Roman Numerals Scala (2)

Roman.scala

A more functional version would be:
package kata
import org.scalatest.matchers.ShouldMatchers
import org.scalatest.{BeforeAndAfterEach, FlatSpec}

class Roman extends FlatSpec with ShouldMatchers  {

  case class Symbol(latin:Int, roman:String)
  var symbols = List(Symbol(5,"V"), Symbol(4, "IV"), Symbol(1,"I"))

  def toRoman(number:Int): String = symbols.foldLeft((number, "")){case((remaining, result),symbol)=> {
      val occurrences = remaining / symbol.latin
      (remaining - (occurrences * symbol.latin), result + symbol.roman * occurrences)
    }}._2

  it should "convert a 1 to I" in {
    assert(toRoman(1) === "I")
  }

  it should "convert a 2 to II" in {
    assert(toRoman(2) === "II")
  }

  it should "convert a 5 to V" in {
    assert(toRoman(5) === "V")
  }

  it should "convert a 4 to IV" in {
    assert(toRoman(4) === "IV")
  }
}