介紹
Mock本身也是單元測試的一種,對於原生的Junit進行了包裝升級。比較常見的類庫有easymock、jMock、Mockito、Unitils Mock、PowerMock、JMockit等等,其中比較優秀的是easymock、mockito和powermock。
PowerMock本身集成了easymock和mockito,同時,powermock使用一個自定義類加載器和字節碼操作來模擬靜態方法,構造函數,final類和方法,私有方法,去除靜態初始化器等等,功能更加強大。
Maven引用
<!-- PowerMock JUnit 4.4+ Module -->
<dependency>
<groupId>org.powermock</groupId>
<artifactId>powermock-module-junit4</artifactId>
<version>2.0.0</version>
<scope>test</scope>
</dependency>
<!-- PowerMock Mockito2 API -->
<dependency>
<groupId>org.powermock</groupId>
<artifactId>powermock-api-mockito2</artifactId>
<version>2.0.0</version>
<scope>test</scope>
</dependency>
<dependency>
<groupId>junit</groupId>
<artifactId>junit</artifactId>
<version>4.11</version>
<scope>test</scope>
</dependency>
PowerMock的jar包依賴樹:
可以看到:
(1)PowerMock基於javassit做的動態編程,從而實現了對字節碼的操作;
(2)PowerMock大量依賴junit;
(3)PowerMock默認引入了mockito-core包。
實戰
package com.example.demo.mock.controller;
import com.example.demo.junit.spring.service.JunitDemoService;
import com.example.demo.mock.service.MockDemoService;
import com.example.demo.mock.service.MockDemoServiceImpl;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.*;
import org.powermock.modules.junit4.PowerMockRunner;
import org.springframework.boot.test.mock.mockito.MockBean;
/**
* Junit演示服務
*
* @ClassName JunitDemoService
* @Author zhaoguang
* @Date 2019/12/14
* @Version 1.0
*/
@RunWith(PowerMockRunner.class)
public class MockDemoServiceTest {
@Mock
private MockDemoServiceImpl mockDemoService;
@Test
public void testAdd() {
Mockito.when(mockDemoService.add(1,2)).thenReturn(3);
Assert.assertEquals(3, mockDemoService.add(1, 2));
}
}