## Rewriting Responses

If transparent compression was used, OkHttp will drop the corresponding response headers `Content-Encoding` and `Content-Length` because they don’t apply to the decompressed response body.

If a conditional GET was successful, responses from the network and cache are merged as directed by the spec.

## Follow-up Requests

from fastapi import FastAPI
from fastapi.responses import JSONResponse
from pydantic import BaseModel


class Item(BaseModel):
    id: str
    value: str


class Message(BaseModel):
    message: str


app = FastAPI()


@app.get(
    "/items/{item_id}",
    response_model=Item,
    responses={
        404: {"model": Message, "description": "The item was not found"},
        200: {

    with path.open("rb") as file:
        response = client.post("/uploadfile/", files={"file": file})
    assert response.status_code == 200, response.text
    assert response.json() == {"filename": "test.txt"}


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",

        response = client.post("/uploadfile/", files={"file": file})
    assert response.status_code == 200, response.text
    assert response.json() == {"filename": "test.txt"}


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",

    client = TestClient(app)
    response = client.get("/")
    assert response.status_code == 200, response.text
    assert b"<form" in response.content


@needs_py39
def test_openapi_schema(client: TestClient):
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == {
        "openapi": "3.1.0",

    response = client.get("/users")
    assert response.status_code == 200, response.text
    assert response.json() == [{"user_id": "u1"}, {"user_id": "u2"}]


def test_get_user():
    """Check that /users/{user_id} returns expected data"""
    response = client.get("/users/abc123")
    assert response.status_code == 200, response.text
    assert response.json() == {"user_id": "abc123"}

# 自定义响应 - HTML，流，文件和其他

**FastAPI** 默认会使用 `JSONResponse` 返回响应。

你可以通过直接返回 `Response` 来重载它，参见 [直接返回响应](response-directly.md){.internal-link target=_blank}。

但如果你直接返回 `Response`，返回数据不会自动转换，也不会自动生成文档（例如，在 HTTP 头 `Content-Type` 中包含特定的「媒体类型」作为生成的 OpenAPI 的一部分）。

你还可以在 *路径操作装饰器* 中声明你想用的 `Response`。

你从 *路径操作函数* 中返回的内容将被放在该 `Response` 中。

    )
    assert response.status_code == 200, response.text
    assert response.json() == {"item_id": "plumbus", "name": "The great Plumbus"}


@needs_py39
def test_put_forbidden(client: TestClient):
    response = client.put(
        "/items/bar?token=jessica", headers={"X-Token": "fake-super-secret-token"}
    )
    assert response.status_code == 403, response.text

                operation.setdefault("responses", {}).setdefault(
                    status_code, {}
                ).setdefault("content", {}).setdefault(route_response_media_type, {})[
                    "schema"
                ] = response_schema
            if route.responses:
                operation_responses = operation.setdefault("responses", {})
                for (

    assert response.status_code == 400, response.text
    assert response.json() == {"detail": "Incorrect username or password"}


def test_login_incorrect_username():
    response = client.post("/token", data={"username": "foo", "password": "secret"})
    assert response.status_code == 400, response.text
    assert response.json() == {"detail": "Incorrect username or password"}


def test_no_token():
    response = client.get("/users/me")