Scala : add scala/example

12 files changed, 1659 insertions, 0 deletions

diff --git a/Scala/example/project/CourseraHttp.scala b/Scala/example/project/CourseraHttp.scala
new file mode 100644
index 0000000..792c2bf
--- /dev/null
+++ b/Scala/example/project/CourseraHttp.scala
@@ -0,0 +1,227 @@
+import dispatch.{Request, Http, NoLogging, StatusCode, url}
+import cc.spray.json.{JsNull, JsonParser, DefaultJsonProtocol, JsValue}
+import RichJsValue._
+import org.apache.commons.codec.digest.DigestUtils
+import org.apache.commons.codec.binary.{Hex, Base64}
+import java.io.{IOException, File, FileInputStream}
+import scalaz.Scalaz.{mkIdentity, ValidationNEL}
+
+import Settings._
+
+case class JsonSubmission(api_state: String, user_info: JsValue, submission_metadata: JsValue, solutions: JsValue, submission_encoding: String, submission: String)
+//case class JsonQueueResult(submission: JsonSubmission)
+object SubmitJsonProtocol extends DefaultJsonProtocol {
+  implicit val jsonSubmissionFormat = jsonFormat6(JsonSubmission)
+//  implicit val jsonQueueResultFormat = jsonFormat1(JsonQueueResult)
+}
+
+object CourseraHttp {
+  private lazy val http = new Http with NoLogging
+
+  private def executeRequest[T](req: Request)(parse: String => ValidationNEL[String, T]): ValidationNEL[String, T] = {
+    try {
+      http(req >- { res =>
+        parse(res)
+      })
+    } catch {
+      case ex: IOException =>
+        ("Connection failed\n"+ ex.toString()).failNel
+      case StatusCode(code, message) =>
+        ("HTTP failed with status "+ code +"\n"+ message).failNel
+    }
+  }
+
+
+  /******************************
+   * SUBMITTING
+   */
+
+  def getChallenge(email: String, submitProject: ProjectDetails): ValidationNEL[String, Challenge] = {
+    val baseReq = url(challengeUrl(submitProject.courseId))
+    val withArgs = baseReq << Map("email_address" -> email,
+                                  "assignment_part_sid" -> submitProject.assignmentPartId,
+                                  "response_encoding" -> "delim")
+
+    executeRequest(withArgs) { res =>
+      // example result. there might be an `aux_data` value at the end.
+      // |email_address|a@b.com|challenge_key|XXYYXXYYXXYY|state|XXYYXXYYXXYY|challenge_aux_data|
+      val parts = res.split('|').filterNot(_.isEmpty)
+      if (parts.length < 7)
+        ("Unexpected challenge format: \n"+ res).failNel
+      else
+        Challenge(parts(1), parts(3), parts(5)).successNel
+    }
+  }
+
+  def submitSolution(sourcesJar: File, submitProject: ProjectDetails, challenge: Challenge, chResponse: String): ValidationNEL[String, String] = {
+    val fileLength = sourcesJar.length()
+    if (!sourcesJar.exists()) {
+      ("Sources jar archive does not exist\n"+ sourcesJar.getAbsolutePath).failNel
+    } else if (fileLength == 0l) {
+      ("Sources jar archive is empty\n"+ sourcesJar.getAbsolutePath).failNel
+    } else if (fileLength > maxSubmitFileSize) {
+      ("Sources jar archive is too big. Allowed size: "+
+        maxSubmitFileSize +" bytes, found "+ fileLength +" bytes.\n"+
+        sourcesJar.getAbsolutePath).failNel
+    } else {
+      val bytes = new Array[Byte](fileLength.toInt)
+      val sizeRead = try {
+        val is = new FileInputStream(sourcesJar)
+        val read = is.read(bytes)
+        is.close()
+        read
+      } catch {
+        case ex: IOException =>
+          ("Failed to read sources jar archive\n"+ ex.toString()).failNel
+      }
+      if (sizeRead != bytes.length) {
+        ("Failed to read the sources jar archive, size read: "+ sizeRead).failNel
+      } else {
+        val fileData = encodeBase64(bytes)
+        val surl = submitUrl(submitProject.courseId)
+        println("courseId: " + submitProject.courseId)
+        println("submitUrl: " + surl)
+        val baseReq = url(submitUrl(submitProject.courseId))
+        println(baseReq)
+        val withArgs = baseReq << Map("assignment_part_sid" -> submitProject.assignmentPartId,
+                                      "email_address" -> challenge.email,
+                                      "submission" -> fileData,
+                                      "submission_aux" -> "",
+                                      "challenge_response" -> chResponse,
+                                      "state" -> challenge.state)
+        executeRequest(withArgs) { res =>
+          // the API returns HTTP 200 even if there are failures, how impolite...
+          if (res.contains("Your submission has been accepted"))
+            res.successNel
+          else
+            res.failNel
+        }
+      }
+    }
+  }
+
+  def challengeResponse(challenge: Challenge, otPassword: String): String =
+    shaHexDigest(challenge.challengeKey + otPassword)
+
+
+  /********************************
+   * DOWNLOADING SUBMISSIONS
+   */
+
+  // def downloadFromQueue(queue: String, targetJar: File, apiKey: String): ValidationNEL[String, QueueResult] = {
+  //   val baseReq = url(Settings.submitQueueUrl)
+  //   val withArgsAndHeader = baseReq << Map("queue" -> queue) <:< Map("X-api-key" -> apiKey)
+
+  //   executeRequest(withArgsAndHeader) { res =>
+  //     extractJson(res, targetJar)
+  //   }
+  // }
+
+  def readJsonFile(jsonFile: File, targetJar: File): ValidationNEL[String, QueueResult] = {
+    extractJson(sbt.IO.read(jsonFile), targetJar)
+  }
+
+  def extractJson(jsonData: String, targetJar: File): ValidationNEL[String, QueueResult] = {
+    import SubmitJsonProtocol._
+    for {
+      jsonSubmission <- {
+        try {
+          val parsed = JsonParser(jsonData)
+          val submission = parsed \ "submission"
+          if (submission == JsNull) {
+            ("Nothing to grade, queue is empty.").failNel
+          } else {
+            submission.convertTo[JsonSubmission].successNel
+          }
+        } catch {
+          case e: Exception =>
+            ("Could not parse submission\n"+ jsonData +"\n"+ fullExceptionString(e)).failNel
+        }
+      }
+      queueResult <- {
+        val encodedFile = jsonSubmission.submission
+        val jarContent = decodeBase64(encodedFile)
+        try {
+          sbt.IO.write(targetJar, jarContent)
+          QueueResult(jsonSubmission.api_state).successNel
+        } catch {
+          case e: IOException =>
+            ("Failed to write jar file to "+ targetJar.getAbsolutePath +"\n"+ e.toString).failNel
+        }
+      }
+    } yield queueResult
+  }
+
+  def unpackJar(file: File, targetDirectory: File): ValidationNEL[String, Unit] = {
+    try {
+      val files = sbt.IO.unzip(file, targetDirectory)
+      if (files.isEmpty)
+        ("No files found when unpacking jar file "+ file.getAbsolutePath).failNel
+      else
+        ().successNel
+    } catch {
+      case e: IOException =>
+        val msg = "Error while unpacking the jar file "+ file.getAbsolutePath +" to "+ targetDirectory.getAbsolutePath +"\n"+ e.toString
+        if (Settings.offlineMode) {
+          println("[offline mode] "+ msg)
+          ().successNel
+        } else {
+          msg.failNel
+        }
+    }
+  }
+
+
+  /********************************
+   * SUBMITTING GRADES
+   */
+
+  def submitGrade(feedback: String, score: String, apiState: String, apiKey: String, gradeProject: ProjectDetails): ValidationNEL[String, Unit] = {
+    import DefaultJsonProtocol._
+    val baseReq = url(Settings.uploadFeedbackUrl(gradeProject.courseId))
+    val withArgs = baseReq << Map("api_state" -> apiState, "score" -> score, "feedback" -> feedback) <:< Map("X-api-key" -> apiKey)
+    executeRequest(withArgs) { res =>
+      try {
+        val js = JsonParser(res)
+        val status = (js \ "status").convertTo[String]
+        if (status == "202")
+          ().successNel
+        else
+          ("Unexpected result from submit request: "+ status).failNel
+      } catch {
+        case e: Exception =>
+          ("Failed to parse response while submitting grade\n"+ res +"\n"+ fullExceptionString(e)).failNel
+      }
+    }
+  }
+
+
+  /*********************************
+   * TOOLS AND STUFF
+   */
+
+  def shaHexDigest(s: String): String = {
+    val chars = Hex.encodeHex(DigestUtils.sha(s))
+    new String(chars)
+  }
+
+
+  def fullExceptionString(e: Throwable) =
+    e.toString +"\n"+ e.getStackTrace.map(_.toString).mkString("\n")
+
+
+  /* Base 64 tools */
+
+  def encodeBase64(bytes: Array[Byte]): String =
+    new String(Base64.encodeBase64(bytes))
+
+  def decodeBase64(str: String): Array[Byte] = {
+    // codecs 1.4 has a version accepting a string, but not 1.2; jar hell.
