Remove use of system properties in SparkContextSuite

Author: JoshRosen

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

@@ -17,17 +17,16 @@
 
 package org.apache.spark
 
-import org.apache.spark.util.ResetSystemProperties
 import org.scalatest.FunSuite
 
 import org.apache.hadoop.io.BytesWritable
 
-class SparkContextSuite extends FunSuite with ResetSystemProperties with LocalSparkContext {
+class SparkContextSuite extends FunSuite with LocalSparkContext {
 
   test("Only one SparkContext may be active at a time") {
     // Regression test for SPARK-4180
-    System.setProperty("spark.driver.allowMultipleContexts", "false")
     val conf = new SparkConf().setAppName("test").setMaster("local")
+      .set("spark.driver.allowMultipleContexts", "false")
     sc = new SparkContext(conf)
     // A SparkContext is already running, so we shouldn't be able to create a second one
     intercept[SparkException] { new SparkContext(conf) }
@@ -37,20 +36,20 @@ class SparkContextSuite extends FunSuite with ResetSystemProperties with LocalSp
   }
 
   test("Can still construct a new SparkContext after failing to construct a previous one") {
-    System.setProperty("spark.driver.allowMultipleContexts", "false")
+    val conf = new SparkConf().set("spark.driver.allowMultipleContexts", "false")
     // This is an invalid configuration (no app name or master URL)
     intercept[SparkException] {
-      new SparkContext(new SparkConf())
+      new SparkContext(conf)
     }
     // Even though those earlier calls failed, we should still be able to create a new context
-    sc = new SparkContext(new SparkConf().setMaster("local").setAppName("test"))
+    sc = new SparkContext(conf.setMaster("local").setAppName("test"))
   }
 
   test("Check for multiple SparkContexts can be disabled via undocumented debug option") {
-    System.setProperty("spark.driver.allowMultipleContexts", "true")
     var secondSparkContext: SparkContext = null
     try {
       val conf = new SparkConf().setAppName("test").setMaster("local")
+        .set("spark.driver.allowMultipleContexts", "true")
       sc = new SparkContext(conf)
       secondSparkContext = new SparkContext(conf)
     } finally {