Maven项目中RandomGeneratorServiceImplTest测试类无法执行的问题排查与解决

问题现象 #

• 项目目录结构：
  
• 执行mvn test命令时，仅运行3个测试类：
  • SocialMultiplicationApplicationTests
  • MultiplicationServiceTest
  • RandomGeneratorServiceTest
• 单独执行RandomGeneratorServiceImplTest时，运行命令mvn test -Dtest=RandomGeneratorServiceImplTest出现报错：

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.22.2:test (default-test) 
on project social-multiplication: No tests were executed!  (Set -DfailIfNoTests=false to ignore this error.) -> [Help 1]

项目pom.xml配置 #

<?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>2.7.3</version>
        <relativePath/> <!-- lookup parent from repository -->
    </parent>
    <groupId>microservices.book</groupId>
    <artifactId>social-multiplication</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>social-multiplication</name>
    <description>Social Multiplication App</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>
        </dependency>
        <dependency>
            <groupId>org.springframework</groupId>
            <artifactId>spring-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.junit.jupiter</groupId>
            <artifactId>junit-jupiter-api</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-test</artifactId>
        </dependency>
        <dependency>
            <groupId>org.mockito</groupId>
            <artifactId>mockito-core</artifactId>
        </dependency>
        <dependency>
            <groupId>org.assertj</groupId>
            <artifactId>assertj-core</artifactId>
        </dependency>
        <dependency>
            <groupId>junit</groupId>
            <artifactId>junit</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>

    <build>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>

</project>

无法运行的测试类代码 #

package microservices.book.multiplication.service;


import static org.assertj.core.api.Assertions.assertThat;
import org.junit.Before;
import org.junit.Test;

import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

public class RandomGeneratorServiceImplTest {

    private RandomGeneratorServiceImpl randomGeneratorServiceImp;

    @Before
    public void setUp(){
        randomGeneratorServiceImp = new RandomGeneratorServiceImpl();
    }

    @Test
    public void generateRandomFactorIsBetweenExpectedLimits() {
        List<Integer> randomFactors = IntStream.range(0,1000)
                .map(i -> randomGeneratorServiceImp.generateRandomFactor())
                .boxed()
                .collect(Collectors.toList());

        for(Integer i: randomFactors){
            assertThat(i).isIn(
                    IntStream.range(11, 100).
                            boxed().collect(Collectors.toList()));
        }
    }
}

问题根源与解决方案 #

问题根源 #

项目依赖同时引入了JUnit4和JUnit5，导致测试引擎冲突，Maven Surefire插件无法识别JUnit4风格的测试类。

解决方案 #

将测试类迁移至JUnit5规范：

1. 替换@Before注解为@BeforeAll
2. 在测试类上添加@TestInstance(Lifecycle.PER_CLASS)注解

修改后的测试类代码：

package microservices.book.multiplication.service;

import static org.assertj.core.api.Assertions.assertThat;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import org.junit.jupiter.api.TestInstance;
import org.junit.jupiter.api.TestInstance.Lifecycle;

import java.util.List;
import java.util.stream.Collectors;
import java.util.stream.IntStream;

@TestInstance(Lifecycle.PER_CLASS)
public class RandomGeneratorServiceImplTest {

    private RandomGeneratorServiceImpl randomGeneratorServiceImp;

    @BeforeAll
    public void setUp(){
        randomGeneratorServiceImp = new RandomGeneratorServiceImpl();
    }

    @Test
    public void generateRandomFactorIsBetweenExpectedLimits() {
        List<Integer> randomFactors = IntStream.range(0,1000)
                .map(i -> randomGeneratorServiceImp.generateRandomFactor())
                .boxed()
                .collect(Collectors.toList());

        for(Integer i: randomFactors){
            assertThat(i).isIn(
                    IntStream.range(11, 100).
                            boxed().collect(Collectors.toList()));
        }
    }
}

内容的提问来源于stack exchange，提问作者IDK