+    Base64.decodeBase64(str.getBytes)
+  }
+}
+
+case class Challenge(email: String, challengeKey: String, state: String)
+
+case class QueueResult(apiState: String)
+
diff --git a/Scala/example/project/GradingFeedback.scala b/Scala/example/project/GradingFeedback.scala
new file mode 100644
index 0000000..5d78c54
--- /dev/null
+++ b/Scala/example/project/GradingFeedback.scala
@@ -0,0 +1,218 @@
+import collection.mutable.ListBuffer
+import org.apache.commons.lang3.StringEscapeUtils
+
+object GradingFeedback {
+
+  private val feedbackSummary = new ListBuffer[String]()
+  private val feedbackDetails = new ListBuffer[String]()
+
+  private def addSummary(msg: String) { feedbackSummary += msg; feedbackSummary += "\n\n" }
+  private def addDetails(msg: String) { feedbackDetails += msg; feedbackDetails += "\n\n" }
+
+  /**
+   * Converts the string to HTML - coursera displays the feedback in an html page.
+   */
+  def feedbackString(html: Boolean = true) = {
+    val total = totalGradeMessage(totalScore) + "\n\n"
+    // trim removes the newlines at the end
+    val s = (total + feedbackSummary.mkString + feedbackDetails.mkString).trim
+    if (html)
+      "<pre>"+ StringEscapeUtils.escapeHtml4(s) +"</pre>"
+    else
+      s
+  }
+
+  private var vTestScore: Double = 0d
+  private var   vStyleScore: Double = 0d
+  def totalScore = vTestScore + vStyleScore
+
+  private var vMaxTestScore: Double = 0d
+  private var vMaxStyleScore: Double = 0d
+  def maxTestScore = vMaxTestScore
+  def maxStyleScore = vMaxStyleScore
+
+  // a string obtained from coursera when downloading an assignment. it has to be
+  // used again when uploading the grade.
+  var apiState: String = ""
+
+  /**
+   * `failed` means that there was an unexpected error during grading. This includes
+   *  - student's code does not compile
+   *  - our tests don't compile (against the student's code)
+   *  - crash while executing ScalaTest (not test failures, but problems trying to run the tests!)
+   *  - crash while executing the style checker (again, not finding style problems!)
+   *
+   * When failed is `true`, later grading stages will not be executed: this is handled automatically
+   * by SBT, tasks depending on a failed one are not run.
+   *
+   * However, these dependent tasks still fail (i.e. mapR on them is invoked). The variable below
+   * allows us to know if something failed before. In this case, we don't add any more things to
+   * the log. (see `ProgFunBuild.handleFailure`)
+   */
+  private var failed = false
+  def isFailed = failed
+
+  def initialize() {
+    feedbackSummary.clear()
+    feedbackDetails.clear()
+    vTestScore = 0d
+    vStyleScore = 0d
+    apiState = ""
+    failed = false
+  }
+
+  def setMaxScore(maxScore: Double, styleScoreRatio: Double) {
+    vMaxTestScore = maxScore * (1-styleScoreRatio)
+    vMaxStyleScore = maxScore * styleScoreRatio
+  }
+
+
+  /* Methods to build up the feedback log */
+
+  def downloadUnpackFailed(log: String) {
+    failed = true
+    addSummary(downloadUnpackFailedMessage)
+    addDetails("======== FAILURES WHILE DOWNLOADING OR EXTRACTING THE SUBMISSION ========")
+    addDetails(log)
+  }
+
+
+  def compileFailed(log: String) {
+    failed = true
+    addSummary(compileFailedMessage)
+    addDetails("======== COMPILATION FAILURES ========")
+    addDetails(log)
+  }
+
+  def testCompileFailed(log: String) {
+    failed = true
+    addSummary(testCompileFailedMessage)
+    addDetails("======== TEST COMPILATION FAILURES ========")
+    addDetails(log)
+  }
+
+
+
+  def allTestsPassed() {
+    addSummary(allTestsPassedMessage)
+    vTestScore = maxTestScore
+  }
+
+  def testsFailed(log: String, score: Double) {
+    addSummary(testsFailedMessage(score))
+    vTestScore = score
+    addDetails("======== LOG OF FAILED TESTS ========")
+    addDetails(log)
+  }
+
+  def testExecutionFailed(log: String) {
+    failed = true
+    addSummary(testExecutionFailedMessage)
+    addDetails("======== ERROR LOG OF TESTING TOOL ========")
+    addDetails(log)
+  }
+
+  def testExecutionDebugLog(log: String) {
+    addDetails("======== DEBUG OUTPUT OF TESTING TOOL ========")
+    addDetails(log)
+  }
+
+
+
+  def perfectStyle() {
+    addSummary(perfectStyleMessage)
+    vStyleScore = maxStyleScore
+  }
+
+  def styleProblems(log: String, score: Double) {
+    addSummary(styleProblemsMessage(score))
+    vStyleScore = score
+    addDetails("======== CODING STYLE ISSUES ========")
+    addDetails(log)
+  }
+
+
+
+  /* Feedback Messages */
+
+  private val downloadUnpackFailedMessage =
+    """We were not able to download your submission from the coursera servers, or extracting the
+      |archive containing your source code failed.
+      |
+      |If you see this error message as your grade feedback, please contact one of the teaching
+      |assistants. See below for a detailed error log.""".stripMargin
+
+  private val compileFailedMessage =
+    """We were not able to compile the source code you submitted. This is not expected to happen,
+      |because the `submit` command in SBT can only be executed if your source code compiles.
+      |
+      |Please verify the following points:
+      | - You should use the `submit` command in SBT to upload your solution
+      | - You should not perform any changes to the SBT project definition files, i.e. the *.sbt
+      |   files, and the files in the `project/` directory
+      |
+      |Take a careful look at the compiler output below - maybe you can find out what the problem is.
+      |
+      |If you cannot find a solution, ask for help on the discussion forums on the course website.""".stripMargin
+
+
+  private val testCompileFailedMessage =
+    """We were not able to compile our tests, and therefore we could not correct your submission.
+      |
+      |The most likely reason for this problem is that your submitted code uses different names
+      |for methods, classes, objects or different types than expected.
+      |
+      |In principle, this can only arise if you changed some names or types in the code that we
+      |provide, for instance a method name or a parameter type.
+      |
+      |To diagnose your problem, perform the following steps:
+      | - Run the tests that we provide with our hand-out. These tests verify that all names and
+      |   types are correct. In case these tests pass, but you still see this message, please post
+      |   a report on the forums [1].
+      | - Take a careful look at the error messages from the Scala compiler below. They should give
+      |   you a hint where your code has an unexpected shape.
+      |
+      |If you cannot find a solution, ask for help on the discussion forums on the course website.""".stripMargin
+
+
+  private def testsFailedMessage(score: Double) =
+    """The code you submitted did not pass all of our tests: your submission achieved a score of
+      |%.2f out of %.2f in our tests.
+      |
+      |In order to find bugs in your code, we advise to perform the following steps:
+      | - Take a close look at the test output that you can find below: it should point you to
+      |   the part of your code that has bugs.
+      | - Run the tests that we provide with the handout on your code.
+      | - The tests we provide do not test your code in depth: they are very incomplete. In order
+      |   to test more aspects of your code, write your own unit tests.
+      | - Take another very careful look at the assignment description. Try to find out if you
+      |   misunderstood parts of it. While reading through the assignment, write more tests.
+      |
+      |Below you can find a short feedback for every individual test that failed.""".stripMargin.format(score, vMaxTestScore)
+
+  // def so that we read the right value of vMaxTestScore (initialize modifies it)
+  private def allTestsPassedMessage =
+    """Your solution passed all of our tests, congratulations! You obtained the maximal test
+      |score of %.2f.""".stripMargin.format(vMaxTestScore)
+
+  private val testExecutionFailedMessage =
+    """An error occured while running our tests on your submission. This is not expected to
+      |happen, it means there is a bug in our testing environment.
