@Value 变量在使用 @TestPropertySource 的单元测试中为 NULL

在下面的单元测试中，我手动提供属性并尝试从现有的 YAML 资源文件中读取它们（尝试了不同的策略）@TestPropertySource), the @Value{..}属性未设置，我总是为它们获取 NULL：

@SpringBootConfiguration
@RunWith(SpringJUnit4ClassRunner.class)
@TestPropertySource(properties = {
        "eligible_filename = xyz"
})
@ExtendWith(MockitoExtension.class)
public class AppServiceTest {
    
    @Value("${eligible_filename}") // This var is always NULL

也

@SpringBootConfiguration
@RunWith(SpringJUnit4ClassRunner.class)
@TestPropertySource(properties = "application-test.yaml") /* File exists, also tried resources/application-test.yaml */
@ExtendWith(MockitoExtension.class)
public class AppServiceTest {
    
    @Value("${eligible_filename}") // This var is always NULL

这就是我最终决定的。我们must use @SpringBootTest加载测试属性（application-test.yaml）并得到@Value(..)，但不幸的是这会导致整个应用程序运行。要屏蔽正在使用的真实对象并替换模拟对象，我们可以使用@SpringBootTest with @Import(SomeConfiguration.class)如下。这将使模拟对象在运行时被拾取@SpringBootTest test:

@SpringBootTest
@Import(value = {MockAppServiceConfiguration.class, 
                 MockEmailServiceConfiguration.class}) // etc. any other mocked objects
public class MyTest {
}

模拟服务配置示例：

public class MockEmailServiceConfiguration {
    
    // Replace with mock EmailService when running full-application @SpringBootTest tests
    @Bean
    public EmailService emailService(){
        return new EmailService() {
           //... Override any service methods with a mock result (no real processing)
        }

现在您可以运行测试，而无需连接真实的对象。但由于我们仍然需要对实际的服务类进行单元测试，因此我手动创建自己的 Service 对象并对其进行 Mockito 测试openMocks / @Mock / @InjectMocks)。这是测试实际服务类的第 2 部分：

@SpringBootTest
@Import(value = {MockAr11ApplicationServiceConfiguration.class, /* Prevent the loading of the real Ar11ApplicationService during @SpringBootTest's full-application launch */
                 MockEmailServiceConfiguration.class}) /* Prevent the loading of the real EmailService during @SpringBootTest's full-application launch */
@ExtendWith(MockitoExtension.class)
public class Ar11ApplicationServiceTest {
    
    // Custom object to be constructed for unit testing, includes DAO sub-object via InjectMocks
    @InjectMocks
    Ar11ApplicationServiceImpl ar11ApplicationServiceImpl;
    // Custom DAO sub-object to be constructed for this unit test via Mock
    @Mock
    private Ar11ApplicationDAO ar11ApplicationDAO;

    @BeforeEach
    void setUp() throws Exception {
        // Manually construct/wire my own custom objects for unit testing
        ar11ApplicationServiceImpl = new Ar11ApplicationServiceImpl();
        ar11ApplicationDAO = new Ar11ApplicationDAO();
        ar11ApplicationServiceImpl.setAr11ApplicationDAO(ar11ApplicationDAO);
        MockitoAnnotations.openMocks(this);

        // Set up mock behaviors for the DAO sub-object with when/then
        when(ar11ApplicationDAO.method(filename)).thenReturn(..)
        doNothing().when(ar11ApplicationDAO).voidMethod(params);