【项目经验】Mockito教程

一、教程

转载：https://blog.csdn.net/sdyy321/article/details/38757135/

官网： http://mockito.org

源码分析：https://www.cnblogs.com/dengshihuang/p/7903550.html

属性默认值：https://yanbin.blog/mockito-mocked-default-fields-method-returns/#more-8359

API文档：http://docs.mockito.googlecode.com/hg/org/mockito/Mockito.html

项目源码：https://github.com/mockito/mockito
使用案例:https://blog.csdn.net/Christopher36/article/details/81036683

首先添加maven依赖

 <dependency>
          <groupId>org.mockito</groupId>
          <artifactId>mockito-all</artifactId>
          <version>1.9.5</version>
          <scope>test</scope>
      </dependency>

当然mockito需要junit配合使用

<dependency>
        <groupId>junit</groupId>
        <artifactId>junit</artifactId>
        <version>4.11</version>
        <scope>test</scope>
      </dependency>

然后为了使代码更简洁，最好在测试类中导入静态资源

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

下面我们开始使用mockito来做测试

package com.spring.sxf.mockito;

import org.junit.Test;
import org.mockito.ArgumentMatcher;
import org.mockito.InOrder;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;
import org.mockito.exceptions.verification.NoInteractionsWanted;

import java.io.IOException;
import java.io.OutputStream;
import java.io.OutputStreamWriter;
import java.util.ArrayList;
import java.util.Comparator;
import java.util.List;

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

/**
 * @author <a href="mailto:shangxiaofei@meituan.com">尚晓飞</a>
 * @date 7:52 PM 2019/4/26
 */
public class MockitoTest {

    //验证要mock的对象，是否发生过某些行为
    @Test
    public void testArrayList() {
        //生成mock对象
        ArrayList<String> mockList = mock(ArrayList.class);
        //使用mock的对象
        mockList.add("SXF");
        mockList.add("456");

        //验证行为add("SXF"),add("123")是否发生过
        verify(mockList).add("SXF");
        verify(mockList).add("456");
    }

    //模拟我们所期望的结果
    @Test
    public void testArrayList1() {
        //生成mock对象
        ArrayList<String> mockList = mock(ArrayList.class);
        //
        when(mockList.size()).thenReturn(2);
        int size = mockList.size();
        assertEquals(2, size);

    }

    //模拟我们期望的结果
    @Test(expected = NullPointerException.class)
    public void when_thenThrow() throws IOException {
        OutputStream outputStream = mock(OutputStream.class);
        OutputStreamWriter writer = new OutputStreamWriter(outputStream);
        //预设当流关闭时抛出异常
        doThrow(new IOException()).when(outputStream).close();
        outputStream.close();
    }

    //参数匹配
    @Test
    public void with_arguments() {
        Comparable comparable = mock(Comparable.class);
        //预设根据不同的参数返回不同的结果
        when(comparable.compareTo("Test")).thenReturn(1);
        when(comparable.compareTo("Omg")).thenReturn(2);
        assertEquals(1, comparable.compareTo("Test"));
        assertEquals(2, comparable.compareTo("Omg"));
        //对于没有预设的情况会返回默认值
        assertEquals(0, comparable.compareTo("Not stub"));
    }

    //除了匹配制定参数外，还可以匹配自己想要的任意参数
    @Test
    public void with_unspecified_arguments() {
        List list = mock(List.class);
        //匹配任意参数
        when(list.get(anyInt())).thenReturn(1);
        when(list.contains(argThat(new IsValid()))).thenReturn(true);
        assertEquals(1, list.get(1));
        assertEquals(1, list.get(999));
        assertTrue(list.contains(1));
        assertTrue(!list.contains(3));
    }

    private class IsValid extends ArgumentMatcher<List> {
        @Override
        public boolean matches(Object o) {
            return (Integer) o == 1 || (Integer) o == 2;
        }
    }

    //需要注意的是如果你使用了参数匹配，那么所有的参数都必须通过matchers来匹配
    @Test
    public void all_arguments_provided_by_matchers() {
        Comparator comparator = mock(Comparator.class);
        comparator.compare("nihao", "hello");
        //如果你使用了参数匹配，那么所有的参数都必须通过matchers来匹配
        verify(comparator).compare(anyString(), eq("hello"));
        //下面的为无效的参数匹配使用
        //verify(comparator).compare(anyString(),"hello");
    }

