Spring Boot 基于 JUnit 5 实现单元测试-阿里云开发者社区

简介

Spring Boot 2.2.0 版本开始引入 JUnit 5 作为单元测试默认库，在 Spring Boot 2.2.0 版本之前，spring-boot-starter-test 包含了 JUnit 4 的依赖，Spring Boot 2.2.0 版本之后替换成了 Junit Jupiter。

JUnit 4 和 JUnit 5 的差异

1. 忽略测试用例执行

JUnit 4：

@Test
@Ignore
public void testMethod() {
   // ...
}

JUnit 5：

@Test
@Disabled("explanation")
public void testMethod() {
   // ...
}

2. RunWith 配置

JUnit 4：

@RunWith(SpringRunner.class)
@SpringBootTest
public class ApplicationTests {
    @Test
    public void contextLoads() {
    }
}

JUnit 5：

@ExtendWith(SpringExtension.class)
@SpringBootTest
public class ApplicationTests {
    @Test
    public void contextLoads() {
    }
}

3. @Before、@BeforeClass、@After、@AfterClass 被替换

@BeforeEach 替换 @Before
@BeforeAll 替换 @BeforeClass
@AfterEach 替换 @After
@AfterAll 替换 @AfterClass

开发环境

JDK 8

示例

1.创建 Spring Boot 工程。

2.添加 spring-boot-starter-web 依赖，最终 pom.xml 如下。

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>2.2.6.RELEASE</version>
        <relativePath/>
    </parent>
    <groupId>tutorial.spring.boot</groupId>
    <artifactId>spring-boot-junit5</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>spring-boot-junit5</name>
    <description>Demo project for Spring Boot Unit Test with JUnit 5</description>
 
    <properties>
        <java.version>1.8</java.version>
    </properties>
 
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
            <exclusions>
                <exclusion>
                    <groupId>org.junit.vintage</groupId>
                    <artifactId>junit-vintage-engine</artifactId>
                </exclusion>
            </exclusions>
        </dependency>
    </dependencies>
 
    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 
</project>

3.工程创建好之后自动生成了一个测试类。

package tutorial.spring.boot.junit5;
 
import org.junit.jupiter.api.Test;
import org.springframework.boot.test.context.SpringBootTest;
 
@SpringBootTest
class SpringBootJunit5ApplicationTests {
 
    @Test
    void contextLoads() {
    }
 
}

这个测试类的作用是检查应用程序上下文是否可正常启动。

@SpringBootTest 注解告诉 Spring Boot 查找带 @SpringBootApplication 注解的主配置类，并使用该类启动 Spring

应用程序上下文。

4.补充待测试应用逻辑代码

4.1. 定义 Service 层接口

package tutorial.spring.boot.junit5.service;
 
public interface HelloService {
 
    String hello(String name);
}

4.2. 定义 Controller 层

package tutorial.spring.boot.junit5.controller;
 
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PathVariable;
import org.springframework.web.bind.annotation.RestController;
import tutorial.spring.boot.junit5.service.HelloService;
 
@RestController
public class HelloController {
 
    private final HelloService helloService;
 
    public HelloController(HelloService helloService) {
        this.helloService = helloService;
    }
 
    @GetMapping("/hello/{name}")
    public String hello(@PathVariable("name") String name) {
        return helloService.hello(name);
    }
}

4.3. 定义 Service 层实现

package tutorial.spring.boot.junit5.service.impl;
 
import org.springframework.stereotype.Service;
import tutorial.spring.boot.junit5.service.HelloService;
 
@Service
public class HelloServiceImpl implements HelloService {
 
    @Override
    public String hello(String name) {
        return "Hello, " + name;
    }
}

5.编写发送 HTTP 请求的单元测试。

package tutorial.spring.boot.junit5;
 
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.boot.test.web.client.TestRestTemplate;
import org.springframework.boot.web.server.LocalServerPort;
 
@SpringBootTest(webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT)
public class HttpRequestTest {
 
    @LocalServerPort
    private int port;
 
    @Autowired
    private TestRestTemplate restTemplate;
 
    @Test
    public void testHello() {
        String requestResult = this.restTemplate.getForObject("http://127.0.0.1:" + port + "/hello/spring",
                String.class);
        Assertions.assertThat(requestResult).contains("Hello, spring");
    }
}

说明：

webEnvironment = SpringBootTest.WebEnvironment.RANDOM_PORT 使用本地的一个随机端口启动服务；
@LocalServerPort 相当于 @Value("${local.server.port}")；
在配置了 webEnvironment 后，Spring Boot 会自动提供一个 TestRestTemplate 实例，可用于发送 HTTP 请求。
除了使用 TestRestTemplate 实例发送 HTTP 请求外，还可以借助 org.springframework.test.web.servlet.MockMvc 完成类似功能，代码如下：

package tutorial.spring.boot.junit5.controller;
 
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
import org.springframework.boot.test.context.SpringBootTest;
import org.springframework.test.web.servlet.MockMvc;
import org.springframework.test.web.servlet.request.MockMvcRequestBuilders;
import org.springframework.test.web.servlet.result.MockMvcResultHandlers;
import org.springframework.test.web.servlet.result.MockMvcResultMatchers;
 
@SpringBootTest
@AutoConfigureMockMvc
public class HelloControllerTest {
 
    @Autowired
    private HelloController helloController;
 
    @Autowired
    private MockMvc mockMvc;
 
    @Test
    public void testNotNull() {
        Assertions.assertThat(helloController).isNotNull();
    }
 
    @Test
    public void testHello() throws Exception {
        this.mockMvc.perform(MockMvcRequestBuilders.get("/hello/spring"))
                .andDo(MockMvcResultHandlers.print())
                .andExpect(MockMvcResultMatchers.status().isOk())
                .andExpect(MockMvcResultMatchers.content().string("Hello, spring"));
    }
}

以上测试方法属于整体测试，即将应用上下文全都启动起来，还有一种分层测试方法，譬如仅测试 Controller 层。

6.分层测试。

package tutorial.spring.boot.junit5.controller;
 
import org.assertj.core.api.Assertions;
import org.junit.jupiter.api.Test;
import org.mockito.Mockito;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.autoconfigure.web.servlet.WebMvcTest;
import org.springframework.boot.test.mock.mockito.MockBean;
import org.springframework.test.web.servlet.MockMvc;
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 tutorial.spring.boot.junit5.service.HelloService;
 
@WebMvcTest
public class HelloControllerTest {
 
    @Autowired
    private HelloController helloController;
 
    @Autowired
    private MockMvc mockMvc;
 
    @MockBean
    private HelloService helloService;
 
    @Test
    public void testNotNull() {
        Assertions.assertThat(helloController).isNotNull();
    }
 
    @Test
    public void testHello() throws Exception {
        Mockito.when(helloService.hello(Mockito.anyString())).thenReturn("Mock hello");
        this.mockMvc.perform(MockMvcRequestBuilders.get("/hello/spring"))
                .andDo(MockMvcResultHandlers.print())
                .andExpect(MockMvcResultMatchers.status().isOk())
                .andExpect(MockMvcResultMatchers.content().string("Mock hello"));
    }
}