1  import org.junit.Test;

  2  import org.junit.Assert;

  3  

  4  public class CashRegisterTest

  5  {

  6     private static final double EPSILON = 1E-12;

  7  

  8     @Test public void twoPurchases()

  9     {

 10        CashRegister register = new CashRegister();

 11        register.recordPurchase(0.75);

 12        register.recordPurchase(1.50);

 13        register.receivePayment(2, 0, 5, 0, 0);

 14        double expected = 0.25;

 15        Assert.assertEquals(expected, register.giveChange(), EPSILON);

 16     }

 17  

 18     @Test public void testZeroBalance() 

 19     {

 20        CashRegister register = new CashRegister();

 21        register.recordPurchase(2.25);

 22        register.recordPurchase(19.25);

 23        register.receivePayment(21, 2, 0, 0, 0);

 24        Assert.assertEquals(0, register.giveChange(), EPSILON);

 25     }

 26  

 27     // More test cases 

 28     // . . .

 29  }