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Since Spring Boot 3.4.0, @MockBean and @SpyBean annotations in spring-boot-test are deprecated (#39860). In favor of @MockitoBean and @MockitoSpyBean annotations from spring-test.

Bean Overriding in Tests

The Spring team discourages developers from using bean overriding. In Spring Boot 2.1, Bean overriding has been disabled by default. However, in integration tests, developers may need to override some beans in the ApplicationContext, either to mock them or to provide a different implementation.

In Spring Framework 6.2, they implemented a mechanism to override beans in integration tests.

Two implementations of this bean overriding mechanism are provided:

  • A generic @TestBean annotation that allows the override of a bean with a static 0-argument factory method.
  • A Mockito-based implementation with two annotations @MockitoBean and @MockitoSpyBean.

The bean override mechanism can be extended with custom implementations (as explained at the end of this blog post).

@MockitoBean and @MockitoSpyBean

The two annotations will replace @MockBean and @SpyBean. However, they do not provide the same features. For example :

  • @MockitoBean is not supported on @Configuration class unlike @MockBean (#33934).
  • @MockitoBean is not supported in @Component class unlike @MockBean (#34415).

However, the Spring team continues to improve the new annotations with existing @MockBean features. For example, they added @Primary support (#33819), class-level @MockitoBean support (#33925)…

Both annotation sets rely on BeanFactoryPostProcessor to register and replace bean definitions in the spring context.

⚠ Mock annotations and Spring context in tests
Like @MockBean and @SpyBean, the new annotations modify the ApplicationContext to override beans. Thus, there has been no improvement in the context’s cache management. Spring context cannot be cached between tests that don’t share the same mocks.

Conclusion

Spring now offers a proper, extensible, and unified way of overriding beans in tests directly in the Spring framework.

As explained by the team, @MockitoBean and @MockitoSpyBean are not a “simple 1-1 replacement” for @MockBean and @SpyBean. While differences remain, the Spring team has actively incorporated community feedback enhancing the new annotations.

References