+      |
+      |In order for us to help you, please contact one of the teaching assistants and send
+      |them the entire feedback message that you recieved.""".stripMargin
+
+  // def so that we read the right value of vMaxStyleScore (initialize modifies it)
+  private def perfectStyleMessage =
+    """Our automated style checker tool could not find any issues with your code. You obtained the maximal
+      |style score of %.2f.""".stripMargin.format(vMaxStyleScore)
+
+
+  private def styleProblemsMessage(score: Double) =
+    """Our automated style checker tool found issues in your code with respect to coding style: it
+      |computed a style score of %.2f out of %.2f for your submission. See below for detailed feedback.""".stripMargin.format(score, vMaxStyleScore)
+
+
+  private def totalGradeMessage(score: Double) =
+    """Your overall score for this assignment is %.2f out of %.2f""".format(score, vMaxTestScore + vMaxStyleScore)
+}
diff --git a/Scala/example/project/ProgFunBuild.scala b/Scala/example/project/ProgFunBuild.scala
new file mode 100644
index 0000000..93d4b9d
--- /dev/null
+++ b/Scala/example/project/ProgFunBuild.scala
@@ -0,0 +1,646 @@
+import sbt._
+import Keys._
+
+import scalaz.Scalaz.mkIdentity
+import scalaz.{Success, Failure}
+import com.typesafe.sbteclipse.plugin.EclipsePlugin.EclipseKeys
+
+/**
+ * See README.md for high-level overview
+ *
+ * Libraries Doc Links
+ *
+ * Coursera API
+ *  - http://support.coursera.org/customer/portal/articles/573466-programming-assignments
+ *  - the python script 'submit.py' that can be downloaded from the above site
+ *
+ * SBT
+ *  - https://github.com/harrah/xsbt/wiki/Getting-Started-Full-Def
+ *  - https://github.com/harrah/xsbt/wiki/Getting-Started-Custom-Settings
+ *  - https://github.com/harrah/xsbt/wiki/Getting-Started-More-About-Settings
+ *  - https://github.com/harrah/xsbt/wiki/Input-Tasks
+ *  - https://github.com/harrah/xsbt/wiki/Tasks
+ *  - http://harrah.github.com/xsbt/latest/api/index.html
+ *  - https://groups.google.com/forum/?fromgroups#!forum/simple-build-tool
+ *
+ * Dispatch
+ *  - http://dispatch-classic.databinder.net/Response+Bodies.html
+ *  - http://www.flotsam.nl/dispatch-periodic-table.html
+ *  - http://databinder.net/dispatch-doc/
+ *
+ * Scalaz
+ *  - http://www.lunatech-research.com/archives/2012/03/02/validation-scala
+ *  - http://scalaz.github.com/scalaz/scalaz-2.9.1-6.0.4/doc/index.html#scalaz.Validation
+ *
+ * Apache Commons Codec 1.4
+ *  - http://www.jarvana.com/jarvana/view/commons-codec/commons-codec/1.4/commons-codec-1.4-javadoc.jar!/index.html
+ *
+ * Scalatest
+ *  - http://doc.scalatest.org/1.9.1/index.html#org.scalatest.package
+ */
+object ProgFunBuild extends Build {
+
+  /***********************************************************
+   * MAIN PROJECT DEFINITION
+   */
+
+  lazy val assignmentProject = Project(id = "assignment", base = file(".")) settings(
+    // 'submit' depends on 'packageSrc', so needs to be a project-level setting: on build-level, 'packageSrc' is not defined
+    submitSetting,
+    createHandoutSetting,
+    // put all libs in the lib_managed directory, that way we can distribute eclipse project files
+    retrieveManaged := true,
+    EclipseKeys.relativizeLibs := true,
+    // Avoid generating eclipse source entries for the java directories
+    (unmanagedSourceDirectories in Compile) <<= (scalaSource in Compile)(Seq(_)),
+    (unmanagedSourceDirectories in Test) <<= (scalaSource in Test)(Seq(_)),
+    commonSourcePackages := Seq(), // see build.sbt
+    gradingTestPackages := Seq(),  // see build.sbt
+    selectMainSources,
+    selectTestSources,
+    scalaTestSetting,
+    styleCheckSetting,
+    setTestPropertiesSetting,
+    setTestPropertiesHook
+  ) settings (packageSubmissionFiles: _*)
+
+
+  /***********************************************************
+   * SETTINGS AND TASKS
+   */
+
+  /** The 'submit' task uses this project name (defined in the build.sbt file) to know where to submit the solution */
+  val submitProjectName = SettingKey[String]("submitProjectName")
+
+  /** Project-specific settings, see main build.sbt */
+  val projectDetailsMap = SettingKey[Map[String, ProjectDetails]]("projectDetailsMap")
+
+  /**
+   * The files that are handed out to students. Accepts a string denoting the project name for
+   * which a handout will be generated.
+   */
+  val handoutFiles = TaskKey[String => PathFinder]("handoutFiles")
+
+  /**
+   * This setting allows to restrict the source files that are compiled and tested
+   * to one specific project. It should be either the empty string, in which case all
+   * projects are included, or one of the project names from the projectDetailsMap.
+   */
+  val currentProject = SettingKey[String]("currentProject")
+
+  /** Package names of source packages common for all projects, see comment in build.sbt */
+  val commonSourcePackages = SettingKey[Seq[String]]("commonSourcePackages")
+
+  /** Package names of test sources for grading, see comment in build.sbt */
+  val gradingTestPackages = SettingKey[Seq[String]]("gradingTestPackages")
+
+  /************************************************************
+   * SUBMITTING A SOLUTION TO COURSERA
+   */
+
+  val packageSubmission = TaskKey[File]("packageSubmission")
+
+  val packageSubmissionFiles = {
+    // the packageSrc task uses Defaults.packageSrcMappings, which is defined as concatMappings(resourceMappings, sourceMappings)
+    // in the packageSubmisson task we only use the sources, not the resources.
+    inConfig(Compile)(Defaults.packageTaskSettings(packageSubmission, Defaults.sourceMappings))
+  }
+
+  /** Task to submit a solution to coursera */
+  val submit = InputKey[Unit]("submit")
+
+  lazy val submitSetting = submit <<= inputTask { argTask =>
+    (argTask, compile in Compile, currentProject, (packageSubmission in Compile), submitProjectName, projectDetailsMap, streams) map { (args, _, currentProject, sourcesJar, projectName, detailsMap, s) =>
+      if (currentProject != "") {
+        val msg =
+          """The 'currentProject' setting is not empty: '%s'
+            |
+            |This error only appears if there are mistakes in the build scripts. Please re-download the assignment
+            |from the coursera webiste. Make sure that you did not perform any changes to the build files in the
+            |`project/` directory. If this error persits, ask for help on the course forums.""".format(currentProject).stripMargin +"\n "
+        s.log.error(msg)
+        failSubmit()
+      } else {
+        lazy val wrongNameMsg =
+          """Unknown project name: %s
+            |
+            |This error only appears if there are mistakes in the build scripts. Please re-download the assignment
+            |from the coursera webiste. Make sure that you did not perform any changes to the build files in the
+            |`project/` directory. If this error persits, ask for help on the course forums.""".format(projectName).stripMargin +"\n "
+        // log strips empty lines at the ond of `msg`. to have one we add "\n "
+        val details = detailsMap.getOrElse(projectName, {s.log.error(wrongNameMsg); failSubmit()})
+        args match {
+          case email :: otPassword :: Nil =>
+            submitSources(sourcesJar, details, email, otPassword, s.log)
+          case _ =>
+            val msg =
+              """No e-mail address and / or submission password provided. The required syntax for `submit` is
+                |  submit <e-mail> <submissionPassword>
+                |
+                |The submission password, which is NOT YOUR LOGIN PASSWORD, can be obtained from the assignment page
+                |  https://class.coursera.org/%s/assignment/index""".format(details.courseId).stripMargin +"\n "
+            s.log.error(msg)
+            failSubmit()
+        }
+      }
+    }
+  }
+
+
+  def submitSources(sourcesJar: File, submitProject: ProjectDetails, email: String, otPassword: String, logger: Logger) {
+    import CourseraHttp._
+    logger.info("Connecting to coursera. Obtaining challenge...")
+    val res = for {
+      challenge  <- getChallenge(email, submitProject)
+      chResponse <- {
+        logger.info("Computing challenge response...")
+        challengeResponse(challenge, otPassword).successNel[String]
+      }
+      response   <- {
+        logger.info("Submitting solution...")
+        submitSolution(sourcesJar, submitProject, challenge, chResponse)
+      }
+    } yield response
+
+    res match {
+      case Failure(msgs) =>
+        for (msg <- msgs.list) logger.error(msg)
+        failSubmit()
+      case Success(response) =>
+        logger.success("Your code was successfully submitted: "+ response)
+    }
+  }
+
+
+  def failSubmit(): Nothing = {
+    sys.error("Submission failed")
+  }
+
+
+
+  /***********************************************************
+   * CREATE THE HANDOUT ZIP FILE
+   */
+
+  val createHandout = InputKey[File]("createHandout")
+
+  // depends on "compile in Test" to make sure everything compiles. also makes sure that
+  // all dependencies are downloaded, because we pack the .jar files into the handout.
