///

### Перевірте документацію { #check-the-docs }

Тепер ви можете запустити застосунок і перейти за адресою [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs).

Ви побачите вашу документацію з розділом «Callbacks» для вашої операції шляху, який показує, як має виглядати зовнішній API:

## URLs der OpenAPI-Dokumentationen { #openapi-docs-urls }

///

### Проверьте документацию { #check-the-docs }

Теперь вы можете запустить приложение и перейти по адресу [http://127.0.0.1:8000/docs](http://127.0.0.1:8000/docs).

Вы увидите документацию, включающую раздел «Callbacks» для вашей *операции пути*, который показывает, как должен выглядеть *внешний API*:

 * static final} constants.
 *
 * {@snippet :
 * // Bad! Do not do this!
 * Joiner joiner = Joiner.on(',');
 * joiner.skipNulls(); // does nothing!
 * return joiner.join("wrong", null, "wrong");
 * }
 *
 * <p>See the Guava User Guide article on <a
 * href="https://github.com/google/guava/wiki/StringsExplained#joiner">{@code Joiner}</a>.
 *

    # Load the client after setting the env var
    client = get_client()
    response = client.get("/openapi.json")
    assert response.status_code == 404, response.text
    response = client.get("/docs")
    assert response.status_code == 404, response.text
    response = client.get("/redoc")
    assert response.status_code == 404, response.text


def test_root():
    client = get_client()

from fastapi.testclient import TestClient

swagger_ui_oauth2_redirect_url = "/docs/redirect"

app = FastAPI(swagger_ui_oauth2_redirect_url=swagger_ui_oauth2_redirect_url)


@app.get("/items/")
async def read_items():
    return {"id": "foo"}


client = TestClient(app)


def test_swagger_ui():
    response = client.get("/docs")
    assert response.status_code == 200, response.text

# WebSockets

When defining WebSockets, you normally declare a parameter of type `WebSocket` and with it you can read data from the client and send data to it.

Read more about it in the [FastAPI docs for WebSockets](https://fastapi.tiangolo.com/advanced/websockets/)

It is provided directly by Starlette, but you can import it from `fastapi`:

```python
from fastapi import WebSocket
```

/// tip

# CORS (Partage des ressources entre origines) { #cors-cross-origin-resource-sharing }

[CORS ou « Cross-Origin Resource Sharing »](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS) fait référence aux situations où un frontend exécuté dans un navigateur contient du code JavaScript qui communique avec un backend, et où le backend se trouve dans une « origine » différente de celle du frontend.

## Origine { #origin }

		},
		{
			name:       "date_diff_month_neg",
			query:      `SELECT date_diff(MONTH, '2020-01-20T', '2019-10-20T') FROM S3Object LIMIT 1`,
			wantResult: `{"_1":-3}`,
		},
		// Examples from https://docs.aws.amazon.com/AmazonS3/latest/userguide/s3-glacier-select-sql-reference-date.html#s3-glacier-select-sql-reference-date-diff
		{
			name:       "date_diff_year",

* `allow_credentials` - Indicate that cookies should be supported for cross-origin requests. Defaults to `False`.

    None of `allow_origins`, `allow_methods` and `allow_headers` can be set to `['*']` if `allow_credentials` is set to `True`. All of them must be [explicitly specified](https://developer.mozilla.org/en-US/docs/Web/HTTP/CORS#credentialed_requests_and_wildcards).