单元测试案例

在日常的springboot项目开发中,总会需要写一些单元测试用例,一些单元测试的方法用的比较少,编写时又需要去查询,因此在此总结一些测试案例

Junit是目前主流的单元测试框架,我,常用的为Junit4,以下测试案例是基于Junit4来编写

代码地址:https://github.com/x104859/test-case

单元测试的目的与好处

  1. 单元测试能有效地帮你发现代码中的 bug

    单元测试往往需要走通方法中的各条路径,通过单元测试常常会发现代码中的很多考虑不全面的地方

  2、写单元测试能帮你发现代码设计上的问题

    对于一段代码,如果很难为其编写单元测试,或者单元测试写起来很吃力,需要依靠单元测试框架里很高级的特性才能完成,那往往就意味着代码设计得不够合理

  3、单元测试是对集成测试的有力补充

    对于一些复杂系统来说,集成测试也无法覆盖得很全面。复杂系统往往有很多模块。每个模块都有各种输入、输出、异常情况,组合起来,整个系统就有无数测试场景需要模拟,无数的测试用例需要设计,再强大的测试团队也无法穷举完备

  4、写单元测试的过程本身就是代码重构的过程

    设计和实现代码的时候,我们很难把所有的问题都想清楚。而编写单元测试就相当于对代码的一次自我 Code Review,在这个过程中,我们可以发现一些设计上的问题(比如代码设计的不可测试)以及代码编写方面的问题(比如一些边界条件处理不当)等,然后针对性的进行重构。

 

所需依赖

<!-- 使用MockMvc发起请求时需要该依赖, Spring Boot 2.2.0版本开始引入 JUnit5 作为单元测试默认库
        JUnit5和JUnit4之间会有冲突,这里屏蔽掉JUnit5-->
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.jupiter</groupId>
                    <artifactId>junit-jupiter-api</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.junit.jupiter</groupId>
                    <artifactId>junit-jupiter</artifactId>
                </exclusion>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
            <scope>test</scope>
        </dependency>
        <!-- junit4所需测试依赖 -->
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
        <!-- 使用powermock所需依赖 -->
        <dependency>
            <groupId>org.powermock</groupId>
            <artifactId>powermock-module-junit4</artifactId>
            <version>2.0.9</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.powermock</groupId>
            <artifactId>powermock-api-mockito2</artifactId>
            <version>2.0.9</version>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
            <version>3.12.4</version>
            <scope>test</scope>
        </dependency>

 

 常见注解

  @Before:初始化方法,在任何一个测试方法执行之前,必须执行的代码
  @BeforeClass:针对所有测试,也就是整个测试类中,在所有测试方法执行前,都会先执行由它注解的方法,而且只执行一次,修饰符必须是 public static void
  @After:释放资源,在任何一个测试方法执行之后,需要进行的收尾工作
  @AfterClass:针对所有测试,也就是整个测试类中,在所有测试方法都执行完之后,才会执行由它注解的方法,而且只执行一次。修饰符必须是 public static void
  @Test:测试方法,表明这是一个测试方法。在 JUnit 中将会自动被执行。对与方法的声明也有如下要求:名字可以随便取,没有任何限制,但是返回值必须为 void ,而且不能有任何参数
@RunWith(MockitoJUnitRunner.class)
public class AnnotationTest {
    public static final Logger log = LoggerFactory.getLogger(AnnotationTest.class);
    @Before
    public void init(){
        log.info("@Before call");
    }
    @BeforeClass
    public static void beforeClass(){
        log.info("@BeforeClass call");
    }

    @After
    public void after(){
        log.info("@After call");
    }

    @AfterClass
    public static void afterClass(){
        log.info("@AfterClass call");
    }

    @Test
    public void test01(){
        log.info("test01 call");
    }

    @Test
    public void test02(){
        log.info("test02 call");
    }
}

方法执行结果如下所示,两个测试方法,@Before和@After都执行了两次,而@BeforeClass和@AfterClass都只执行了一次;执行顺序:@BeforeClass --> @Before  --> @Test  --> @After  --> @AfterClass

断言

Junit提供的断言主要有如下几种类型:

  Assert.assertTrue():验证条件是否为真
  Assert.assertFalse():验证条件是否为假
  Assert.assertEquals():验证两个值是否相等
  Assert.assertNotNull():验证对象是否为空
  Assert.assertThrows():验证执行代码是否抛出了指定类型的异常

verify:

@Test
    public void test(){
        List list = Mockito.mock(List.class);
        list.add("a");
        //Mockito.times()不写默认指调用1次
        Mockito.verify(list).add("a");
        Mockito.verify(list,Mockito.times(1)).add("a");
        //判读list.add方法被调用2次
        list.add("a");
        Mockito.verify(list,Mockito.times(2)).add("a");
    }

