JettySetup.scala

import org.scalatest._
import org.scalatest.time._
import org.scalatest.selenium._
import org.openqa.selenium._
import org.mortbay.jetty.Server
import org.mortbay.jetty.webapp.WebAppContext
import org.apache.log4j.Logger

trait JettySetup extends FlatSpec
  with BeforeAndAfterAll
  with Firefox { // <-- THIS LINE can also say "with HtmlUnit"

  private val runServer = false
  private var server: Server = null
  private val GUI_PORT = 8080
  protected var host = "http://localhost:" + GUI_PORT.toString

  override def beforeAll() {
    Logger.getRootLogger.debug("hello from test")
    if (runServer) {
      // Setting up the jetty instance which will be running the
      // GUI for the duration of the tests
      server = new Server(GUI_PORT)
      val context = new WebAppContext()
      context.setServer(server)
      context.setContextPath("/")
      context.setWar("src/main/webapp")
      server.addHandler(context)
      server.start()
    }
    implicitlyWait(Span(2, Seconds));
  }

  override def afterAll() {
    // Close everything when done
    close()
    if (runServer) {
      server.stop()
    }
  }

}

pom.xml

...
      <dependency>
	      <groupId>org.seleniumhq.selenium</groupId>
	      <artifactId>selenium-java</artifactId>
	      <version>2.25.0</version>
	      <scope>test</scope>
	    </dependency>
      <dependency>
	      <groupId>org.scalatest</groupId>
	      <artifactId>scalatest_2.9.1</artifactId>
	      <version>2.0.M4</version>
	      <scope>test</scope>
	    </dependency>
...

Tests.scala

import net.liftweb.util._
import net.liftweb.util.Helpers._
import net.liftweb.common._
import org.scalatest._
import org.scalatest.time._
import org.scalatest.selenium._
import org.openqa.selenium._
import scala.xml._

class M02TestsBrowser extends JettySetup
  with ShouldMatchers {

  def basics = {
    "The home page" should "have the correct title" in {
      goTo(host)
      title should be("Home | My Website")
    }
  }

  basics
}