gistfile1.scala

FactorialSpec.scala:

import org.specs._

class FactorialSpec extends Specification{
  "polynomial" should {
    "return 1 for n = 1" in {
      Factorial(1) must be (1)
    }
    "return 2 for n = 2" in {
      Factorial(2) must be (2*1)
    }
    "return 6 for n = 3" in {
      Factorial(3) must be (3*2*1)
    }
    "return 6*5*4*3*2*1 for n = 6" in {
      Factorial(6) must be (6*5*4*3*2*1)
    }
    "handle large factorial" in {
      Factorial(10) must be(3628800)
    }
  }
}

Factorial.scala:
object Factorial extends (Int => Int){
  override def apply(n:Int) =  (1 to n).foldRight(1)(_ * _)
}