Spring JUnit:如何在自动装配的组件中模拟自动装配的组件

Question

我有一个我想测试的Spring组件,这个组件有一个autowired属性,我需要更改它以进行单元测试.问题是,该类在后构造方法中使用自动装配的组件,因此在实际使用之前我无法替换它(即通过ReflectionTestUtils).

我该怎么办？

这是我要测试的类:

@Component
public final class TestedClass{

    @Autowired
    private Resource resource;

    @PostConstruct
    private void init(){
        //I need this to return different result
        resource.getSomething();
    }
}

这是测试用例的基础:

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations= "classpath:applicationContext.xml")
public class TestedClassTest{

    @Autowired
    private TestedClass instance;

    @Before
    private void setUp(){
        //this doesn't work because it's executed after the bean is instantiated
        ReflectionTestUtils.setField(instance, "resource", new Resource("something"));
    }
}

在调用postconstruct方法之前,有没有办法用其他东西替换资源？想告诉Spring JUnit跑步者自动装配不同的实例？

Answer 1

你可以使用Mockito.我不确定PostConstruct具体,但这通常有效:

// Create a mock of Resource to change its behaviour for testing
@Mock
private Resource resource;

// Testing instance, mocked `resource` should be injected here 
@InjectMocks
@Resource
private TestedClass testedClass;

@Before
public void setUp() throws Exception {
    // Initialize mocks created above
    MockitoAnnotations.initMocks(this);
    // Change behaviour of `resource`
    when(resource.getSomething()).thenReturn("Foo");   
}

Answer 2

Spring Boot 1.4引入了测试注释@MockBean.因此,Spring Boot本身支持对Spring bean进行模拟和监视.

Answer 3

您可以提供一个新的testContext.xml,@Autowired您定义的bean是您测试所需的类型.

Answer 4

我创建了关于该主题的博客文章.它还包含带有工作示例的Github存储库的链接.

诀窍是使用测试配置,你可以用假的覆盖原始的spring bean.你可以使用@Primary和@Profile注释这个技巧.

Answer 5

您可以使用spring-reinject https://github.com/sgri/spring-reinject/使用模拟覆盖bean定义

Answer 6

集成测试的另一种方法是定义一个新的 Configuration 类并将其作为您的@ContextConfiguration. 在配置中，您将能够模拟您的 bean，并且您还必须定义在测试流程中使用的所有类型的 bean。举个例子：

@RunWith(SpringRunner.class)
@ContextConfiguration(loader = AnnotationConfigContextLoader.class)
public class MockTest{
 @Configuration
 static class ContextConfiguration{
 // ... you beans here used in test flow
 @Bean
    public MockMvc mockMvc() {
        return MockMvcBuilders.standaloneSetup(/*you can declare your controller beans defines on top*/)
                .addFilters(/*optionally filters*/).build();
    }
 //Defined a mocked bean
 @Bean
    public MyService myMockedService() {
        return Mockito.mock(MyService.class);
    }
 }

 @Autowired
 private MockMvc mockMvc;

 @Autowired
 MyService myMockedService;

 @Before
 public void setup(){
  //mock your methods from MyService bean 
  when(myMockedService.myMethod(/*params*/)).thenReturn(/*my answer*/);
 }

 @Test
 public void test(){
  //test your controller which trigger the method from MyService
  MvcResult result = mockMvc.perform(get(CONTROLLER_URL)).andReturn();
  // do your asserts to verify
 }
}