public void When_The_Points_Spent_Is_More_Than_The_Points_Earnt_An_Exception_Is_Thrown()
{
// Arrange
var customer = new StubCustomer();
customer.SetPointsEarned(5);
customer.PointsSpent = 10;
//Assert
Assert.Throws(typeof (ArgumentOutOfRangeException), () => customer.GetPointsBalance());
}
public void The_Balance_Is_Equal_To_The_Number_Of_Points_Earnt_Minus_Number_Of_Points_Spent()
{
//Arrange
var customer = new StubCustomer();
customer.SetPointsEarned(5);
customer.PointsSpent = 3;
//Act
var result = customer.GetPointsBalance();
//Assert
Assert.AreEqual(2, result);
}