mockito Getting started with mockito Simple minimal Mockito Test

Example

This example shows a minimal Mockito test using a mocked ArrayList:

import static org.mockito.Mockito.*;
import static org.junit.Assert.*;

import java.util.ArrayList;

import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.runners.MockitoJUnitRunner;

@RunWith(MockitoJUnitRunner.class)
public class MockitoTest
{
    @Mock
    ArrayList<String> listMock;

    @Test
    public void testAppend() {
        // configure the mock to return "foobar" whenever "get()" 
        // is called on "listMock" with an int value as parameter
        doReturn("foobar").when(listMock).get(anyInt());            
        String result = listMock.get(0);
        
        assertEquals("foobar", result);
    }
}