Testing

Testing Scala.js application is as easy as testing regular Scala applications, except you have to choose a test framework that is OK with the limitations of the JavaScript environment. Many popular frameworks like Specs2 depend on JVM features (like reflection) that are not available in the JS land, so Li Haoyi went ahead and created uTest, a simple yet powerful testing framework that works wonderfully well with Scala.js. ScalaTest has now been ported to work with Scala.js (version 3.0.0-M5 and above) so that's another option you can use.

To define tests, you just need to extend from TestSuite and override the tests method.

object SPACircuitTests extends TestSuite {
  override def tests = TestSuite {
    'test { ... }
  }
}

Take a look at SPACircuitTests.scala for some examples of test cases.

To run tests in SBT, you'll need to add a dependency for "com.lihaoyi" %%% "utest" % "0.3.1" and configure the test framework with testFrameworks += new TestFramework("utest.runner.Framework"). Now you can run the tests using regular test and testOnly commands in the SBT prompt.