How do I use JUnit with Mockito for testing?

How do I use JUnit with Mockito for testing?

JUnit is a testing framework for Java, and Mockito is a mocking framework. You can use them together to create unit tests that isolate the code being tested.

Can you give me a simple example of a test using JUnit and Mockito?

Sure! Here's a basic example:

import static org.mockito.Mockito.*;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.junit.MockitoJUnitRunner;

@RunWith(MockitoJUnitRunner.class)
public class MyServiceTest {
    @Test
    public void testServiceMethod() {
        MyDependency mockDependency = mock(MyDependency.class);
        MyService service = new MyService(mockDependency);
        when(mockDependency.someMethod()).thenReturn("mocked value");

        String result = service.serviceMethod();

        assertEquals("expected value", result);
    }
}

This test mocks MyDependency and verifies the behavior of MyService.

What are some common pitfalls when using Mockito?

Common pitfalls include:

1. Not resetting mocks between tests, which can lead to unexpected behavior.
2. Overusing mocks instead of real objects, which can make tests less meaningful.
3. Forgetting to verify interactions with mocks, which can result in tests that pass but don't actually validate behavior.