如何判断 JUnit 测试出了什么问题？ [关闭]

Question

我必须根据 JUnit 测试修复我的代码，但我不确定如何判断出了什么问题？

比如这个测试代码的函数我运行的时候出错了

@Test
    public void lastValidDay() {
        DayOfWeek dow = new DayOfWeek(12, 31, 2099);
        assertTrue(dow.getDayOfWeek().compareTo("Thursday") == 0);
        assertTrue(dow.getNumericDayOfWeek() == 5);
    }

不知道如何更改它以使其顺利运行？这是我的课程，正在测试这些不同的 JUnit。这是我必须更改的课程，以便所有测试都能顺利运行。

public class DayOfWeek1 {
    int myMonth, myDayOfMonth, myYear, myAdjustment, numericDayOfWeek;
    /*
     * @param what the date was
     */
    public DayOfWeek1(int month, int dayOfMonth, int  year){
        myMonth = month;
        myDayOfMonth = dayOfMonth;
        myYear = year;
    }
    /*
     * @return the numeric day of the week
     */
    public int getNumericDayOfWeek(){
        if(myMonth==1){
            myAdjustment = 1;
            if(myYear%4==0){
                myAdjustment=0;
            }
        }
        if(myMonth==2){
            myAdjustment = 4;
            if(myYear%4==0){
                myAdjustment=3;
            }
        }
        if(myMonth==3){
            myAdjustment = 4;
        }
        if(myMonth==4){
            myAdjustment = 0;
        }
        if(myMonth==5){
            myAdjustment = 2;
        }
        if(myMonth==6){
            myAdjustment = 5;
        }
        if(myMonth==7){
            myAdjustment = 0;
        }
        if(myMonth==8){
            myAdjustment = 3;
        }
        if(myMonth==9){
            myAdjustment = 6;
        }
        if(myMonth==10){
            myAdjustment = 1;
        }
        if(myMonth==11){
            myAdjustment = 4;
        }
        if(myMonth==12){
            myAdjustment = 6;
        }
        int fourDivides = myYear / 4;
        numericDayOfWeek = myAdjustment + myDayOfMonth + (myYear-1900) + fourDivides; 
        return numericDayOfWeek;

    }
    /*
     * returns what day of the week it was
     */
     public String getDayOfWeek(){
         if(numericDayOfWeek==0){
             return "Saturday";
         }
         if(numericDayOfWeek==1){
             return "Sunday";
         }
         if(numericDayOfWeek==2){
             return "Monday";
         }
        if(numericDayOfWeek==3){
             return "Tuesday";
         }
        if(numericDayOfWeek==4){
            return "Wednesday";
         }
        if(numericDayOfWeek==5){
            return "Thursday";
         }
         if(numericDayOfWeek==6){
             return "Friday";
         }
         else{
             return "NO_VALUE";
         }
     }
     /*
      * @return the month in an int
      */
     public int getMonth(){
         return myMonth;
     }
     /*
      * @return the month in a string
      */
     public String getMonthString(){
         if(myMonth==1){
             return "January";
         }
         if(myMonth==2){
             return "February";
         }
         if(myMonth==3){
             return "March";
         }
         if(myMonth==4){
             return "April";
         }
         if(myMonth==5){
             return "May";
         }
         if(myMonth==6){
             return "June";
         }
         if(myMonth==7){
             return "July";
         }
         if(myMonth==8){
             return "August";
         }
         if(myMonth==9){
             return "September";
         }
         if(myMonth==10){
             return "October";
         }
         if(myMonth==11){
             return "November";
         }
         if(myMonth==12){
             return "December";
         }
         else{
             return "NO_VALUE";
         }
     }
     /*
      * @return what day of the month it was
      */
     public int getDayOfMonth(){
         return myDayOfMonth;
     }
     /*
      * @return what year it was
      */
     public int getYear(){
         return myYear;
     }

}

关于找出我的代码中究竟是什么导致错误消失的任何提示？

Answer 1

问题是你在getNumbericDayOfWeek() 之前调用getDayOfWeek()。在您的构造函数中，您不会初始化 numericDayOfWeek，因此它会获得默认值 0（所有未初始化的原始类型都可以）。

public DayOfWeek1(int month, int dayOfMonth, int  year){
    myMonth = month;
    myDayOfMonth = dayOfMonth;
    myYear = year;
}

然后你打电话

assertTrue(dow.getDayOfWeek().compareTo("Thursday") == 0);

将返回

 public String getDayOfWeek(){
     if(numericDayOfWeek==0){
         return "Saturday";
     }

"Saturday" 的值，当 compareTo("Thursday") 不返回 0 时，您的测试将失败。

您需要先调用getNumericDayOfWeek() 将numericDayOfWeek 字段设置为其真正的语义值。

---

关于实际问题

关于弄清楚我的代码中究竟是什么的任何提示 错误消失了吗？

断言语句会告诉您条件为假。从那里开始，您的第一直觉应该是精简 dow.getDayOfWeek() 返回的内容，因为它不等于 "Thursday"。解决这个问题的一种方法是这样做

assertEquals("Thursday", dow.getDayOfWeek());

它会立即告诉您期望值和实际值不同以及它们的值是什么。您会看到dow.getDayOfWeek() 返回了"Saturday"，然后您可以看到numericDayOfWeek 的值为0，依此类推。