
 class Choices(enum.Enum, metaclass=ChoicesMeta):
     def __str__(self) -> Any: ...
@@ -15,24 +19,10 @@ class Choices(enum.Enum, metaclass=ChoicesMeta):
     @property
     def value(self) -> Any: ...
 
-# fake
-class _IntegerChoicesMeta(ChoicesMeta):
-    names: list[str] = ...
-    choices: list[tuple[int, str]] = ...
-    labels: list[str] = ...
-    values: list[int] = ...
-
-class IntegerChoices(int, Choices, metaclass=_IntegerChoicesMeta):
+class IntegerChoices(int, Choices):
     @property
     def value(self) -> int: ...
 
-# fake
-class _TextChoicesMeta(ChoicesMeta):
-    names: list[str] = ...
-    choices: list[tuple[str, str]] = ...
-    labels: list[str] = ...
-    values: list[str] = ...
-
-class TextChoices(str, Choices, metaclass=_TextChoicesMeta):
+class TextChoices(str, Choices):
     @property
     def value(self) -> str: ...

tests/trout/models.py

@@ -43,6 +43,28 @@
 from psycopg2.extras import execute_values
 
 
+class CustomChoices(models.enums.Choices):
+    A = "B", "A"
+
+    def go(self) -> None:
+        pass
+
+
+CustomChoices.values[0].go()
+CustomChoices.choices[0][0].go()
+
+
+class CustomIntegerChoices(models.enums.IntegerChoices):
+    A = 1, "A"
+
+    def go(self) -> None:
+        pass
+
+
+CustomIntegerChoices.values[0].go()
+CustomIntegerChoices.choices[0][0].go()
+
+
 class User(models.Model):
     pass