public void Add_shoudul_add_two_integers()
{
// Arrange
Chain calc = new AddNumber(new SubstractNumber(new MultiplyNumbers(null)));
// Act
int result = calc.CalculateNumbers(new Numbers(1, 2, "add"));
// Assert
Assert.AreEqual(3, result);
}
public void Substract_should_substract_integer()
{
// Arrange
Chain calc = new AddNumber(new SubstractNumber(null));
// Act
int result = calc.CalculateNumbers(new Numbers(1, 2, "substract"));
// Assert
Assert.AreEqual(-1, result);
}