Blog/UT/difference_for_mock_and_spy

java

package com.sankuai.zcm.trade.core.reverse;

import javafx.beans.binding.When;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.MockitoAnnotations;
import org.mockito.Spy;
import org.mockito.runners.MockitoJUnitRunner;

import java.util.ArrayList;
import java.util.List;

import static org.junit.Assert.assertEquals;

/**
 * Created by luo on 14/05/2018.
 */
@RunWith(MockitoJUnitRunner.class)
public class SpyAndMockDiff {

    @Mock
    List<String> mockList;

//    @Spy
//    List<String> spyList;

    @Spy
    List<String> spyList = new ArrayList<String>();

    @Before
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(this);

    }

    @Test
    public void testMock() {
        mockList.add("one");
        assertEquals(0, mockList.size());
        Mockito.when(mockList.size()).thenReturn(100);
        assertEquals(100, mockList.size());

    }


    @Test
    public void testSpy() {
        spyList.add("one");
        assertEquals(1, spyList.size());

        Mockito.verify(spyList).add("one");
        Mockito.when(spyList.size()).thenReturn(100);

        assertEquals(100, spyList.size());
    }
}