 

@Mock与@InjectMocks的区别

  @Mock: 创建一个Mock.
  @InjectMocks: 创建一个实例,简单的说是这个Mock可以调用真实代码的方法,其余用@Mock注解创建的mock将被注入到用该实例中。

Mockito的初始化

当我们要使用注解(比如@Mock)来mock对象的使用,就要初始化Mockito,这样用@Mock标注的对象才会被实例化,否则直接使用会报Null指针异常。其有两种初始化的方法:

  1、使用MockitoAnnotations.initMocks方法

public class InitMockA {
    public static final Logger log = LoggerFactory.getLogger(InitMockA.class);
    
    @Before
    public void init(){
        MockitoAnnotations.initMocks(this);
    }
    
    @Test
    public void test01(){
        log.info("run test01");
    } 
}

  2、类上使用@RunWith(MockitoJUnitRunner.class)

@RunWith(MockitoJUnitRunner.class)
public class InitMockB {
    public static final Logger log = LoggerFactory.getLogger(InitMockB.class);
    @Test
    public void test01(){
        log.info("run test01");
    }
}

 

 

案例

  1、常见简单测试案例

@Service
public class AComponent {
    @Value("${test-case.key}")
    private String key;
    @Autowired
    private UserInfoMapper userInfoMapper;
    @Autowired
    private BComponent bComponent;

    public UserInfo normalMethod(Integer id){
        UserInfo userInfo = userInfoMapper.getById(id);
        System.out.println(userInfo.getSex());
        return userInfo;
    }

    public boolean compareUser(Integer originId,Integer targetId){
        UserInfo originUser = userInfoMapper.getById(originId);
        UserInfo targetUser = userInfoMapper.getById(targetId);
        return originUser.getSex().equals(targetUser.getSex());
    }


    public void complicatedService(ServiceEntity serviceEntity, String name){
        //...
        bComponent.complicatedMethod(serviceEntity,name);
        //...
    }

    public UserInfo exceptionService(Integer id){
        UserInfo userInfo = null;
        try {
            userInfo = bComponent.exceptionMethod(id);
        }catch (Exception e){
            return null;
        }
        return userInfo;
    }

    public void updateUserInfo(UserInfo userInfo){
        userInfoMapper.updateUserInfo(userInfo);
    }

    public String getKey(){
        return key;
    }
}

  测试方法:

@RunWith(MockitoJUnitRunner.class)
public class SimpleTest {
    @Mock
    private UserInfoMapper userInfoMapper;
    @Mock
    private BComponent bComponent;

    /**
     * 创建一个实例,简单的说是这个Mock可以调用真实代码的方法,其余用@Mock注解创建的mock将被注入到用该实例中
     */
    @InjectMocks
    AComponent aComponent;

    @Before
    public void intit(){
        // 为aComponent注入对象
        ReflectionTestUtils.setField(aComponent,"key","abcdefg");
    }

    /**
     * 最常见的测试用例,mock返回值
     */
    @Test
    public void normalTest(){
        Integer id = 1;
        Mockito.when(userInfoMapper.getById(id)).thenReturn(getManUserInfo());
        aComponent.normalMethod(id);
        Mockito.verify(userInfoMapper).getById(id);
    }

    /**
     * 测试同一个方法,入参不同的,返回值也不相同
     */
    @Test
    public void differentParamTest(){
        Integer user1 = 1;
        Integer user2 = 2;
        Mockito.when(userInfoMapper.getById(user1)).thenReturn(getManUserInfo());
        Mockito.when(userInfoMapper.getById(user2)).thenReturn(getFemaleUserInfo());
        boolean result = aComponent.compareUser(user1,user2);
        Assert.assertFalse(result);
    }

    /**
     * 入参比较复杂的时候可以使用Mockito.any,入参也是可以mock的
     * Mockito.any()可以有多种类型,比如:
     *      Mockito.any(ServiceEntity.class);
     *      Mockito.anyString();
     *      Mockito.anyCollection();
     *      Mockito.anyList();
     */
    @Test
    public void paramComplicated(){
        aComponent.complicatedService(Mockito.any(),Mockito.anyString());
        Mockito.verify(bComponent).complicatedMethod(Mockito.any(),Mockito.anyString());
    }

    /**
     * 当方法中出现异常的时候,可以使用doThrow方法自己制造异常
     */
    @Test
    public void exceptionTest(){
        Integer id = 1;
        Mockito.doThrow(new IllegalArgumentException()).when(bComponent).exceptionMethod(id);
        UserInfo userInfo = aComponent.exceptionService(id);
        Assert.assertTrue(userInfo == null);
    }

