spring-framework

Spring Framework

Sam Brannen 1565f4b83e Introduce ApplicationEvents to assert events published during tests This commit introduces a new feature in the Spring TestContext Framework (TCF) that 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 one to process the events as a java.util.Stream. The following example demonstrates usage of this new feature. @SpringJUnitConfig(/* ... /) @RecordApplicationEvents class OrderServiceTests { @Autowired OrderService orderService; @Autowired ApplicationEvents events; @Test void submitOrder() { // Invoke method in OrderService that publishes an event orderService.submitOrder(new Order(/ ... */)); // Verify that an OrderSubmitted event was published int numEvents = events.stream(OrderSubmitted.class).count(); assertThat(numEvents).isEqualTo(1); } } To enable the feature, a test class must be annotated or meta-annotated with @RecordApplicationEvents. Behind the scenes, a new ApplicationEventsTestExecutionListener manages the registration of ApplicationEvents for the current thread at various points within the test execution lifecycle and makes the current instance of ApplicationEvents available to tests via an @Autowired field in the test class. The latter is made possible by a custom ObjectFactory that is registered as a "resolvable dependency". Thanks to the magic of ObjectFactoryDelegatingInvocationHandler in the spring-beans module, the ApplicationEvents instance injected into test classes is effectively a scoped-proxy that always accesses the ApplicationEvents managed for the current test. The current ApplicationEvents instance is stored in a ThreadLocal variable which is made available in the ApplicationEventsHolder. Although this class is public, it is only intended for use within the TCF or in the implementation of third-party extensions. ApplicationEventsApplicationListener is responsible for listening to all application events and recording them in the current ApplicationEvents instance. A single ApplicationEventsApplicationListener is registered with the test's ApplicationContext by the ApplicationEventsTestExecutionListener. The SpringExtension has also been updated to support parameters of type ApplicationEvents via the JUnit Jupiter ParameterResolver extension API. This allows JUnit Jupiter based tests to receive access to the current ApplicationEvents via test and lifecycle method parameters as an alternative to @Autowired fields in the test class. Closes gh-25616	5 years ago
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main	Introduce ApplicationEvents to assert events published during tests	5 years ago
test	Introduce ApplicationEvents to assert events published during tests	5 years ago

Sam Brannen 1565f4b83e Introduce ApplicationEvents to assert events published during tests

This commit introduces a new feature in the Spring TestContext
Framework (TCF) that 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 one to process the events as a java.util.Stream.

The following example demonstrates usage of this new feature.

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

    @Autowired
    OrderService orderService;

    @Autowired
    ApplicationEvents events;

    @Test
    void submitOrder() {
        // Invoke method in OrderService that publishes an event
        orderService.submitOrder(new Order(/* ... */));
        // Verify that an OrderSubmitted event was published
        int numEvents = events.stream(OrderSubmitted.class).count();
        assertThat(numEvents).isEqualTo(1);
    }
}

To enable the feature, a test class must be annotated or meta-annotated
with @RecordApplicationEvents. Behind the scenes, a new
ApplicationEventsTestExecutionListener manages the registration of
ApplicationEvents for the current thread at various points within the
test execution lifecycle and makes the current instance of
ApplicationEvents available to tests via an @Autowired field in the
test class. The latter is made possible by a custom ObjectFactory that
is registered as a "resolvable dependency". Thanks to the magic of
ObjectFactoryDelegatingInvocationHandler in the spring-beans module,
the ApplicationEvents instance injected into test classes is
effectively a scoped-proxy that always accesses the ApplicationEvents
managed for the current test.

The current ApplicationEvents instance is stored in a ThreadLocal
variable which is made available in the ApplicationEventsHolder.
Although this class is public, it is only intended for use within the
TCF or in the implementation of third-party extensions.

ApplicationEventsApplicationListener is responsible for listening to
all application events and recording them in the current
ApplicationEvents instance. A single
ApplicationEventsApplicationListener is registered with the test's
ApplicationContext by the ApplicationEventsTestExecutionListener.

The SpringExtension has also been updated to support parameters of type
ApplicationEvents via the JUnit Jupiter ParameterResolver extension
API. This allows JUnit Jupiter based tests to receive access to the
current ApplicationEvents via test and lifecycle method parameters as
an alternative to @Autowired fields in the test class.

Closes gh-25616

5 years ago

main

Introduce ApplicationEvents to assert events published during tests

5 years ago

test

Introduce ApplicationEvents to assert events published during tests

5 years ago