public void EqualExpressions()
{
var expr1 = new IntegerExpression(1);
var expr2 = new IntegerExpression(2);
var expr3 = new IntegerExpression(1);
var expr4 = new DoubleExpression(3.14159);
var expr5 = new DoubleExpression(1.2);
var expr6 = new DoubleExpression(3.14159);
Assert.IsFalse(expr1.Equals(expr2));
Assert.IsFalse(expr1.Equals(null));
Assert.IsFalse(expr2.Equals(expr1));
Assert.IsFalse(expr1.Equals(expr4));
Assert.IsFalse(expr1.Equals(expr5));
Assert.IsFalse(expr4.Equals(expr1));
Assert.IsFalse(expr5.Equals(expr1));
Assert.IsFalse(expr4.Equals(expr5));
Assert.IsFalse(expr5.Equals(expr4));
Assert.IsTrue(expr1.Equals(expr3));
Assert.IsTrue(expr3.Equals(expr1));
Assert.IsTrue(expr4.Equals(expr6));
Assert.IsTrue(expr6.Equals(expr4));
Assert.AreEqual(expr1.GetHashCode(), expr3.GetHashCode());
Assert.AreEqual(expr4.GetHashCode(), expr6.GetHashCode());
}
