用powermock编写单元测试

1、pom文件引入jar包

<!-- 单元测试 start -->
<dependency><groupId>org.springframework.boot</groupId><artifactId>spring-boot-starter-test</artifactId><scope>test</scope>
</dependency>
<dependency><groupId>junit</groupId><artifactId>junit</artifactId><scope>test</scope>
</dependency>
<dependency><groupId>org.powermock</groupId><artifactId>powermock-module-junit4</artifactId><version>2.0.2</version><scope>test</scope>
</dependency>
<dependency><groupId>org.powermock</groupId><artifactId>powermock-api-mockito2</artifactId><version>2.0.2</version><scope>test</scope>
</dependency>
<dependency><groupId>com.github.jsonzou</groupId><artifactId>jmockdata</artifactId><version>4.1.2</version><scope>test</scope>
</dependency>
<!-- 单元测试 end -->

2、创建单元测试用例目录

保持与main级别一致，并且具体的测试用例存放目录也跟源代码的目录级别保持一致

3、单元测试类的基本框架

@RunWith(PowerMockRunner.class)
@PrepareForTest({CommonUtils.class}) // 工具类
public class OrderServiceTest {@InjectMocksprivate OrderService orderService;@Mockprivate OrderMapper orderMapper;@Mockprivate OrderHelper orderHelper;@Beforepublic void setUp() throws Exception {PowerMockito.mockStatic(CommonUtils.class);}// 被测试的方法 orderService.pageOrderRecord有返回值@Testpublic void testPageOrderRecord() {// GievnOrderRecordDTO orderRecordDTO = new OrderRecordDTO();orderRecordDTO.setId("111");orderRecordDTO.setPageIndex(1);orderRecordDTO.setPageSize(10);// WhenOrderRecordEntity orderRecord = JMockData.mock(OrderRecordEntity.class);List<OrderRecordEntity> mock = Lists.newArrayList();mock.add(orderRecord);PowerMockito.when(orderMapper.selectEntityListPage(any())).thenReturn(mock); // mock的方法有返回值PowerMockito.doNothing().when(orderHelper).fillData(any()); // mock的方法没有返回值PowerMockito.when(CommonUtils.doPageQuery(Mockito.any(), Mockito.any(), Mockito.any())).thenReturn(new PageRows<>()); // mock工具类方法// Run the testPageRows<OrderRecordDTO> rt = orderService.pageOrderRecord(OrderRecordDTO);// Verify the resultsAssert.assertNotNull(rt);}}

4、常见单元测试问题

4.1、静态方法如何mock

参见基本框架里的CommonUtils.doPageQuery()的mock。

如果被测试类的方法中调用到了静态方法CommonUtils.doPageQuery()，在写测试类的时候就需要主要注意：

@PrepareForTest（{CommonUtils.class}）、 

PowerMockito.mockStatic(CommonUtils.class);

4.2、返回类型为void的方法如何mock

参见基本框架里的orderHelper.fillData()方法的mock。

4.3、被@Value注解的值如何mock

    ReflectionTestUtils.setField(对象,"成员变量","变量mock值");

被测试类：

@Component
public class OrderExternalFacade {@Autowiredprivate OrderAbility OrderAbility;@Autowiredprivate OrderExternalConvertor OrderExternalConvertor;@Value("${switch.new.system:false}")protected boolean switchNewSystem;public PageRows<OrderVO> listOrder(OrderQueryVO OrderQueryVO) {if (switchNewSystem) {return OrderExternalConvertor.pageDto2PageVo(OrderAbility.listOrder(OrderExternalConvertor.queryVo2ModelQuery(OrderQueryVO)));}return OrderExternalConvertor.pageDto2PageVo(OrderAbility.listOrderFromEpm(OrderExternalConvertor.queryVo2QueryDto(OrderQueryVO)));}
}

单元测试类：

@RunWith(PowerMockRunner.class)
public class OrderExternalFacadeTest {@InjectMocksprivate OrderExternalFacade OrderExternalFacade;@Mockprivate OrderAbility OrderAbility;@Mockprivate OrderExternalConvertor OrderExternalConvertor;@Testpublic void listOrder() {ReflectionTestUtils.setField(OrderExternalFacade, "switchNewSystem", true);when(OrderExternalConvertor.queryVo2ModelQuery(any())).thenReturn(new OrderModelQueryDTO());when(OrderAbility.listOrder(any())).thenReturn(new PageRows<>());when(OrderExternalConvertor.pageDto2PageVo(any())).thenReturn(new PageRows<>());PageRows<OrderVO> rt = OrderExternalFacade.listOrder(new OrderQueryVO());Assert.assertNotNull(rt);}
}

4.4、返回类型为void的方法如何断言

验证调用次数：verify(OrderService, times(1)).insertOrder(orderBO);

被测试类：

public class OrderService{@Autowiredprivate OrderDao OrderDao;/*** 添加订单* @param OrderBO* @throws Exception*/@Overridepublic void insertOrder(OrderBO OrderBO) throws Exception{OrderDao.insertOrder(OrderBO);}
}

单元测试类：

@RunWith(PowerMockRunner.class)
public class OrderServiceTest {@InjectMocksprivate OrderService OrderService;@Mockprivate OrderDao OrderDao;@Beforepublic void setUp() throws Exception {}@Testpublic void testinsertOrder() throws Exception {OrderBO orderBO = new OrderBO();orderBO.setHandleType("order");orderBO.setBoId("1234568");orderBO.setHandeleSuggest("submit");// 如何mock 返回类型为void的方法PowerMockito.doNothing().when(OrderDao).insertOrder(any());//whenOrderService.insertOrder(orderBO);verify(OrderService, times(1)).insertOrder(orderBO);}}

4.5、异常如何断言

被测试类：

public void delete(List<String> ids, String requiredBillId) {RequiredBillEntity requiredBill = requiredBillMapper.selectEntity(requiredBillId);if (requiredBill == null){throw new BusinessException(RetCode.BUSINESSERROR_CODE, MessageConst.REQUIRED_BILL_NOT_FOUND);}if (!RequiredBillStatusEnum.DRAFT.getStatus().equals(requiredBill.getStatus())){throw new BusinessException(RetCode.BUSINESSERROR_CODE, MessageConst.REQUIRED_BILL_STATUS_NOT_DRAFT);}requiredBillDetailMapper.deleteEntities(new ParamsMap("id_IN", ids));
}

测试类：

@Test
public void testDelete() {List<String> ids = Lists.newArrayList();ids.add("dddd");String requiredBillId = "ddd";when(requiredBillMapper.selectEntity(anyString())).thenReturn(null);// 断言业务异常try {requiredBillDetailService.delete(ids,requiredBillId);fail("Expected BusiException");} catch (BusiException e) {assertEquals(RetCode.BUSINESSERROR_CODE, e.getExCode());assertEquals(REQUIRED_BILL_NOT_FOUND, e.getMessage());}}

简洁的一点的话：

@Test
public void testDelete() {List<String> ids = Lists.newArrayList();ids.add("dddd");String requiredBillId = "ddd";when(requiredBillMapper.selectEntity(anyString())).thenReturn(null);// 断言业务异常Assert.assertThrows(BusinessException.class, () ->requiredBillDetailService.delete(requiredBillDetailDTO));}