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...

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 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")

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.tutorial001 import app

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

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_py310


@pytest.fixture(name="client")
def get_client():
    from docs_src.additional_status_codes.tutorial001_an_py310 import app

    client = TestClient(app)
    return client


@needs_py310
def test_update(client: TestClient):
    response = client.put("/items/foo", json={"name": "Wrestlers"})
    assert response.status_code == 200, response.text

import pytest
from fastapi.testclient import TestClient

from ...utils import needs_pydanticv2


@pytest.fixture(name="client")
def get_client():
    from docs_src.path_operation_advanced_configuration.tutorial007 import app

    client = TestClient(app)
    return client


@needs_pydanticv2
def test_post(client: TestClient):
    yaml_data = """
        name: Deadpoolio
        tags:
        - x-force
        - x-men