This version is still in development and is not considered stable yet. For the latest stable version, please use Spring Framework 6.2.10!

Application Events

The TestContext framework provides support for recording application events published in the ApplicationContext so that assertions can be performed against those events within tests. All events published during the execution of a single test are made available via the ApplicationEvents API which allows you to process the events as a java.util.Stream.

To use ApplicationEvents in your tests, do the following.

  • Ensure that your test class is annotated or meta-annotated with @RecordApplicationEvents.

  • Ensure that the ApplicationEventsTestExecutionListener is registered. Note, however, that ApplicationEventsTestExecutionListener is registered by default and only needs to be manually registered if you have custom configuration via @TestExecutionListeners that does not include the default listeners.

  • When using the SpringExtension for JUnit Jupiter, declare a method parameter of type ApplicationEvents in a @Test, @BeforeEach, or @AfterEach method.

    • Since ApplicationEvents is scoped to the lifecycle of the current test method, this is the recommended approach.

  • Alternatively, you can annotate a field of type ApplicationEvents with @Autowired and use that instance of ApplicationEvents in your test and lifecycle methods.

ApplicationEvents is registered with the ApplicationContext as a resolvable dependency which is scoped to the lifecycle of the current test method. Consequently, ApplicationEvents cannot be accessed outside the lifecycle of a test method and cannot be @Autowired into the constructor of a test class.

The following test class uses the SpringExtension for JUnit Jupiter and AssertJ to assert the types of application events published while invoking a method in a Spring-managed component:

  • Java

  • Kotlin

@SpringJUnitConfig(/* ... */)
@RecordApplicationEvents (1)
class OrderServiceTests {

	@Test
	void submitOrder(@Autowired OrderService service, ApplicationEvents events) { (2)
		// Invoke method in OrderService that publishes an event
		service.submitOrder(new Order(/* ... */));
		// Verify that an OrderSubmitted event was published
		long numEvents = events.stream(OrderSubmitted.class).count(); (3)
		assertThat(numEvents).isEqualTo(1);
	}
}
1 Annotate the test class with @RecordApplicationEvents.
2 Inject the ApplicationEvents instance for the current test.
3 Use the ApplicationEvents API to count how many OrderSubmitted events were published. 
@SpringJUnitConfig(/* ... */)
@RecordApplicationEvents (1)
class OrderServiceTests {

	@Test
	fun submitOrder(@Autowired service: OrderService, events: ApplicationEvents) { (2)
		// Invoke method in OrderService that publishes an event
		service.submitOrder(Order(/* ... */))
		// Verify that an OrderSubmitted event was published
		val numEvents = events.stream(OrderSubmitted::class).count() (3)
		assertThat(numEvents).isEqualTo(1)
	}
}
1 Annotate the test class with @RecordApplicationEvents.
2 Inject the ApplicationEvents instance for the current test.
3 Use the ApplicationEvents API to count how many OrderSubmitted events were published.

See the ApplicationEvents javadoc for further details regarding the ApplicationEvents API.