Update PR tests to complete all tests before returning results. (#1065)

* Return results of all tests.

* Use for loop instead of while.

.kokoro/tests/diff_tests.sh

@@ -38,37 +38,47 @@ gcloud auth activate-service-account\
     --project=$GOOGLE_CLOUD_PROJECT
 
 echo -e "\n******************** TESTING AFFECTED PROJECTS ********************"
+set +e
 # Diff to find out what has changed from master
+RESULT=0
 cd github/java-docs-samples
-find * -name pom.xml -print0 | sort -z | while read -d $'\0' file
-do
+# For every pom.xml (may break on whitespace)
+for file in **/pom.xml; do
     # Navigate to project
     file=$(dirname "$file")
     pushd "$file" > /dev/null
 
-    set +e
     # Only tests changed projects
     git diff --quiet master.. .
     CHANGED=$?
     # Only test leafs to prevent testing twice
     PARENT=$(grep "<modules>" pom.xml -c)
-    set -e
 
     # Check for changes to the current folder
     if [ "$CHANGED" -eq 1 ] && [ "$PARENT" -eq 0 ]; then
         echo "------------------------------------------------------------"
         echo "- testing $file"
         echo "------------------------------------------------------------"
 
+        # Run tests and update RESULT if failed
         mvn -q --batch-mode --fail-at-end clean verify \
            -Dfile.encoding="UTF-8" \
            -Dorg.slf4j.simpleLogger.log.org.apache.maven.cli.transfer.Slf4jMavenTransferListener=warn \
            -Dmaven.test.redirectTestOutputToFile=true \
            -Dbigtable.projectID="${GOOGLE_CLOUD_PROJECT}" \
            -Dbigtable.instanceID=instance
-        echo -e "\n Tests complete. \n"
+        EXIT=$?
+
+        if [ $EXIT -ne 0 ]; then
+            echo -e "\n Tests failed. \n"
+            RESULT=1
+        else
+            echo -e "\n Tests complete. \n"
+        fi
     fi
 
     popd > /dev/null
 
 done
+
+exit $RESULT