+  lazy val createHandoutSetting = createHandout <<= inputTask { argTask =>
+    (argTask, currentProject, baseDirectory, handoutFiles, submitProjectName, target, projectDetailsMap, compile in Test) map { (args, currentProject, basedir, filesFinder, submitProject, targetDir, detailsMap, _) =>
+      if (currentProject != "")
+        sys.error("\nthe 'currentProject' setting in build.sbt needs to be \"\" in order to create a handout")
+      else args match {
+        case handoutProjectName :: eclipseDone :: Nil if eclipseDone == "eclipseWasCalled" =>
+          if (handoutProjectName != submitProject)
+            sys.error("\nThe `submitProjectName` setting in `build.sbt` must match the project name for which a handout is generated\n ")
+          val files = filesFinder(handoutProjectName).get
+          val filesWithRelativeNames = files.x_!(relativeTo(basedir)) map {
+            case (file, name) => (file, handoutProjectName+"/"+name)
+          }
+          val targetZip = targetDir / (handoutProjectName +".zip")
+          IO.zip(filesWithRelativeNames, targetZip)
+          targetZip
+        case _ =>
+          val msg ="""
+            |
+            |Failed to create handout. Syntax: `createHandout <projectName> <eclipseWasCalled>`
+            |
+            |Valid project names are: %s
+            |
+            |The argument <eclipseWasCalled> needs to be the string "eclipseWasCalled". This is to remind
+            |you that you **need** to manually run the `eclipse` command before running `createHandout`.
+            | """.stripMargin.format(detailsMap.keys.mkString(", "))
+          sys.error(msg)
+      }
+    }
+  }
+
+
+  /************************************************************
+   * LIMITING SOURCES TO CURRENT PROJECT
+   */
+
+  def filter(basedir: File, packages: Seq[String]) = new FileFilter {
+    def accept(file: File) = {
+      basedir.equals(file) || {
+        IO.relativize(basedir, file) match {
+          case Some(str) =>
+            packages exists { pkg =>
+              str.startsWith(pkg)
+            }
+          case _ =>
+            sys.error("unexpected test file: "+ file +"\nbase dir: "+ basedir)
+        }
+      }
+    }
+  }
+
+  def projectFiles(allFiles: Seq[File], basedir: File, projectName: String, globalPackages: Seq[String], detailsMap: Map[String, ProjectDetails]) = {
+    if (projectName == "") allFiles
+    else detailsMap.get(projectName) match {
+      case Some(project) =>
+        val finder = allFiles ** filter(basedir, globalPackages :+ project.packageName)
+        finder.get
+      case None =>
+        sys.error("currentProject is set to an invalid name: "+ projectName)
+    }
+  }
+
+  /**
+   * Only include source files of 'currentProject', helpful when preparign a specific assignment.
+   * Also keeps the source packages in 'commonSourcePackages'.
+   */
+  val selectMainSources = {
+    (unmanagedSources in Compile) <<= (unmanagedSources in Compile, scalaSource in Compile, projectDetailsMap, currentProject, commonSourcePackages) map { (sources, srcMainScalaDir, detailsMap, projectName, commonSrcs) =>
+      projectFiles(sources, srcMainScalaDir, projectName, commonSrcs, detailsMap)
+    }
+  }
+
+  /**
+   * Only include the test files which are defined in the package of the current project.
+   * Also keeps test sources in packages listed in 'gradingTestPackages'.
+   */
+  val selectTestSources = {
+    (unmanagedSources in Test) <<= (unmanagedSources in Test, scalaSource in Test, projectDetailsMap, currentProject, gradingTestPackages) map { (sources, srcTestScalaDir, detailsMap, projectName, gradingSrcs) =>
+      projectFiles(sources, srcTestScalaDir, projectName, gradingSrcs, detailsMap)
+    }
+  }
+
+
+  /************************************************************
+   * PARAMETERS FOR RUNNING THE TESTS
+   *
+   * Setting some system properties that are parameters for the GradingSuite test
+   * suite mixin. This is for running the `test` task in SBT's JVM. When running
+   * the `scalaTest` task, the ScalaTestRunner creates a new JVM and passes the
+   * same properties.
+   */
+
+  val setTestProperties = TaskKey[Unit]("setTestProperties")
+  val setTestPropertiesSetting = setTestProperties := {
+    import scala.util.Properties._
+    import Settings._
+    setProp(scalaTestIndividualTestTimeoutProperty, individualTestTimeout.toString)
+    setProp(scalaTestDefaultWeigthProperty, scalaTestDefaultWeigth.toString)
+  }
+
+  val setTestPropertiesHook = (test in Test) <<= (test in Test).dependsOn(setTestProperties)
+
+
+  /************************************************************
+   * RUNNING WEIGHTED SCALATEST & STYLE CHECKER ON DEVELOPMENT SOURCES
+   */
+
+  def copiedResourceFiles(copied: collection.Seq[(java.io.File, java.io.File)]): List[File] = {
+    copied collect {
+      case (from, to) if to.isFile => to
+    } toList
+  }
+
+  val scalaTest = TaskKey[Unit]("scalaTest")
+  val scalaTestSetting = scalaTest <<=
+    (compile in Compile,
+      compile in Test,
+      fullClasspath in Test,
+      copyResources in Compile,
+      classDirectory in Test,
+      baseDirectory,
+      streams) map { (_, _, classpath, resources, testClasses, basedir, s) =>
+    // we use `map`, so this is only executed if all dependencies succeed. no need to check `GradingFeedback.isFailed`
+      val logger = s.log
+      val outfile = basedir / Settings.testResultsFileName
+      val policyFile = basedir / Settings.policyFileName
+      val (score, maxScore, feedback, runLog) = ScalaTestRunner.runScalaTest(classpath, testClasses, outfile, policyFile, copiedResourceFiles(resources), logger.error(_))
+      logger.info(feedback)
+      logger.info("Test Score: "+ score +" out of "+ maxScore)
+      if (!runLog.isEmpty) {
+        logger.info("Console output of ScalaTest process")
+        logger.info(runLog)
+      }
+    }
+
+  val styleCheck = TaskKey[Unit]("styleCheck")
+
+  /**
+   * depend on compile to make sure the sources pass the compiler
+   */
+  val styleCheckSetting = styleCheck <<= (compile in Compile, sources in Compile, streams) map { (_, sourceFiles, s) =>
+    val logger = s.log
+    val (feedback, score) = StyleChecker.assess(sourceFiles)
+    logger.info(feedback)
+    logger.info("Style Score: "+ score +" out of "+ StyleChecker.maxResult)
+  }
+
+
+  /************************************************************
+   * PROJECT DEFINITION FOR GRADING
+   */
+
+  lazy val submissionProject = Project(id = "submission", base = file(Settings.submissionDirName)) settings(
+    /** settings we take over from the assignment project */
+    version <<= (version in assignmentProject),
+    name <<= (name in assignmentProject),
+    scalaVersion <<= (scalaVersion in assignmentProject),
+    scalacOptions <<= (scalacOptions in assignmentProject),
+    libraryDependencies <<= (libraryDependencies in assignmentProject),
+
+    /** settings specific to the grading project */
+    initGradingSetting,
+    // default value, don't change. see comment on `val partIdOfGradingProject`
+    partIdOfGradingProject := "",
+    gradeProjectDetailsSetting,
+    setMaxScoreSetting,
+    setMaxScoreHook,
+    // default value, don't change. see comment on `val apiKey`
+    apiKey := "",
+    getSubmissionSetting,
+    getSubmissionHook,
+    submissionLoggerSetting,
+    readCompileLog,
+    readTestCompileLog,
+    setTestPropertiesSetting,
+    setTestPropertiesHook,
+    resourcesFromAssignment,
+    selectResourcesForProject,
+    testSourcesFromAssignment,
+    selectTestsForProject,
+    scalaTestSubmissionSetting,
+    styleCheckSubmissionSetting,
+    gradeSetting,
+    EclipseKeys.skipProject := true
+  )
+
+  /**
+   * The assignment part id of the project to be graded. Don't hard code this setting in .sbt or .scala, this
+   * setting should remain a (command-line) parameter of the `submission/grade` task, defined when invoking sbt.
+   * See also feedback string in "val gradeProjectDetailsSetting".
+   */
+  val partIdOfGradingProject = SettingKey[String]("partIdOfGradingProject")
+
+  /**
+   * The api key to access non-public api parts on coursera. This key is secret! It's defined in
+   * 'submission/settings.sbt', which is not part of the handout.
