编写可测试代码. Junit测试

Question

目前正在进行一个项目，该项目要求我为我实现的所有代码编写单元测试。我刚开始编写单元测试，最近我学到了使用@MockBeans、@InjectMocks、@Spy等注释编写测试用例的知识，以帮助我测试特定的方法。

然而，有时我确实为编写无法模拟的测试用例而挣扎，最终它变成了一个集成测试。下面是我在编写测试用例时遇到的一些场景。

服务层的

1. 单元测试最终成为一个集成测试，因为它与回购层交互。

- The repo layer returns a list of Tuple (`javax.persistence.tuple`) back to the service layer.
- Mocked the repo layer, no issue on that.
- Tried creating the list of Tuple that was supposed to be returned when the repo layer is called through Mockito.when(), however, I could not create the list of tuple as it does not have any setter method.
- Ended up with a unit test that performing the actual query to the database to retrieve the values out which makes the unit test more like an integration test.

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1. 是一种包含工厂方法调用的方法。工厂类作为静态类编写，返回的具体类随后使用AutowireCapableBeanFactory

自动写入spring上下文中。

- Since I could not mock a static factory, I just pass in the value into the factory and let it return the concrete class accordingly. 
- The concrete class returned by the factory could not be mocked.
- The unit test would end up testing the concrete class as well.

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1. 实例化一个新类的方法，它使用new ConcreteClass()而不是@Autowired.

来实例化一个新类

- I think this is similar to the 2nd scenario I mentioned above.
- @MockBeans will not work here since the concrete class is not created using @Autowired.

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这就是我目前面临的场景，我花了很多时间试图找出编写测试用例的正确方法，或者更确切地说，我应该如何设计代码以避免所有这些问题？感谢您对这些场景的反馈和帮助，以改进我编写单元测试或代码设计的方式，使其更具可测试性！

Answer 1

1. 您可以使用PowerMockito来模拟新对象的创建。

.withAnyArguments().thenReturn(concreteObject);

• Reflection可以用来模拟工厂类。