Simple testing with Kotlin

KotlinTest.kt

fun doTests() {
//  println("run test 1")
//  runTest(::test1)

  println("\nrun test 2")
  runTest(::test2)

  println("\nrun test 3")
  runTest(::test3)
}

fun runTest(test: (() -> String)) {
  println("Warming up Kotlin")
  test()
  test()
  test()
  println("Measuring Kotlin")
  val time = (1..10).map { measureTimeMillis { test() } }

  println("Tests took ${time.sum()} ms, average run ${time.average()} ms")
}

fun trans(nucleotide: Char) =
    when (nucleotide) {
      'G' -> 'C'
      'C' -> 'G'
      'T' -> 'A'
      else -> 'U'
    }

val testDna = "GGCTCCGAAA".repeat(1_000_000)

fun test1() =
    testDna.fold("") { rna, nucleotide ->
      rna + trans(nucleotide.toUpperCase())
    }

fun test2() =
    testDna.fold(StringBuffer()) { rna, nucleotide ->
      rna.append(trans(nucleotide.toUpperCase()))
    }.toString()

fun test3() = testDna.map { trans(it.toUpperCase()) }.joinToString("")