How to use successIfEveryThreadHasItsOwnMock method of org.mockitousage.bugs.ShouldNotDeadlockAnswerExecutionTest class

@Spy and @InjectMocks cannot be used well together (see Google Code issue #489 and GitHub issue #169), and for what they do it is not clear or common that they should be used together at all. In well-written Mockito usage, you generally should not even want to apply them to the same object.

• @InjectMocks works as a sort of stand-in dependency injection for the system under test: If you have a test that defines a @Mock or @Spy of the right type, Mockito will initialize any fields in your @InjectMocks instance with the contents of those test fields. This might be handy if you haven't otherwise structured your system-under-test for dependency injection (or if you use a DI framework that does field injection) and you want to replace those dependencies with mocks. It can be pretty fragile—unmatched fields will be silently ignored and will remain null if not set in an initializer—but remains a decent annotation for your system under test.

• @Spy, like @Mock, is designed to set up test doubles; you should use it when you have a collaborator that you want to stub or verify. Though there are cases where you could spy on your system under test, @Spy and @Mock are meant for dependencies, and not for the functionality you are testing.

Ideally, you should not have any class that fulfills both roles in the same test, or else you may find yourself writing a test that painstakingly tests behavior that you've stubbed rather than actual production behavior. In any case it will be more difficult to tell exactly what the test covers versus the behavior you've stubbed.

Of course, this may not apply if you're trying to use Mockito to test a single method in isolation, and you want to stub calls to one method while testing the other. This can be accomplished by creating a spy of your system-under-test and mocking some of its methods to avoid calling collaborators. However, this might also be an indication that your class is violating the Single Responsibility Principle, and that you should break down the class into multiple independent classes that work together. Then, in your test, you can allow instances to have exactly one role and never need both annotations at once.

You need to replace the code inside the infinite loop with a function.

You then write a unit test for that function.

I ran into this yesterday, for spies is best to do:

doReturn(X).when(spy).method(any())

I read this question and the issue carefully but not sure if I understood them clearly - From my understanding, it's correct that powermock raise the exception when you pass k and x but only verify k.

Because you are mocking the static method StaticObj.put, when you pass parameter k and x and verify it with

PowerMockito.verifyStatic(times(1));
StaticObj.put("k1", "k1");

PowerMockito.verifyStatic(times(1));
StaticObj.put("x1", "x"); 

This should work. And when you verify parameter k and x with verification for k is commented out.

// PowerMockito.verifyStatic(times(1));
// StaticObj.put("k1", "k1");

PowerMockito.verifyStatic(times(1));
StaticObj.put("x1", "x");

Powermock will get the invocation with put("k1"...) first apparently, so the verification of x will raise an error. Your verification process is sequenced.

Wiremock provides a simulator for HTTP-based APIs while Mockito provides the mock implementation of the method/object.

If we are using Mockito to mock HTTP-based method, it means we are trying to return the object/response without testing any code to invoke REST service, getting HTTP response and deserializing the same.

If we use the Wiremock, we will able to test close to reality as it will test invocation of REST call as well as deserialization of the response.

https://www.linkedin.com/pulse/what-difference-between-stub-mock-virtual-service-wojciech-bulaty/ is one good article to read, of course not by me :-)

I think what you are trying to test is aspect weaving and pointcut matching. Please note that that would be an integration rather than a unit test. If you really want to unit test your aspect logic and because you have tagged the question by "mockito" anyway, I suggest you do just that: Write a unit test and mock the aspect's joinpoint and maybe its other parameters, if any. Here is a slightly more complex example with some intra-aspect logic:

Java class to be targeted by aspect:

package de.scrum_master.app;

public class Application {
    public static void main(String[] args) {
        new Application().doSomething(11);
        new Application().doSomething(-22);
        new Application().doSomething(333);
    }

    public void doSomething(int number) {
        System.out.println("Doing something with number " + number);
    }
}

Aspect under test:

package de.scrum_master.aspect;

import org.aspectj.lang.ProceedingJoinPoint;
import org.aspectj.lang.annotation.Around;
import org.aspectj.lang.annotation.Aspect;

@Aspect
public class SampleAspect {
    @Around("execution(* doSomething(int)) && args(number)")
    public Object intercept(final ProceedingJoinPoint thisJoinPoint, int number) throws Throwable {
        System.out.println(thisJoinPoint + " -> " + number);
        if (number < 0)
            return thisJoinPoint.proceed(new Object[] { -number });
        if (number > 99)
            throw new RuntimeException("oops");
        return thisJoinPoint.proceed();
    }
}

Console log when running Application.main(..):

