git commit hook using node to ensure commit message follows a convention

commit-msg

#!/usr/bin/env python3

# NOTES:
# 1. This is one of the three implementation, this one is in Python. if you do not have python installed, there are 'node' and 'scala' counterparts.
# 2. To use this file, place it in .git/hooks/ in your repository.
# 3. You can also use this script with the 'husky' npm module.

import sys
import os
import re

filename = sys.argv[1] or os.getenv('GIT_PARAMS')
with open(filename, 'r') as f:
    msg = f.read()

msg = re.sub(r'\r\n|\r|\n', ' ', msg)
maxLen = 50 if len(msg) > 50 else len(msg)
msg = msg[0:maxLen]
matchTest = re.search('([A-Z]+-?\d+|Adhoc)\: (.+: )?(Added|Removed|BugFix|Modified|Feature|Merged|Refactored|Release): (.+){15,}$', msg)

exitCode = 0 if (not (matchTest is None)) else 1

if (exitCode == 0):
	print("SUCCESS: Commit ACCEPTED.")
else:
	print("ERROR: Commit REJECTED. REASON: Your commit message: '" + msg + "' does not follow the commit message convention.");
	print("Convention: '[JIRAID]: [Optional clientId]: [One Primary Change Type: Added|Removed|BugFix|Modified|Feature|Merged|Refactored|Release]: [Message describing the change. If absolutely necessary, you can add multiple Change types here.]");
	print("Sample: IT-123: Added: git hook to validate commit message.");


exit(exitCode)