如何使用JUnit和Mockito测试void方法？

Question

My void method changes boolean variable value in the class. How do DI check that?

I have:

• mocked class object
• called the method with proper parameters
• checked the instance variable

But that doesn't change the value of instance variable. How do I do this?

ReferenceLettersBean rf = Mockito.mock(ReferenceLettersBean.class);
     rf.setBoolcheck(false);

Mockito.doNothing().when(rf).checkForDuplicates(anyString(),     anyString(), anyString());
         rf.checkForDuplicates("abcd@emal.com","abd@gmail.com","abcd@gmail.com");
assertEquals(true,rf.getBoolcheck());

Answer 1

• DON'T mock the class you are trying to test.
• DO mock the classes that interact with the class you are trying to test.

If you want to test that a field in aa class changes from false to true, what you really want to do is something like (I don't have your actual constructor, I'm just guessing):

SomeDependency dependency = mock(SomeDependency.class);

// Make a REAL ReferenceLettersBean
ReferenceLettersBean bean = new ReferenceLettersBean(dependency);

// now make your test
rf.checkForDuplicates("abcd@emal.com","abd@gmail.com","abcd@gmail.com");
assertEquals(true,rf.getBoolcheck());

Answer 2

This boolean value seems to be an internal state. This is not something you can directly test with unit tests unless you make it public or it is detectable by influencing the behavior of another method.