}
    for test_type, expect in types.items():
        app = FastAPI()

        @app.post("/", response_model=test_type)
        def post_endpoint(input: test_type):
            return input

        res = TestClient(app).post("/", json=expect)
        assert res.status_code == 200, res.json()

                But when using `Item` for output, for a response body, `tags` is always
                available because it has a default value, even if it's just an empty
                list. So, the client should be able to always expect it.

                In this case, there would be two different schemas, one for input and
                another one for output.
                """
            ),
        ] = True,

    ) -> Dict[str, Any]:
        override_mode: Union[Literal["validation"], None] = (
            None if separate_input_output_schemas else "validation"
        )
        # This expects that GenerateJsonSchema was already used to generate the definitions
        json_schema = field_mapping[(field, override_mode or field.mode)]
        if "$ref" not in json_schema: