git pre-commit gist for catching merge conflict markers

pre-commit

#!/usr/bin/env python3

import subprocess
import sys

def get_diff():
    base_commit = subprocess.run(['git', 'rev-parse', '--verify', 'HEAD'], stdout=subprocess.PIPE).stdout.decode('utf-8').strip()
    return subprocess.run(['git', 'diff', '--cached', base_commit], stdout=subprocess.PIPE).stdout.decode('utf-8').strip()

def check_for_merge_markers(diff):
    if (
        diff.find("<<<<<<<") > -1
        or diff.find(">>>>>>>") > -1
        or diff.find("=======") > -1
    ):
        print("Attempting to commit merge markers")
        return False
    else:
        return True

# add more functions of diff above for more checks, then add them to
# this list here.  these functions should return True if the diff
# passes.
CHECKS = [
    check_for_merge_markers,
]

def main():
    diff = get_diff()
    passed = all([check(diff) for check in CHECKS])
    if passed:
        sys.exit(0)
    else:
        sys.exit(1)

if __name__ == "__main__":
    main()