Save return type generated from type annotation in ComputedFieldInfo (#…

…7889)

pydantic/_internal/_generate_schema.py

@@ -1515,6 +1515,9 @@ def _computed_field_schema(
             )
 
         return_type = replace_types(return_type, self._typevars_map)
+        # Create a new ComputedFieldInfo so that different type parametrizations of the same
+        # generic model's computed field can have different return types.
+        d.info = dataclasses.replace(d.info, return_type=return_type)
         return_type_schema = self.generate_schema(return_type)
         # Apply serializers to computed field if there exist
         return_type_schema = self._apply_field_serializers(

tests/test_computed_fields.py

@@ -736,6 +736,10 @@ def double_x(self) -> T:
     assert A[int](x=1).model_dump() == {'x': 1, 'double_x': 2}
     assert A[str](x='abc').model_dump() == {'x': 'abc', 'double_x': 'abcabc'}
 
+    assert A(x='xxxxxx').model_computed_fields['double_x'].return_type == T
+    assert A[int](x=123).model_computed_fields['double_x'].return_type == int
+    assert A[str](x='x').model_computed_fields['double_x'].return_type == str
+
     class B(BaseModel, Generic[T]):
         @computed_field
         @property