* Then it returns the `response` generated by the corresponding *path operation*.
* You can then further modify the `response` before returning it.

{* ../../docs_src/middleware/tutorial001_py39.py hl[8:9,11,14] *}

/// tip

Keep in mind that custom proprietary headers can be added <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers" class="external-link" target="_blank">using the `X-` prefix</a>.

import importlib
import runpy
import sys
import unittest

import pytest
from fastapi.testclient import TestClient

MOD_NAME = "docs_src.debugging.tutorial001_py39"


@pytest.fixture(name="client")
def get_client():
    mod = importlib.import_module(MOD_NAME)
    client = TestClient(mod.app)
    return client


def test_uvicorn_run_is_not_called_on_import():
    if sys.modules.get(MOD_NAME):

from fastapi.testclient import TestClient

from docs_src.path_operation_advanced_configuration.tutorial001_py39 import app

client = TestClient(app)


def test_get():
    response = client.get("/items/")
    assert response.status_code == 200, response.text
    assert response.json() == [{"item_id": "Foo"}]


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

from fastapi.testclient import TestClient
from inline_snapshot import snapshot

from docs_src.behind_a_proxy.tutorial004_py39 import app

client = TestClient(app)


def test_main():
    response = client.get("/app")
    assert response.status_code == 200
    assert response.json() == {"message": "Hello World", "root_path": "/api/v1"}


def test_openapi_schema():
    response = client.get("/openapi.json")

import pytest
from fastapi.testclient import TestClient

from docs_src.path_params.tutorial001_py39 import app

client = TestClient(app)


@pytest.mark.parametrize(
    ("item_id", "expected_response"),
    [
        (1, {"item_id": "1"}),
        ("alice", {"item_id": "alice"}),
    ],
)
def test_get_items(item_id, expected_response):
    response = client.get(f"/items/{item_id}")

from fastapi.testclient import TestClient

from docs_src.advanced_middleware.tutorial001_py39 import app


def test_middleware():
    client = TestClient(app, base_url="https://testserver")
    response = client.get("/")
    assert response.status_code == 200, response.text

    client = TestClient(app)
    response = client.get("/", follow_redirects=False)
    assert response.status_code == 307, response.text

Нужно импортировать `WSGIMiddleware`.

Затем оберните WSGI‑приложение (например, Flask) в middleware (Промежуточный слой).

После этого смонтируйте его на путь.

{* ../../docs_src/wsgi/tutorial001_py39.py hl[2:3,3] *}

## Проверьте { #check-it }

Теперь каждый HTTP‑запрос по пути `/v1/` будет обрабатываться приложением Flask.

А всё остальное будет обрабатываться **FastAPI**.

from fastapi.testclient import TestClient

from docs_src.events.tutorial003_py39 import (
    app,
    fake_answer_to_everything_ml_model,
    ml_models,
)


def test_events():
    assert not ml_models, "ml_models should be empty"
    with TestClient(app) as client:
        assert ml_models["answer_to_everything"] == fake_answer_to_everything_ml_model
        response = client.get("/predict", params={"x": 2})

        shutil.rmtree("./templates")
    shutil.copytree("./docs_src/templates/templates/", "./templates")
    shutil.copytree("./docs_src/templates/static/", "./static")
    from docs_src.templates.tutorial001_py39 import app

    client = TestClient(app)
    response = client.get("/items/foo")
    assert response.status_code == 200, response.text
    assert (

from fastapi.testclient import TestClient

from docs_src.response_change_status_code.tutorial001_py39 import app

client = TestClient(app)


def test_path_operation():
    response = client.put("/get-or-create-task/foo")
    print(response.content)
    assert response.status_code == 200, response.text
    assert response.json() == "Listen to the Bar Fighters"
    response = client.put("/get-or-create-task/bar")