java如何在RestController类中模拟私有变量

Question

我正在用Spring做一些web单元测试。有没有一种方法可以模拟MyProcessor的实例，它是在@PostConstruct中设置的？我试过使用@MockBean，但它被设置为null，并且得到null指针异常

我正在使用一个工厂根据一些布尔标志实例化MyProcessor。但如果有一种完全不同的方法可以让我的测试更干净，我愿意接受各种想法

请注意，我使用的是Junit 5

public class Controller {

    private final AProcessorFactory factory;

    @Value("${tt.f.processor.async}")
    private boolean isAsync;

    private MyProcessor myProcessor;

    public Controller(final AProcessorFactory factory) {
        this.factory= factory;
    }

    @PostConstruct
    public void init() {
        myProcessor = factory.getInstance(isAsync);
    }

}


@WebMvcTest(Controller.class)
public class ControllerTest{

    @MockBean
    private MyProcessor processor;


    @MockBean
    private AProcessorFactory factory;

    @Autowired
    private MockMvc mockMvc;


    @Test
    public void test() throws Exception {           

        when(processor.process(any(Request.class), any(String.class)))
                .thenReturn(new TestResponse("123", SUCCESS, "", ""));

}

Answer 1

看起来myProcessor实际上是由AProcessorFactory在PostConstruct init（）方法中构建的

您需要为AProcessorFactorymock提供一个行为

首先，您可能希望在构造函数中设置myProcessor，因为@PostConstruct{}方法没有特殊的上下文加载逻辑

public class Controller {

    @Value("${tt.f.processor.async}")
    private boolean isAsync;

    private MyProcessor myProcessor;

    public Controller(final AProcessorFactory factory) {
        this.myProcessor = factory.getInstance(isAsync);
    }
}

您可以在测试的@Before步骤中指定这一点

 @MockBean
 private AProcessorFactory factory;

 @Before
 public void setUp() {
     when(processor.process(any(Request.class), any(String.class)))
            .thenReturn(new TestResponse("123", SUCCESS, "", ""));
     when(factory.getInstance(any())).thenReturn(processor)
 }

Spring将注册已加载适当行为的ProcessorFactory模拟