How to use JUnit's @Rule annotation with Scala Specs2 tests?

Question

In our project we use Scala Specs2 together with Selenium. I'm trying to implement screenshot-on-failure mechanism "in a classic way (link)" for my tests, using JUnit annotations, but, the rule doesn't called on test failure at all.

The structure of the test is as follows:

class Tests extends SpecificationWithJUnit{

      trait Context extends LotsOfStuff {
        @Rule
        val screenshotOnFailRule = new ScreenshotOnFailRule(driver)
      }

      "test to verify stuff that will fail" should {
        "this test FAILS" in new Context {
         ...
      }
}

The ScreenshotOnFailRule looks like this:

class ScreenshotOnFailRule (webDriver: WebDriver) extends TestWatcher {

  override def failed(er:Throwable, des:Description) {
    val scrFile = webDriver.asInstanceOf[TakesScreenshot].getScreenshotAs(OutputType.FILE)
    FileUtils.copyFile(scrFile, new File(s"/tmp/automation_screenshot${Platform.currentTime}.png"))
  }
}

I understand that probably it doesn't work now because the tests aren't annotated with @Test annotation. Is it possible to annotate the Specs2 tests with JUnit @Rule annotation?

Answer 1

According to this question it seems as if JUnit Rules aren't supported. But you could try to make use of the AroundExample trait:

import org.specs2.execute.{AsResult, Result}
import org.specs2.mutable._
import org.specs2.specification.AroundExample

class ExampleSpec extends Specification with AroundExample {

  // execute tests in sequential order
  sequential

  "The 'Hello world' string" should {
    "contain 11 characters" in  {
      "Hello world" must have size (10)
    }

   // more tests..
  }

  override protected def around[T](t: => T)(implicit ev: AsResult[T]): Result = {
    try {
      AsResult.effectively(t)
    } catch {
      case e: Throwable => {
        // take screenshot here
        throw e
      }
    }
  }
}