[SPARK-6765] Fix test code style for streaming.

So we can turn style checker on for test code.

Author: Reynold Xin <rxin@databricks.com>

Closes apache#5409 from rxin/test-style-streaming and squashes the following commits:

7aea69b [Reynold Xin] [SPARK-6765] Fix test code style for streaming.

external/flume/src/test/scala/org/apache/spark/streaming/flume/FlumePollingStreamSuite.scala

@@ -1,21 +1,20 @@
 /*
- * Licensed to the Apache Software Foundation (ASF) under one
- * or more contributor license agreements.  See the NOTICE file
- * distributed with this work for additional information
- * regarding copyright ownership.  The ASF licenses this file
- * to you 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
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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
+ *    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.
+ * 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.
  */
+
 package org.apache.spark.streaming.flume
 
 import java.net.InetSocketAddress
@@ -213,7 +212,7 @@ class FlumePollingStreamSuite extends FunSuite with BeforeAndAfter with Logging
     assert(counter === totalEventsPerChannel * channels.size)
   }
 
-  def assertChannelIsEmpty(channel: MemoryChannel) = {
+  def assertChannelIsEmpty(channel: MemoryChannel): Unit = {
     val queueRemaining = channel.getClass.getDeclaredField("queueRemaining")
     queueRemaining.setAccessible(true)
     val m = queueRemaining.get(channel).getClass.getDeclaredMethod("availablePermits")

external/flume/src/test/scala/org/apache/spark/streaming/flume/FlumeStreamSuite.scala

@@ -151,7 +151,9 @@ class FlumeStreamSuite extends FunSuite with BeforeAndAfter with Matchers with L
   }
 
   /** Class to create socket channel with compression */
-  private class CompressionChannelFactory(compressionLevel: Int) extends NioClientSocketChannelFactory {
+  private class CompressionChannelFactory(compressionLevel: Int)
+    extends NioClientSocketChannelFactory {
+
     override def newChannel(pipeline: ChannelPipeline): SocketChannel = {
       val encoder = new ZlibEncoder(compressionLevel)
       pipeline.addFirst("deflater", encoder)

external/mqtt/src/test/scala/org/apache/spark/streaming/mqtt/MQTTStreamSuite.scala

@@ -139,7 +139,8 @@ class MQTTStreamSuite extends FunSuite with Eventually with BeforeAndAfter {
             msgTopic.publish(message)
           } catch {
             case e: MqttException if e.getReasonCode == MqttException.REASON_CODE_MAX_INFLIGHT =>
-              Thread.sleep(50) // wait for Spark streaming to consume something from the message queue
+              // wait for Spark streaming to consume something from the message queue
+              Thread.sleep(50)
           }
         }
       }

streaming/src/test/scala/org/apache/spark/streaming/BasicOperationsSuite.scala

@@ -171,7 +171,9 @@ class BasicOperationsSuite extends TestSuiteBase {
   test("flatMapValues") {
     testOperation(
       Seq( Seq("a", "a", "b"), Seq("", ""), Seq() ),
-      (s: DStream[String]) => s.map(x => (x, 1)).reduceByKey(_ + _).flatMapValues(x => Seq(x, x + 10)),
+      (s: DStream[String]) => {
+        s.map(x => (x, 1)).reduceByKey(_ + _).flatMapValues(x => Seq(x, x + 10))
+      },
       Seq( Seq(("a", 2), ("a", 12), ("b", 1), ("b", 11)), Seq(("", 2), ("", 12)), Seq() ),
       true
     )
@@ -474,7 +476,7 @@ class BasicOperationsSuite extends TestSuiteBase {
       stream.foreachRDD(_ => {})  // Dummy output stream
       ssc.start()
       Thread.sleep(2000)
-      def getInputFromSlice(fromMillis: Long, toMillis: Long) = {
+      def getInputFromSlice(fromMillis: Long, toMillis: Long): Set[Int] = {
         stream.slice(new Time(fromMillis), new Time(toMillis)).flatMap(_.collect()).toSet
       }
 

streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala

@@ -43,7 +43,7 @@ class CheckpointSuite extends TestSuiteBase {
 
   var ssc: StreamingContext = null
 
-  override def batchDuration = Milliseconds(500)
+  override def batchDuration: Duration = Milliseconds(500)
 
   override def beforeFunction() {
     super.beforeFunction()
@@ -72,7 +72,7 @@ class CheckpointSuite extends TestSuiteBase {
     val input = (1 to 10).map(_ => Seq("a")).toSeq
     val operation = (st: DStream[String]) => {
       val updateFunc = (values: Seq[Int], state: Option[Int]) => {
-        Some((values.sum + state.getOrElse(0)))
+        Some(values.sum + state.getOrElse(0))
       }
       st.map(x => (x, 1))
       .updateStateByKey(updateFunc)
@@ -199,7 +199,12 @@ class CheckpointSuite extends TestSuiteBase {
     testCheckpointedOperation(
       Seq( Seq("a", "a", "b"), Seq("", ""), Seq(), Seq("a", "a", "b"), Seq("", ""), Seq() ),
       (s: DStream[String]) => s.map(x => (x, 1)).reduceByKey(_ + _),
-      Seq( Seq(("a", 2), ("b", 1)), Seq(("", 2)), Seq(), Seq(("a", 2), ("b", 1)), Seq(("", 2)), Seq() ),
+      Seq(
+        Seq(("a", 2), ("b", 1)),
+        Seq(("", 2)),
+        Seq(),
+        Seq(("a", 2), ("b", 1)),
+        Seq(("", 2)), Seq() ),
       3
     )
   }
@@ -212,7 +217,8 @@ class CheckpointSuite extends TestSuiteBase {
     val n = 10
     val w = 4
     val input = (1 to n).map(_ => Seq("a")).toSeq
-    val output = Seq(Seq(("a", 1)), Seq(("a", 2)), Seq(("a", 3))) ++ (1 to (n - w + 1)).map(x => Seq(("a", 4)))
+    val output = Seq(
+      Seq(("a", 1)), Seq(("a", 2)), Seq(("a", 3))) ++ (1 to (n - w + 1)).map(x => Seq(("a", 4)))
     val operation = (st: DStream[String]) => {
       st.map(x => (x, 1))
         .reduceByKeyAndWindow(_ + _, _ - _, batchDuration * w, batchDuration)
@@ -236,7 +242,13 @@ class CheckpointSuite extends TestSuiteBase {
             classOf[TextOutputFormat[Text, IntWritable]])
           output
         },
-        Seq(Seq(("a", 2), ("b", 1)), Seq(("", 2)), Seq(), Seq(("a", 2), ("b", 1)), Seq(("", 2)), Seq()),
+        Seq(
+          Seq(("a", 2), ("b", 1)),
+          Seq(("", 2)),
+          Seq(),
+          Seq(("a", 2), ("b", 1)),
+          Seq(("", 2)),
+          Seq()),
         3
       )
     } finally {
@@ -259,7 +271,13 @@ class CheckpointSuite extends TestSuiteBase {
             classOf[NewTextOutputFormat[Text, IntWritable]])
           output
         },
-        Seq(Seq(("a", 2), ("b", 1)), Seq(("", 2)), Seq(), Seq(("a", 2), ("b", 1)), Seq(("", 2)), Seq()),
+        Seq(
+          Seq(("a", 2), ("b", 1)),
+          Seq(("", 2)),
+          Seq(),
+          Seq(("a", 2), ("b", 1)),
+          Seq(("", 2)),
+          Seq()),
         3
       )
     } finally {
@@ -298,7 +316,13 @@ class CheckpointSuite extends TestSuiteBase {
             output
           }
         },
-        Seq(Seq(("a", 2), ("b", 1)), Seq(("", 2)), Seq(), Seq(("a", 2), ("b", 1)), Seq(("", 2)), Seq()),
+        Seq(
+          Seq(("a", 2), ("b", 1)),
+          Seq(("", 2)),
+          Seq(),
+          Seq(("a", 2), ("b", 1)),
+          Seq(("", 2)),
+          Seq()),
         3
       )
     } finally {
@@ -533,7 +557,8 @@ class CheckpointSuite extends TestSuiteBase {
    * Advances the manual clock on the streaming scheduler by given number of batches.
    * It also waits for the expected amount of time for each batch.
    */
-  def advanceTimeWithRealDelay[V: ClassTag](ssc: StreamingContext, numBatches: Long): Seq[Seq[V]] = {
+  def advanceTimeWithRealDelay[V: ClassTag](ssc: StreamingContext, numBatches: Long): Seq[Seq[V]] =
+  {
     val clock = ssc.scheduler.clock.asInstanceOf[ManualClock]
     logInfo("Manual clock before advancing = " + clock.getTimeMillis())
     for (i <- 1 to numBatches.toInt) {
@@ -543,7 +568,7 @@ class CheckpointSuite extends TestSuiteBase {
     logInfo("Manual clock after advancing = " + clock.getTimeMillis())
     Thread.sleep(batchDuration.milliseconds)
 
