[SPARK-3479] [Build] Report failed test category

This PR allows SparkQA (i.e. Jenkins) to report in its posts to GitHub what category of test failed, if one can be determined.

The failure categories are:
* general failure
* RAT checks failed
* Scala style checks failed
* Python style checks failed
* Build failed
* Spark unit tests failed
* PySpark unit tests failed
* MiMa checks failed

This PR also fixes the diffing logic used to determine if a patch introduces new classes.

Author: Nicholas Chammas <nicholas.chammas@gmail.com>

Closes #2606 from nchammas/report-failed-test-category and squashes the following commits:

d67df03 [Nicholas Chammas] report what test category failed

1 files changed, 30 insertions, 2 deletions

diff --git a/dev/run-tests b/dev/run-tests
index c3d8f49cdd..4be2baaf48 100755
--- a/dev/run-tests
+++ b/dev/run-tests
@@ -24,6 +24,16 @@ cd "$FWDIR"
 # Remove work directory
 rm -rf ./work
 
+source "$FWDIR/dev/run-tests-codes.sh"
+
+CURRENT_BLOCK=$BLOCK_GENERAL
+
+function handle_error () {
+  echo "[error] Got a return code of $? on line $1 of the run-tests script."
+  exit $CURRENT_BLOCK
+}
+
+
 # Build against the right verison of Hadoop.
 {
   if [ -n "$AMPLAB_JENKINS_BUILD_PROFILE" ]; then
@@ -91,26 +101,34 @@ if [ -n "$AMPLAB_JENKINS" ]; then
   fi
 fi
 
-# Fail fast
-set -e
 set -o pipefail
+trap 'handle_error $LINENO' ERR
 
 echo ""
 echo "========================================================================="
 echo "Running Apache RAT checks"
 echo "========================================================================="
+
+CURRENT_BLOCK=$BLOCK_RAT
+
 ./dev/check-license
 
 echo ""
 echo "========================================================================="
 echo "Running Scala style checks"
 echo "========================================================================="
+
+CURRENT_BLOCK=$BLOCK_SCALA_STYLE
+
 ./dev/lint-scala
 
 echo ""
 echo "========================================================================="
 echo "Running Python style checks"
 echo "========================================================================="
+
+CURRENT_BLOCK=$BLOCK_PYTHON_STYLE
+
 ./dev/lint-python
 
 echo ""
@@ -118,6 +136,8 @@ echo "========================================================================="
 echo "Building Spark"
 echo "========================================================================="
 
+CURRENT_BLOCK=$BLOCK_BUILD
+
 {
   # We always build with Hive because the PySpark Spark SQL tests need it.
   BUILD_MVN_PROFILE_ARGS="$SBT_MAVEN_PROFILES_ARGS -Phive"
@@ -141,6 +161,8 @@ echo "========================================================================="
 echo "Running Spark unit tests"
 echo "========================================================================="
 
+CURRENT_BLOCK=$BLOCK_SPARK_UNIT_TESTS
+
 {
   # If the Spark SQL tests are enabled, run the tests with the Hive profiles enabled.
   # This must be a single argument, as it is.
@@ -175,10 +197,16 @@ echo ""
 echo "========================================================================="
 echo "Running PySpark tests"
 echo "========================================================================="
+
+CURRENT_BLOCK=$BLOCK_PYSPARK_UNIT_TESTS
+
 ./python/run-tests
 
 echo ""
 echo "========================================================================="
 echo "Detecting binary incompatibilites with MiMa"
 echo "========================================================================="
+
+CURRENT_BLOCK=$BLOCK_MIMA
+
 ./dev/mima