Changed type inference logic that infers the type of the value attr…

…ibute in an enum. If the enum class has a custom metaclass (one that is not part of the stdlib), pyright now assumes that the custom metaclass may perform some runtime magic that modifies the `value`. This occurs, for example, in django's `TextChoices` class. This addresses #5092.

packages/pyright-internal/src/analyzer/enums.ts

@@ -394,6 +394,15 @@ export function getTypeOfEnumMember(
     }
 
     if (memberName === 'value' || memberName === '_value_') {
+        // If the enum class has a custom metaclass, it may implement some
+        // "magic" that computes different values for the "value" attribute.
+        // This occurs, for example, in the django TextChoices class. If we
+        // detect a custom metaclass, we'll assume the value is Any.
+        const metaclass = classType.details.effectiveMetaclass;
+        if (metaclass && isClass(metaclass) && !ClassType.isBuiltIn(metaclass)) {
+            return { type: AnyType.create(), isIncomplete };
+        }
+
         if (literalValue) {
             assert(literalValue instanceof EnumLiteral);
             return { type: literalValue.itemType, isIncomplete };

packages/pyright-internal/src/tests/samples/enums1.py

@@ -1,6 +1,6 @@
 # This sample tests the type checker's handling of Enum.
 
-from enum import Enum, IntEnum
+from enum import Enum, EnumMeta, IntEnum
 
 
 TestEnum1 = Enum("TestEnum1", "   A   B, , ,C , \t D\t")
@@ -141,3 +141,20 @@ def __new__(cls, value: str, other1: int, other2: int):
 reveal_type(te9_A._value_, expected_text="Any")
 reveal_type(te9_A.name, expected_text="Literal['A']")
 reveal_type(te9_A._name_, expected_text="Literal['A']")
+
+
+class CustomEnumMeta1(EnumMeta):
+    pass
+
+
+class TestEnum10(Enum, metaclass=CustomEnumMeta1):
+    A = 1
+    B = 2
+
+
+te10_A = TestEnum10.A
+reveal_type(te10_A, expected_text="Literal[TestEnum10.A]")
+reveal_type(te10_A.value, expected_text="Any")
+reveal_type(te9_A._value_, expected_text="Any")
+reveal_type(te9_A.name, expected_text="Literal['A']")
+reveal_type(te9_A._name_, expected_text="Literal['A']")