外部模拟方法在实际类中返回Null

Question

当我测试模拟外部调用时，我没有看到报告的模拟值，而是Null，我的测试失败了。我可以在测试类中看到模拟值(报告)，但在BusinessServiceImpl类中看不到，应用程序(方法返回)没有按照我的预期进行修改。

我的期望:当我在Impl类中模拟外部调用时，模拟值应该在那里可用，其余的一切都应该发生，就像调用真正的方法来完成单元测试一样。

实现代码:

package com.core.business.service.dp.fulfillment;
import com.core.business.service.dp.payment.PaymentBusinessService;
public class BusinessServiceImpl implements BusinessService { // Actual Impl Class
    private PaymentBusinessService paymentBusinessService = PluginSystem.INSTANCE.getPluginInjector().getInstance(PaymentBusinessService.class);
    @Transactional( rollbackOn = Throwable.class)
    public Application  applicationValidation (final Deal deal) throws BasePersistenceException {
        Application application = (Application) ApplicationDTOFactory.eINSTANCE.createApplication();
        //External Call we want to Mock
        String report = paymentBusinessService.checkForCreditCardReport(deal.getId());
        if (report != null) {
            application.settingSomething(true); //report is Null and hence not reaching here
        }
        return application;
    }
}

测试代码:

@Test(enabled = true)// Test Class
public void testReCalculatePrepaids() throws Exception {
    PaymentBusinessService paymentBusinessService = mock(PaymentBusinessService.class);
    //Mocking External Call
    when(paymentBusinessService.checkForCreditCardReport(this.deal.getId())).thenReturn(new String ("Decline by only Me"));
    String report = paymentBusinessService.checkForCreditCardReport(this.deal.getId());
    // Mocked value of report available here
    //Calling Impl Class whose one external call is mocked
    //Application is not modified as expected since report is Null in Impl class
    Application sc = BusinessService.applicationValidation(this.deal);
}

Answer 1

Mockito的主要目的是隔离测试。在测试BusinessServiceImpl时，应该模拟它的所有依赖项。

这正是你在上面的例子中想要做的。现在要使mock 起作用，必须将mock对象注入您要测试的类中，在本例中为BusinessServiceImpl。

一种方法是通过类的构造器传递依赖项，即依赖注入。或者你可以看看Spring和ReflectionTestUtils是如何做到的。

Answer 2

我完成了它，我成功地获得了mock值，而完全没有触及BusinessServiceImpl类。我遵循的步骤是:1. @Mock PaymentBusinessService = mock(PaymentBusinessService.class);2. @ injectmock private PaymentBusinessService = PluginSystem.INSTANCE.getPluginInjector().getInstance(PaymentBusinessService.class);

然后简单地运行上面的测试，我可以在BusinessServiceImpl中看到报告的值为"Decline by only Me"，我的测试用例通过了