from pydantic import BaseModel

app = FastAPI()


class Item(BaseModel):
    name: Optional[str] = None


class ExtendedItem(Item):
    age: int


@app.post("/items/")
def save_union_different_body(item: Union[ExtendedItem, Item]):
    return {"item": item}


client = TestClient(app)


def test_post_extended_item():
    response = client.post("/items/", json={"name": "Foo", "age": 5})

                                    "schema": {
                                        "title": "Response Get Items Items  Get",
                                        "type": "array",
                                        "items": {"$ref": "#/components/schemas/Item"},
                                    }
                                }
                            },
                        }

app = FastAPI()

items = {"foo": {"name": "Fighters", "size": 6}, "bar": {"name": "Tenders", "size": 3}}


@app.put("/items/{item_id}")
async def upsert_item(
    item_id: str,
    name: Union[str, None] = Body(default=None),
    size: Union[int, None] = Body(default=None),
):
    if item_id in items:
        item = items[item_id]
        item["name"] = name
        item["size"] = size

                            "type": "array",
                            "items": {"type": "string"},
                            "uniqueItems": True,
                        },
                        "images": {
                            "anyOf": [
                                {
                                    "items": {
                                        "$ref": "#/components/schemas/Image",

                                    "schema": {
                                        "title": "Response Get Items Items  Get",
                                        "type": "array",
                                        "items": {"$ref": "#/components/schemas/Item"},
                                    }
                                }
                            },
                        }

        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/": {
                "get": {
                    "tags": ["items"],
                    "summary": "Get Items",
                    "operationId": "items-get_items",
                    "responses": {
                        "200": {
                            "description": "Successful Response",

    response = client.put(
        "/items/5",
        json={"description": "A very nice Item"},
    )
    assert response.status_code == 422, response.text
    assert response.json() == {
        "detail": [
            {
                "loc": ["body", "name"],
                "input": {"description": "A very nice Item"},
                "msg": "Field required",
                "type": "missing",

    assert response.json() == {
        "openapi": "3.1.0",
        "info": {"title": "FastAPI", "version": "0.1.0"},
        "paths": {
            "/items/": {
                "get": {
                    "tags": ["items"],
                    "summary": "Read Items",
                    "operationId": "read_items_items__get",
                    "responses": {
                        "200": {

        "paths": {
            "/items/": {
                "post": {
                    "summary": "Create Item",
                    "operationId": "create_item_items__post",
                    "requestBody": {
                        "content": {
                            "application/json": {
                                "schema": {"$ref": "#/components/schemas/Item"}
                            }

                                "application/json": {
                                    "schema": {
                                        "items": {"$ref": "#/components/schemas/Item"},
                                        "type": "array",
                                        "title": "Response Read Items Items  Get",
                                    }
                                }
                            },
                        }