[SPARK-16779][TRIVIAL] Avoid using postfix operators where they do not add much and remove whitelisting

## What changes were proposed in this pull request?

Avoid using postfix operation for command execution in SQLQuerySuite where it wasn't whitelisted and audit existing whitelistings removing postfix operators from most places. Some notable places where postfix operation remains is in the XML parsing & time units (seconds, millis, etc.) where it arguably can improve readability.

## How was this patch tested?

Existing tests.

Author: Holden Karau <holden@us.ibm.com>

Closes apache#14407 from holdenk/SPARK-16779.

Author: holdenk

core/src/main/scala/org/apache/spark/deploy/SparkHadoopUtil.scala

@@ -25,7 +25,6 @@ import java.util.{Arrays, Comparator, Date}
 
 import scala.collection.JavaConverters._
 import scala.concurrent.duration._
-import scala.language.postfixOps
 import scala.util.control.NonFatal
 
 import com.google.common.primitives.Longs

core/src/main/scala/org/apache/spark/scheduler/TaskSchedulerImpl.scala

@@ -25,7 +25,6 @@ import java.util.concurrent.atomic.AtomicLong
 import scala.collection.mutable.ArrayBuffer
 import scala.collection.mutable.HashMap
 import scala.collection.mutable.HashSet
-import scala.language.postfixOps
 import scala.util.Random
 
 import org.apache.spark._

core/src/main/scala/org/apache/spark/util/RpcUtils.scala

@@ -17,8 +17,6 @@
 
 package org.apache.spark.util
 
-import scala.language.postfixOps
-
 import org.apache.spark.SparkConf
 import org.apache.spark.rpc.{RpcAddress, RpcEndpointRef, RpcEnv, RpcTimeout}
 

core/src/test/scala/org/apache/spark/HeartbeatReceiverSuite.scala

@@ -22,7 +22,6 @@ import java.util.concurrent.{ExecutorService, TimeUnit}
 import scala.collection.Map
 import scala.collection.mutable
 import scala.concurrent.duration._
-import scala.language.postfixOps
 
 import org.mockito.Matchers
 import org.mockito.Matchers._

core/src/test/scala/org/apache/spark/deploy/history/ApplicationCacheSuite.scala

@@ -23,7 +23,6 @@ import javax.servlet.http.{HttpServletRequest, HttpServletResponse}
 
 import scala.collection.mutable
 import scala.collection.mutable.ListBuffer
-import scala.language.postfixOps
 
 import com.codahale.metrics.Counter
 import com.google.common.cache.LoadingCache

core/src/test/scala/org/apache/spark/rdd/PipedRDDSuite.scala

@@ -21,7 +21,6 @@ import java.io.File
 
 import scala.collection.Map
 import scala.io.Codec
-import scala.language.postfixOps
 import scala.sys.process._
 import scala.util.Try
 
@@ -215,7 +214,8 @@ class PipedRDDSuite extends SparkFunSuite with SharedSparkContext {
   }
 
   def testCommandAvailable(command: String): Boolean = {
-    Try(Process(command) !!).isSuccess
+    val attempt = Try(Process(command).run().exitValue())
+    attempt.isSuccess && attempt.get == 0
   }
 
   def testExportInputFile(varName: String) {

core/src/test/scala/org/apache/spark/storage/MemoryStoreSuite.scala

@@ -20,7 +20,6 @@ package org.apache.spark.storage
 import java.nio.ByteBuffer
 
 import scala.language.implicitConversions
-import scala.language.postfixOps
 import scala.language.reflectiveCalls
 import scala.reflect.ClassTag
 

external/kafka-0-10/src/main/scala/org/apache/spark/streaming/kafka010/KafkaTestUtils.scala

@@ -25,7 +25,6 @@ import java.util.concurrent.TimeoutException
 
 import scala.annotation.tailrec
 import scala.collection.JavaConverters._
-import scala.language.postfixOps
 import scala.util.control.NonFatal
 
 import kafka.admin.AdminUtils
@@ -279,4 +278,3 @@ private[kafka010] class KafkaTestUtils extends Logging {
     }
   }
 }
-

external/kafka-0-8/src/main/scala/org/apache/spark/streaming/kafka/KafkaTestUtils.scala

@@ -25,7 +25,6 @@ import java.util.concurrent.TimeoutException
 
 import scala.annotation.tailrec
 import scala.collection.JavaConverters._
-import scala.language.postfixOps
 import scala.util.control.NonFatal
 
 import kafka.admin.AdminUtils
@@ -274,4 +273,3 @@ private[kafka] class KafkaTestUtils extends Logging {
     }
   }
 }
-

graphx/src/main/scala/org/apache/spark/graphx/lib/PageRank.scala

@@ -17,7 +17,6 @@
 
 package org.apache.spark.graphx.lib
 
-import scala.language.postfixOps
 import scala.reflect.ClassTag
 
 import org.apache.spark.graphx._
@@ -109,7 +108,7 @@ object PageRank extends Logging {
     require(resetProb >= 0 && resetProb <= 1, s"Random reset probability must belong" +
       s" to [0, 1], but got ${resetProb}")
 