    //验证确切的调用次数
    @Test
    public void verifying_number_of_invocations() {
        List list = mock(List.class);
        list.add(1);
        list.add(2);
        list.add(2);
        list.add(3);
        list.add(3);
        list.add(3);
        //验证是否被调用一次，等效于下面的times(1)
        verify(list).add(1);
        verify(list, times(1)).add(1);
        //验证是否被调用2次
        verify(list, times(2)).add(2);
        //验证是否被调用3次
        verify(list, times(3)).add(3);
        //验证是否从未被调用过
        verify(list, never()).add(4);
        //验证至少调用一次
        verify(list, atLeastOnce()).add(1);
        //验证至少调用2次
        verify(list, atLeast(2)).add(2);
        //验证至多调用3次
        verify(list, atMost(3)).add(3);

    }

    //模拟方法体抛出异常
    @Test(expected = RuntimeException.class)
    public void doThrow_when() {
        List list = mock(List.class);
        doThrow(new Exception()).when(list).add(1);
        list.add(1);
    }

    //验证执行顺序
    @Test
    public void verification_in_order() {
        List list = mock(List.class);
        List list2 = mock(List.class);
        list.add(1);
        list2.add("hello");
        list.add(2);
        list2.add("world");
        //将需要排序的mock对象放入InOrder
        InOrder inOrder = inOrder(list, list2);
        //下面的代码不能颠倒顺序，验证执行顺序
        inOrder.verify(list).add(1);
        inOrder.verify(list2).add("hello");
        inOrder.verify(list).add(2);
        inOrder.verify(list2).add("world");
    }

    //确保模拟对象上无互动发生
    @Test
    public void verify_interaction(){
        List list = mock(List.class);
        List list2 = mock(List.class);
        List list3 = mock(List.class);
        list.add(1);
        verify(list).add(1);
        verify(list,never()).add(2);
        //验证零互动行为
        verifyZeroInteractions(list2,list3);
    }

    //找出冗余的互动(即未被验证到的)
    @Test(expected = NoInteractionsWanted.class)
    public void find_redundant_interaction(){
        List list = mock(List.class);
        list.add(1);
        list.add(2);
        verify(list,times(2)).add(anyInt());
        //检查是否有未被验证的互动行为，因为add(1)和add(2)都会被上面的anyInt()验证到，所以下面的代码会通过
        verifyNoMoreInteractions(list);

        List list2 = mock(List.class);
        list2.add(1);
        list2.add(2);
        verify(list2).add(1);
        //检查是否有未被验证的互动行为，因为add(2)没有被验证，所以下面的代码会失败抛出异常
        verifyNoMoreInteractions(list2);
    }

    //9、使用注解来快速模拟
    //在上面的测试中我们在每个测试方法里都mock了一个List对象，为了避免重复的mock，是测试类更具有可读性，我们可以使用下面的注解方式来快速模拟对象：
    @Mock
    private List mockList;
    //构造方法
    public MockitoTest(){
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void shorthand(){
        mockList.add(1);
        verify(mockList).add(1);
    }

}

二、spring项目+单元测试使用mockito

一、单元测试类

@Slf4j
@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(locations = {"classpath:spring/applicationContext.xml"})
public class RouteServiceTest {

    //要被mock的接口
    @Mock
    private IChannelQueueCountService iChannelQueueCountService;

    //使用了要被mock对象的类，需要注入mock对象
    @InjectMocks
    @Autowired
    private ChannelChooseService channelChooseService;

    //发起调用的接口
    @Autowired
    private TRouteService.Iface tRouteService;

    //mock对象注入
    @Before
    public void setUp() {
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void test01() throws TException {

        when(iChannelQueueCountService.getChannelQueueCounts(anyList(), anyLong(), anyBoolean())).thenAnswer(new Answer<Map<Integer, Integer>>() {

            @Override
            public Map<Integer, Integer> answer(InvocationOnMock invocation) throws Throwable {
                HashMap<Integer, Integer> map = new HashMap<>();
                Object[] args = invocation.getArguments();
                List<Integer> ids = (List<Integer>) args[0];
                for (Integer id : ids) {
                    map.put(id, 1);
                }
                return map;
            }
        });

        TChooseChannelReq tChooseChannelReq = new TChooseChannelReq(56789, 219, 999, 6000, "shangxiaofei", "6212260200052453285", TPPType.PRIVATE, 10, 34, 99999);
        TChooseChannelRes res = tRouteService.chooseChannel(tChooseChannelReq);
        System.out.println("接口调用返回:" + res.getLogicalChannelId());

    }
}