MockMvc和Mockito之酷炫使用

由于项目中需要添加单元测试，所以查询之后发现Mockito非常适合现在的web项目。

首先需要添加pom依赖：

<dependency>
    <groupId>junit</groupId>
    <artifactId>junit</artifactId>
    <version>4.11</version>
    <scope>test</scope>
</dependency>
<dependency>
    <groupId>org.mockito</groupId>
    <artifactId>mockito-all</artifactId>
    <version>1.9.5</version>
</dependency>

在ControllerTest类上需要添加如下配置：

//XML风格
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration(value = "src/main/webapp")
@ContextHierarchy({
        @ContextConfiguration(name = "parent", locations = "classpath:spring-config.xml"),
        @ContextConfiguration(name = "child", locations = "classpath:spring-others.xml")
})  

OR

//注解风格
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration(value = "src/main/webapp")
@ContextHierarchy({
        @ContextConfiguration(name = "parent", classes = AppConfig.class),
        @ContextConfiguration(name = "child", classes = MvcConfig.class)
}) 

MockMvc为spring测试下的一个非常好用的类，配合Mockito使用能达到非常好的效果，他们的初始化需要在setUp中进行，具体代码如下：

@Autowired
private WebApplicationContext wac;
private MockMvc mockMvc;

@Mock
private DemoService demoService;

@Before
public void setUp() throws Exception {
    // 构造appcontext
    mockMvc = MockMvcBuilders.webAppContextSetup(wac).build();
    // 初始化Mock
    MockitoAnnotations.initMocks(this);
}

这样mockMvc和Mockito的方法就可以在下面顺利使用了，例如：

@Test
public void testHelloWorld() throws Exception {
    // 1. controller mvc test
    MvcResult result = mockMvc.perform(MockMvcRequestBuilders.get("/demo/hello"))                
　　　　.andExpect(MockMvcResultMatchers.handler().handlerType(DemoController.class))            
　　　　.andExpect(MockMvcResultMatchers.handler().methodName("helloWorld"))                
　　　　.andExpect(MockMvcResultMatchers.view().name("demo/hello"))                
　　　　.andExpect(MockMvcResultMatchers.model().attributeExists("msg"))                
　　　　.andExpect(MockMvcResultMatchers.status().isOk())                
　　　　.andDo(MockMvcResultHandlers.print())                
　　　　.andReturn();
    Assert.assertNotNull(result.getModelAndView().getModel().get("msg"));

    // 2. demo service stub test
    String stub = "except result";
    Mockito.when(demoService.demoShow()).thenReturn(stub);
    Assert.assertEquals(stub, demoService.demoShow());
    Mockito.verify(demoService).demoShow();
}

MockMvc可以对controller中的一次调用进行模拟，perform就是一次请求，MockMvcRequestBuilders进行url的请求，andExcept方法为对Controller类、调用方法、视图和model的预期设置，andDo进行这次请求的执行，最后andReturn返回。

Mockito通过方法when()、thenReturn()等方法可以对方法进行打桩，让后续方法按照自己的数据桩来返回，达到了隔离依赖的效果。

整体的测试代码如下：

import com.demo.service.DemoService;
import junit.framework.Assert;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.Mockito;
import org.mockito.MockitoAnnotations;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.test.context.ContextConfiguration;
import org.springframework.test.context.ContextHierarchy;
import org.springframework.test.context.junit4.SpringJUnit4ClassRunner;
import org.springframework.test.context.web.WebAppConfiguration;
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.result.MockMvcResultHandlers;
import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
import org.springframework.test.web.servlet.setup.MockMvcBuilders;
import org.springframework.web.context.WebApplicationContext;

/**
 * DemoControllerTest.
 */
//注解风格
@RunWith(SpringJUnit4ClassRunner.class)
@WebAppConfiguration(value = "src/main/webapp")
@ContextHierarchy({
        @ContextConfiguration(name = "parent", locations = "classpath:spring-config.xml")
})
public class DemoControllerTest {

    @Autowired
    private WebApplicationContext wac;
    private MockMvc mockMvc;

    @Mock
    private DemoService demoService;

    @Before
    public void setUp() throws Exception {
        // 构造appcontext
        mockMvc = MockMvcBuilders.webAppContextSetup(wac).build();
        // 初始化Mock
        MockitoAnnotations.initMocks(this);
    }

    @Test
    public void testIndex() throws Exception {
        MvcResult result = mockMvc.perform(MockMvcRequestBuilders.get("/demo/"))
                .andExpect(MockMvcResultMatchers.handler().handlerType(DemoController.class))
                .andExpect(MockMvcResultMatchers.handler().methodName("index"))
                .andExpect(MockMvcResultMatchers.view().name("demo/index"))
                .andExpect(MockMvcResultMatchers.status().isOk())
                .andDo(MockMvcResultHandlers.print())
                .andReturn();

        Assert.assertNotNull(result.getModelAndView().getViewName());
    }

    @Test
    public void testHelloWorld() throws Exception {
        // 1. controller mvc test
        MvcResult result = mockMvc.perform(MockMvcRequestBuilders.get("/demo/hello"))
                .andExpect(MockMvcResultMatchers.handler().handlerType(DemoController.class))
                .andExpect(MockMvcResultMatchers.handler().methodName("helloWorld"))
                .andExpect(MockMvcResultMatchers.view().name("demo/hello"))
                .andExpect(MockMvcResultMatchers.model().attributeExists("msg"))
                .andExpect(MockMvcResultMatchers.status().isOk())
                .andDo(MockMvcResultHandlers.print())
                .andReturn();
        Assert.assertNotNull(result.getModelAndView().getModel().get("msg"));

        // 2. demo service stub test
        String stub = "except result";
        Mockito.when(demoService.demoShow()).thenReturn(stub);
        Assert.assertEquals(stub, demoService.demoShow());
        Mockito.verify(demoService).demoShow();
    }
}