Question

In java, using assertEquals, create unit test cases for the withdraw method in the class below. Use boundary value analysis to find the values to use for input to your test cases.

package assignment7;

//Use boundary value analysis to create junit tests for the assignment.

public class assignment {

private double balance =0;

public double withdraw(double amtToWithdraw) {

if(amtToWithdraw < 0) return 0.0; //can't withdraw a negative amount

if(amtToWithdraw >100.0) return 0.0; //can't withdraw more that $100.00

if(amtToWithdraw%20.0!=0) return 0.0; //can only withdraw in $20 increments

if(amtToWithdraw > this.balance) return 0.0; //can't withdraw more than the balance

else {

this.balance -= amtToWithdraw;

return amtToWithdraw; //return the amount successfully withdrawn

}

}

public void setBalance(double initialBalance) {//set the initial balance value

this.balance = initialBalance;

}

public double getBalance() { // get the current balance value

return this.balance;

}

}

Answer 1

The Junit test file is written below

package assignment7;

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

import org.junit.jupiter.api.Test;

class TestAssignment {
  
   assignment a = new assignment();
  
   /*
   * Just above and just below boundary values for input range are -0.01 and 100.01
   *   
   */
  
   @Test
   void testWithdraw() {
      
       //Returns 0.0 as it is just below lower boundary value
       assertEquals(a.withdraw(-0.01),0.0);
      
       //Returns 0.0 as it is just above upper boundary value
       assertEquals(a.withdraw(100.01),0.0);
      
       //Inserting 100.00 as balance
       a.setBalance(100.00);
      
       //Returns 100.00 as the value is just at the boundary value
       assertEquals(a.withdraw(100.00),100.00);
      
       //Inserting 0.00 as balance
   a.setBalance(100.00);
              
       //Returns 0.00 as the value is just at the boundary value
       assertEquals(a.withdraw(0.00),0.00);
      
       a.setBalance(20.0);
      
       //Returns 0.0 as it is not divisible by 20.0
       assertEquals(a.withdraw(15.0),0.0);
              
       //Returns 0.0 as the withdrawal is above the balance amount
       assertEquals(a.withdraw(21.0),0.0);
      
       //Returns the amount as the withdrawal is less than or equal to balance
       assertEquals(a.withdraw(20.0),20.0);
   }

}

The screenshot of the code is given below :-

The output of the test is given below