How do I test a void method using JUnit and Mockito?

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("[email protected]","[email protected]","[email protected]");
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 a a 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("[email protected]","[email protected]","[email protected]");
assertEquals(true,rf.getBoolcheck());