public void TestFactorialOfOneIsOne()
{
// act
BigInteger result1 = BigIntegerMathLib.Factorial1(1);
BigInteger result2 = BigIntegerMathLib.Factorial2(1);
// assert
BigInteger one = 1;
Assert.AreEqual(one, result1);
Assert.AreEqual(one, result2);
}
public void TestBothVersionsOfFactorialAreEqual()
{
for (BigInteger n = 0; n < 100; n++)
{
// act
BigInteger factorial1 = BigIntegerMathLib.Factorial1(n);
BigInteger factorial2 = BigIntegerMathLib.Factorial2(n);
// assert
Assert.AreEqual(factorial1, factorial2);
}
}
public void TestFactorialBigIntegerEqualsFactorialInt()
{
for (int n = 0; n < 10; n++)
{
// act
int factorial0 = BigIntegerMathLib.Factorial0(n);
BigInteger factorial1 = BigIntegerMathLib.Factorial1(n);
// assert
Assert.AreEqual((BigInteger)factorial0, factorial1);
Assert.AreEqual(factorial0, (int)factorial1);
}
}
public void TestFactorial1OfNegativeNumberThrowsArgumentException()
{
// assert
Assert.That(() => BigIntegerMathLib.Factorial1(-1), Throws.TypeOf <ArgumentException>());
}