-    val outputStream = ssc.graph.getOutputStreams.filter { dstream =>
+    val outputStream = ssc.graph.getOutputStreams().filter { dstream =>
       dstream.isInstanceOf[TestOutputStreamWithPartitions[V]]
     }.head.asInstanceOf[TestOutputStreamWithPartitions[V]]
     outputStream.output.map(_.flatten)
@@ -552,4 +577,4 @@ class CheckpointSuite extends TestSuiteBase {
 
 private object CheckpointSuite extends Serializable {
   var batchThreeShouldBlockIndefinitely: Boolean = true
-}
+}

streaming/src/test/scala/org/apache/spark/streaming/FailureSuite.scala

@@ -29,9 +29,9 @@ class FailureSuite extends TestSuiteBase with Logging {
   val directory = Utils.createTempDir()
   val numBatches = 30
 
-  override def batchDuration = Milliseconds(1000)
+  override def batchDuration: Duration = Milliseconds(1000)
 
-  override def useManualClock = false
+  override def useManualClock: Boolean = false
 
   override def afterFunction() {
     Utils.deleteRecursively(directory)

streaming/src/test/scala/org/apache/spark/streaming/InputStreamsSuite.scala

@@ -52,7 +52,7 @@ class InputStreamsSuite extends TestSuiteBase with BeforeAndAfter {
       "localhost", testServer.port, StorageLevel.MEMORY_AND_DISK)
     val outputBuffer = new ArrayBuffer[Seq[String]] with SynchronizedBuffer[Seq[String]]
     val outputStream = new TestOutputStream(networkStream, outputBuffer)
-    def output = outputBuffer.flatMap(x => x)
+    def output: ArrayBuffer[String] = outputBuffer.flatMap(x => x)
     outputStream.register()
     ssc.start()
 
@@ -164,7 +164,7 @@ class InputStreamsSuite extends TestSuiteBase with BeforeAndAfter {
     val countStream = networkStream.count
     val outputBuffer = new ArrayBuffer[Seq[Long]] with SynchronizedBuffer[Seq[Long]]
     val outputStream = new TestOutputStream(countStream, outputBuffer)
-    def output = outputBuffer.flatMap(x => x)
+    def output: ArrayBuffer[Long] = outputBuffer.flatMap(x => x)
     outputStream.register()
     ssc.start()
 
@@ -196,15 +196,15 @@ class InputStreamsSuite extends TestSuiteBase with BeforeAndAfter {
     val queueStream = ssc.queueStream(queue, oneAtATime = true)
     val outputBuffer = new ArrayBuffer[Seq[String]] with SynchronizedBuffer[Seq[String]]
     val outputStream = new TestOutputStream(queueStream, outputBuffer)
-    def output = outputBuffer.filter(_.size > 0)
+    def output: ArrayBuffer[Seq[String]] = outputBuffer.filter(_.size > 0)
     outputStream.register()
     ssc.start()
 
