ExecutorService service = mock(ExecutorService.class);
    application.addDelayedShutdownHook(service, 2, SECONDS);
    verify(service, Mockito.never()).shutdown();
    application.shutdown();
    InOrder shutdownFirst = Mockito.inOrder(service);
    shutdownFirst.verify(service).shutdown();
    shutdownFirst.verify(service).awaitTermination(2, SECONDS);
  }

# Testing Events: lifespan and startup - shutdown { #testing-events-lifespan-and-startup-shutdown }

When you need `lifespan` to run in your tests, you can use the `TestClient` with a `with` statement:

{* ../../docs_src/app_testing/tutorial004_py39.py hl[9:15,18,27:28,30:32,41:43] *}


You can read more details about the ["Running lifespan in tests in the official Starlette documentation site."](https://www.starlette.dev/lifespan/#running-lifespan-in-tests)

### Evento `shutdown` { #shutdown-event }

Para adicionar uma função que deve ser executada quando a aplicação estiver encerrando, declare-a com o evento `"shutdown"`:

{* ../../docs_src/events/tutorial002_py39.py hl[6] *}

Aqui, a função de manipulador do evento `shutdown` escreverá uma linha de texto `"Application shutdown"` no arquivo `log.txt`.

/// info | Informação

from fastapi import FastAPI

app = FastAPI()


@app.on_event("shutdown")
def shutdown_event():
    with open("log.txt", mode="a") as log:
        log.write("Application shutdown")


@app.get("/items/")
async def read_items():

  public void testStop_failed() {
    Exception exception = new Exception("deliberate");
    TestService service =
        new TestService() {
          @Override
          protected void shutDown() throws Exception {
            super.shutDown();
            throw exception;
          }
        };
    service.startAsync().awaitRunning();
    assertEquals(1, service.startUpCalled);
    assertEquals(0, service.shutDownCalled);

  @Test
  fun shutdownWithoutStart() {
    val server = MockWebServer()
    server.shutdown()
  }

  @Test
  fun closeViaClosable() {
    val server: Closeable = MockWebServer()
    server.close()
  }

  @Test
  fun shutdownWithoutEnqueue() {
    val server = MockWebServer()
    server.start()
    server.shutdown()
  }

  @Test
  fun portImplicitlyStarts() {

本例中，`startup` 事件处理器函数为项目数据库（只是**字典**）提供了一些初始值。

**FastAPI** 支持多个事件处理器函数。

只有所有 `startup` 事件处理器运行完毕，**FastAPI** 应用才开始接收请求。

### `shutdown` 事件

使用 `shutdown` 事件声明 `app` 关闭时运行的函数：

{* ../../docs_src/events/tutorial002.py hl[6] *}

此处，`shutdown` 事件处理器函数在 `log.txt` 中写入一行文本 `Application shutdown`。

/// info | 说明

`open()` 函数中，`mode="a"` 指的是**追加**。因此这行文本会添加在文件已有内容之后，不会覆盖之前的内容。

///

/// tip | 提示

		return srv.Serve(l)
	}

	return serve, err
}

// Shutdown - shuts down HTTP server.
func (srv *Server) Shutdown() error {
	srv.listenerMutex.Lock()
	if srv.listener == nil {
		srv.listenerMutex.Unlock()
		return http.ErrServerClosed
	}
	srv.listenerMutex.Unlock()

	if atomic.AddUint32(&srv.inShutdown, 1) > 1 {
		// shutdown in progress
		return http.ErrServerClosed
	}

                  // which case we should skip right down to shutdown.
                  if (isRunning()) {
                    try {
                      AbstractExecutionThreadService.this.run();
                    } catch (Throwable t) {
                      restoreInterruptIfIsInterruptedException(t);
                      try {
                        shutDown();
                      } catch (Exception ignored) {

	natsserver "github.com/nats-io/nats-server/v2/test"
)

func TestNatsConnTLSCustomCA(t *testing.T) {
	s, opts := natsserver.RunServerWithConfig(filepath.Join("testdata", "contrib", "nats_tls.conf"))
	defer s.Shutdown()

	clientConfig := &NATSArgs{
		Enable: true,
		Address: xnet.Host{
			Name:      "localhost",
			Port:      (xnet.Port(opts.Port)),
			IsPortSet: true,
		},
		Subject:       "test",