Code coverage for Spark tests using JaCoCo

gistfile1.sh

$ sbt/sbt "jacoco:cover"
$ open core/target/scala-2.9.2/jacoco/html/index.html 

jacoco-coverage.patch

diff --git a/project/SparkBuild.scala b/project/SparkBuild.scala
index 842d0fa..3219ec0 100644
--- a/project/SparkBuild.scala
+++ b/project/SparkBuild.scala
@@ -4,6 +4,8 @@ import Keys._
 import sbtassembly.Plugin._
 import AssemblyKeys._
 import twirl.sbt.TwirlPlugin._
+import de.johoop.jacoco4sbt._
+import JacocoPlugin._
 // For Sonatype publishing
 //import com.jsuereth.pgp.sbtplugin.PgpKeys._
 
@@ -17,6 +19,7 @@ object SparkBuild extends Build {
   //val HADOOP_VERSION = "2.0.0-mr1-cdh4.1.1"
   //val HADOOP_MAJOR_VERSION = "2"
 
+
   lazy val root = Project("root", file("."), settings = rootSettings) aggregate(core, repl, examples, bagel)
 
   lazy val core = Project("core", file("core"), settings = coreSettings)
@@ -92,6 +95,7 @@ object SparkBuild extends Build {
       "com.novocode" % "junit-interface" % "0.8" % "test"
     ),
     parallelExecution := false,
+    parallelExecution in jacoco.Config := false,
     /* Workaround for issue #206 (fixed after SBT 0.11.0) */
     watchTransitiveSources <<= Defaults.inDependencies[Task[Seq[File]]](watchSources.task,
       const(std.TaskExtra.constant(Nil)), aggregate = true, includeRoot = true) apply { _.join.map(_.flatten) },
@@ -103,7 +107,7 @@ object SparkBuild extends Build {
     publishMavenStyle in MavenCompile := true,
     publishLocal in MavenCompile <<= publishTask(publishLocalConfiguration in MavenCompile, deliverLocal),
     publishLocalBoth <<= Seq(publishLocal in MavenCompile, publishLocal).dependOn
-  )
+  ) ++ Seq(jacoco.settings:_*)
 
   val slf4jVersion = "1.6.1"
 
diff --git a/project/plugins.sbt b/project/plugins.sbt
index 4d0e696..226bd81 100644
--- a/project/plugins.sbt
+++ b/project/plugins.sbt
@@ -16,3 +16,9 @@ addSbtPlugin("cc.spray" %% "sbt-twirl" % "0.5.2")
 //resolvers += Resolver.url("sbt-plugin-releases", new URL("http://scalasbt.artifactoryonline.com/scalasbt/sbt-plugin-releases/"))(Resolver.ivyStylePatterns)
 
 //addSbtPlugin("com.jsuereth" % "xsbt-gpg-plugin" % "0.6")
+
+libraryDependencies ++= Seq(
+  "org.jacoco" % "org.jacoco.core" % "0.5.7.201204190339" artifacts(Artifact("org.jacoco.core", "jar", "jar")),
+  "org.jacoco" % "org.jacoco.report" % "0.5.7.201204190339" artifacts(Artifact("org.jacoco.report", "jar", "jar")))
+
+addSbtPlugin("de.johoop" % "jacoco4sbt" % "1.2.3")

Note that the coverage may be an underestimate since it doesn't seem to detect code executed in UDFs: