Contents

1. 1. Spring如何对ApplicationEventPublisher进行Mock
   1. 1.1. 前言
   2. 1.2. 解决方案
   3. 1.3. 示例代码

Spring如何对ApplicationEventPublisher进行Mock

前言

Spring框架里，ApplicationEventPublisher默认是不能Mock的，因为ApplicationEventPublisher是一个复杂的Bean，不能简单的被Mock，会报错：

Failed to instantiate [org.springframework.context.ApplicationEventPublisher]: Specified class is an interface

GitHub上也有相关的Issue：ApplicationEventPublisher mocked with MockBean is not injected

解决方案

在GitHub上有一个解决方案：Make it possible to mock ApplicationEventPublisher

简单来说，就是构建一个TestConfiguration，启动时注入自定义的Mock publisher。

1. 创建一个TestConfiguration，覆盖默认的ApplicationEventPublisher:

   @TestConfiguration
   public class MockitoConfiguration {
   
   @Bean
   @Primary
   public ApplicationEventPublisher publisher() {
        return mock(ApplicationEventPublisher.class);
       }
   }
   

2. 测试类中使用@Import注解引入该配置：

   @RunWith(SpringRunner.class)
   @SpringBootTest(classes = PublisherApplication.class)
   @ActiveProfiles("dev")
   @Slf4j
   @Import(MockitoConfiguration.class)
   public class PublisherApplicationTests {
   }
   

3. 调用被测试方法，进行验证：

   @Test
   public void mock_publisher_ok() {
       MockitoAnnotations.openMocks(this);
   
       service.foo();
   
       verify(publisher).publishEvent(isA(FooEvent.class));
   }
   

4. 完整代码：

   @RunWith(SpringRunner.class)
   @SpringBootTest(classes = PublisherApplication.class)
   @ActiveProfiles("dev")
   @Slf4j
   @Import(MockitoConfiguration.class)
   public class PublisherApplicationTests {
   @Autowired
   @SpyBean
   private ApplicationEventPublisher publisher;
   @Autowired
   private BizService service;
   
   @Test
   public void mock_publisher_ok() {
       MockitoAnnotations.openMocks(this);
   
       service.foo();
   
       verify(publisher).publishEvent(isA(FooEvent.class));
       }
   }
   

示例代码

完整示例代码：Mock publisher