+   *
+   * Default value 'apiKey' to make the handout sbt project work
+   *  - In the handout, apiKey needs to be defined, otherwise the build doesn't compile
+   *  - When correcting, we define 'apiKey' in the 'submission/sectrets.sbt' file
+   *  - The value in the .sbt file will take precedence when correcting (settings in .sbt take
+   *    precedence over those in .scala)
+   */
+  val apiKey = SettingKey[String]("apiKey")
+
+
+  /************************************************************
+   * GRADING INITIALIZATION
+   */
+
+  val initGrading = TaskKey[Unit]("initGrading")
+  lazy val initGradingSetting = initGrading <<= (clean, sourceDirectory, baseDirectory) map { (_, submissionSrcDir, basedir) =>
+    deleteFiles(submissionSrcDir, basedir)
+    GradingFeedback.initialize()
+    RecordingLogger.clear()
+  }
+
+  def deleteFiles(submissionSrcDir: File, basedir: File) {
+    // don't delete anything in offline mode, useful for us when hacking testing / stylechecking
+    if (!Settings.offlineMode){
+      IO.delete(submissionSrcDir)
+      IO.delete(basedir / Settings.submissionJarFileName)
+      IO.delete(basedir / Settings.testResultsFileName)
+    }
+  }
+
+  /** ProjectDetails of the project that we are grading */
+  val gradeProjectDetails = TaskKey[ProjectDetails]("gradeProjectDetails")
+
+  // here we depend on `initialize` because we already use the GradingFeedback
+  lazy val gradeProjectDetailsSetting = gradeProjectDetails <<= (initGrading, partIdOfGradingProject, projectDetailsMap in assignmentProject) map { (_, partId, detailsMap) =>
+    detailsMap.find(_._2.assignmentPartId == partId) match {
+      case Some((_, details)) =>
+        details
+      case None =>
+        val validIds = detailsMap.map(_._2.assignmentPartId)
+        val msgRaw =
+          """Unknown assignment part id: %s
+            |Valid part ids are: %s
+            |
+            |In order to grade a project, the `partIdOfGradingProject` setting has to be defined. If you are running
+            |interactively in the sbt console, type `set (partIdOfGradingProject in submissionProject) := "idString"`.
+            |When running the grading task from the command line, add the above `set` command, e.g. execute
+            |
+            |  sbt 'set (partIdOfGradingProject in submissionProject) := "idString"' submission/grade"""
+        val msg = msgRaw.stripMargin.format(partId, validIds.mkString(", ")) + "\n "
+        GradingFeedback.downloadUnpackFailed(msg)
+        sys.error(msg)
+    }
+  }
+
+  val setMaxScore = TaskKey[Unit]("setMaxScore")
+  val setMaxScoreSetting = setMaxScore <<= (gradeProjectDetails) map { project =>
+    GradingFeedback.setMaxScore(project.maxScore, project.styleScoreRatio)
+  }
+
+  // set the maximal score before running compile / test / ...
+  val setMaxScoreHook = (compile in Compile) <<= (compile in Compile).dependsOn(setMaxScore)
+
+
+  /************************************************************
+   * DOWNLOADING AND EXTRACTING SUBMISSION
+   */
+
+  val getSubmission = TaskKey[Unit]("getSubmission")
+  val getSubmissionSetting = getSubmission <<= (baseDirectory, scalaSource in Compile) map { (baseDir, scalaSrcDir) =>
+    readAndUnpackSubmission(baseDir, scalaSrcDir)
+  }
+
+  def readAndUnpackSubmission(baseDir: File, targetSourceDir: File) {
+    try {
+      val jsonFile = baseDir / Settings.submissionJsonFileName
+      val targetJar = baseDir / Settings.submissionJarFileName
+      val res = for {
+        queueResult <- {
+          if (Settings.offlineMode) {
+            println("[not unpacking from json file]")
+            QueueResult("").successNel
+          } else {
+            CourseraHttp.readJsonFile(jsonFile, targetJar)
+          }
+        }
+        _ <- {
+          GradingFeedback.apiState = queueResult.apiState
+          CourseraHttp.unpackJar(targetJar, targetSourceDir)
+        }
+      } yield ()
+
+      res match {
+        case Failure(msgs) =>
+          GradingFeedback.downloadUnpackFailed(msgs.list.mkString("\n"))
+        case _ =>
+          ()
+      }
+    } catch {
+      case e: Throwable =>
+        // generate some useful feedback in case something fails
+        GradingFeedback.downloadUnpackFailed(CourseraHttp.fullExceptionString(e))
+        throw e
+    }
+    if (GradingFeedback.isFailed) failDownloadUnpack()
+  }
+
+  // dependsOn makes sure that `getSubmission` is executed *before* `unmanagedSources`
+  val getSubmissionHook = (unmanagedSources in Compile) <<= (unmanagedSources in Compile).dependsOn(getSubmission)
+
+  def failDownloadUnpack(): Nothing = {
+    sys.error("Download or Unpack failed")
+  }
+
+  /************************************************************
+   * READING COMPILATION AND TEST COMPILATION LOGS
+   */
+
+
+  // extraLoggers need to be defined globally. (extraLoggers in Compile) does not work - sbt only
+  // looks at the global extraLoggers when creating the LogManager.
+  val submissionLoggerSetting = extraLoggers ~= { currentFunction =>
+    (key: ScopedKey[_]) => {
+      new FullLogger(RecordingLogger) +: currentFunction(key)
+    }
+  }
+
+  val readCompileLog = (compile in Compile) <<= (compile in Compile) mapR handleFailure(compileFailed)
+  val readTestCompileLog = (compile in Test) <<= (compile in Test) mapR handleFailure(compileTestFailed)
+
+  def handleFailure[R](handler: (Incomplete, String) => Unit) = (res: Result[R]) => res match {
+    case Inc(inc) =>
+      // Only call the handler of the task that actually failed. See comment in GradingFeedback.failed
+      if (!GradingFeedback.isFailed)
+        handler(inc, RecordingLogger.readAndClear())
+      throw inc
+    case Value(v) => v
+  }
+
+  def compileFailed(inc: Incomplete, log: String) {
+    GradingFeedback.compileFailed(log)
+  }
+
+  def compileTestFailed(inc: Incomplete, log: String) {
+    GradingFeedback.testCompileFailed(log)
+  }
+
+
+  /************************************************************
+   * RUNNING SCALATEST
+   */
+
+  /** The submission project takes resource files from the main (assignment) project */
+  val resourcesFromAssignment = {
+    (resourceDirectory in Compile) <<= (resourceDirectory in (assignmentProject, Compile))
+  }
+
+  /**
+   * Only include the resource files which are defined in the package of the current project.
+   */
+  val selectResourcesForProject = {
+    (resources in Compile) <<= (resources in Compile, resourceDirectory in (assignmentProject, Compile), gradeProjectDetails) map { (resources, resourceDir, project) =>
+      val finder = resources ** filter(resourceDir, List(project.packageName))
+      finder.get
+    }
+  }
+
+  /** The submission project takes test files from the main (assignment) project */
+  val testSourcesFromAssignment = {
+    (sourceDirectory in Test) <<= (sourceDirectory in (assignmentProject, Test))
+  }
+
+  /**
+   * Only include the test files which are defined in the package of the current project.
+   * Also keeps test sources in packages listed in 'gradingTestPackages'
+   */
+  val selectTestsForProject = {
+    (unmanagedSources in Test) <<= (unmanagedSources in Test, scalaSource in (assignmentProject, Test), gradingTestPackages in assignmentProject, gradeProjectDetails) map { (sources, testSrcScalaDir, gradingSrcs, project) =>
+      val finder = sources ** filter(testSrcScalaDir, gradingSrcs :+ project.packageName)
+      finder.get
+    }
+  }
+
+  val scalaTestSubmission = TaskKey[Unit]("scalaTestSubmission")
+  val scalaTestSubmissionSetting = scalaTestSubmission <<=
+    (compile in Compile,
+     compile in Test,
+     fullClasspath in Test,
+     copyResources in Compile,
+     classDirectory in Test,
+     baseDirectory) map { (_, _, classpath, resources, testClasses, basedir) =>
+      // we use `map`, so this is only executed if all dependencies succeed. no need to check `GradingFeedback.isFailed`
+      val outfile = basedir / Settings.testResultsFileName
+      val policyFile = basedir / ".." / Settings.policyFileName
+      ScalaTestRunner.scalaTestGrade(classpath, testClasses, outfile, policyFile, copiedResourceFiles(resources))
+  }
+
+
+
+  /************************************************************
+   * STYLE CHECKING
+   */
+
+  val styleCheckSubmission = TaskKey[Unit]("styleCheckSubmission")
+
+  /**
+   * - depend on scalaTestSubmission so that test get executed before style checking. the transitive
+   *   dependencies also ensures that the "sources in Compile" don't have compilation errors
+   * - using `map` makes this task execute only if all its dependencies succeeded.
