Leap year kata in Scala using ScalaTest

build.sbt

name := "LeapYear"

version := "1.0"

scalaVersion := "2.11.1"

libraryDependencies += "org.scalatest" %% "scalatest" % "2.1.7" % "test"

LeapYear.scala

package com.bigcompany.utils.test

import org.scalatest._

object LeapYear {
  def isLeapYear(year: Int) = (year % 4, year % 100, year % 400) match {
    case (_, _, 0) => true
    case (_, 0, _) => false
    case (0, _, _) => true
    case _         => false
  }
}

class LeapYearSpec extends FunSpec {

  describe("Validate Leap Year calculation") {
    it("should return true for year 4") {
      assert(LeapYear.isLeapYear(4) == true)
    }

    it("should return true for year 1") {
      assert(LeapYear.isLeapYear(1) == false)
    }

    it("should return true for year 64") {
      assert(LeapYear.isLeapYear(64) == true)
    }

    it("should return true for year 2000") {
      assert(LeapYear.isLeapYear(2000) == true)
    }

    it("should return true for year 1900") {
      assert(LeapYear.isLeapYear(1900) == false)
    }
  }
}

See my blog post which goes with this: http://comp-phil.blogspot.com/2014/06/leap-year-in-key-of-c-f-haskell-and.html