Play Framework/Scala example source code file (TestChannel.scala)

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

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

Play Framework tags/keywords

a, assertionerror, boolean, concurrent, duration, eof, input, jboolean, lib, library, linkedblockingqueue, play, play framework, t, time, unit

The TestChannel.scala Play Framework example source code

/*
 * Copyright (C) 2009-2013 Typesafe Inc. <http://www.typesafe.com>
 */
package play.api.libs.iteratee

import java.lang.{ Boolean => JBoolean }
import java.util.concurrent.LinkedBlockingQueue
import play.libs.F
import scala.concurrent.duration._

/**
 * Implementation of Concurrent.Channel for testing.
 * Can be queried for expected chunks and end calls.
 */
class TestChannel[A](defaultTimeout: Duration) extends Concurrent.Channel[A] {
  def this() = this(5.seconds)

  private val chunks = new LinkedBlockingQueue[Input[A]]
  private val ends = new LinkedBlockingQueue[Option[Throwable]]

  def push(chunk: Input[A]): Unit = {
    chunks.offer(chunk)
  }

  def end(e: Throwable): Unit = {
    ends.offer(Some(e))
  }

  def end(): Unit = {
    ends.offer(None)
  }

  private def takeChunk(timeout: Duration): Input[A] = {
    if (timeout.isFinite)
      chunks.poll(timeout.length, timeout.unit)
    else
      chunks.take
  }

  def expect(expected: A): A = expect(expected, defaultTimeout)

  def expect(expected: A, timeout: Duration): A = expect(expected, timeout, _ == _)

  def expect(expected: A, test: F.Function2[A, A, JBoolean]): A = expect(expected, defaultTimeout, test)

  def expect(expected: A, timeout: Duration, test: F.Function2[A, A, JBoolean]): A = expect(expected, timeout, test.apply(_, _))

  def expect(expected: A, test: (A, A) => Boolean): A = expect(expected, defaultTimeout, test)

  def expect(expected: A, timeout: Duration, test: (A, A) => Boolean): A = {
    takeChunk(timeout) match {
      case null =>
        throw new AssertionError(s"timeout ($timeout) waiting for $expected")
      case Input.El(input) =>
        assert(test(expected, input), s"expected [$expected] but found [$input]")
        input
      case other =>
        throw new AssertionError(s"expected Input.El [$expected] but found [$other]")
    }
  }

  def expectEOF(): Input[A] = expectEOF(defaultTimeout)

  def expectEOF(timeout: Duration): Input[A] = {
    takeChunk(timeout) match {
      case null => throw new AssertionError(s"timeout ($timeout) waiting for EOF")
      case eof @ Input.EOF => eof
      case other => throw new AssertionError(s"expected EOF but found [$other]")
    }
  }

  private def takeEnd(timeout: Duration): Option[Throwable] = {
    if (timeout.isFinite)
      ends.poll(timeout.length, timeout.unit)
    else
      ends.take
  }

  def expectEnd[T](expected: Class[T]): T = expectEnd(expected, defaultTimeout)

  def expectEnd[T](expected: Class[T], timeout: Duration): T = {
    val end = takeEnd(timeout)
    assert(end ne null, s"timeout ($timeout) waiting for end with failure [$expected]")
    end match {
      case Some(throwable) =>
        assert(expected isInstance throwable, s"expected end with failure [$expected] but found [$throwable]")
        throwable.asInstanceOf[T]
      case None =>
        throw new AssertionError(s"expected end with failure [$expected] but found end (without failure)")
    }
  }

  def expectEnd(): Unit = expectEnd(defaultTimeout)

  def expectEnd(timeout: Duration): Unit = {
    val end = takeEnd(timeout)
    assert(end ne null, s"timeout ($timeout) waiting for end")
    if (end.isDefined)
      throw new AssertionError(s"expected end (without failure) but found [${end.get}]")
  }

  def expectEmpty(): Unit = {
    assert(chunks.isEmpty, s"expected empty chunks but found $chunks")
    assert(ends.isEmpty, s"expected empty ends but found $ends")
  }
}