You can use the `TestClient` class to test FastAPI applications without creating an actual HTTP and socket connection, just communicating directly with the FastAPI code.

Read more about it in the [FastAPI docs for Testing](https://fastapi.tiangolo.com/tutorial/testing/).

You can import it directly from `fastapi.testclient`:

```python
from fastapi.testclient import TestClient
```

# Testclient – `TestClient`

Sie können die `TestClient`-Klasse verwenden, um FastAPI-Anwendungen zu testen, ohne eine tatsächliche HTTP- und Socket-Verbindung zu erstellen, Sie kommunizieren einfach direkt mit dem FastAPI-Code.

Lesen Sie mehr darüber in der [FastAPI-Dokumentation über Testen](../tutorial/testing.md).

Sie können sie direkt von `fastapi.testclient` importieren:

```python
from fastapi.testclient import TestClient
```

from starlette.testclient import TestClient as TestClient  # noqa...

        assertEquals(2, testClient.count);
    }

    public void test_doGet_with4Exception_interval100() {
        final FaultTolerantClient client = new FaultTolerantClient();
        client.setRetryInterval(100);
        final TestClient testClient = new TestClient();
        testClient.exceptionCount = 4;
        testClient.interval = 100;

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient


@pytest.fixture(name="client")
def get_client():
    from docs_src.bigger_applications.app.main import app

    client = TestClient(app)
    return client


def test_users_token_jessica(client: TestClient):
    response = client.get("/users?token=jessica")
    assert response.status_code == 200

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.dependencies.tutorial008d_an_py39 import app

    client = TestClient(app)
    return client


@needs_py39
def test_get_no_item(client: TestClient):
    response = client.get("/items/foo")
    assert response.status_code == 404, response.text

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.dependencies.tutorial008b_an_py39 import app

    client = TestClient(app)
    return client


@needs_py39
def test_get_no_item(client: TestClient):
    response = client.get("/items/foo")
    assert response.status_code == 404, response.text

import pytest
from dirty_equals import IsDict
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.bigger_applications.app_an_py39.main import app

    client = TestClient(app)
    return client


@needs_py39
def test_users_token_jessica(client: TestClient):
    response = client.get("/users?token=jessica")

import os
from pathlib import Path

import pytest
from fastapi.testclient import TestClient


@pytest.fixture(scope="module")
def client():
    static_dir: Path = Path(os.getcwd()) / "static"
    print(static_dir)
    static_dir.mkdir(exist_ok=True)
    from docs_src.custom_docs_ui.tutorial002 import app

    with TestClient(app) as client:
        yield client
    static_dir.rmdir()

import pytest
from fastapi.exceptions import FastAPIError
from fastapi.testclient import TestClient

from ...utils import needs_py39


@pytest.fixture(name="client")
def get_client():
    from docs_src.dependencies.tutorial008c_an_py39 import app

    client = TestClient(app)
    return client


@needs_py39
def test_get_no_item(client: TestClient):
    response = client.get("/items/foo")