2 files changed, 73 insertions(+), 0 deletions(-)

M .github/workflows/main.yml
A tools/check_commit_messages.py

@@ 3,6 3,16 @@ name: CI
 on: [pull_request]
 
 jobs:
+  check_commit_messages:
+    name: check commit messages
+    runs-on: self-hosted
+    steps:
+      - name: clone repository
+        uses: actions/checkout@v2
+        with:
+          fetch-depth: 0
+      - name: check commit messages
+        run: ./tools/check_commit_messages.py
   build:
     runs-on: self-hosted
     steps:

@@ 0,0 1,63 @@
+#!/usr/bin/env python3
+'''
+Copyright (c) 2017-2020, Mudita Sp. z.o.o. All rights reserved.
+For licensing, see https://github.com/mudita/MuditaOS/LICENSE.md
+'''
+
+import os
+from git import Repo
+import re
+
+
+def get_pull_request_commits():
+  github_base_ref = os.environ['GITHUB_BASE_REF']
+  github_head_ref = os.environ['GITHUB_HEAD_REF']
+
+  return Repo('.').iter_commits(rev=f'origin/{github_base_ref}..origin/{github_head_ref}')
+
+
+def validate_commit(commit):
+  errors = []
+
+  lines = commit.message.split('\n')
+
+  if len(lines) < 3:
+    errors.append(f'[{commit.hexsha}] commit message should be composed of at least 3 lines: a subject, an empty line and a body')
+    return errors
+
+  line_length_limit = 72
+  if any(len(line) > line_length_limit for line in lines):
+    errors.append(f'[{commit.hexsha}] maximum allowed line length is {line_length_limit}')
+
+  subject = lines[0]
+  empty_line = lines[1]
+  body = ''.join(lines[2:]).strip()
+
+  subject_format = r'^\[\w+-\d+\] (?:Add|Change|Fix) .+[^.]$'
+  if not re.match(subject_format, subject):
+    errors.append(f'[{commit.hexsha}] invalid subject "{subject}", should match format "{subject_format}"')
+
+  if empty_line:
+    errors.append(f'[{commit.hexsha}] the second line in a commit message should be empty')
+
+  if not body:
+    errors.append(f"[{commit.hexsha}] message body can't be empty")
+
+  return errors
+
+
+def main():
+  errors = []
+
+  for commit in get_pull_request_commits():
+    errors.extend(validate_commit(commit))
+
+  for error in errors:
+    print(error)
+
+  if errors:
+    exit(1)
+
+
+if __name__ == '__main__':
+  main()