Add nodeDetailString field and update tests

Author: charlesmyu

dd-java-agent/instrumentation/spark/src/main/java/datadog/trace/instrumentation/spark/SparkSQLUtils.java

@@ -13,13 +13,18 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
+import org.apache.commons.lang.StringUtils;
 import org.apache.spark.scheduler.AccumulableInfo;
 import org.apache.spark.sql.execution.SparkPlanInfo;
 import org.apache.spark.sql.execution.metric.SQLMetricInfo;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
 import scala.Tuple2;
 import scala.collection.JavaConverters;
 
 public class SparkSQLUtils {
+  private static final Logger log = LoggerFactory.getLogger(SparkSQLUtils.class);
+
   public static void addSQLPlanToStageSpan(
       AgentSpan span,
       SparkPlanInfo plan,
@@ -165,6 +170,15 @@ private void toJson(JsonGenerator generator, Map<Long, AccumulatorWithStage> acc
       generator.writeStringField("node", plan.nodeName());
       generator.writeNumberField("nodeId", plan.hashCode());
 
+      String nodeDetails = plan.simpleString();
+      if (StringUtils.startsWith(nodeDetails, plan.nodeName())) {
+        nodeDetails =
+            StringUtils.right(nodeDetails, nodeDetails.length() - plan.nodeName().length()).trim();
+      }
+      if (!nodeDetails.isEmpty()) {
+        generator.writeStringField("nodeDetailString", nodeDetails);
+      }
+
       // Metadata is only present for FileSourceScan nodes
       if (!plan.metadata().isEmpty()) {
         generator.writeFieldName("meta");