     // Setup data queued into the stream
     val clock = ssc.scheduler.clock.asInstanceOf[ManualClock]
     val input = Seq("1", "2", "3", "4", "5")
     val expectedOutput = input.map(Seq(_))
-    //Thread.sleep(1000)
+
     val inputIterator = input.toIterator
     for (i <- 0 until input.size) {
       // Enqueue more than 1 item per tick but they should dequeue one at a time
@@ -239,7 +239,7 @@ class InputStreamsSuite extends TestSuiteBase with BeforeAndAfter {
     val queueStream = ssc.queueStream(queue, oneAtATime = false)
     val outputBuffer = new ArrayBuffer[Seq[String]] with SynchronizedBuffer[Seq[String]]
     val outputStream = new TestOutputStream(queueStream, outputBuffer)
-    def output = outputBuffer.filter(_.size > 0)
+    def output: ArrayBuffer[Seq[String]] = outputBuffer.filter(_.size > 0)
     outputStream.register()
     ssc.start()
 
@@ -352,7 +352,8 @@ class TestServer(portToBind: Int = 0) extends Logging {
           logInfo("New connection")
           try {
             clientSocket.setTcpNoDelay(true)
-            val outputStream = new BufferedWriter(new OutputStreamWriter(clientSocket.getOutputStream))
+            val outputStream = new BufferedWriter(
+              new OutputStreamWriter(clientSocket.getOutputStream))
 
             while(clientSocket.isConnected) {
               val msg = queue.poll(100, TimeUnit.MILLISECONDS)
@@ -384,7 +385,7 @@ class TestServer(portToBind: Int = 0) extends Logging {
 
   def stop() { servingThread.interrupt() }
 
-  def port = serverSocket.getLocalPort
+  def port: Int = serverSocket.getLocalPort
 }
 
 /** This is a receiver to test multiple threads inserting data using block generator */

streaming/src/test/scala/org/apache/spark/streaming/ReceivedBlockHandlerSuite.scala

@@ -96,7 +96,7 @@ class ReceivedBlockHandlerSuite extends FunSuite with BeforeAndAfter with Matche
       testBlockStoring(handler) { case (data, blockIds, storeResults) =>
         // Verify the data in block manager is correct
         val storedData = blockIds.flatMap { blockId =>
-          blockManager.getLocal(blockId).map { _.data.map {_.toString}.toList }.getOrElse(List.empty)
+          blockManager.getLocal(blockId).map(_.data.map(_.toString).toList).getOrElse(List.empty)
         }.toList
         storedData shouldEqual data
 
@@ -120,7 +120,7 @@ class ReceivedBlockHandlerSuite extends FunSuite with BeforeAndAfter with Matche
       testBlockStoring(handler) { case (data, blockIds, storeResults) =>
         // Verify the data in block manager is correct
         val storedData = blockIds.flatMap { blockId =>
-          blockManager.getLocal(blockId).map { _.data.map {_.toString}.toList }.getOrElse(List.empty)
+          blockManager.getLocal(blockId).map(_.data.map(_.toString).toList).getOrElse(List.empty)
         }.toList
         storedData shouldEqual data
 

streaming/src/test/scala/org/apache/spark/streaming/ReceivedBlockTrackerSuite.scala

@@ -228,7 +228,8 @@ class ReceivedBlockTrackerSuite
    * Get all the data written in the given write ahead log files. By default, it will read all
    * files in the test log directory.
    */
-  def getWrittenLogData(logFiles: Seq[String] = getWriteAheadLogFiles): Seq[ReceivedBlockTrackerLogEvent] = {
+  def getWrittenLogData(logFiles: Seq[String] = getWriteAheadLogFiles)
+    : Seq[ReceivedBlockTrackerLogEvent] = {
     logFiles.flatMap {
       file => new WriteAheadLogReader(file, hadoopConf).toSeq
     }.map { byteBuffer =>
@@ -244,7 +245,8 @@ class ReceivedBlockTrackerSuite
   }
 
