[gnome-shell-extensions/check-commits] ci: Check for issue/MR URLs in commit messages

[Florian Müllner <fmuellner src gnome org>]

commit cbd981351e4987f0e9f6dc5e356c8fd353045ec8
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Feb 15 23:59:36 2019 +0100

    ci: Check for issue/MR URLs in commit messages
    
    Commit messages should include the full URL to an issue or merge
    request to keep associated information easily available in future
    log digging.
    
    Jonas came up with a script to enforce that policy for mutter and
    gnome-shell. It's an excellent idea, so adopt it here as well.
    
    https://gitlab.gnome.org/GNOME/gnome-shell-extensions/merge_requests/52

 .gitlab-ci.yml                 | 17 +++++++++++++++++
 .gitlab-ci/check-commit-log.sh | 31 +++++++++++++++++++++++++++++++
 2 files changed, 48 insertions(+)
---
diff --git a/.gitlab-ci.yml b/.gitlab-ci.yml
index af003a1..72c42e0 100644
--- a/.gitlab-ci.yml
+++ b/.gitlab-ci.yml
@@ -1,15 +1,31 @@
 stages:
+ - commit_check
  - source_check
  - build
 
 variables:
  LINT_LOG: "eslint-report.txt"
 
+.only_default: &only_default
+    only:
+        - branches
+        - tags
+        - merge_requests
+
+check_commit_log:
+    image: registry.gitlab.gnome.org/gnome/gjs:fedora.static-analysis
+    stage: commit_check
+    script:
+        - ./.gitlab-ci/check-commit-log.sh
+    only:
+        - merge_requests
+
 eslint:
   image: registry.gitlab.gnome.org/gnome/gjs:fedora.static-analysis
   stage: source_check
   script:
     - sh lint/generate-report.sh -o $LINT_LOG || { cat $LINT_LOG; false; }
+  <<: *only_default
   artifacts:
     paths:
       - ${LINT_LOG}
@@ -23,3 +39,4 @@ build-shell-extensions:
   script:
     - meson _build .
     - ninja -C _build test install
+  <<: *only_default
diff --git a/.gitlab-ci/check-commit-log.sh b/.gitlab-ci/check-commit-log.sh
new file mode 100755
index 0000000..cc3bcee
--- /dev/null
+++ b/.gitlab-ci/check-commit-log.sh
@@ -0,0 +1,31 @@
+#!/usr/bin/env bash
+
+if [ -z "$CI_MERGE_REQUEST_TARGET_BRANCH_NAME" ]; then
+  echo Cannot review non-merge request
+  exit 1
+fi
+
+git fetch $CI_MERGE_REQUEST_PROJECT_URL.git $CI_MERGE_REQUEST_TARGET_BRANCH_NAME
+
+branch_point=$(git merge-base HEAD FETCH_HEAD)
+
+commits=$(git log --format='format:%H' $branch_point..$CI_COMMIT_SHA)
+
+if [ -z "$commits" ]; then
+  echo Commit range empty
+  exit 1
+fi
+
+function commit_message_has_url() {
+  commit=$1
+  commit_message=$(git show -s --format='format:%b' $commit)
+  echo "$commit_message" | grep -qe 
"\($CI_MERGE_REQUEST_PROJECT_URL/\(issues\|merge_requests\)/[0-9]\+\|https://bugzilla.gnome.org/show_bug.cgi?id=[0-9]\+\)"
+  return $?
+}
+
+for commit in $commits; do
+  if ! commit_message_has_url $commit; then
+    echo "Missing merge request or issue URL on commit $(echo $commit | cut -c -8)"
+    exit 1
+  fi
+done