    @Test
    public void keyTest(){
        String key = aComponent.getKey();
        Assert.assertTrue("abcdefg".endsWith(key));
    }

    private UserInfo getManUserInfo(){
        UserInfo userInfo = new UserInfo();
        userInfo.setId(1);
        userInfo.setUserName("zhansan");
        userInfo.setAge(12);
        userInfo.setSex("M");
        return userInfo;
    }

    private UserInfo getFemaleUserInfo(){
        UserInfo userInfo = new UserInfo();
        userInfo.setId(2);
        userInfo.setUserName("李四");
        userInfo.setAge(12);
        userInfo.setSex("F");
        return userInfo;
    }

}

 

  2、Mock静态方法:

@Service
public class StaticComponent {
    /**
     * 这里为是shiro登录时,存放登录对象信息的位置
     * @return
     */
    public String getUserId(){
        Subject localSubject = ThreadContext.getSubject();
        String userId = (String) localSubject.getPrincipals().getPrimaryPrincipal();
        return userId;
    }
}

  测试方法:

/**
 * 静态Mock需要使用PowerMockRunner
 * 并使用PrepareForTest,该测试代表不会实际执行ThreadContext这个类
 */
@RunWith(PowerMockRunner.class)
@PrepareForTest({ThreadContext.class})
public class StaticComponentTest {

    @InjectMocks
    StaticComponent staticComponent;

    @Test
    public void getUserId(){
        String userId = "12345";
        PowerMockito.mockStatic(ThreadContext.class);
        Subject localSubject = PowerMockito.mock(Subject.class);
        when(ThreadContext.getSubject()).thenReturn(localSubject);

        PrincipalCollection principalCollection = PowerMockito.mock(PrincipalCollection.class);
        when(localSubject.getPrincipals()).thenReturn(principalCollection);
        when(principalCollection.getPrimaryPrincipal()).thenReturn("12345");

        String resultUserId = staticComponent.getUserId();

        Assert.assertTrue(userId.equals(resultUserId));
    }
}

  

  3、方法内部有new对象的测试

@Service
public class CreateComponent {

    @Autowired
    private RestTemplate restTemplate;

    public MethodResult addUser(UserInfo user)throws Exception{
        Map<String,String> map = new HashMap<>();
        map.put("name",String.valueOf(user.getId()));
        map.put("email",user.getEmail());
        map.put("nickname",user.getNickname());
        MultiValueMap<String, String> header = new LinkedMultiValueMap();
        header.put(HttpHeaders.CONTENT_TYPE, Collections.singletonList(MediaType.APPLICATION_JSON_VALUE));
        HttpEntity request = new HttpEntity(JSONObject.toJSONString(map), header);
        String url = "http://127.0.0.1:8088/add/user";
        try{
            ResponseEntity<String> response = restTemplate.postForEntity(url, request, String.class);
            MethodResult result = JSONObject.parseObject(response.getBody(), MethodResult.class);
            return result;
        }catch (Exception e){
            e.printStackTrace();
            return null;
        }
    }
}

  测试方法

@RunWith(PowerMockRunner.class)
public class CreateComponentTest {

    @Mock
    private  RestTemplate restTemplate;
    @InjectMocks
    private CreateComponent component;

    @Test
    public void createTest()throws Exception{
        UserInfo param = new UserInfo();
        param.setNickname("zhangsan");
        param.setEmail("zhangsan@supermap.com");
        param.setId(123);

        Map<String,String> map = new HashMap<>();
        map.put("name",String.valueOf(param.getId()));
        map.put("email",param.getEmail());
        map.put("nickname",param.getNickname());
        MultiValueMap<String, String> header = new LinkedMultiValueMap();
        header.put(HttpHeaders.CONTENT_TYPE, Collections.singletonList(MediaType.APPLICATION_JSON_VALUE));
        HttpEntity request = new HttpEntity(JSONObject.toJSONString(map), header);
        PowerMockito.whenNew(HttpEntity.class).withAnyArguments().thenReturn(request);

        ResponseEntity responseEntity = PowerMockito.mock(ResponseEntity.class);
        Mockito.when(restTemplate.postForEntity("http://127.0.0.1:8088/add/user",request,String.class)).thenReturn(responseEntity);
        MethodResult result = new MethodResult();
        result.setSucceed(true);
        PowerMockito.when(responseEntity.getBody()).thenReturn(JSONObject.toJSONString(result));
        MethodResult methodResult = component.addUser(param);
        Assert.assertTrue(methodResult.isSucceed());
    }
}

 

