Minor style changes and tests

Author: pwendell

core/src/main/scala/org/apache/spark/ui/jobs/JobProgressListener.scala

@@ -76,7 +76,7 @@ class JobProgressListener(conf: SparkConf) extends SparkListener {
     poolToActiveStages(stageIdToPool(stageId)).remove(stageId)
 
     val accumulables = stageIdToAccumulables.getOrElseUpdate(stageId, HashMap[String, String]())
-    stageCompleted.stageInfo.accumulatedValues.foreach { case (name, value) =>
+    for ((name, value) <- stageCompleted.stageInfo.accumulatedValues) {
       accumulables(name) = value
     }
 
@@ -156,7 +156,7 @@ class JobProgressListener(conf: SparkConf) extends SparkListener {
 
     if (info != null) {
       val accumulables = stageIdToAccumulables.getOrElseUpdate(sid, HashMap[String, String]())
-      info.accumulableValues.map { case (name, value) =>
+      for ((name, value) <- info.accumulableValues) {
         accumulables(name) = value
       }
 

core/src/main/scala/org/apache/spark/ui/jobs/StagePage.scala

@@ -290,7 +290,9 @@ private[ui] class StagePage(parent: JobProgressTab) extends WebUIPage("stage") {
         <td sorttable_customkey={gcTime.toString}>
           {if (gcTime > 0) UIUtils.formatDuration(gcTime) else ""}
         </td>
-        <td>{Unparsed(info.accumulableValues.map{ case (k, v) => s"$k: $v" }.mkString("<br/>"))}</td>
+        <td>
+          {Unparsed(info.accumulableValues.map{ case (k, v) => s"$k: $v" }.mkString("<br/>"))}
+        </td>
         <!--
         TODO: Add this back after we add support to hide certain columns.
         <td sorttable_customkey={serializationTime.toString}>

core/src/test/scala/org/apache/spark/util/JsonProtocolSuite.scala

@@ -123,15 +123,22 @@ class JsonProtocolSuite extends FunSuite {
     testBlockId(StreamBlockId(1, 2L))
   }
 
-  test("StageInfo.details backward compatibility") {
-    // StageInfo.details was added after 1.0.0.
+  test("StageInfo backward compatibility") {
     val info = makeStageInfo(1, 2, 3, 4L, 5L)
-    assert(info.details.nonEmpty)
     val newJson = JsonProtocol.stageInfoToJson(info)
-    val oldJson = newJson.removeField { case (field, _) => field == "Details" }
+
+    // Fields added after 1.0.0.
+    assert(info.details.nonEmpty)
+    assert(info.accumulatedValues.nonEmpty)
+    val oldJson = newJson
+      .removeField { case (field, _) => field == "Details" }
+      .removeField { case (field, _) => field == "Accumulated Values" }
+
     val newInfo = JsonProtocol.stageInfoFromJson(oldJson)
+
     assert(info.name === newInfo.name)
     assert("" === newInfo.details)
+    assert(0 === newInfo.accumulatedValues.size)
   }
 
   test("InputMetrics backward compatibility") {