Build: Add back leaveTemporary and ifNoTests

This change adds back the last of the missing test options to the juni4
wrapper. leaveTemporary is important in that setting it to true (which
is how we had it set in maven) removes the warnings we currently get
about a leftover file that cannot be deleted (from jna).

buildSrc/src/main/groovy/com/carrotsearch/gradle/junit4/RandomizedTestingTask.groovy

@@ -2,6 +2,7 @@ package com.carrotsearch.gradle.junit4
 
 import com.carrotsearch.ant.tasks.junit4.ListenersList
 import com.carrotsearch.ant.tasks.junit4.listeners.AggregatedEventListener
+import com.esotericsoftware.kryo.serializers.FieldSerializer
 import groovy.xml.NamespaceBuilder
 import groovy.xml.NamespaceBuilderSupport
 import org.apache.tools.ant.BuildException
@@ -58,6 +59,14 @@ class RandomizedTestingTask extends DefaultTask {
     @Input
     boolean enableSystemAssertions = true
 
+    @Optional
+    @Input
+    boolean leaveTemporary = false
+
+    @Optional
+    @Input
+    String ifNoTests = 'ignore'
+
     TestLoggingConfiguration testLoggingConfig = new TestLoggingConfiguration()
 
     BalancersConfiguration balancersConfig = new BalancersConfiguration(task: this)
@@ -172,9 +181,6 @@ class RandomizedTestingTask extends DefaultTask {
         }
     }
 
-    // TODO: add leaveTemporary
-    // TODO: add ifNoTests!
-
     @TaskAction
     void executeTests() {
         Map attributes = [
@@ -184,7 +190,9 @@ class RandomizedTestingTask extends DefaultTask {
             dir: workingDir,
             tempdir: new File(workingDir, 'temp'),
             haltOnFailure: true, // we want to capture when a build failed, but will decide whether to rethrow later
-            shuffleOnSlave: shuffleOnSlave
+            shuffleOnSlave: shuffleOnSlave,
+            leaveTemporary: leaveTemporary,
+            ifNoTests: ifNoTests
         ]
 
         DefaultLogger listener = null

buildSrc/src/main/groovy/org/elasticsearch/gradle/BuildPlugin.groovy

@@ -322,6 +322,8 @@ class BuildPlugin implements Plugin<Project> {
         return {
             jvm "${project.javaHome}/bin/java"
             parallelism System.getProperty('tests.jvms', 'auto')
+            ifNoTests 'fail'
+            leaveTemporary true
 
             // TODO: why are we not passing maxmemory to junit4?
             jvmArg '-Xmx' + System.getProperty('tests.heap.size', '512m')