As you can see, the aspect passes on 11, negates -22 and throws an exception for 333:

execution(void de.scrum_master.app.Application.doSomething(int)) -> 11
Doing something with number 11
execution(void de.scrum_master.app.Application.doSomething(int)) -> -22
Doing something with number 22
execution(void de.scrum_master.app.Application.doSomething(int)) -> 333
Exception in thread "main" java.lang.RuntimeException: oops
    at de.scrum_master.aspect.SampleAspect.intercept(SampleAspect.aj:15)
    at de.scrum_master.app.Application.doSomething(Application.java:10)
    at de.scrum_master.app.Application.main(Application.java:7)

Unit test for aspect:

Now we really want to verify that the aspect does what it should and cover all execution paths:

package de.scrum_master.aspect;

import org.aspectj.lang.ProceedingJoinPoint;
import org.junit.Rule;
import org.junit.Test;
import org.mockito.Mock;
import org.mockito.junit.MockitoJUnit;
import org.mockito.junit.MockitoRule;

import static org.mockito.Mockito.*;

public class SampleAspectTest {
    @Rule
    public MockitoRule mockitoRule = MockitoJUnit.rule();

    @Mock
    private ProceedingJoinPoint proceedingJoinPoint;

    private SampleAspect sampleAspect = new SampleAspect();

    @Test
    public void testPositiveSmallNumber() throws Throwable {
        sampleAspect.intercept(proceedingJoinPoint, 11);
        // 'proceed()' is called exactly once
        verify(proceedingJoinPoint, times(1)).proceed();
        // 'proceed(Object[])' is never called
        verify(proceedingJoinPoint, never()).proceed(null);
    }

    @Test
    public void testNegativeNumber() throws Throwable {
        sampleAspect.intercept(proceedingJoinPoint, -22);
        // 'proceed()' is never called
        verify(proceedingJoinPoint, never()).proceed();
        // 'proceed(Object[])' is called exactly once
        verify(proceedingJoinPoint, times(1)).proceed(new Object[] { 22 });
    }

    @Test(expected = RuntimeException.class)
    public void testPositiveLargeNumber() throws Throwable {
        sampleAspect.intercept(proceedingJoinPoint, 333);
    }
}

Now run this simple JUnit + Mockito test in order to test the aspect logic in isolation, not the wiring/weaving logic. For the latter you would need another type of test.

P.S.: Only for you I used JUnit and Mockito. Usually I just use Spock and its built-in mocking capabilities. ;-)

You can chain doReturn() method calls:

doReturn(true).doReturn(true).doReturn(false).when(rs).next();

Or, as mentioned in the comments, chain thenReturn method calls:

when(rs.next()).thenReturn(true).thenReturn(true).thenReturn(false);

Or, if you want to take things even further, you can use Mockito Answers:

when(rs.next()).thenAnswer(new Answer() {
    private int iterations = 2;

    Object answer(InvocationOnMock invocation) {
        return iterations-- > 0;
    }
});

The error message you are getting is expected since you are using argument matcher for only one argument and not the other. From Matchers Javadoc:

If you are using argument matchers, all arguments have to be provided by matchers.

Therefore, the fix is to use a matcher for the second parameter of the method as well. In this case, it would be a matcher matching null. Depending on the version of Mockito and Java, you can have:

• Starting with Mockito 2, you can use ArgumentMatchers.isNull(). This works with Java 8 and above:

  verify(objectDemo, times(1)).objectDemoMethod(any(String.class), isNull());
  

  Note that if you're running with Java 7 or older, you'll need an explicit cast to make this work, because the type inference in those versions of Java does not take into account the types of the method called:

  verify(objectDemo, times(1)).objectDemoMethod(any(String.class), (String) isNull());
  

• If you're using Mockito 1, you can use the Matchers.isNull(clazz) instead:

  verify(objectDemo, times(1)).objectDemoMethod(any(String.class), isNull(String.class));
  

For the Java ≤ 7 or Mockito 1 cases, the examples uses a case where the second parameter was of type String: it would need to be replaced with the actual type of the method parameter.

If there is a lot of such methods, the thing which you might want to test here is that updateScreen() uses the right string, "some-command-green" and that the System.out is being invoked. In order to do this you might want to extract System.out into an object field and mock it (i.e. with Mockito's spy()) to test the string that was provided to println.

I.e.

class MyClass{
     PrintStream out = System.out;

     public void updateGreen() { ... }
}

In test:

@Test
public void testUpdate(){
     MyClass myClass = new MyClass();
     myClass.out = Mockito.spy(new PrintStream(...));

     // mock a call with an expected input
     doNothing().when(myClass.out).println("expected command");

     myClass.updateGreen();

     // test that there was a call
     Mockito.verify(myClass.out, Mockito.times(1)).println("expected command");
}