Enhanced WithApplication class to test Play 2.4 applications with dependency injection using

WithFancyApp.scala

/**
  * Provides Messages implicit and the default Guice-Container
  * into the context for testing Play 2.4 applications.
  *
  * Sample:
  *
  * "use the overridden bindigs" in new WithFancyApp(
  *       lang = Lang("en", "US"),
  *       overrideModules = Seq(bind[MyInterface].to[MyImplementation])
  * ) {
  *   // test stuff with all regular bindings plus the ones from above
  * }
  *
  */
class WithFancyApp(lang: Lang = Lang.defaultLang,
                   overrideModules: Seq[GuiceableModule] = Seq()) extends
  WithApplication(
    app =
      new GuiceApplicationBuilder()
      .in(Environment(new File("."), getClass.getClassLoader, Mode.Test))
      .loadConfig(env => Configuration.load(env))
      .overrides(overrideModules:_*)
      .bindings()
      .build
 ) {

  implicit def messages: Messages = Messages(lang, app.injector.instanceOf[MessagesApi])

}