+   */
+  val styleCheckSubmissionSetting = styleCheckSubmission <<= (sources in Compile, scalaTestSubmission) map { (sourceFiles, _) =>
+    val (feedback, score) = StyleChecker.assess(sourceFiles)
+    if (score == StyleChecker.maxResult) {
+      GradingFeedback.perfectStyle()
+    } else {
+      val gradeScore = GradingFeedback.maxStyleScore * score / StyleChecker.maxResult
+      GradingFeedback.styleProblems(feedback, gradeScore)
+    }
+  }
+
+
+
+  /************************************************************
+   * SUBMITTING GRADES TO COURSERA
+   */
+
+  val grade = TaskKey[Unit]("grade")
+
+  // mapR: submit the grade / feedback in any case, also on failure
+  val gradeSetting = grade <<= (scalaTestSubmission, styleCheckSubmission, apiKey, gradeProjectDetails, streams) mapR { (_, _, apiKeyR, projectDetailsR, s) =>
+    val logOpt = s match {
+      case Value(v) => Some(v.log)
+      case _ => None
+    }
+    logOpt.foreach(_.info(GradingFeedback.feedbackString(html = false)))
+    apiKeyR match {
+      case Value(apiKey) if (!apiKey.isEmpty) =>
+        // if build failed early, we did not even get the api key from the submission queue
+        if (!GradingFeedback.apiState.isEmpty && !Settings.offlineMode) {
+          val scoreString = "%.2f".format(GradingFeedback.totalScore)
+          val Value(projectDetails) = projectDetailsR
+          CourseraHttp.submitGrade(GradingFeedback.feedbackString(), scoreString, GradingFeedback.apiState, apiKey, projectDetails) match {
+            case Failure(msgs) =>
+              sys.error(msgs.list.mkString("\n"))
+            case _ =>
+              ()
+          }
+        } else if(Settings.offlineMode) {
+          logOpt.foreach(_.info(" \nSettings.offlineMode enabled, not uploading the feedback"))
+        } else {
+          sys.error("Could not submit feedback - apiState not initialized")
+        }
+      case _ =>
+        sys.error("Could not submit feedback - apiKey not defined: "+ apiKeyR)
+    }
+  }
+}
+
+case class ProjectDetails(packageName: String,
+                          assignmentPartId: String,
+                          maxScore: Double,
+                          styleScoreRatio: Double,
+                          courseId: String)
diff --git a/Scala/example/project/RecordingLogger.scala b/Scala/example/project/RecordingLogger.scala
new file mode 100644
index 0000000..b886768
--- /dev/null
+++ b/Scala/example/project/RecordingLogger.scala
@@ -0,0 +1,35 @@
+import sbt._
+import collection.mutable.ListBuffer
+
+/**
+ * Logger to capture compiler output, test output
+ */
+
+object RecordingLogger extends Logger {
+  private val buffer = ListBuffer[String]()
+
+  def hasErrors = buffer.nonEmpty
+
+  def readAndClear() = {
+    val res = buffer.mkString("\n")
+    buffer.clear()
+    res
+  }
+
+  def clear() {
+    buffer.clear()
+  }
+
+  def log(level: Level.Value, message: => String) =
+    if (level == Level.Error) {
+      buffer += message
+    }
+
+  // we don't log success here
+  def success(message: => String) = ()
+
+  // invoked when a task throws an exception. invoked late, when the exception is logged, i.e.
+  // just before returning to the prompt. therefore we do nothing: storing the exception in the
+  // buffer would happen *after* the `handleFailure` reads the buffer.
+  def trace(t: => Throwable) = ()
+}
diff --git a/Scala/example/project/RichJsValue.scala b/Scala/example/project/RichJsValue.scala
new file mode 100644
index 0000000..ca9ad94
--- /dev/null
+++ b/Scala/example/project/RichJsValue.scala
@@ -0,0 +1,28 @@
+import cc.spray.json._
+
+class RichJsValue(js: JsValue) {
+  def \ (name: String): JsValue = js match {
+    case JsObject(fields) =>
+      fields(name)
+    case _ =>
+      throw new IllegalArgumentException("Cannot select field "+ name +" from non-JsObject "+ js)
+  }
+
+  def hasFieldNamed(name: String) = js match {
+    case JsObject(fields) =>
+      fields.contains(name)
+    case _ =>
+      false
+  }
+
+  def arrayValues: List[JsValue] = js match {
+    case JsArray(values) =>
+      values
+    case _ =>
+      throw new IllegalArgumentException("Trying to select values from non-JsArray"+ js)
+  }
+}
+
+object RichJsValue {
+  implicit def enrichJsValue(js: JsValue) = new RichJsValue(js)
+}
diff --git a/Scala/example/project/ScalaTestRunner.scala b/Scala/example/project/ScalaTestRunner.scala
new file mode 100644
index 0000000..af63495
--- /dev/null
+++ b/Scala/example/project/ScalaTestRunner.scala
@@ -0,0 +1,169 @@
+import sbt._
+import Keys._
+import sys.process.{Process => SysProc, ProcessLogger}
+import java.util.concurrent._
+import collection.mutable.ListBuffer
+
+object ScalaTestRunner {
+
+  class LimitedStringBuffer {
+    val buf = new ListBuffer[String]()
+    private var lines = 0
+    private var lengthCropped = false
+
+    override def toString() = buf.mkString("\n").trim
+
+    def append(s: String) =
+      if (lines < Settings.maxOutputLines) {
+        val shortS =
+          if (s.length > Settings.maxOutputLineLength) {
+            if (!lengthCropped) {
+              val msg =
+                """WARNING: OUTPUT LINES CROPPED
+                  |Your program generates very long lines on the standard (or error) output. Some of
+                  |the lines have been cropped.
+                  |This should not have an impact on your grade or the grading process; however it is
+                  |bad style to leave `print` statements in production code, so consider removing and
+                  |replacing them by proper tests.
+                  |""".stripMargin
+              buf.prepend(msg)
+              lengthCropped = true
+            }
+            s.substring(0, Settings.maxOutputLineLength)
+          } else s
+        buf.append(shortS)
+        lines += 1
+      } else if (lines == Settings.maxOutputLines) {
+        val msg =
+          """WARNING: PROGRAM OUTPUT TOO LONG
+            |Your program generates massive amounts of data on the standard (or error) output.
+            |You are probably using `print` statements to debug your code.
+            |This should not have an impact on your grade or the grading process; however it is
+            |bad style to leave `print` statements in production code, so consider removing and
+            |replacing them by proper tests.
+            |""".stripMargin
+        buf.prepend(msg)
+        lines += 1
+      }
+  }
+
+  private def forkProcess(proc: SysProc, timeout: Int) {
+    val executor = Executors.newSingleThreadExecutor()
+    val future: Future[Unit] = executor.submit(new Callable[Unit] {
+      def call { proc.exitValue() }
+    })
+    try {
+      future.get(timeout, TimeUnit.SECONDS)
+    } catch {
+      case to: TimeoutException =>
+        future.cancel(true)
+        throw to
+    } finally {
+      executor.shutdown()
+    }
+  }
+
+  private def runPathString(file: File) = file.getAbsolutePath().replace(" ", "\\ ")
+
+  private def extractWeights(s: String, logError: String => Unit) = {
+    try {
+      val (nums, rest) = s.span(c => c != '\n')
+      val List(grade, max) = nums.split(';').toList
+      (grade.toInt, max.toInt, rest.drop(1))
+    } catch {
+      case e: Throwable =>
+        val msg = "Could not extract weight from grading feedback\n"+ s
+        logError(msg)
+        throw e
+    }
+  }
+
+
+  def runScalaTest(classpath: Classpath, testClasses: File, outfile: File, policyFile: File, resourceFiles: List[File], logError: String => Unit) = {
+    val classpathString = classpath map {
+      case Attributed(file) => file.getAbsolutePath()
+    } mkString(":")
+
+    val testRunpath = runPathString(testClasses)
+
+    val outfileStr = outfile.getAbsolutePath
+    val policyFileStr = policyFile.getAbsolutePath
+    val resourceFilesString = resourceFiles.map(_.getAbsolutePath).mkString(":")
+    // Deleting the file is helpful: it makes reading the file below crash in case ScalaTest doesn't
+    // run as expected. Problem is, it's hard to detect if ScalaTest ran successfully or not: it
+    // exits with non-zero if there are failed tests, and also if it crashes...
+    new java.io.File(outfileStr).delete()
+
+    def prop(name: String, value: String) = "-D"+ name +"="+ value
+
+    // we don't specify "-w packageToTest" - the build file only compiles the tests
+    // for the current project. so we don't need to do it again here.
+    val cmd = "java" ::
+      "-Djava.security.manager" ::
+      prop("java.security.policy", policyFileStr) ::
+      prop(Settings.scalaTestReportFileProperty, outfileStr) ::
+      prop(Settings.scalaTestIndividualTestTimeoutProperty, Settings.individualTestTimeout.toString) ::
+      prop(Settings.scalaTestReadableFilesProperty, resourceFilesString) ::
+      prop(Settings.scalaTestDefaultWeigthProperty, Settings.scalaTestDefaultWeigth.toString) ::
+      "-cp" :: classpathString ::
+      "org.scalatest.tools.Runner" ::
+      "-R" :: testRunpath ::
+      "-C" :: "grading.CourseraReporter" ::
+      Nil
+
+    // process deadlocks in Runner.PassFailReporter.allTestsPassed on runDoneSemaphore.acquire() when
+    // something is wrong, e.g. when there's an error.. So we have to run it with a timeout.
