HelloPageTest.scala

package org.hyperscala.hello

import org.scalatest.WordSpec
import org.scalatest.Matchers
import org.scalatest.BeforeAndAfter

class HelloPageTest extends WordSpec with Matchers with BeforeAndAfter  {

  "HelloPage" when {
    "when rendered" should {
      "have Hello, World!" in {
        val page = new HelloPage()
        // what/how to test here?
      }
    }
  }

}

HelloSiteDirectTest.scala

package org.hyperscala.hello

import org.scalatest.WordSpec
import org.scalatest.Matchers
import org.scalatest.BeforeAndAfter
import org.hyperscala.html._

class HelloSiteDirectTest extends WordSpec with Matchers with BeforeAndAfter {

  before {
    System.setProperty("port", "3333")
    // start application
    HelloSite.main(Array.empty[String])
  }

  after {
    HelloSite.dispose() // end application
  }

  "HelloSite" when {
    "showing the index page" should {
      "have Hello, World!" in {
        val page = HelloSite.index
        // how / what to test here?
      }
    }
  }

}

HelloSiteSeleniumTest.scala

package org.hyperscala.hello

import org.scalatest.WordSpec
import org.scalatest.Matchers
import org.scalatest.BeforeAndAfter
import org.scalatest.selenium.WebBrowser
import org.openqa.selenium.htmlunit.HtmlUnitDriver
import org.openqa.selenium.WebDriver

class HelloSiteSeleniumTest extends WordSpec with Matchers with BeforeAndAfter with WebBrowser {

  implicit val webDriver: WebDriver = new HtmlUnitDriver

  before {
    System.setProperty("port", "3333")
    // start application
    HelloSite.main(Array.empty[String])
  }

  after {
    quit() // browser
    HelloSite.dispose() // end application
  }

  object HomePage extends org.scalatest.selenium.Page {
    val url = "http://localhost:3333/"
  }

  "HelloSite" when {
    "showing the index page" should {
      "have Hello, World!" in {
        go to HomePage
        find(tagName("body")) map { body =>
          body.text should be("Hello, World!")
        } getOrElse fail("Element not found")
      }
    }
  }

}

As you can see, I managed to test the HelloSite application using Selenium.

What it's not clear to me is how to test with the other approaches, and what makes sense to test...