nadavwr / makeshift

Makeshift unit testing library for Scala Native


A unit testing library I quickly hacked together for personal use, until one of the established libraries becomes available for Scala Native.

To use it:

resolvers += Resolver.bintrayRepo("nadavwr", "maven")
libraryDependencies += "com.github.nadavwr" %%% "makeshift" % "0.1.1"
  • Unit tests are aggregated under Spec instances.
  • Each unit test makes use of a Fixture
  • Using fixtures enables sharing code across test cases, as well as orderly resource initialization and cleanup.
  • The method assertThat() provides some rudimentary papertrail for what specific checks pass/fail. Make sure your terminal can render ๐Ÿ‘ and โ—.
  • No effort is made by the library to aggregate specs into test suites. Having a Spec extend App has been a guilty pleasure for me so far.
  • SBT test framework integration isn't there yet, so just place your specs in a separate module and plain-old run them.

Given a heap-allocated buffer such as the following:

class Buffer(val size: Int) {
  import scalanative.native._
  val ptr: Ptr[Byte] = stdlib.malloc(1024)
  def dispose(): Unit =

  def put(bytes: Array[Byte]): Unit =
    bytes.zipWithIndex.foreach { case (b, i) => !(ptr+i) = b }
  def get(size: Int): Array[Byte] = {
    val out = new Array[Byte](size)
    for (i <- 0 until size) {
      out(i) = !(ptr+i)

It can be tested as seen below:

import com.github.nadavwr.makeshift._

object MySpec extends Spec with App {

  trait BufferFixture extends Fixture {
    lazy val buffer = new Buffer(1024)
      .withCleanup("buffer") { _.dispose() }

  test("manipulate heap memory") runWith new BufferFixture {
    val message = "hello"
    val messageBytes =
    val output = buffer.get(messageBytes.length)
    assertThat(output sameElements messageBytes,
      s"buffer should be assigned expected value '$message'")

producing the following output:

โ–manipulate heap memory
bufer created
๐Ÿ‘ buffer should be assigned expected value 'hello'
cleaning up bufer

See more usage examples in SampleSpec