public void TestComplexExpression()
{
IItem item1 = new AddItem(ONE, TWO);
Assert.AreEqual(3, item1.Value);
IItem item2 = new MulItem(item1, TWO);
Assert.AreEqual(6, item2.Value);
Assert.IsTrue(item1.Equals(item1));
Assert.IsTrue(item2.Equals(item2));
Assert.IsFalse(item1.Equals(item2));
IItem item3 = new AddItem(ONE, TWO);
Assert.AreEqual(3, item1.Value);
IItem item4 = new MulItem(item1, TWO);
Assert.AreEqual(6, item2.Value);
Assert.IsTrue(item1.Equals(item3));
Assert.IsTrue(item2.Equals(item4));
Assert.IsFalse(item1.Equals(item4));
Assert.IsFalse(item2.Equals(item3));
Assert.IsFalse(item3.Equals(item4));
item3 = new MulItem(TWO, TWO);
Assert.AreEqual(4, item3.Value);
item4 = new AddItem(item3, TWO);
Assert.AreEqual(6, item4.Value);
Assert.IsFalse(item2.Equals(item4));
Assert.AreEqual(item2.Value, item4.Value);
}
public void TestMulItemEquals()
{
var item = new MulItem(ONE, TWO);
Assert.IsTrue(item.Equals(item));
Assert.IsTrue(item.Equals(new MulItem(ONE, TWO)));
Assert.IsFalse(item.Equals(new MulItem(TWO, ONE)));
Assert.IsFalse(item.Equals(new MulItem(TWO, (IntegerItem)(-1))));
Assert.IsFalse(item.Equals(null));
Assert.IsFalse(item.Equals(new AddItem(ONE, ZERO)));
}