public void Independent()
{
Calc calc = new Calc();
calc.Receive("1+2=");
Assert.AreEqual("3", calc.Display);
calc.Receive("40-10=");
Assert.AreEqual("30", calc.Display);
}
public void UseResult()
{
Calc calc = new Calc();
calc.Receive("10-1=");
Assert.AreEqual("9", calc.Display);
calc.Receive("-2=");
Assert.AreEqual("7", calc.Display);
calc.Receive("-3=");
Assert.AreEqual("4", calc.Display);
}
public void ReapplySameOp()
{
Calc calc = new Calc();
calc.Receive("10-2=");
Assert.AreEqual("8", calc.Display);
calc.Receive("100=");
Assert.AreEqual("98", calc.Display);
calc.Receive("1000=");
Assert.AreEqual("998", calc.Display);
}
public void Double()
{
Calc calc = new Calc();
calc.Receive("2+=");
Assert.AreEqual("4", calc.Display);
calc.Receive("+=");
Assert.AreEqual("8", calc.Display);
calc.Receive("+=");
Assert.AreEqual("16", calc.Display);
}
public void Basic()
{
Calc calc = new Calc();
calc.Receive("123");
Assert.AreEqual("123", calc.Display);
calc.Receive("+");
Assert.AreEqual("123", calc.Display);
calc.Receive("45");
Assert.AreEqual("45", calc.Display);
calc.Receive("=");
Assert.AreEqual("168", calc.Display);
}
public void Overflow()
{
Calc calc = new Calc();
calc.Receive("99999999+1=");
Assert.AreEqual("overflow", calc.Display);
calc.Receive("C");
Assert.AreEqual("0", calc.Display);
calc.Receive("0-9999999=");
Assert.AreEqual("-9999999", calc.Display);
calc.Receive("-1=");
Assert.AreEqual("overflow", calc.Display);
}
public void BackspaceWorksOnlyAfterInput()
{
Calc calc = new Calc();
calc.Receive("123<");
Assert.AreEqual("12", calc.Display);
calc.Receive("+<");
Assert.AreEqual("12", calc.Display);
calc.Receive("456<");
Assert.AreEqual("45", calc.Display);
calc.Receive("=");
Assert.AreEqual("57", calc.Display);
calc.Receive("<");
Assert.AreEqual("57", calc.Display);
}
public void RepeatEq()
{
Calc calc = new Calc();
calc.Receive("2+=");
Assert.AreEqual("4", calc.Display);
calc.Receive("=");
Assert.AreEqual("6", calc.Display);
calc.Receive("=");
Assert.AreEqual("8", calc.Display);
calc = new Calc();
calc.Receive("2-=");
Assert.AreEqual("0", calc.Display);
calc.Receive("=");
Assert.AreEqual("-2", calc.Display);
calc.Receive("=");
Assert.AreEqual("-4", calc.Display);
}
public void Chain()
{
Calc calc = new Calc();
calc.Receive("10+5-1=");
Assert.AreEqual("14", calc.Display);
calc = new Calc();
calc.Receive("10+5-1+2+");
Assert.AreEqual("16", calc.Display);
}
public void Fuzz()
{
var rnd = new System.Random(42);
string choices = "1290C<+-=";
Calc calc = new Calc();
for (int i = 0; i < 1000000; i++)
{
calc.Receive(choices[rnd.Next(0, choices.Length)]);
}
}