-    val personalized = srcId isDefined
+    val personalized = srcId.isDefined
     val src: VertexId = srcId.getOrElse(-1L)
 
     // Initialize the PageRank graph with each edge attribute having

mllib/src/main/scala/org/apache/spark/mllib/util/MFDataGenerator.scala

@@ -19,7 +19,6 @@ package org.apache.spark.mllib.util
 
 import java.{util => ju}
 
-import scala.language.postfixOps
 import scala.util.Random
 
 import org.apache.spark.SparkContext

repl/src/test/scala/org/apache/spark/repl/ExecutorClassLoaderSuite.scala

@@ -27,7 +27,6 @@ import java.util
 import scala.concurrent.duration._
 import scala.io.Source
 import scala.language.implicitConversions
-import scala.language.postfixOps
 
 import com.google.common.io.Files
 import org.mockito.Matchers.anyString

sql/catalyst/src/test/scala/org/apache/spark/sql/types/DecimalSuite.scala

@@ -17,8 +17,6 @@
 
 package org.apache.spark.sql.types
 
-import scala.language.postfixOps
-
 import org.scalatest.PrivateMethodTester
 
 import org.apache.spark.SparkFunSuite

sql/core/src/test/scala/org/apache/spark/sql/DataFrameSuite.scala

@@ -21,7 +21,6 @@ import java.io.File
 import java.nio.charset.StandardCharsets
 import java.util.UUID
 
-import scala.language.postfixOps
 import scala.util.Random
 
 import org.scalatest.Matchers._

sql/core/src/test/scala/org/apache/spark/sql/DatasetAggregatorSuite.scala

@@ -17,8 +17,6 @@
 
 package org.apache.spark.sql
 
-import scala.language.postfixOps
-
 import org.apache.spark.sql.catalyst.encoders.ExpressionEncoder
 import org.apache.spark.sql.expressions.Aggregator
 import org.apache.spark.sql.expressions.scalalang.typed

sql/core/src/test/scala/org/apache/spark/sql/DatasetCacheSuite.scala

@@ -17,8 +17,6 @@
 
 package org.apache.spark.sql
 
-import scala.language.postfixOps
-
 import org.apache.spark.sql.functions._
 import org.apache.spark.sql.test.SharedSQLContext
 

sql/core/src/test/scala/org/apache/spark/sql/DatasetPrimitiveSuite.scala

@@ -17,8 +17,6 @@
 
 package org.apache.spark.sql
 
-import scala.language.postfixOps
-
 import org.apache.spark.sql.test.SharedSQLContext
 
 case class IntClass(value: Int)

sql/core/src/test/scala/org/apache/spark/sql/DatasetSuite.scala

@@ -20,8 +20,6 @@ package org.apache.spark.sql
 import java.io.{Externalizable, ObjectInput, ObjectOutput}
 import java.sql.{Date, Timestamp}
 
-import scala.language.postfixOps
-
 import org.apache.spark.sql.catalyst.encoders.{OuterScopes, RowEncoder}
 import org.apache.spark.sql.catalyst.util.sideBySide
 import org.apache.spark.sql.execution.streaming.MemoryStream

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala

@@ -1790,6 +1790,7 @@ class SQLQuerySuite extends QueryTest with SQLTestUtils with TestHiveSingleton {
   }
 
   def testCommandAvailable(command: String): Boolean = {
-    Try(Process(command) !!).isSuccess
+    val attempt = Try(Process(command).run().exitValue())
+    attempt.isSuccess && attempt.get == 0
   }
 }

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

@@ -25,7 +25,6 @@ import java.util.concurrent.atomic.AtomicInteger
 
 import scala.collection.JavaConverters._
 import scala.collection.mutable
-import scala.language.postfixOps
 
 import com.google.common.io.Files
 import org.apache.hadoop.fs.Path

yarn/src/main/scala/org/apache/spark/deploy/yarn/AMDelegationTokenRenewer.scala

@@ -19,8 +19,6 @@ package org.apache.spark.deploy.yarn
 import java.security.PrivilegedExceptionAction
 import java.util.concurrent.{Executors, TimeUnit}
 
-import scala.language.postfixOps
-
 import org.apache.hadoop.conf.Configuration
 import org.apache.hadoop.fs.{FileSystem, Path}
 import org.apache.hadoop.security.UserGroupInformation
@@ -128,7 +126,7 @@ private[yarn] class AMDelegationTokenRenewer(
     try {
       val remoteFs = FileSystem.get(freshHadoopConf)
       val credentialsPath = new Path(credentialsFile)
-      val thresholdTime = System.currentTimeMillis() - (daysToKeepFiles days).toMillis
+      val thresholdTime = System.currentTimeMillis() - (daysToKeepFiles.days).toMillis
       hadoopUtil.listFilesSorted(
         remoteFs, credentialsPath.getParent,
         credentialsPath.getName, SparkHadoopUtil.SPARK_YARN_CREDS_TEMP_EXTENSION)