1.scala

package foo

import java.io.{PrintWriter, StringWriter}

import org.fusesource.scalate.{TemplateEngine, DefaultRenderContext}

class SimpleTemplateEngine(templateSource: String) {

  val templateEngine = new TemplateEngine()

  def layoutTemplate(path: String, attributes: (String, Any)*): String = {
    val uri = f"$templateSource/$path"
    val buffer = new StringWriter()
    val out = new PrintWriter(buffer)
    val context = new DefaultRenderContext("", templateEngine, out)
    attributes foreach {
      case (k, v) => context.attributes(k) = v
    }
    templateEngine.layout(uri, context)
    buffer.toString
  }

}

2.scala

package tests

import com.typesafe.config.ConfigFactory
import org.specs2.mutable._

import scala.concurrent.Await

class TemplateSpecs extends Specification {

  val templateEngine = new SimpleTemplateEngine("/home/user/code/path/to/templates")

  "Template engine" should {
    "Render a jade template" in {
      val text = templateEngine.layoutTemplate("mail.verify-account-html.jade", attrs1: _*)
      text must not empty
    }

    "Render a mustache template" in {
      val text = templateEngine.layoutTemplate("mail.verify-account-text.mustache", attrs1: _*)
      text must not empty
    }
  }

}