Scala : add streams assignment

1 files changed, 646 insertions, 0 deletions

diff --git a/Scala/streams/project/ProgFunBuild.scala b/Scala/streams/project/ProgFunBuild.scala
new file mode 100644
index 0000000..93d4b9d
--- /dev/null
+++ b/Scala/streams/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)