A Python Script for checking Pull Request title conventions.

ci-check-pr-title-format.py

import sys
import re
from typing import Callable, List

VALID_PR_TAGS = {
    # this pr implements new features
    "Feature",
    # this pr fixes bugs
    "Bugfix",
    # this pr updates documentation
    "Doc",
    # this pr updates or implements ci, cd or devops related stuff
    "DevOps",
    # this pr adds or updates tests
    "Test",
    # this pr focuses on code refactor
    "Refactor",
    # this pr improves the performance
    "Perf",
    # this pr is a release
    "Release",
}

registered_checkers = []


def register(func: Callable) -> Callable:
    registered_checkers.append(func)
    return func


@register
def check_pr_tags(title: str) -> List[str]:
    """Make sure PR title has valid tags."""
    error_array = []

    if not title.startswith("[") and not title.startswith("Revert "):
        error_array.append(f"🚫 Pull Request title doesn't start with any tag: {title}")

    if title.endswith(" "):
        error_array.append(f"🚫 Pull Request title should not end with a space: {title}")

    if title.endswith("]"):
        error_array.append(
            f"🚫 Pull Request title should have content besides tags: {title}"
        )

    for x in title.split("]")[1:]:
        if x[0] != " ":
            error_array.append(f"🚫 No space found before: {x}")
        if x[1] == " ":
            error_array.append(f"🚫 Extra space found before: {x[2:]}")

    for tag in re.findall(r"\[([^]]+)]", title):
        if tag not in VALID_PR_TAGS:
            error_array.append(
                f"🚫 Pull Request title contains invalid tag: [{tag}], allowed tags are: {VALID_PR_TAGS}"
            )
    return error_array


@register
def check_pr_length(title: str) -> List[str]:
    """Make sure PR title is descriptive enough."""
    error_array = []

    if len(title) <= 34:
        error_array.append(
            f"🚫 Pull Request title is too short, please add more description (> 35 characters)!: {title}"
        )
    return error_array


@register
def check_invalid_chars(title: str) -> List[str]:
    """Make sure PR title has no invalid characters."""
    error_array = []

    if "`" in title:
        error_array.append(
            f"🚫 Pull Request title should not contain backquotes (`): {title}"
        )
    return error_array


def main(title) -> None:
    """Main function."""
    print(f"Checking your Pull Request title: {title}")

    errors = ""
    for checker in registered_checkers:
        if len(error_array := checker(title)) > 0:
            for error in error_array:
                errors += f"{error} \n"

    if errors != "":
        exit(errors)

    print("🎉 Your Pull Request looks good!")


if __name__ == "__main__":
    main(sys.argv[1])