unit-test-application-events

Testing Spring ApplicationEvent publishers and listeners with mocked dependencies and event capture patterns. Provides actionable patterns for testing Spring ApplicationEvent publishers and @EventListener consumers using JUnit 5 and Mockito — without booting the full Spring context. - Mock ApplicationEventPublisher in unit tests and use ArgumentCaptor to verify published events and their data integrity - Test @EventListener method invocation directly by instantiating listeners and invoking handler methods with captured events - Handle asynchronous event processing with Thread.sleep() or Awaitility to verify async listener completion - Verify listener side effects on mocked dependencies and test error handling in both publishers and listeners - Writing unit tests for event publishers or listeners - Verifying that an event was published with correct payload - Testing @EventListener method invocation and side effects - Testing event propagation through multiple listeners - Validating async event handling ( @Async + @EventListener ) - Mocking ApplicationEventPublisher in service tests - Add test dependencies : spring-boot-starter , JUnit 5, Mockito, AssertJ - Mock ApplicationEventPublisher : use @Mock on the publisher field in the service under test - Capture events with ArgumentCaptor : ArgumentCaptor.forClass(EventType.class) to inspect published payload - Verify listener side...