#!/usr/bin/env python3import jsonimport osimport reimport subprocessimport sysfrom collections.abc import Callablefrom typing import Optional  def call(cmd) -> str:    sys.stdout.flush()    ret = subprocess.run(cmd, check=True, stdout=subprocess.PIPE, text=True)    return ret.stdout lint_rules: dict[str, tuple[Callable, str]] = {} # A lint rule should return True if everything is okaydef lint_rule(description: str):    def f(func):        assert func.__name__ not in lint_rules        lint_rules[func.__name__] = (func, description)    return f def get_commit_range() -> Optional[str]:    if len(sys.argv) > 1:        return sys.argv[1]    # https://github.com/actions/runner/issues/342#issuecomment-590670059    event_name = os.environ["GITHUB_EVENT_NAME"]    with open(os.environ["GITHUB_EVENT_PATH"], "rb") as f:        event = json.load(f)    if event_name == "push":        if event["created"] or event["forced"]:            print("Skipping logic on branch creation or force-push")            return None        return event["before"] + "..." + event["after"]    elif event_name == "pull_request":        base = event["pull_request"]["base"]["sha"]        head = event["pull_request"]["head"]["sha"]        return f"{base}..{head}"    return None def do_lint(commit_range: str) -> bool:    commits = call(["git", "log", "--pretty=format:%H %s", commit_range]).splitlines()    print(f"Linting {len(commits)} commit(s):")    any_failed = False    for commit in commits:        sha, _, _ = commit.partition(" ")        body = call(["git", "show", "-s", "--format=%B", sha]).splitlines()        failed = []        if len(body) == 0:            failed.append("* Commit message must not be empty")        else:            for k, v in lint_rules.items():                if not v[0](body):                    failed.append(f"* {v[1]} [{k}]")        if failed:            any_failed = True            print("-" * 40)            sys.stdout.flush()            subprocess.run(["git", "-P", "show", "-s", sha])            print("\nhas the following issues:")            print("\n".join(failed))            print("-" * 40)    return any_failed ################################################################################ NO_PREFIX_WHITELIST = \    r"^Revert \"(.*)\"|^Reapply \"(.*)\"|^Release [0-9]|^Update MPV_VERSION$" @lint_rule("Subject line must contain a prefix identifying the sub system")def subsystem_prefix(body):    return (re.search(NO_PREFIX_WHITELIST, body[0]) or            re.search(r"^[\w/\.{},-]+: ", body[0])) @lint_rule("First word after : must be lower case")def description_lowercase(body):    # Allow all caps for acronyms and options with --    return (re.search(NO_PREFIX_WHITELIST, body[0]) or            re.search(r": (?:[A-Z]{2,} |--[a-z]|[a-z0-9])", body[0])) @lint_rule("Subject line must not end with a full stop")def no_dot(body):    return not body[0].rstrip().endswith(".") @lint_rule("There must be an empty line between subject and extended description")def empty_line(body):    return len(body) == 1 or body[1].strip() == "" # been seeing this one all over github lately, must be the webshits@lint_rule("Do not use 'conventional commits' style")def no_cc(body):    return not re.search(r"(?i)^(feat|fix|chore|refactor)[!:(]", body[0]) @lint_rule("History must be linear, no merge commits")def no_merge(body):    return not body[0].startswith("Merge ") @lint_rule("Subject line should be shorter than 72 characters")def line_too_long(body):    revert = re.search(r"^Revert \"(.*)\"|^Reapply \"(.*)\"", body[0])    return revert or len(body[0]) <= 72 @lint_rule(    "Prefix should not include file extension (use `vo_gpu: ...` not `vo_gpu.c: ...`)",)def no_file_exts(body):    return not re.search(r"[a-z0-9]\.([chm]|cpp|swift|rst): ", body[0]) ################################################################################ if __name__ == "__main__":    commit_range = get_commit_range()    if commit_range is None:        exit(0)    print("Commit range:", commit_range)    any_failed = do_lint(commit_range)    exit(1 if any_failed else 0)