In this case, the `startup` event handler function will initialize the items "database" (just a `dict`) with some values.

You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

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

To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

# 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.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.io/lifespan/#running-lifespan-in-tests)

  fun assertExhausted() {
    assertThat(events).isEmpty()
  }

  fun assertEvent(
    id: String?,
    type: String?,
    data: String,
  ) {
    assertThat(nextEvent()).isEqualTo(Event(id, type, data))
  }

  fun assertOpen(): EventSource {
    val event = nextEvent() as Open
    return event.eventSource
  }

  fun assertClose() {
    nextEvent() as Closed
  }

  fun assertFailure(

        assertEquals(1, events.size());
        assertEquals("listener1", events.get(0));

        // Switch to listener2
        factory.setOnDestroyListener(listener2);
        assertEquals(listener2, factory.getOnDestroyListener());
        factory.destroyObject(pooledObject);
        assertEquals(2, events.size());
        assertEquals("listener2", events.get(1));

        // Clear listener

        assertEquals(Long.valueOf(1), stats.get(EventType.AUTHENTICATION_SUCCESS), "Should have 1 authentication success event");
        assertEquals(Long.valueOf(1), stats.get(EventType.AUTHENTICATION_FAILURE), "Should have 1 authentication failure event");
        assertEquals(Long.valueOf(1), stats.get(EventType.FILE_ACCESS), "Should have 1 file access event");
    }

    @Test
    @DisplayName("Test reset statistics")
    void testResetStatistics() {

name: OSV-Scanner Scheduled Scan

on:
  schedule:
    - cron: 0 4 * * 1

permissions:
  # Require writing security events to upload SARIF file to security tab
  security-events: write
  # Only need to read contents
  contents: read

jobs:
  scan-scheduled:
    if: github.repository == 'tensorflow/tensorflow'

  /**
   * Invoked when an event source has been accepted by the remote peer and may begin transmitting
   * events.
   */
  open fun onOpen(
    eventSource: EventSource,
    response: Response,
  ) {
  }

  /**
   * Invoked when a new event has been sent to the client.
   *
   * @param id The `id` line of the event, might be null.
   * @param type The `event` line of the event, might be null.

/// tip

Note that we're using async/await with the new `AsyncClient` - the request is asynchronous.

///

/// warning

If your application relies on lifespan events, the `AsyncClient` won't trigger these events. To ensure they are triggered, use `LifespanManager` from <a href="https://github.com/florimondmanca/asgi-lifespan#usage" class="external-link" target="_blank">florimondmanca/asgi-lifespan</a>.

///

https://yourapi.com/invoices/?callback_url=https://www.external.org/events
```

with a JSON body of:

```JSON
{
    "id": "2expen51ve",
    "customer": "Mr. Richie Rich",
    "total": "9999"
}
```

then *your API* will process the invoice, and at some point later, send a callback request to the `callback_url` (the *external API*):

```
https://www.external.org/events/invoices/2expen51ve
```

    name: Scorecards analysis
    runs-on: ubuntu-latest
    permissions:
      # Needed to upload the results to code-scanning dashboard.
      security-events: write
      # Needed to publish results and get a badge (see publish_results below).
      id-token: write

    steps:
      - name: "Checkout code"