这里入门junit 为单元测试做准备,,以前随便写的
https://junit.org/junit5/
github https://github.com/junit-team/junit5/

依照的官方文档为https://junit.org/junit5/docs/current/user-guide/#overview-java-versions

此官方文档有中文版本https://sjyuan.cc/junit5/user-guide-cn/

什么是Junit

自动化测试框架

示例工程

示例工程在github上
https://github.com/junit-team/junit5-samples/tree/r5.3.0/junit5-jupiter-starter-maven

编写测试

package com.ming.servlet;

import com.sun.org.glassfish.gmbal.ParameterNames;
import org.junit.jupiter.api.*;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvFileSource;

import static org.junit.jupiter.api.Assertions.*;

class CoverageSampleMethodsTest {
    private final CoverageSampleMethods coverageSampleMethods = new CoverageSampleMethods();

    @BeforeEach
    void setUp() {
    }

    @AfterEach
    void tearDown() {
    }

    @Test
    @DisplayName("ming")
    void testMethod() {
        assertTrue(coverageSampleMethods.testMethod(1,2,3));
    }

}

此时的maven工程

<?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.ming</groupId>
  <artifactId>messageBoard</artifactId>
  <version>1.0-SNAPSHOT</version>
  <packaging>war</packaging>

  <name>messageBoard Maven Webapp</name>
  <!-- FIXME change it to the project's website -->
  <url>http://www.example.com</url>

  <properties>
    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
    <maven.compiler.source>1.7</maven.compiler.source>
    <maven.compiler.target>1.7</maven.compiler.target>
  </properties>

  <dependencies>
    <dependency>
      <groupId>tomcat</groupId>
      <artifactId>servlet</artifactId>
      <version>4.0.6</version>
    </dependency>
    <dependency>
      <groupId>mysql</groupId>
      <artifactId>mysql-connector-java</artifactId>
      <version>8.0.15</version>
    </dependency>
    <dependency>
      <groupId>org.mybatis</groupId>
      <artifactId>mybatis</artifactId>
      <version>3.5.1</version>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-api</artifactId>
      <version>5.5.0-M1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-params</artifactId>
      <version>5.5.0-M1</version>
      <scope>test</scope>
    </dependency>
    <dependency>
      <groupId>org.junit.jupiter</groupId>
      <artifactId>junit-jupiter-engine</artifactId>
      <version>5.5.0-M1</version>
      <scope>test</scope>
    </dependency>
  </dependencies>

  <build>
    <finalName>messageBoard</finalName>
    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
      <plugins>
        <plugin>
          <artifactId>maven-clean-plugin</artifactId>
          <version>3.1.0</version>
        </plugin>
        <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_war_packaging -->
        <plugin>
          <artifactId>maven-resources-plugin</artifactId>
          <version>3.0.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <version>3.8.0</version>
        </plugin>
        <plugin>
          <artifactId>maven-surefire-plugin</artifactId>
          <version>2.22.1</version>
        </plugin>
        <plugin>
          <artifactId>maven-war-plugin</artifactId>
          <version>3.2.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-install-plugin</artifactId>
          <version>2.5.2</version>
        </plugin>
        <plugin>
          <artifactId>maven-deploy-plugin</artifactId>
          <version>2.8.2</version>
        </plugin>
      </plugins>
    </pluginManagement>
  </build>
</project>

测试覆盖率

行覆盖

行覆盖,为语句覆盖,度量可执行的语句是否执行到

package com.ming.servlet;

import org.junit.jupiter.api.*;

import static org.junit.jupiter.api.Assertions.*;

class CoverageSampleMethodsTest {

    @BeforeEach
    void setUp() {
    }

    @AfterEach
    void tearDown() {
    }

    @Test
    @DisplayName("testMethod")
    void testMethod() {
        CoverageSampleMethods coverageSampleMethods = new CoverageSampleMethods();
        Assertions.assertTrue(coverageSampleMethods.testMethod(1,2,0));
    }
}