+
+    val out = new LimitedStringBuffer()
+    var p: SysProc = null
+    try {
+      p = SysProc(cmd).run(ProcessLogger(out.append(_), out.append(_)))
+      forkProcess(p, Settings.scalaTestTimeout)
+    } catch {
+      case e: TimeoutException =>
+        val msg = "Timeout when running ScalaTest\n"+ out.toString()
+        logError(msg)
+        p.destroy()
+        sys.error(msg)
+
+      case e: Throwable =>
+        val msg = "Error occured while running the ScalaTest command\n"+ e.toString +"\n"+ out.toString()
+        logError(msg)
+        p.destroy()
+        throw e
+    }
+
+
+    val feedbackFileContent = try {
+      io.Source.fromFile(outfileStr).mkString
+    } catch {
+      case e: Throwable =>
+        val msg = "Error occured while reading the output file of ScalaTest\n"+ e.toString +"\n"+ out.toString()
+        logError(msg)
+        throw e
+    }
+
+    val (score, maxScore, feedback) = extractWeights(feedbackFileContent, logError)
+    val runLog = out.toString()
+    (score, maxScore, feedback, runLog)
+  }
+
+  def scalaTestGrade(classpath: Classpath, testClasses: File, outfile: File, policyFile: File, resourceFiles: List[File]) {
+    val (score, maxScore, feedback, runLog) = runScalaTest(classpath, testClasses, outfile, policyFile, resourceFiles, GradingFeedback.testExecutionFailed)
+      if (score == maxScore) {
+      GradingFeedback.allTestsPassed()
+    } else {
+      val scaledScore = GradingFeedback.maxTestScore * score / maxScore
+      GradingFeedback.testsFailed(feedback, scaledScore)
+    }
+
+    // The output `out` should in principle be empty: the reporter we use writes its results to a file.
+    // however, `out` contains valuable logs in case scalatest fails. We need to put them into the student
+    // feedback in order to have a chance of debugging problems.
+
+    if (!runLog.isEmpty) {
+      GradingFeedback.testExecutionDebugLog(runLog)
+    }
+  }
+}
+
diff --git a/Scala/example/project/Settings.scala b/Scala/example/project/Settings.scala
new file mode 100644
index 0000000..c8de201
--- /dev/null
+++ b/Scala/example/project/Settings.scala
@@ -0,0 +1,48 @@
+object Settings {
+  // when changing this, also look at 'scripts/gradingImpl' and the files in s3/settings
+  // val courseId = "progfun-2012-001"
+
+  def challengeUrl(courseId: String) = "https://class.coursera.org/"+ courseId +"/assignment/challenge"
+
+  def submitUrl(courseId: String) = "https://class.coursera.org/"+ courseId +"/assignment/submit"
+
+  // def forumUrl(courseId: String) = "https://class.coursera.org/"+ courseId +"/forum/index"
+
+  // def submitQueueUrl(courseId: String) = "https://class.coursera.org/"+ courseId +"/assignment/api/pending_submission"
+
+  def uploadFeedbackUrl(courseId: String) = "https://class.coursera.org/"+ courseId +"/assignment/api/score"
+
+  val maxSubmitFileSize = {
+    val mb = 1024 * 1024
+    10 * mb
+  }
+
+  val submissionDirName = "submission"
+
+  val testResultsFileName = "scalaTestLog.txt"
+  val policyFileName = "allowAllPolicy"
+  val submissionJsonFileName = "submission.json"
+  val submissionJarFileName = "submittedSrc.jar"
+
+  // time in seconds that we give scalatest for running
+  val scalaTestTimeout = 240
+  val individualTestTimeout = 30
+
+  // default weight of each test in a GradingSuite, in case no weight is given
+  val scalaTestDefaultWeigth = 10
+
+  // when students leave print statements in their code, they end up in the output of the
+  // system process running ScalaTest (ScalaTestRunner.scala); we need some limits.
+  val maxOutputLines = 10*1000
+  val maxOutputLineLength = 1000
+
+  val scalaTestReportFileProperty = "scalatest.reportFile"
+  val scalaTestIndividualTestTimeoutProperty = "scalatest.individualTestTimeout"
+  val scalaTestReadableFilesProperty = "scalatest.readableFiles"
+  val scalaTestDefaultWeigthProperty = "scalatest.defaultWeight"
+
+  // debugging / developping options
+
+  // don't decode json and unpack the submission sources, don't upload feedback
+  val offlineMode = false
+}
diff --git a/Scala/example/project/StyleChecker.scala b/Scala/example/project/StyleChecker.scala
new file mode 100644
index 0000000..c7b57a2
--- /dev/null
+++ b/Scala/example/project/StyleChecker.scala
@@ -0,0 +1,77 @@
+import sbt.File
+import java.io.ByteArrayOutputStream
+import java.io.PrintStream
+import org.scalastyle._
+
+object StyleChecker {
+  val maxResult = 100
+
+  class CustomTextOutput[T <: FileSpec]() extends Output[T] {
+    private val messageHelper = new MessageHelper(this.getClass().getClassLoader())
+
+    var fileCount: Int = _
+    override def message(m: Message[T]): Unit = m match {
+      case StartWork() =>
+      case EndWork() =>
+      case StartFile(file) =>
+        print("Checking file " + file + "...")
+        fileCount = 0
+      case EndFile(file) =>
+        if (fileCount == 0) println(" OK!")
+      case StyleError(file, clazz, key, level, args, line, column, customMessage) =>
+        report(line, column, messageHelper.text(level.name),
+            findMessage(messageHelper, clazz, key, args, customMessage))
+      case StyleException(file, clazz, message, stacktrace, line, column) =>
+        report(line, column, "error", message)
+    }
+
+    private def report(line: Option[Int], column: Option[Int], level: String, message: String) {
+      if (fileCount == 0) println("")
+      fileCount += 1
+      println("  " + fileCount + ". " + level + pos(line, column) + ":")
+      println("     " + message)
+    }
+
+    private def pos(line: Option[Int], column: Option[Int]): String = line match {
+      case Some(line) => " at line " + line + (column match {
+        case Some(column) => " character " + column
+        case None => ""
+      })
+      case None => ""
+    }
+  }
+
+  def score(outputResult: OutputResult) = {
+    val penalties = outputResult.errors + outputResult.warnings
+    scala.math.max(maxResult - penalties, 0)
+  }
+
+  def assess(allSources: Seq[File]): (String, Int) = {
+    val configFile = new File("project/scalastyle_config.xml").getAbsolutePath
+
+    val sources = allSources.filterNot{ f =>
+      val path = f.getAbsolutePath
+      path.contains("interpreter") ||
+      path.contains("simulations") ||
+      path.contains("fetchtweets")
+    }
+
+    val messages = new ScalastyleChecker().checkFiles(
+      ScalastyleConfiguration.readFromXml(configFile),
+      Directory.getFiles(sources : _*))
+
+    val output = new ByteArrayOutputStream()
+    val outputResult = Console.withOut(new PrintStream(output)) {
+      new CustomTextOutput().output(messages)
+    }
+
+    val msg =
+      output.toString +
+      "Processed " + outputResult.files + " file(s)\n" +
+      "Found " + outputResult.errors + " errors\n" +
+      "Found " + outputResult.warnings + " warnings\n" +
+      (if (outputResult.errors+outputResult.warnings > 0) "Consult the style guide at http://goo.gl/5CIum" else "")
+
+    (msg, score(outputResult))
+  }
+}
diff --git a/Scala/example/project/build.properties b/Scala/example/project/build.properties
new file mode 100644
index 0000000..4474a03
--- /dev/null
+++ b/Scala/example/project/build.properties
@@ -0,0 +1 @@
+sbt.version=0.12.1
diff --git a/Scala/example/project/buildSettings.sbt b/Scala/example/project/buildSettings.sbt
new file mode 100644
index 0000000..1ed6540
--- /dev/null
+++ b/Scala/example/project/buildSettings.sbt
@@ -0,0 +1,72 @@
+// needed for custom scalastyle package
+resolvers += "namin.github.com/maven-repository" at "http://namin.github.com/maven-repository/"
+
+resolvers += "Spray Repository" at "http://repo.spray.cc/"
+
+libraryDependencies += "net.databinder" %% "dispatch-http" % "0.8.8"
+
+  libraryDependencies += "org.scalastyle" % "scalastyle_2.9.1" % "0.1.3-SNAPSHOT"
+
+libraryDependencies += "cc.spray" %%  "spray-json" % "1.1.1"
+
+// need scalatest also as a build dependency: the build implements a custom reporter
+libraryDependencies += "org.scalatest" %% "scalatest" % "1.9.1"
+
+// dispatch uses commons-codec, in version 1.4, so we can't  go for 1.6.
