1  #!/usr/bin/env python3
 2  #
 3  # Copyright (c) 2020-2022 The Bitcoin Core developers
 4  # Distributed under the MIT software license, see the accompanying
 5  # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 6  #
 7  # Linter to check that commit messages have a new line before the body
 8  # or no body at all
 9  
10  import argparse
11  import os
12  import sys
13  
14  from subprocess import check_output
15  
16  
17  def parse_args():
18      """Parse command line arguments."""
19      parser = argparse.ArgumentParser(
20          description="""
21              Linter to check that commit messages have a new line before
22              the body or no body at all.
23          """,
24          epilog=f"""
25              You can manually set the commit-range with the COMMIT_RANGE
26              environment variable (e.g. "COMMIT_RANGE='HEAD~n..HEAD'
27              {sys.argv[0]}") for the last 'n' commits.
28          """)
29      return parser.parse_args()
30  
31  
32  def main():
33      parse_args()
34      exit_code = 0
35  
36      assert os.getenv("COMMIT_RANGE")  # E.g. COMMIT_RANGE='HEAD~n..HEAD'
37      commit_range = os.getenv("COMMIT_RANGE")
38  
39      commit_hashes = check_output(["git", "log", commit_range, "--format=%H"], text=True, encoding="utf8").splitlines()
40  
41      for hash in commit_hashes:
42          commit_info = check_output(["git", "log", "--format=%B", "-n", "1", hash], text=True, encoding="utf8").splitlines()
43          if len(commit_info) >= 2:
44              if commit_info[1]:
45                  print(f"The subject line of commit hash {hash} is followed by a non-empty line. Subject lines should always be followed by a blank line.")
46                  exit_code = 1
47  
48      sys.exit(exit_code)
49  
50  
51  if __name__ == "__main__":
52      main()