关于java:JUnit-5简明教程

概述

写测试用例对于开发来说有2点益处，一是开发阶段写完的性能能够疾速验证，第二就是在前期需要变动或批改BUG后能够疾速测试以后改变是否带来其它问题。上面就理解一下Junit5写测试用例。

筹备

创立一个maven我的项目

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

增加依赖

引入第三方断言库assertj
反对json测试
反对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>                <!-- 在这里申明的目标是应用指定的版本 -->                <!-- 执行测试用例工作的插件，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>                <!-- 用来执行编译工作的插件，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>

创立一个User

public record User(String name, Integer age, Boolean blocked, LocalDate birthDate) {}

测试

测试用例命名最佳实际

首先测试类名应该以Test结尾，测试用例名称最好听从以下规定

测试名称应表白特定要求
测试名称应蕴含预期的输出或预期的后果
测试名称应以陈说的模式

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

测试类和测试方法能够申明自定义显示名称，能够应用空格、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

参数化测试能够用不同的参数屡次运行测试。它们和一般的@Test办法一样申明，然而应用@ParameterizedTest注解。还必须申明至多一个将为每次调用提供参数的来

应用@ValueSource来指定参数起源

它能够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文件内容作为参数起源

它能够让你应用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.csv

name,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);}

总结

本文介绍了如何应用Junit5写测试用例。

参考

Unit test naming best practices Unit test naming best practices - Stack Overflow
https://osherove.com/blog/2005/4/3/naming-standards-for-unit-tests.html
AssertJ Homepage https://assertj.github.io/doc/
Gradle: https://stackoverflow.com/a/64986861
https://junit.org/junit5/docs/current/user-guide/#running-tests-tag-expressions
further reading
JUnit 5 User Guide
JUnit 5 中文文档 https://doczhcn.gitbook.io/junit5/
AssertJ - fluent assertions java library
Jupiter / JUnit 5 - Testcontainers
awaitility/awaitility: Awaitility is a small Java DSL for synchronizing asynchronous operations (github.com)

概述

筹备