+// libraryDependencies += "commons-codec" % "commons-codec" % "1.4"
+
+libraryDependencies += "org.apache.commons" % "commons-lang3" % "3.1"
+
+// sbteclipse-plugin uses scalaz-core 6.0.3, so we can't go 6.0.4
+// libraryDependencies += "org.scalaz" %% "scalaz-core" % "6.0.3"
+
+scalacOptions ++= Seq("-deprecation")
+
+addSbtPlugin("com.typesafe.sbteclipse" % "sbteclipse-plugin" % "2.1.0")
+
+// for dependency-graph plugin
+// net.virtualvoid.sbt.graph.Plugin.graphSettings
+
+
+// [info] default:default-3fdafc_2.9.1:0.1-SNAPSHOT
+// [info]   +-cc.spray:spray-json_2.9.1:1.1.1
+// [info]   | +-org.parboiled:parboiled-scala:1.0.2
+// [info]   | | +-org.parboiled:parboiled-core:1.0.2
+// [info]   | | +-org.scala-lang:scala-library:2.9.1
+// [info]   | | 
+// [info]   | +-org.scala-lang:scala-library:2.9.1
+// [info]   | 
+// [info]   +-com.typesafe.sbteclipse:sbteclipse-plugin:2.1.0
+// [info]   | +-com.typesafe.sbteclipse:sbteclipse-core:2.1.0
+// [info]   |   +-org.scalaz:scalaz-core_2.9.1:6.0.3
+// [info]   |     +-org.scala-lang:scala-library:2.9.1
+// [info]   |     
+// [info]   +-net.databinder:dispatch-http_2.9.1:0.8.8
+// [info]   | +-net.databinder:dispatch-core_2.9.1:0.8.8
+// [info]   | | +-org.apache.httpcomponents:httpclient:4.1.3
+// [info]   | | | +-commons-codec:commons-codec:1.4
+// [info]   | | | +-commons-logging:commons-logging:1.1.1
+// [info]   | | | +-org.apache.httpcomponents:httpcore:4.1.4
+// [info]   | | | 
+// [info]   | | +-org.scala-lang:scala-library:2.9.1
+// [info]   | | 
+// [info]   | +-net.databinder:dispatch-futures_2.9.1:0.8.8
+// [info]   | | +-org.scala-lang:scala-library:2.9.1
+// [info]   | | 
+// [info]   | +-org.apache.httpcomponents:httpclient:4.1.3
+// [info]   | | +-commons-codec:commons-codec:1.4
+// [info]   | | +-commons-logging:commons-logging:1.1.1
+// [info]   | | +-org.apache.httpcomponents:httpcore:4.1.4
+// [info]   | | 
+// [info]   | +-org.scala-lang:scala-library:2.9.1
+// [info]   | 
+// [info]   +-org.scala-lang:scala-library:2.9.1
+// [info]   +-org.scalastyle:scalastyle_2.9.1:0.1.3-SNAPSHOT
+// [info]   | +-com.github.scopt:scopt_2.9.1:2.0.0
+// [info]   | | +-org.scala-lang:scala-library:2.9.1
+// [info]   | | 
+// [info]   | +-org.scalariform:scalariform_2.9.1:0.1.1
+// [info]   |   +-org.scala-lang:scala-library:2.9.1
+// [info]   |   
+// [info]   +-org.scalatest:scalatest_2.9.1:1.8
+// [info]     +-org.scala-lang:scala-library:2.9.1
diff --git a/Scala/example/project/project/buildPlugins.sbt b/Scala/example/project/project/buildPlugins.sbt
new file mode 100644
index 0000000..47557f4
--- /dev/null
+++ b/Scala/example/project/project/buildPlugins.sbt
@@ -0,0 +1,2 @@
+// the dependency-graph plugin
+// addSbtPlugin("net.virtual-void" % "sbt-dependency-graph" % "0.6.0")
diff --git a/Scala/example/project/scalastyle_config.xml b/Scala/example/project/scalastyle_config.xml
new file mode 100644
index 0000000..9171ed3
--- /dev/null
+++ b/Scala/example/project/scalastyle_config.xml
@@ -0,0 +1,136 @@
+<scalastyle commentFilter="disabled">
+ <name>scalastyle Coursera Configuration</name>
+ <check level="warning" class="org.scalastyle.file.FileTabChecker" enabled="false"></check>
+ <check level="warning" class="org.scalastyle.file.FileLengthChecker" enabled="true">
+  <parameters>
+   <parameter name="maxFileLength"><![CDATA[800]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.file.HeaderMatchesChecker" enabled="false">
+  <parameters>
+   <parameter name="header"><![CDATA[// Copyright (C) 2011-2012 the original author or authors.
+// See the LICENCE.txt file distributed with this work for additional
+// information regarding copyright ownership.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.SpacesAfterPlusChecker" enabled="false"></check>
+ <check level="warning" class="org.scalastyle.file.WhitespaceEndOfLineChecker" enabled="false"></check>
+ <check level="warning" class="org.scalastyle.scalariform.SpacesBeforePlusChecker" enabled="false"></check>
+ <check level="warning" class="org.scalastyle.file.FileLineLengthChecker" enabled="false">
+  <parameters>
+   <parameter name="maxLineLength"><![CDATA[160]]></parameter>
+   <parameter name="tabSize"><![CDATA[4]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.ClassNamesChecker" enabled="true">
+  <parameters>
+   <parameter name="regex"><![CDATA[[A-Z][A-Za-z]*]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.ObjectNamesChecker" enabled="true">
+  <parameters>
+   <parameter name="regex"><![CDATA[[A-Z][A-Za-z]*]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.PackageObjectNamesChecker" enabled="true">
+  <parameters>
+   <parameter name="regex"><![CDATA[^[a-z][A-Za-z]*$]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.EqualsHashCodeChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.IllegalImportsChecker" enabled="true">
+  <parameters>
+   <parameter name="illegalImports"><![CDATA[sun._,java.awt._]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.ParameterNumberChecker" enabled="true">
+  <parameters>
+   <parameter name="maxParameters"><![CDATA[8]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.MagicNumberChecker" enabled="false">
+  <parameters>
+   <parameter name="ignore"><![CDATA[-1,0,1,2,3]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.NoWhitespaceBeforeLeftBracketChecker" enabled="false"></check>
+ <check level="warning" class="org.scalastyle.scalariform.NoWhitespaceAfterLeftBracketChecker" enabled="false"></check>
+ <check level="warning" class="org.scalastyle.scalariform.ReturnChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.NullChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.NoCloneChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.NoFinalizeChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.CovariantEqualsChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.StructuralTypeChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.file.RegexChecker" enabled="false">
+  <parameters>
+   <parameter name="regex"><![CDATA[println]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.TokenChecker" enabled="false">
+  <parameters>
+   <parameter name="regex"><![CDATA[^isInstanceOf$]]></parameter>
+   <customMessage>Avoid isInstanceOf.</customMessage>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.NumberOfTypesChecker" enabled="true">
+  <parameters>
+   <parameter name="maxTypes"><![CDATA[30]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.CyclomaticComplexityChecker" enabled="true">
+  <parameters>
+   <parameter name="maximum"><![CDATA[10]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.UppercaseLChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.SimplifyBooleanExpressionChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.IfBraceChecker" enabled="false">
+  <parameters>
+   <parameter name="singleLineAllowed"><![CDATA[true]]></parameter>
+   <parameter name="doubleLineAllowed"><![CDATA[false]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.MethodLengthChecker" enabled="true">
+  <parameters>
+   <parameter name="maxLength"><![CDATA[50]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.MethodNamesChecker" enabled="false">
+  <parameters>
+   <parameter name="regex"><![CDATA[^[a-z][A-Za-z0-9]*$]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.MethodNamesChecker" enabled="true">
+  <parameters>
+   <parameter name="regex"><![CDATA[^[^A-Z].*$]]></parameter>
+   <customMessage>Method name should not start with an upper case letter.</customMessage>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.NumberOfMethodsInTypeChecker" enabled="true">
+  <parameters>
+   <parameter name="maxMethods"><![CDATA[30]]></parameter>
+  </parameters>
+ </check>
+ <check level="warning" class="org.scalastyle.scalariform.VarFieldChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.VarLocalChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.WhileChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.RedundantIfChecker" enabled="true"></check>
+ <check level="warning" class="org.scalastyle.scalariform.TokenChecker" enabled="true">
+  <parameters>
+   <parameter name="regex"><![CDATA[^(ArrayList|ArrayBuffer|mutable)$]]></parameter>
+   <customMessage>Avoid using mutable collections.</customMessage>
+  </parameters>
+ </check>
+</scalastyle>
\ No newline at end of file