how to test the setter methods

[Cali Kim]

I've gotten the class done, and the driver is getting close. Any pointers in the right direction would help. I don't want you to do it for me, but perhaps a hint or two?

Here is the class with the setter methods(I needed to make it mutable):

public class Date
{
  // Data fields
  private int day;
  private int year;
  private int month;

  // Constructors
  public Date(int newDay, int newMonth, int newYear)
  {
     year = newYear;
     month = newMonth;
     day = newDay;
  }
  public Date()
  {
  month = 1 ;
  day = 1;
  year = 1900;
  }
  
  // Methods
  public void setDay(int newDay)
  {
    day = newDay;
  }
  public int getDay()
  {
    return day;
  }
  public void setMonth(int newMonth)
  {
    month = newMonth;
  }
  public int getMonth()
  {
    return month;
  }
  public void setYear(int newYear)
  {
    year = newYear;
  }
  public int getYear()
  {    
    return year;
  }
  public String toString()
  {
    String myMonth = Integer.toString(month);
    if (month == 1)
     myMonth = "January";
    else if (month == 2)
      myMonth = "February";
    else if (month == 3)
      myMonth = "March";
    else if (month == 4)
      myMonth = "April";
    else if (month == 5)
      myMonth = "May";
    else if (month == 6)
      myMonth = "June";
    else if (month == 7)
      myMonth = "July";
    else if (month == 8)
      myMonth = "August";
    else if (month == 9)
      myMonth = "September";
    else if (month == 10)
      myMonth = "October";
    else if (month == 11)
      myMonth = "November";
    else if (month == 12)
      myMonth = "December";
    else
      System.out.println("This is not a valid month.");

      
     return myMonth + " " + day + ", " + year;
  }
}
 

and here is the test driver as it sits:

 
import java.util.Scanner;
public class TestDate
{
     public static void main(String[] args)
     {
        boolean getDayWorks;
        boolean getMonthWorks;
        boolean getYearWorks;
        Date testdate;
        testdate = new Date(6, 12, 1944);
        
        getDayWorks = testdate.getDay() == 6;
        getMonthWorks = testdate.getMonth() == 12;
        getYearWorks = testdate.getYear() == 1944;
        System.out.println(testdate.toString());
          
       if(getDayWorks && getMonthWorks && getYearWorks)
          System.out.println("All tests passed");
       else if(getDayWorks != true)
          System.out.println("getDay() does not work properly");
       else if(getMonthWorks != true)
          System.out.println("getMonth() does not work properly");
       else if(getYearWorks != true)
          System.out.println("getYear() does not work properly");
       
  }
}
  

[dennis deems]

In your test, examine the attribute before calling the setter. Then call the setter with a new value. Examine the attribute again and compare the value to what you saw before.

[Cali Kim]

Dennis Deems wrote:In your test, examine the attribute before calling the setter. Then call the setter with a new value. Examine the attribute again and compare the value to what you saw before.

This is French to me. I understand creating a new value, but I'm having a problem deciding what values to use. The initial values (day, month, year) are all locked as private and will not transfer over into a test driver. Should I create new ones within the test driver? If so, how then will I be sure that it is calling the setter methods for testing?

[Paul Clapham]

Cali Kim wrote:I understand creating a new value, but I'm having a problem deciding what values to use. The initial values (day, month, year) are all locked as private and will not transfer over into a test driver. Should I create new ones within the test driver? If so, how then will I be sure that it is calling the setter methods for testing?

That's all Greek to me. Like Dennis said, if you want to test a setter method, then here's what you do:

(1) Get the value of the variable which the setter affects. Store it in a local variable. (If that counts as "creating a new one", then yes, create a new one.) If you're concerned that the variable in question is private, then use some public method of getting that value.

(2) Call the setter method to assign a different value than what you just got. (Why would you not be sure that the test driver would be calling the setter method?)

(3) Get the value of the variable again. Check that it is the value that the setter method assigned in step 2 and not the value originally acquired in step 1.

[Cali Kim]

Paul Clapham wrote:

Cali Kim wrote:I understand creating a new value, but I'm having a problem deciding what values to use. The initial values (day, month, year) are all locked as private and will not transfer over into a test driver. Should I create new ones within the test driver? If so, how then will I be sure that it is calling the setter methods for testing?

That's all Greek to me. Like Dennis said, if you want to test a setter method, then here's what you do:

(1) Get the value of the variable which the setter affects. Store it in a local variable. (If that counts as "creating a new one", then yes, create a new one.) If you're concerned that the variable in question is private, then use some public method of getting that value.

(2) Call the setter method to assign a different value than what you just got. (Why would you not be sure that the test driver would be calling the setter method?)

(3) Get the value of the variable again. Check that it is the value that the setter method assigned in step 2 and not the value originally acquired in step 1.

Thank you...the way you put it made it a bit easier to understand. I've had a bit of a rough week so my head just isn't functioning as it normally would.