概述写测试用例对于开发来说有2点好处，一是开发阶段写完的功能可以快速验证，第二就是在后期需求变动或修改BUG后可以快速测试当前改动是否带来其它问题。下面就了解一下Junit5写测试用例。准备创建一个maven项目mkdir junit5-tutorialcd junit5-tutorialmkdir -p src/main/javamkdir -p src/test/javamkdir -p src/main/resourcesmkdir -p src/test/resources# 编写pom.xmlvi pom.xml添加依赖引入第三方断言库assertj支持json测试支持xml测试pom.xml<?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 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.example.xxx</groupId> <artifactId>junit5-tutorial</artifactId> <version>1.0-SNAPSHOT</version> <name>junit5-tutorial</name> <url>https://www.xxx.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>17</maven.compiler.source> <maven.compiler.target>17</maven.compiler.target> </properties> <build> <pluginManagement> <plugins> <!-- 在这里声明的目的是使用指定的版本 --> <!-- 执行测试用例任务的插件，默认绑定test生命周期的test阶段 --> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>3.0.0-M6</version> </plugin> <!-- 用来执行编译任务的插件，默认绑定default生命周期compile阶段 --> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.10.1</version> </plugin> </plugins> </pluginManagement> </build> <dependencyManagement> <dependencies> <!-- XML Unit - Dependency Management --> <dependency> <groupId>net.bytebuddy</groupId> <artifactId>byte-buddy</artifactId> <version>1.12.10</version> </dependency> <dependency> <groupId>net.bytebuddy</groupId> <artifactId>byte-buddy-agent</artifactId> <version>1.12.10</version> <scope>test</scope> </dependency> <!-- Mockito Dependency --> <dependency> <groupId>org.mockito</groupId> <artifactId>mockito-junit-jupiter</artifactId> <version>4.5.1</version> <scope>test</scope> </dependency> </dependencies> </dependencyManagement> <dependencies> <dependency> <groupId>org.assertj</groupId> <artifactId>assertj-core</artifactId> <version>3.22.0</version> <scope>test</scope> </dependency> <dependency> <groupId>io.github.classgraph</groupId> <artifactId>classgraph</artifactId> <version>4.8.146</version> </dependency> <dependency> <groupId>org.junit.jupiter</groupId> <artifactId>junit-jupiter</artifactId> <version>5.8.2</version> </dependency> <!-- JSON Unit - Dependencies --> <dependency> <groupId>net.javacrumbs.json-unit</groupId> <artifactId>json-unit-assertj</artifactId> <version>2.33.0</version> <scope>test</scope> </dependency> <dependency> <groupId>com.fasterxml.jackson.core</groupId> <artifactId>jackson-databind</artifactId> <version>2.13.2.2</version> </dependency> <dependency> <groupId>com.fasterxml.jackson.datatype</groupId> <artifactId>jackson-datatype-jsr310</artifactId> <version>2.13.2</version> </dependency> <!-- XML Unit - Dependencies --> <dependency> <groupId>org.xmlunit</groupId> <artifactId>xmlunit-assertj</artifactId> <version>2.9.0</version> <scope>test</scope> </dependency> </dependencies></project>创建一个Userpublic record User(String name, Integer age, Boolean blocked, LocalDate birthDate) {}测试测试用例命名最佳实践首先测试类名应该以Test结尾，测试用例名称最好遵从以下规则测试名称应表达特定要求测试名称应包含预期的输入或预期的结果测试名称应以陈述的形式具体参考：https://osherove.com/blog/2005/4/3/naming-standards-for-unit-tests.html断言@Test@DisplayName("User should be at least 18")void user_should_be_at_least_18() { // junit5 的断言 assertTrue(user.age() >= 18); // assertj 的断言 assertThat(user.age()).isGreaterThanOrEqualTo(18);}显示名称测试类和测试方法可以声明自定义显示名称，可以使用空格、特殊字符、甚至emojis表情符号，这些名称会在runner和测试报告中显示。参数化测试参数化测试可以用不同的参数多次运行测试。它们和普通的@Test方法一样声明，但是使用@ParameterizedTest注解。还必须声明至少一个将为每次调用提供参数的来使用@ValueSource来指定参数来源它可以指定一个原生类型的数组，并且只能为每次调用提供一个参数@ParameterizedTest@ValueSource(ints = {20, 50, 80})void test_value_source(int age) { assertThat(age).isGreaterThanOrEqualTo(18);}读取CSV文件内容作为参数来源它可以让你使用classpath中的csv文件。csv文件中的每一行都会导致参数测试的一次调用src/test/resources/friends.csvname,agelisa,20hans,30hanna,40@ParameterizedTest@CsvFileSource(resources = "/friends.csv", numLinesToSkip = 1)void test_value_source_by_csv_file_source(String name, int age) { assertThat(age).isGreaterThanOrEqualTo(18);}标签我们可以给测试类或测试用例上面通过@Tag加标签，执行测试的时候可以指定标签，从而达到为测试用例分组的目的。下面就给测试类打上一个integration的标签@Tag("integration")class User01Test { // ...}可以使用如下命令来指定要执行的测试用例：mvn test -Dgroups="integration"左侧只执行了Running com.example.xxx.User01Test一个测试类，右侧则执行了3个总结本文介绍了如何使用Junit5写测试用例。参考Unit test naming best practices Unit test naming best practices - Stack Overflowhttps://osherove.com/blog/2005/4/3/naming-standards-for-unit-tests.htmlAssertJ Homepage https://assertj.github.io/doc/Gradle: https://stackoverflow.com/a/64986861https://junit.org/junit5/docs/current/user-guide/#running-tests-tag-expressionsfurther readingJUnit 5 User GuideJUnit 5 中文文档 https://doczhcn.gitbook.io/junit5/AssertJ - fluent assertions java libraryJupiter / JUnit 5 - Testcontainersawaitility/awaitility: Awaitility is a small Java DSL for synchronizing asynchronous operations (github.com)
