Fix missing enum extra (#2818)

* Allow passing schema_overrides to get_field_info_schema

This function was resetting schema_overrides which prevents **extras on Enum type Fields
from being saved to their json schema

* Add changes file

* Update changes/2697-sammchardy.md

Co-authored-by: Eric Jolibois <em.jolibois@gmail.com>

Co-authored-by: Sam McHardy <sam.mchardy@psma.com.au>
Co-authored-by: Eric Jolibois <em.jolibois@gmail.com>

changes/2697-sammchardy.md

@@ -0,0 +1 @@
+`Enum` fields now properly support extra kwargs in schema generation

pydantic/schema.py

@@ -178,8 +178,7 @@ def model_schema(
     return m_schema
 
 
-def get_field_info_schema(field: ModelField) -> Tuple[Dict[str, Any], bool]:
-    schema_overrides = False
+def get_field_info_schema(field: ModelField, schema_overrides: bool = False) -> Tuple[Dict[str, Any], bool]:
 
     # If no title is explicitly set, we don't set title in the schema for enums.
     # The behaviour is the same as `BaseModel` reference, where the default title
@@ -836,7 +835,7 @@ def field_singleton_schema(  # noqa: C901 (ignore complexity)
         add_field_type_to_schema(field_type, f_schema)
     elif lenient_issubclass(field_type, Enum):
         enum_name = model_name_map[field_type]
-        f_schema, schema_overrides = get_field_info_schema(field)
+        f_schema, schema_overrides = get_field_info_schema(field, schema_overrides)
         f_schema.update(get_schema_ref(enum_name, ref_prefix, ref_template, schema_overrides))
         definitions[enum_name] = enum_process_schema(field_type)
     elif is_namedtuple(field_type):

tests/test_schema.py

@@ -398,6 +398,35 @@ def test_enum_and_model_have_same_behaviour():
     }
 
 
+def test_enum_includes_extra_without_other_params():
+    class Names(str, Enum):
+        rick = 'Rick'
+        morty = 'Morty'
+        summer = 'Summer'
+
+    class Foo(BaseModel):
+        enum: Names
+        extra_enum: Names = Field(..., extra='Extra field')
+
+    assert Foo.schema() == {
+        'definitions': {
+            'Names': {
+                'description': 'An enumeration.',
+                'enum': ['Rick', 'Morty', 'Summer'],
+                'title': 'Names',
+                'type': 'string',
+            },
+        },
+        'properties': {
+            'enum': {'$ref': '#/definitions/Names'},
+            'extra_enum': {'allOf': [{'$ref': '#/definitions/Names'}], 'extra': 'Extra field'},
+        },
+        'required': ['enum', 'extra_enum'],
+        'title': 'Foo',
+        'type': 'object',
+    }
+
+
 def test_list_enum_schema_extras():
     class FoodChoice(str, Enum):
         spam = 'spam'