# 2.1单元测试入门

## 步骤

1.模拟数据

```java
@SpringBootTest
@RunWith(SpringRunner.class)
public class DeviceModelLableServiceTest {

    @Mock
    private DeviceModelLabelRespository repository;

    @Mock
    private DeviceInstanceRepository deviceInstanceRepository;

    @InjectMocks
    private DeviceModelLabelServiceImpl service;

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

    @Test
    public void insertDeviceModelLable() {
     //模拟dao
     DeviceModelLabel deviceModelLable = new DeviceModelLabel();
     when(repository.findByDeviceModelId("deviceModelId")).thenReturn(lables);
     ...
    }
}
```

2.运行待测试代码

```java
    @Test
    public void insertDeviceModelLable() {
     ...
     //单元测试
     List<DeviceModelLabel> results = service.listDeviceModelLabel("deviceModelId");
     ...
    }
```

3.断言

```java
    @Test
    public void insertDeviceModelLable() {
     ...
     //断言
     Assert.assertEquals(deviceModelLable, results.get(0));
     Assert.assertEquals(deviceModelLable1, results.get(1));
     Mockito.verify(data, Mockito.times(1)).add("a");
    }
```

## 常用mockito方法

| 方法                                     | 说明           |
| -------------------------------------- | ------------ |
| when(methodCall).thenReturn(object)    | 有返回值的方法返回对象  |
| when(methodCall).thenThrow(throwables) | 有返回值的方法抛出异常  |
| doNothing().when(mock)                 | 无返回值的方法什么都不做 |
| doThrow(throwable).when(mock)          | 无返回值的方法抛出异常  |

## 常用断言

| 方法                                    | 说明                               |
| ------------------------------------- | -------------------------------- |
| assertArrayEquals(expecteds, actuals) | 查看两个数组是否相等。                      |
| assertEquals(expected, actual)        | 查看两个对象是否相等。类似于字符串比较使用的equals()方法 |
| assertNotEquals(first, second)        | 查看两个对象是否不相等。                     |
| assertNull(object)                    | 查看对象是否为空。                        |
| assertNotNull(object)                 | 查看对象是否不为空。                       |
| assertSame(expected, actual)          | 查看两个对象的引用是否相等。类似于使用“==”比较两个对象    |
| assertNotSame(unexpected, actual)     | 查看两个对象的引用是否不相等。类似于使用“!=”比较两个对象   |
| assertTrue(condition)                 | 查看运行结果是否为true。                   |
| assertFalse(condition)                | 查看运行结果是否为false。                  |
| assertThat(actual, matcher)           | 查看实际值是否满足指定的条件                   |
| fail()                                | 让测试失败                            |

## 参考文档

[Mockito 精萃](https://blog.csdn.net/shangboerds/article/details/99611079)


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