1 files changed, 218 insertions, 0 deletions
diff --git a/Scala/streams/project/GradingFeedback.scala b/Scala/streams/project/GradingFeedback.scala
new file mode 100644
index 0000000..5d78c54
--- /dev/null
+++ b/Scala/streams/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)
+}