  4:方法过于复杂跳过内部私有方法,再单独测试私有方法

@Service
public class PrivateComponent {

    public Integer entranceMethod(Integer i){
        methodA(i);
        System.out.println("call methodA end");
        i = methodB(i);
        System.out.println("call methodB end");
        i = methodC(i);
        System.out.println("call methodC end");
        return i;
    }

    private void methodA(Integer i){
        System.out.println("do methodA i = " + i);
        methodA2(i);
    }

    private void methodA2(Integer i){
        System.out.println("do methodA2 i = " + i);
    }

    private Integer methodB(Integer i){
        ++i;
        System.out.println("do methodB");
        return i;
    }

    private Integer methodC(Integer i){
        ++i;
        System.out.println("do methodC");
        return i;
    }
}

  测试方法:

@RunWith(PowerMockRunner.class)
@PrepareForTest(PrivateComponent.class)
public class PrivateComponentTest {

    @InjectMocks
    private PrivateComponent privateComponent;

    /**
     * 测试复杂的方法,跳过方法内部的私有方法:1、该私有方法没有返回值
     * @throws Exception
     */
    @Test
    public void jumpPrivateMethodTest()throws Exception{
        PrivateComponent component = PowerMockito.spy(privateComponent);
        PowerMockito.doNothing().when(component,"methodA",1);
        Integer i = component.entranceMethod(1);
        System.out.println(i);
        Assert.assertTrue(i == 3);
    }

    /**
     * 测试复杂的方法,跳过方法内部的私有方法:2、该私有方法有返回值
     * @throws Exception
     */
    @Test
    public void jumpPrivateMethodTest2()throws Exception{
        PrivateComponent component = PowerMockito.spy(privateComponent);
        PowerMockito.doReturn(5).when(component,"methodB", Mockito.any());
        Integer i = component.entranceMethod(1);
        System.out.println(i);
        Assert.assertTrue(i == 6);
    }

    /**
     * 测试复杂方法,单独测试方法内部的私有方法
     * @throws Exception
     */
    @Test
    public void privateMethodTest()throws Exception{
        PrivateComponent component = PowerMockito.spy(privateComponent);
        Method method = PowerMockito.method(PrivateComponent.class,"methodB",Integer.class);
        Integer i = (Integer) method.invoke(component,1);
        System.out.println("result i = " + i);
        Assert.assertTrue(i == 2);
    }
}

 

  5、对controller进行测试

@RestController
@RequestMapping("/api/user")
public class AController {

    @Autowired
    private AComponent aComponent;

    @GetMapping(value = "/info")
    public UserInfo testA1(Integer id){
        UserInfo userInfo = aComponent.normalMethod(id);
        return userInfo;
    }

    @PostMapping(value = "/update")
    public String updateUserInfo(@RequestBody UserInfo userInfo){
        aComponent.updateUserInfo(userInfo);
        return "success";
    }
}

  测试方法:

@RunWith(MockitoJUnitRunner.class)
public class ControllerTest {
    @InjectMocks
    private AController aController;
    @Mock
    private AComponent aComponent;

    private MockMvc mockMvc;

    @Before
    public void setUp() {
        mockMvc = MockMvcBuilders.standaloneSetup(aController).build();
    }

    /**
     * 使用http GET方法调用的方式来测试controller
     * @throws Exception
     */
    @Test
    public void getControllerMvcTest() throws Exception {
        Integer id = 1;
        Mockito.when(aComponent.normalMethod(id)).thenReturn(getManUserInfo());
        MvcResult mvcResult = mockMvc.perform(MockMvcRequestBuilders.get("/api/user/info?id="+id))
                .andExpect(MockMvcResultMatchers.status().isOk()).andReturn();
        String content = mvcResult.getResponse().getContentAsString();
        Assert.assertNotNull(content);
    }

    /**
     * 使用http POST方法调用的方式来测试controller
     * @throws Exception
     */
    @Test
    public void postControllerMvcTest() throws Exception {
        UserInfo userInfo = getManUserInfo();
        MvcResult mvcResult = mockMvc.perform(MockMvcRequestBuilders.post("/api/user/update")
                .contentType(MediaType.APPLICATION_JSON).content(JSON.toJSONString(userInfo)))
                .andExpect(MockMvcResultMatchers.status().isOk()).andReturn();
        String content = mvcResult.getResponse().getContentAsString();
        Assert.assertTrue("success".equals(content));
    }

    private UserInfo getManUserInfo(){
        UserInfo userInfo = new UserInfo();
        userInfo.setId(1);
        userInfo.setUserName("zhansan");
        userInfo.setAge(12);
        userInfo.setSex("M");
        return userInfo;
    }
}

 

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