基于Mockito的多层模拟单元测试小结

淩亂°似流年 2022-01-28 08:13 762阅读 0赞

1.首先，我们先来了解下Mock是个什么东西吧。[Mockito教程][Mockito]

2.基本上一些简单unit-test的mock用法可以参照上面那个教程了。我要总结的主要是分为两个方面：

1) 通过Mock来访问Controller；

参考：[基于RESTful风格的SpringMVC的测试][RESTful_SpringMVC] , [Testing Spring MVC Controllers][]

2) 通过Mock来访问Controller，并且模拟Dao层数据入库功能。也就是在不改变原有代码的基础上，处理get请求且取消数据入库。

参考：[多层mock的单元测试][mock]

3.**前提**：我们的项目是MVC的架构，假设分为controller, service, dao。

1) 假设controller代码如下：

package com.bas.controller;
    
    import com.bas.TestService;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.web.bind.annotation.RequestMapping;
    import org.springframework.web.bind.annotation.RequestMethod;
    import org.springframework.web.bind.annotation.RestController;
    
    
    @RestController
    public class TestController {
    
        @Autowired
        private TestService service;
    
        @RequestMapping(value = "/test/abc", method = RequestMethod.GET)
        public Boolean cfginstFileParse() {        
            return service.parse("abc.xml");
        }
    
    }

2) 假设service代码如下：

package com.bas.serviceImpl;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Service;
    
    
    @Service
    public class TestServiceImpl implements TestService {
    
        @Autowired
        private TestDao handler;
        @Value("${size}")
        private Integer size;
    
    
        @Override
        public  Boolean parse(String xpath){
            
            return  handler.parseXml();
    
        }
    }

3) 假设dao代码如下：

package com.bas.dao;
    
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.stereotype.Service;
    
    
    @Service
    public class TestDaoImpl implements TestDao {
    
        @Override
        public  Boolean parseXml(String xpath){
            
            return  true;
    
        }
    }

4) MockUtil工具类：

package com.bas.common.util;
    
    import com.bas.dao;
    import org.springframework.test.web.servlet.MockMvc;
    import org.springframework.test.web.servlet.MvcResult;
    import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
    import org.springframework.test.web.servlet.setup.MockMvcBuilders;
    import org.springframework.web.context.WebApplicationContext;
    
    import java.lang.reflect.Type;
    import java.util.HashMap;
    import java.util.List;
    
    import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
    import static org.mockito.Mockito.doNothing;
    
    
    public class MockUtil {
    
        private volatile static MockUtil mockUtil;
        private static MockMvc mvc; // process request controller
    
        public MockUtil() {}
    
        public static MockUtil builder(WebApplicationContext wac) {
            if(mockUtil == null) {
                synchronized (MockUtil.class){
                    if(mockUtil == null) {
                        mockUtil = new MockUtil();
                        mvc = MockMvcBuilders.webAppContextSetup(wac).build();
                    }
                }
            }
            return mockUtil;
        }
    
        /**
         * Process the get request.
         * @param url controller restful api
         * @return return the result from controller
         * @throws Exception
         */
        public static MvcResult getPerformResult(String url) throws Exception {
            return mvc.perform(MockMvcRequestBuilders
                    .get(url))
                    .andExpect(status().isOk())
                    .andReturn();
        }
    
        /**
         * Process the get request for parsing.
         * @param controller the app entrance we want to test
         * @param handler the object what is mocked , so it would not run
         * @param url controller restful api
         * @return return the result from controller
         * @throws Exception
         */
        public static MvcResult parsePerformResult(Object controller, Dao handler, String url) throws Exception {
            // Setup Spring test in standalone mode
            MockMvc mockMvc = MockMvcBuilders.standaloneSetup(controller).build();
    
            // stub the method handle , to do nothing when is's called.
            doNothing().when(handler).handle(new HashMap<String, List<Object>>());
    
            return mockMvc.perform(MockMvcRequestBuilders
                    .get(url))
                    .andExpect(status().isOk())
                    .andReturn();
        }
    
    }

4.**通过Mock来访问Controller**

package com.bas.test;
    
    import org.junit.After;
    import org.junit.Before;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    import org.springframework.test.web.servlet.MockMvc;
    import org.springframework.test.web.servlet.MvcResult;
    import org.springframework.test.web.servlet.setup.MockMvcBuilders;
    import org.springframework.web.context.WebApplicationContext;
    
    @RunWith(SpringRunner.class)
    @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
    public class Test {
    
        @Autowired
        private WebApplicationContext wac;
        private MockMvc mvc;
    
        @Before
        public void before() {
            mvc = MockMvcBuilders.webAppContextSetup(wac).build();
        }
    
        @Test
        public void unitTest() {
            try {
                MvcResult result = MockUtil.builder(wac).getPerformResult("/test/abc");
                System.out.println(result.getResponse().getContentAsString());
            } catch (Exception e) {
    		
            }
        }
    
    }

5.**通过Mock来访问Controller、dao层模拟的多层Mock**

package com.bas.test;
    
    import com.bas.TestController;
    import com.bas.TestServiceImpl;
    import com.bas.TestDaoImpl;
    import org.junit.After;
    import org.junit.Before;
    import org.junit.Test;
    import org.junit.runner.RunWith;
    import org.mockito.InjectMocks;
    import org.mockito.Mock;
    import org.mockito.MockitoAnnotations;
    import org.springframework.beans.factory.annotation.Autowired;
    import org.springframework.beans.factory.annotation.Value;
    import org.springframework.boot.test.context.SpringBootTest;
    import org.springframework.test.context.junit4.SpringRunner;
    import org.springframework.test.web.servlet.MvcResult;
    
    @RunWith(SpringRunner.class)
    @SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
    public class Test {
    	
    	/* start to mock parse from controller api */
    	@Before
    	public void before() {
    		// initialize mock object , without it would cause in failed mock
    		MockitoAnnotations.initMocks(this);
    	}
    
    	@Autowired
    	private TestController testController;
    	@InjectMocks
    	@Autowired
    	TestServiceImpl mockService;
    	@Mock
    	TestDaoImpl mockHandler;
    
    	@Test
    	public void mockControllerTest() {
    		try {
                // ReflectionTestUtils.setField(mockService, "size", 1);
    			// run controller , mock service and handler
    			MvcResult result = MockUtil.parsePerformResult(testController, mockHandler, "/test/abc");
    			System.out.println(result.getResponse().getContentAsString());
    		}catch (Exception e) {
    		
    		}
    	}
    }

注：

1.@InjectMocks, @Autowired 注入的是TestServiceImpl而不是TestService，因为Mock会创建一个实例而interface是不可以的；

2.MockitoAnnotations.initMocks(this); 如果这一句漏掉了会导致dao真实的执行而模拟失败；

3.细心的可以看到TestServiceImpl的@Value("$\{size\}")，这个如果在service用到的话需要在test这样注入：ReflectionTestUtils.setField(mockService, "size", 1)。

附：

1.[可模拟的数据类型 教程][Link 1]

[Mockito]: https://www.jianshu.com/p/f6e3ab9719b9
[RESTful_SpringMVC]: https://www.jianshu.com/p/91045b0415f0
[Testing Spring MVC Controllers]: https://www.cnblogs.com/wade-xu/p/4311657.html
[mock]: https://blog.csdn.net/weixin_34228387/article/details/86810729
[Link 1]: https://gitee.com/tang006/mock