此时已经测试到了所有的行

条件判定覆盖

判定中的每个可能的条件都执行一遍

package com.ming.servlet;

import com.sun.org.glassfish.gmbal.ParameterNames;
import org.junit.jupiter.api.*;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvFileSource;
import org.junit.jupiter.params.provider.CsvSource;

import static org.junit.jupiter.api.Assertions.*;

class CoverageSampleMethodsTest {

    @BeforeEach
    void setUp() {
    }

    @AfterEach
    void tearDown() {
    }

    @ParameterizedTest
    @DisplayName("testMethod")
    @CsvSource({
            "0 ,2, 3",
            "1, 0, 3",
    })
    void testMethod(int a, int b, int c) {
        CoverageSampleMethods coverageSampleMethods = new CoverageSampleMethods();
        Assertions.assertTrue(coverageSampleMethods.testMethod(a,b,c));
    }
}

可以看到两个测试用例全部通过,此时三种条件全部覆盖掉

分支覆盖

程序中运行的分支都要覆盖掉

条件组合覆盖

条件组合覆盖,判定中的所有条件各种组合都至少出现一次

package com.ming.servlet;

import com.sun.org.glassfish.gmbal.ParameterNames;
import org.junit.jupiter.api.*;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvFileSource;
import org.junit.jupiter.params.provider.CsvSource;

import static org.junit.jupiter.api.Assertions.*;

class CoverageSampleMethodsTest {

    @BeforeEach
    void setUp() {
    }

    @AfterEach
    void tearDown() {
    }

    @ParameterizedTest
    @DisplayName("testMethod")
    @CsvSource({
            "1, 2, 3",
            "1, 2, 0",
            "1, 0, 3",
            "0, 2, 3",
            "0, 0, 3"
    })
    void testMethod(int a, int b, int c) {
        CoverageSampleMethods coverageSampleMethods = new CoverageSampleMethods();
        Assertions.assertTrue(coverageSampleMethods.testMethod(a,b,c));
    }
}

路径覆盖

测试到程序中的所有的可能的路径

package com.ming.servlet;

import com.sun.org.glassfish.gmbal.ParameterNames;
import org.junit.jupiter.api.*;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvFileSource;
import org.junit.jupiter.params.provider.CsvSource;

import static org.junit.jupiter.api.Assertions.*;

class CoverageSampleMethodsTest {

    @BeforeEach
    void setUp() {
    }

    @AfterEach
    void tearDown() {
    }

    @ParameterizedTest
    @DisplayName("testMethod")
    @CsvSource({
            "1, 2, 0",
            "1, 0, 3",
            "0, 0, 3"
    })
    void testMethod(int a, int b, int c) {
        CoverageSampleMethods coverageSampleMethods = new CoverageSampleMethods();
        Assertions.assertTrue(coverageSampleMethods.testMethod(a,b,c));
    }
}

|| 第一个条件为true不再计算后面的值
&& 第一个条件为false 不再计算后面的值

单元测试结构

package com.ming.servlet;

import com.sun.org.glassfish.gmbal.ParameterNames;
import org.junit.jupiter.api.*;
import org.junit.jupiter.params.ParameterizedTest;
import org.junit.jupiter.params.provider.CsvFileSource;
import org.junit.jupiter.params.provider.CsvSource;

import static org.junit.jupiter.api.Assertions.*;

class CoverageSampleMethodsTest {
    // 待测试的实例
    private CoverageSampleMethods coverageSampleMethods;
    
    // 定义整个测试开始的
    // 全局资源 外部资源,测试桩的创建
    @BeforeAll
    static void init(){
        
    }
    
    // 测试完成后执行的操作
    // 全局和外部资源的释放和销毁
    @AfterAll
    static void cleanup(){
        
    }
    
    // 每个测试用例开始的时候执行
    // 基础数据 测试环境
    @BeforeEach
    void setUp() {
    }
    
    // 完成后 数据清理
    @AfterEach
    void tearDown() {
    }

    // 测试用例
    @Test
    void testMethod(int a, int b, int c) {
        CoverageSampleMethods coverageSampleMethods = new CoverageSampleMethods();
        Assertions.assertTrue(coverageSampleMethods.testMethod(a,b,c));
    }
}

断言

用于自动化测试
这里推荐Assertions