LIVY-125. Refactor existing test jobs into a new library.

This will help with writing integration tests, by avoiding
having to create new versions of these simple jobs. It also
serves as a nice cleanup of the existing code.

I also removed the async job from the rsc tests, since the
support code for dealing with async Spark jobs has been
removed from Livy.

Closes apache#115

client-http/pom.xml

@@ -45,6 +45,13 @@
       <version>${project.version}</version>
     </dependency>
 
+    <dependency>
+      <groupId>com.cloudera.livy</groupId>
+      <artifactId>livy-test-lib</artifactId>
+      <version>${project.version}</version>
+      <scope>test</scope>
+    </dependency>
+
     <dependency>
       <groupId>com.fasterxml.jackson.core</groupId>
       <artifactId>jackson-core</artifactId>

client-http/src/test/scala/com/cloudera/livy/client/http/HttpClientSpec.scala

@@ -42,6 +42,7 @@ import com.cloudera.livy.client.common.HttpMessages._
 import com.cloudera.livy.server.WebServer
 import com.cloudera.livy.server.client.{ClientSession, ClientSessionServlet}
 import com.cloudera.livy.sessions.SessionState
+import com.cloudera.livy.test.jobs.Echo
 
 /**
  * The test for the HTTP client is written in Scala so we can reuse the code in the livy-server
@@ -213,7 +214,7 @@ class HttpClientSpec extends FunSpecLike with BeforeAndAfterAll {
     assert(expectedStr === new String(b))
   }
 
-  private def runJob(sync: Boolean, genStatusFn: Long => Seq[JobStatus]): (Long, JFuture[Long]) = {
+  private def runJob(sync: Boolean, genStatusFn: Long => Seq[JobStatus]): (Long, JFuture[Int]) = {
     val jobId = java.lang.Long.valueOf(ID_GENERATOR.incrementAndGet())
     when(session.submitJob(any(classOf[Array[Byte]]))).thenReturn(jobId)
 
@@ -222,7 +223,8 @@ class HttpClientSpec extends FunSpecLike with BeforeAndAfterAll {
     val remaining = statuses.drop(1)
     when(session.jobStatus(meq(jobId))).thenReturn(first, remaining: _*)
 
-    val handle = if (sync) client.run(new DummyJob()) else client.submit(new DummyJob())
+    val job = new Echo(42)
+    val handle = if (sync) client.run(job) else client.submit(job)
     (jobId, handle)
   }
 
@@ -248,13 +250,6 @@ class HttpClientSpec extends FunSpecLike with BeforeAndAfterAll {
 
 }
 
-// Won't really get called, here just so we can use the API.
-class DummyJob extends Job[Long] {
-
-  override def call(jc: JobContext): Long = 42L
-
-}
-
 private object HttpClientSpec {
 
   // Hack warning: keep the session object available so that individual tests can mock

pom.xml

@@ -169,6 +169,7 @@
     <module>repl</module>
     <module>rsc</module>
     <module>server</module>
+    <module>test-lib</module>
     <module>integration-test</module>
   </modules>
 

rsc/pom.xml

@@ -45,6 +45,12 @@
       <artifactId>livy-client-common</artifactId>
       <version>${project.version}</version>
     </dependency>
+    <dependency>
+      <groupId>com.cloudera.livy</groupId>
+      <artifactId>livy-test-lib</artifactId>
+      <version>${project.version}</version>
+      <scope>test</scope>
+    </dependency>
 
     <dependency>
       <groupId>com.esotericsoftware.kryo</groupId>

rsc/src/main/java/com/cloudera/livy/rsc/Utils.java

@@ -91,11 +91,8 @@ public static String stackTraceAsString(Throwable t) {
     StringBuilder sb = new StringBuilder();
     sb.append(t.getClass().getName()).append(": ").append(t.getMessage());
     for (StackTraceElement e : t.getStackTrace()) {
-      sb.append(e.toString());
       sb.append("\n");
-    }
-    if (sb.length() > 0) {
-      sb.setLength(sb.length() - 1);
+      sb.append(e.toString());
     }
     return sb.toString();
   }