@MockBean返回空对象
我正在尝试使用@MockBean；java 版本 11、Spring 框架版本 (5.3.8)、Spring Boot 版本 (2.5.1) 和 Junit Jupiter (5.7.2)。
@SpringBootTest
public class PostEventHandlerTest {
@MockBean
private AttachmentService attachmentService;
@Test
public void handlePostBeforeCreateTest() throws Exception {
Post post = new Post("First Post", "Post Added", null, null, "", "");
Mockito.when(attachmentService.storeFile("abc.txt", "")).thenReturn(new Attachment());
PostEventHandler postEventHandler = new PostEventHandler();
postEventHandler.handlePostBeforeCreate(post);
verify(attachmentService, times(1)).storeFile("abc.txt", "");
}
}
@Slf4j
@Component
@Configuration
@RepositoryEventHandler
public class PostEventHandler {
@Autowired
private AttachmentService attachmentService;
@Autowired
private PostRepository postRepository;
public void handlePostBeforeCreate(Post post) throws Exception {
...
/* Here attachmentService is found null when we execute above test*/
attachmentService.storeFile(fileName, content);
...
}
}
附件服务没有被模拟它返回 null
回答
我认为您误解了 Mocks 的用法。
它真的@MockBean创建了一个模拟（内部使用的Mockito）和看跌期权这个bean到应用程序上下文，以便可以将可用于注射剂等
但是，作为程序员，你有责任指定当你调用一个或另一个方法时，你期望从这个模拟返回什么。
所以，假设你AttachementService有一个方法String foo(int)：
public interface AttachementService { // or class
public String foo(int i);
}
您应该在 Mockito API 的帮助下指定期望：
@Test
public void handlePostBeforeCreateTest() throws Exception {
// note this line, its crucial
Mockito.when(attachmentService.foo(123)).thenReturn("Hello");
Post post = new Post("First Post", "Post Added", null, null, "", "");
PostEventHandler postEventHandler = new PostEventHandler();
postEventHandler.handlePostBeforeCreate(post);
verify(attachmentService, times(1)).storeFile("", null);
}
如果您不指定期望值并且您的被测代码foo在某个时候调用，则此方法调用将返回null