   /** Create batch allocation object from the given info */
-  def createBatchAllocation(time: Long, blockInfos: Seq[ReceivedBlockInfo]): BatchAllocationEvent = {
+  def createBatchAllocation(time: Long, blockInfos: Seq[ReceivedBlockInfo])
+    : BatchAllocationEvent = {
     BatchAllocationEvent(time, AllocatedBlocks(Map((streamId -> blockInfos))))
   }
 

streaming/src/test/scala/org/apache/spark/streaming/ReceiverSuite.scala

@@ -308,7 +308,7 @@ class ReceiverSuite extends TestSuiteBase with Timeouts with Serializable {
     val errors = new ArrayBuffer[Throwable]
 
     /** Check if all data structures are clean */
-    def isAllEmpty = {
+    def isAllEmpty: Boolean = {
       singles.isEmpty && byteBuffers.isEmpty && iterators.isEmpty &&
         arrayBuffers.isEmpty && errors.isEmpty
     }
@@ -320,24 +320,21 @@ class ReceiverSuite extends TestSuiteBase with Timeouts with Serializable {
     def pushBytes(
         bytes: ByteBuffer,
         optionalMetadata: Option[Any],
-        optionalBlockId: Option[StreamBlockId]
-      ) {
+        optionalBlockId: Option[StreamBlockId]) {
       byteBuffers += bytes
     }
 
     def pushIterator(
         iterator: Iterator[_],
         optionalMetadata: Option[Any],
-        optionalBlockId: Option[StreamBlockId]
-      ) {
+        optionalBlockId: Option[StreamBlockId]) {
       iterators += iterator
     }
 
     def pushArrayBuffer(
         arrayBuffer: ArrayBuffer[_],
         optionalMetadata: Option[Any],
-        optionalBlockId: Option[StreamBlockId]
-      ) {
+        optionalBlockId: Option[StreamBlockId]) {
       arrayBuffers +=  arrayBuffer
     }
 

streaming/src/test/scala/org/apache/spark/streaming/StreamingContextSuite.scala

@@ -213,7 +213,7 @@ class StreamingContextSuite extends FunSuite with BeforeAndAfter with Timeouts w
     ssc = new StreamingContext(sc, Milliseconds(100))
     var runningCount = 0
     SlowTestReceiver.receivedAllRecords = false
-    //Create test receiver that sleeps in onStop()
+    // Create test receiver that sleeps in onStop()
     val totalNumRecords = 15
     val recordsPerSecond = 1
     val input = ssc.receiverStream(new SlowTestReceiver(totalNumRecords, recordsPerSecond))
@@ -370,7 +370,8 @@ object TestReceiver {
 }
 
 /** Custom receiver for testing whether a slow receiver can be shutdown gracefully or not */
-class SlowTestReceiver(totalRecords: Int, recordsPerSecond: Int) extends Receiver[Int](StorageLevel.MEMORY_ONLY) with Logging {
+class SlowTestReceiver(totalRecords: Int, recordsPerSecond: Int)
+  extends Receiver[Int](StorageLevel.MEMORY_ONLY) with Logging {
 
   var receivingThreadOption: Option[Thread] = None
 

streaming/src/test/scala/org/apache/spark/streaming/StreamingListenerSuite.scala

@@ -38,8 +38,8 @@ class StreamingListenerSuite extends TestSuiteBase with Matchers {
 
   // To make sure that the processing start and end times in collected
   // information are different for successive batches
-  override def batchDuration = Milliseconds(100)
-  override def actuallyWait = true
+  override def batchDuration: Duration = Milliseconds(100)
+  override def actuallyWait: Boolean = true
 
   test("batch info reporting") {
     val ssc = setupStreams(input, operation)