)
def test_router_events(state: State) -> None:
    app = FastAPI()

    @app.get("/")
    def main() -> dict[str, str]:
        return {"message": "Hello World"}

    @app.on_event("startup")
    def app_startup() -> None:
        state.app_startup = True

    @app.on_event("shutdown")
    def app_shutdown() -> None:
        state.app_shutdown = True

@app.get("/app")
def read_main(request: Request):
    return {"message": "Hello World", "root_path": request.scope.get("root_path")}


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

    }
  }

  @Test
  fun singlePart() {
    val expected =
      """
      |--123
      |
      |Hello, World!
      |--123--
      |
      """.trimMargin().replace("\n", "\r\n")
    val body =
      MultipartBody
        .Builder("123")
        .addPart("Hello, World!".toRequestBody(null))
        .build()
    assertThat(body.boundary).isEqualTo("123")

    assert response.json() == {"message": "Hello World"}
    assert (
        response.headers["access-control-allow-origin"]
        == "https://localhost.tiangolo.com"
    )

    # Test non-CORS response
    response = client.get("/")
    assert response.status_code == 200, response.text
    assert response.json() == {"message": "Hello World"}

    [
        "/optional-list-bytes",
        "/optional-list-uploadfile",
    ],
)
def test_optional_list(path: str):
    client = TestClient(app)
    response = client.post(path, files=[("p", b"hello"), ("p", b"world")])
    assert response.status_code == 200
    assert response.json() == {"file_size": [5, 5]}


# =====================================================================================
# Alias

```txt
Hello, World from Flask!
```

Y si vas a <a href="http://localhost:8000/v2" class="external-link" target="_blank">http://localhost:8000/v2</a> verás el response de FastAPI:

```JSON
{
    "message": "Hello World"
}

        Did you *actually* encounter the need for this feature in a real-world scenario, or is it
        just a feature that seems like a sensible addition to Guava?


        Before new features get added to Guava, we really want to be sure that it's for a use case
        that actually comes up in the real world. We want to hear the real-world use case so the

from fastapi import FastAPI, Response

app = FastAPI()


@app.get("/headers-and-object/")
def get_headers(response: Response):
    response.headers["X-Cat-Dog"] = "alone in the world"

```Python hl_lines="3"
import os

name = os.getenv("MY_NAME", "World")
print(f"Hello {name} from Python")
```

/// tip | Tipp

Das zweite Argument von <a href="https://docs.python.org/3.8/library/os.html#os.getenv" class="external-link" target="_blank">`os.getenv()`</a> ist der Defaultwert, der zurückgegeben wird.

Wenn er nicht angegeben wird, ist er standardmäßig `None`. Hier geben wir `"World"` als den zu verwendenden Defaultwert an.

///

	if count1 != count2 {
		t.Errorf("No user should not be deleted by invalid SQL")
	}
}

func TestSetAndGet(t *testing.T) {
	if value, ok := DB.Set("hello", "world").Get("hello"); !ok {
		t.Errorf("Should be able to get setting after set")
	} else if value.(string) != "world" {
		t.Errorf("Set value should not be changed")
	}

	if _, ok := DB.Get("non_existing"); ok {
		t.Errorf("Get non existing key should return error")
	}