How to use PluginSwitch class of org.mockito.plugins package

Mockito has an isNull matcher, where you can pass in the name of the class. So if you need to use it with other matchers, the correct thing to do is

verify(client).method(eq("String"),isNull(Class<?>.class));

This is now deprecated, see the answer below for the new method - https://stackoverflow.com/a/41250852/1348

I changed TestCompile to androidTestCompile and it's worked without problems.

testCompile 'junit:junit:4.12'

to

androidTestCompile 'junit:junit:4.12'

Try View -> Tool Windows -> Maven projects, then click the blue icon in the top left of the tool window (Reimport all Maven projects). You should be able to find the dependencies in the project view, under external libraries.

If this does not work, there is probably something wrong with your maven config (pom.xml). Try mvn clean install from the command line see if it gives any errors.

This question is ancient, but Mockito v2.1.0+ now has a built-in feature for this.

verify(mock, description("This will print on failure")).someMethod("some arg");

More examples included from @Lambart's comment below:

verify(mock, times(10).description("This will print if the method isn't called 10 times")).someMethod("some arg");
verify(mock, never().description("This will print if someMethod is ever called")).someMethod("some arg");
verify(mock, atLeastOnce().description("This will print if someMethod is never called with any argument")).someMethod(anyString());

In this case do I need to write a captor for each argument in spite of the fact I need to capture only the first argument?

durron597's answer is correct—you do not need to capture all arguments if you want to capture one of them. One point of clarification, though: a call to ArgumentCaptor.capture() counts as a Mockito matcher, and in Mockito if you use a matcher for any method argument you do have to use a matcher for all arguments.

For a method yourMock.yourMethod(int, int, int) and an ArgumentCaptor<Integer> intCaptor:

/*  good: */  verify(yourMock).yourMethod(2, 3, 4);  // eq by default
/*  same: */  verify(yourMock).yourMethod(eq(2), eq(3), eq(4));

/*   BAD: */  verify(yourMock).yourMethod(intCaptor.capture(), 3, 4);
/* fixed: */  verify(yourMock).yourMethod(intCaptor.capture(), eq(3), eq(4));

These also work:

verify(yourMock).yourMethod(intCaptor.capture(), eq(5), otherIntCaptor.capture());
verify(yourMock).yourMethod(intCaptor.capture(), anyInt(), gt(9000));

To answer your question directly, you cannot use Mockito to stub a method called from the constructor. Mockito needs an instance of the class before you can begin mocking, and you haven't given yourself a way to create an instance for testing.

More generally, as mentioned in Effective Java item 17, you should not call overridable methods from constructors. If you do so, for instance, you could provide an override in a subclass that refers to a final field but that runs before the final field is set. It probably won't get you in trouble here, but it's a bad habit in Java.

Luckily, you can restructure your code to do this very easily:

public class MyClass {
  public MyClass() {
    this(true);
  }

  /** For testing. */
  MyClass(boolean runSetup) {
    if (runSetup) {
      setup();
    }
  }

  /* ... */
}

To make it even more obvious, you can make the one-parameter MyClass constructor private, and provide a public static factory method:

/* ... */
  public static MyClass createForTesting() {
    return new MyClass(false);
  }

  private MyClass(boolean runSetup) {
/* ... */

Though some developers think it is a bad practice to write any code in methods that is used mostly for tests, remember that you are in charge of the design of your code, and tests are one of few consumers you absolutely know you will need to accommodate. Though it's still a good idea to avoid explicit test setup in "production" code, creating extra methods or overloads for the sake of testing will usually make your code cleaner overall and can drastically improve your test coverage and readability.

Technically speaking both "mocks" and "spies" are a special kind of "test doubles".

Mockito is unfortunately making the distinction weird.

A mock in mockito is a normal mock in other mocking frameworks (allows you to stub invocations; that is, return specific values out of method calls).

A spy in mockito is a partial mock in other mocking frameworks (part of the object will be mocked and part will use real method invocations).

Use one, or more, ArgumentCaptors.

It is unclear what your types are here, but anyway. Let's suppose you have a mock which has a method doSomething() taking a Foo as an argument, then you do this:

final ArgumentCaptor<Foo> captor = ArgumentCaptor.forClass(Foo.class);

verify(mock).doSomething(captor.capture());

final Foo argument = captor.getValue();

// Test the argument

Also, it looks like your method returns void and you don't want it to do anything. Just write this:

doNothing().when(theMock).doSomething(any());

Since none of your classes are final, you can use "pure mockito" without resorting to PowerMockito:

final CacheWrapper wrapper = Mockito.spy(new CacheWrapper());

Mockito.doThrow(something)
    .when(wrapper).putInSharedMemory(Matchers.any(), Matchers.any());

Note that "method arguments" to a stub are in fact argument matchers; you can put specific values (if not "surrounded" by a specific method it will make a call to .equals()). So, you can guide the stub's behavior differently for different arguments.

Also, no need for any kind of .replay() with Mockito, which is very nice!

Finally, be aware that you can doCallRealMethod() as well. After that, it depends on your scenarios...

(note: last mockito version available on maven is 1.10.17 FWIW)