如何告诉被测对象使用模拟而不是其自己的变量 [英] How to tell the subject under test to use the mock instead of its own variable

问题描述

我正在尝试测试LoginPresenter，并且我正在使用Mockito进行模拟. Mockito不允许我verify在SUT上进行方法调用，因此我必须模拟其依赖项，并且verify他们的方法已由LoginPresenter调用.

I am trying to test a LoginPresenter, and I am using Mockito for the mocks. Mockito doesnt let me verify a method invocation on the SUT so I have to mock its dependencies and verify their methods have been called by the LoginPresenter.

我遇到以下情况:

LoginPresenter有一个名为attemptLogin的方法:

LoginPresenter has a method called attemptLogin:

private void attemptLogin(String username, String password) {
    new LoginNetworkOperation(username, password).execute();
}

我必须模拟LoginNetworkOperation并使用Mockito和verify在execute()上的方法调用.

I have to mock LoginNetworkOperation and using Mockito, verify the method invocation on execute().

@Test
public void testWhenUserNameAndPasswordAreEnteredShouldAttemptLogin() throws Exception {
    LoginView loginView = Mockito.mock(LoginView.class);
    LoginNetworkOperation loginNetworkOperation = Mockito.mock(LoginNetworkOperation.class);
    Mockito.when(loginView.getUserName()).thenReturn("George");
    Mockito.when(loginView.getPassword()).thenReturn("aaaaaa");
    loginPresenter.setLoginView(loginView);
    loginPresenter.onLoginClicked();
    Mockito.verify(loginNetworkOperation.execute());
}

但是，我如何让LoginPresenter使用模拟的LoginNetworkOperation而不是它在attemptLogin方法中创建的那个?我需要更改LoginPresenter的设计以使用成员变量，并为其提供一个setter，这是次优的，因为该方法中的局部变量很多，因为该变量仅在其中使用.

However, how do I make LoginPresenter use the mocked LoginNetworkOperation instead of the one it creates in the attemptLogin method? I need to change the design of LoginPresenter to use a member variable, and provide a setter for it, which is suboptimal because a local variable in the method is plenty, as it is used only there.

我要把这整个事情弄错了吗?

Am I going about this whole thing wrong?

最初，我想验证是否调用了LoginPresenter的attemptLogin，但是Mockito只能验证模拟对象的方法，并且我无法监视LoginPresenter，因为它是最终的(由AndroidAnnotations生成)

Initially, I wanted to verify that LoginPresenter's attemptLogin is called, but Mockito can only verify mocked objects' methods and I cannot spy on LoginPresenter because it is final (generated by AndroidAnnotations)

推荐答案

我在此视频中找到了答案: https://www.youtube.com/watch?v=wEhu57pih5w

I found the answer in this video: https://www.youtube.com/watch?v=wEhu57pih5w

最大的收获是:不要将对象创建逻辑与业务逻辑混在一起 这意味着不要实例化方法或构造函数中的对象(可能改用DI)，因为无论何时调用SUT的构造函数或方法(绑定到new关键字)，测试代码都无法控制链式反应的开始时间

The biggest takeaway is: don't mix object creation logic with business logic which means don't instantiate objects in methods or constructors (probably use DI instead), because the test code has no power over what chain-reaction starts whenever a SUT's constructor or a method is called, that is bound to a new keyword.

这意味着在我的情况下，LoginPresenter不应该负责创建LoginNetworkOperation对象，而应该从外部获取它

That means that in my case, the LoginPresenter shouldn't be responsible for creating the LoginNetworkOperation object but should take it from the outside

这样，我将能够告诉它使用模拟而不是具体的实现，因此，我将能够进行测试

That way I will be able to tell it to use the mock instead of the concrete implementation, and thus, I will be able to do my tests

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