ci/check-commit-log: Generate JUnit report

This means the merge request will see the commit log review issues
causing the pipeline to fail without having to dig through CI log files.

Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1491>

.gitlab-ci.yml

@@ -27,6 +27,12 @@ check_commit_log:
         - ./.gitlab-ci/check-commit-log.sh
     only:
         - merge_requests
+    artifacts:
+        expire_in: 1 week
+        paths:
+            - commit-message-junit-report.xml
+        reports:
+            junit: commit-message-junit-report.xml
 
 js_check:
     image: registry.gitlab.gnome.org/gnome/gnome-shell/extension-ci:v2

.gitlab-ci/check-commit-log.sh

@@ -16,6 +16,42 @@ if [ -z "$commits" ]; then
   exit 1
 fi
 
+JUNIT_REPORT_TESTS_FILE=$(mktemp)
+
+function append_failed_test_case() {
+  test_name="$1"
+  commit="$2"
+  test_message="$3"
+  commit_short=${commit:0:8}
+
+  echo "<testcase name=\"$test_name: $commit_short\"><failure message=\"$commit_short: $test_message\"/></testcase>" >> $JUNIT_REPORT_TESTS_FILE
+  echo &>2 "Commit check failed: $commit_short: $test_message"
+}
+
+function append_passed_test_case() {
+  test_name="$1"
+  commit="$2"
+  commit_short=${commit:0:8}
+  echo "<testcase name=\"$test_name: $commit_short\"></testcase>" >> $JUNIT_REPORT_TESTS_FILE
+}
+
+function generate_junit_report() {
+  junit_report_file="$1"
+  num_tests=$(cat "$JUNIT_REPORT_TESTS_FILE" | wc -l)
+  num_failures=$(grep '<failure />' "$JUNIT_REPORT_TESTS_FILE" | wc -l )
+
+  echo Generating JUnit report \"$(pwd)/$junit_report_file\" with $num_tests tests and $num_failures failures.
+
+  cat > $junit_report_file << __EOF__
+<?xml version="1.0" encoding="utf-8"?>
+<testsuites tests="$num_tests" errors="0" failures="$num_failures">
+<testsuite name="commit-review" tests="$num_tests" errors="0" failures="$num_failures" skipped="0">
+$(< $JUNIT_REPORT_TESTS_FILE)
+</testsuite>
+</testsuites>
+__EOF__
+}
+
 function commit_message_has_mr_url() {
   commit=$1
   commit_message=$(git show -s --format='format:%b' $commit)
@@ -25,7 +61,14 @@ function commit_message_has_mr_url() {
 
 for commit in $commits; do
   if commit_message_has_mr_url $commit; then
-    echo "Commit $(echo $commit | cut -c -8) message must not contain a link to its own merge request"
-    exit 1
+    append_failed_test_case superfluous_url $commit \
+      "Commit message must not contain a link to its own merge request"
+  else
+    append_passed_test_case superfluous_url $commit
   fi
 done
+
+generate_junit_report commit-message-junit-report.xml
+
+! grep -q '<failure' commit-message-junit-report.xml
+exit $?