记录项目中一次单元测试

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• 一、单元测试私有类方法
• 二、使用步骤
• • 1.测试方法
  • 2.具体步骤
• 总结

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这里记录一下单元测试私有类方法时应该注意的点

代码如下（示例）：

//todo AssertUtil.assertTrue会抛出异常，这里也没写怎么处理异常
    private List assembleFrequencyData(List formList, List batteryIdList) {
        List sendList = new ArrayList<>();
        Map mapping = bcaMapper.queryVinBidMapping(batteryIdList);
        for (FrequencyChanges frequencyChanges : formList) {
            AssertUtil.assertTrue(Objects.nonNull(frequencyChanges.getFrequency())
                    && StringUtils.hasText(frequencyChanges.getBatteryId())
                    && Objects.nonNull(frequencyChanges.getDuration()), ApplicationEnum.SDA_HAS_EMPTY_DATA);
            SdaFrequencyChangesForm sdaFrequencyChangesForm = new SdaFrequencyChangesForm();
            sdaFrequencyChangesForm.setFrequency(frequencyChanges.getFrequency());
            sdaFrequencyChangesForm.setBId(frequencyChanges.getBatteryId());
            sdaFrequencyChangesForm.setPeriod(String.valueOf(frequencyChanges.getDuration()));
            sdaFrequencyChangesForm.setVin(mapping.get(sdaFrequencyChangesForm.getBId()).getVin());
            sendList.add(sdaFrequencyChangesForm);
        }
        return sendList;
    }

注意，本文使用的代码中已经使用了@Mock和@InjectMocks模拟了相关类

测试私有类方法时无法直接调用，需要用到java反射机制，同时这里调用了Mapper层的方法，需要用到PowerMockito的when机制
代码如下（示例）：

@Test
    public void assembleFrequencyDataTest() throws Exception {
        List frequencyChangeslist = new ArrayList();
        FrequencyChanges frequencyChanges = new FrequencyChanges();
        frequencyChanges.setFrequency(10);
        frequencyChanges.setBatteryId("BBA76DB39A58E1CF4823220CF2D5F113");
        frequencyChanges.setDuration(BigDecimal.valueOf(2.5));
        frequencyChangeslist.add(frequencyChanges);
        List batteryIdList = new ArrayList<>();;
        batteryIdList.add("BBA76DB39A58E1CF4823220CF2D5F113");
        Map mapping = new HashMap<>();
        VinBatteryIdMappingVO vinBatteryIdMappingVO = new VinBatteryIdMappingVO();
        vinBatteryIdMappingVO.setVin("LR6DACDG0LX200375");
        vinBatteryIdMappingVO.setBatteryId("BBA76DB39A58E1CF4823220CF2D5F113");
        mapping.put("BBA76DB39A58E1CF4823220CF2D5F113",vinBatteryIdMappingVO);
        PowerMockito.when(bcaMapper.queryVinBidMapping(anyList()))
                .thenReturn(mapping);
        Method assembleFrequencyData = bcaServiceImpl.getClass()
                .getDeclaredMethod("assembleFrequencyData",List.class,List.class);
        assembleFrequencyData.setAccessible(true);
        Object formlist = assembleFrequencyData.invoke(bcaServiceImpl,frequencyChangeslist,batteryIdList);
        Assert.assertNotNull(formlist);
        System.out.println(String.valueOf(formlist));

    }

首先是要创建私有类的方法,需要使用类对象，方法名字符串，方法参数的类

Method assembleFrequencyData = bcaServiceImpl.getClass()
                .getDeclaredMethod("assembleFrequencyData",List.class,List.class);
assembleFrequencyData.setAccessible(true);

然后是mock一下调用的其他方法

PowerMockito.when(bcaMapper.queryVinBidMapping(anyList()))
                .thenReturn(mapping);

然后就可以运行得到测试结果了，只不过结果限定是object类型

Object formlist = assembleFrequencyData.invoke(bcaServiceImpl,frequencyChangeslist,batteryIdList);

当然，单元测试要考虑路径覆盖率，像本文方法中使用assert会抛出异常，
但是作者又不去catch这个异常，所有暂时没做其他分支的测试