junit 单元测试指南

摘要：本文主要介绍如何使用junit来编写单元测试，包含mock对象的方法和mock静态方法使用案例，提高开发效率。

`pom.xml`引入依赖包

`springboot`引入依赖包

<dependency>
   <groupId>org.springframework.boot</groupId>
   <artifactId>spring-boot-starter-test</artifactId>
</dependency>
<dependency>
   <groupId>org.mockito</groupId>
   <artifactId>mockito-inline</artifactId>
   <scope>test</scope>
</dependency>

普通`java`项目

<!-- junit5 -->
<dependency>
    <groupId>org.junit.jupiter</groupId>
    <artifactId>junit-jupiter</artifactId>
    <version>5.9.2</version>
    <scope>test</scope>
</dependency>

<dependency>
    <groupId>org.junit.vintage</groupId>
    <artifactId>junit-vintage-engine</artifactId>
    <version>5.9.2</version>
    <scope>test</scope>
</dependency>

<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-core</artifactId>
    <version>4.11.0</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-junit-jupiter</artifactId>
    <version>4.11.0</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-inline</artifactId>
    <version>4.11.0</version>
    <scope>test</scope>
</dependency>

定义的类

`UserEntity`

@Data
@TableName("user")
public class UserEntity {

    @TableId
    private String id;

    private String name;

    private String address;

    private Date createTime;
}

`UserUtils`

作为被mock的静态类

public class UserUtils {

    public static UserEntity getUser(){
        return new UserEntity();
    }

    public static boolean checkName(String name){
        UserEntity userEntity = getUser();
        return userEntity.getName().equals(name);
    }

}

`UserService`

mock的测试类

@Service
public class UserService {

    @Autowired
    private UserMapper userMapper;

    @SDS("dynamic_member")
    @Transactional(rollbackFor = Exception.class)
    public UserEntity add(UserEntity userEntity) throws Exception{
        userEntity.setId(IdWorker.getIdStr());
        userEntity.setCreateTime(new Date());
        userMapper.insert(userEntity);
        return userEntity;
    }

    public UserEntity getLoginUser(){
        return UserUtils.getUser();
    }

    public boolean checkName(String name){
        boolean result = UserUtils.checkName(name);
        System.out.println(result);
        return result;
    }
}

单元测试

`UserServiceTest`

@ExtendWith(MockitoExtension.class)
class UserServiceTest {

    /** mock静态类 */
    private static MockedStatic<UserUtils> userUtils;
    /** mock被测试的类 */
    @InjectMocks
    private UserService userService;

    /** mock注入的类 */
    @Mock
    private UserMapper userMapper;

    @BeforeAll
    static void init(){
        userUtils = Mockito.mockStatic(UserUtils.class);
    }

    @Test
    void add() throws Exception {
        // mock方法中调用的其他方法
        Mockito.when(userMapper.insert(Mockito.any())).thenReturn(1);
        UserEntity result = userService.add(new UserEntity());
        assertNotNull(result.getId());
    }

    @Test
    void getLoginUser() {
        UserEntity userEntity = new UserEntity();
        userEntity.setName("zhangsan");
        // mock无参静态方法
        userUtils.when(UserUtils::getUser).thenReturn(userEntity);
        UserEntity result = userService.getLoginUser();
        assertEquals("zhangsan",result.getName());
    }

    @Test
    void checkName() {
        // mock有参数静态方法
        userUtils.when(() -> UserUtils.checkName(Mockito.anyString())).thenReturn(true);
        boolean result = userService.checkName("zhangsan");
        assertTrue(result);

        // mock有参数静态方法
        userUtils.when(() -> UserUtils.checkName(Mockito.anyString())).thenReturn(false);
        result = userService.checkName("zhangsan");
        assertFalse(result);
    }
}