* So, by using FastAPI you are saving development time, bugs, lines of code, and you would probably get the same performance (or better) you would if you didn't use it (as you would have to implement...

    ArrayList<Integer> list = Lists.newArrayListWithCapacity(0);
    assertEquals(Collections.emptyList(), list);

    ArrayList<Integer> bigger = Lists.newArrayListWithCapacity(256);
    assertEquals(Collections.emptyList(), bigger);
  }

  public void testNewArrayListWithCapacity_negative() {
    try {
      Lists.newArrayListWithCapacity(-1);
      fail();

## Beispiel

Betrachten wir als einfaches Beispiel eine Dateistruktur ähnlich der in [Größere Anwendungen](../tutorial/bigger-applications.md){.internal-link target=_blank} und [Testen](../tutorial/testing.md){.internal-link target=_blank}:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

    ```

## Abhängigkeiten für eine Gruppe von *Pfadoperationen*

Wenn Sie später lesen, wie Sie größere Anwendungen strukturieren ([Größere Anwendungen – Mehrere Dateien](../../tutorial/bigger-applications.md){.internal-link target=_blank}), möglicherweise mit mehreren Dateien, lernen Sie, wie Sie einen einzelnen `dependencies`-Parameter für eine Gruppe von *Pfadoperationen* deklarieren.

## Globale Abhängigkeiten

    in another `APIRouter` (ultimately included in the app).

    Read more about it in the
    [FastAPI docs for Bigger Applications - Multiple Files](https://fastapi.tiangolo.com/tutorial/bigger-applications/).

    ## Example

    ```python
    from fastapi import APIRouter, FastAPI

    app = FastAPI()
    router = APIRouter()

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_an.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 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")

## 🎏 💯

🎰 🈸, 👆 🎲 🔜 ✔️ 👆 💯 🎏 📁.

& 👆 **FastAPI** 🈸 5️⃣📆 ✍ 📚 📁/🕹, ♒️.

### **FastAPI** 📱 📁

➡️ 💬 👆 ✔️ 📁 📊 🔬 [🦏 🈸](bigger-applications.md){.internal-link target=_blank}:

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

📁 `main.py` 👆 ✔️ 👆 **FastAPI** 📱:


```Python

## 分离测试

在实际应用中，你可能会把你的测试放在另一个文件里。

您的**FastAPI**应用程序也可能由一些文件/模块组成等等。

### **FastAPI** app 文件

假设你有一个像 [更大的应用](bigger-applications.md){.internal-link target=_blank} 中所描述的文件结构:

```
.
├── app
│   ├── __init__.py
│   └── main.py
```

在 `main.py` 文件中你有一个 **FastAPI** app:


```Python

func (e PartTooSmall) Error() string {
	return fmt.Sprintf("Part size for %d should be at least 5MB", e.PartNumber)
}

// PartTooBig returned if size of part is bigger than the allowed limit.
type PartTooBig struct{}

func (e PartTooBig) Error() string {
	return "Part size bigger than the allowed limit"
}

// InvalidETag error returned when the etag has changed on disk
type InvalidETag struct{}