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Scala example source code file (ReplTest.scala)

This example Scala source code file (ReplTest.scala) is included in my "Source Code Warehouse" project. The intent of this project is to help you more easily find Scala source code examples by using tags.

All credit for the original source code belongs to; I'm just trying to make examples easier to find. (For my Scala work, see my Scala examples and tutorials.)

Scala tags/keywords

boolean, compiler, console, directtest, expected, nsc, parallel, repltest, scala, sessiontest, settings, string, welcoming

The ReplTest.scala Scala example source code

/* NSC -- new Scala compiler
 * Copyright 2005-2013 LAMP/EPFL
 * @author Paul Phillips


import java.lang.reflect.{ Method => JMethod, Field => JField }

/** A class for testing repl code.
 *  It filters the line of output that mentions a version number.
abstract class ReplTest extends DirectTest {
  // override to transform Settings object immediately before the finish
  def transformSettings(s: Settings): Settings = s
  // final because we need to enforce the existence of a couple settings.
  final override def settings: Settings = {
    val s = super.settings
    // s.Yreplsync.value = true
    s.Xnojline.value = true
  def welcoming: Boolean = false
  lazy val welcome = "(Welcome to Scala) version .*".r
  def normalize(s: String) = s match {
    case welcome(w) => w
    case s          => s
  def unwelcoming(s: String) = s match {
    case welcome(w) => false
    case _          => true
  def eval() = {
    val s = settings
    log("eval(): settings = " + s)
    //ILoop.runForTranscript(code, s).lines drop 1  // not always first line
    val lines = ILoop.runForTranscript(code, s).lines
    if (welcoming) lines map normalize
    else lines filter unwelcoming
  def show() = eval() foreach println

/** Retain and normalize the welcome message. */
trait Welcoming { this: ReplTest =>
  override def welcoming = true

/** Run a REPL test from a session transcript.
 *  The `session` should be a triple-quoted String starting
 *  with the `Type in expressions` message and ending
 *  after the final `prompt`, including the last space.
abstract class SessionTest extends ReplTest  {
  /** Session transcript, as a triple-quoted, multiline, marginalized string. */
  def session: String

  /** Expected output, as an iterator. */
  def expected = session.stripMargin.lines

  /** Code is the command list culled from the session (or the expected session output).
   *  Would be nicer if code were lazy lines.
  override final def code = expected filter (_ startsWith prompt) map (_ drop prompt.length) mkString "\n"

  final def prompt = "scala> "

  /** Default test is to compare expected and actual output and emit the diff on a failed comparison. */
  override def show() = {
    val evaled = eval().toList
    val wanted = expected.toList
    if (evaled.size != wanted.size) Console println s"Expected ${wanted.size} lines, got ${evaled.size}"
    if (evaled != wanted) Console print nest.FileManager.compareContents(wanted, evaled, "expected", "actual")

Other Scala source code examples

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