测试一个简单方法

开发工具:idea

版本管理:maven

pom.xml:

<dependencies>
    <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
      <scope>compile</scope>
    </dependency>
  </dependencies>

Largest.java

package com.lenovo.unit2;

/**
 * 寻找最大数
 */
public class Largest {

    public static int largest(int[] list){
        int index = 0;
        int max=Integer.MIN_VALUE;
        for (index = 0;index < list.length; index++){
            if(list[index] > max){
                max = list[index];
            }
        }
        return max;
    }
}

TestLargest.java

package com.lenovo.unit2;
import junit.framework.*;

/**
 * 输入import junit.framework.*;查看是否能正常编译，如果可以，说明已经正确引入junit jar包
 * 测试Largest的寻找最大数函数
 * 测试类需要继承TestCase基类
 */
public class TestLargest extends TestCase {

    public TestLargest(String name){
        super(name);
    }

    //测试不同顺序是否触发函数错误
    public void testSimple(){
        //断言，第一个参数是期望值，第二个参数是被测试函数的输入参数
        assertEquals(9,Largest.largest(new int[]{7,8,9}));
        assertEquals(9,Largest.largest(new int[]{9,8,7}));
        assertEquals(9,Largest.largest(new int[]{7,9,8}));
    }

    //测试重复数据是否触发函数错误
    public void testRepeatNum(){
        assertEquals(9,Largest.largest(new int[]{7,9,8,9}));
    }

    //测试list一个元素
    public void testOne(){
        assertEquals(1,Largest.largest(new int[]{1}));
    }

    //测试list中含有负值元素
    public void testNegative(){
        assertEquals(-7,Largest.largest(new int[]{-9,-8,-7}));
    }

    //针对list为空情况
    public void testEmpty(){
        try {
            Largest.largest(new int[]{});
            fail("Should have thrown an exception!");
        }catch (RuntimeException e){
            assertTrue(true);
        }
    }
}