Convert pylint output to simplified CodeClimate JSON suitable for Gitlab Code Quality checks

pylint_to_gitlab_codeclimate.py

import hashlib
import html
import json
import sys
from typing import Optional

from pylint.reporters import JSONReporter
from pylint.lint import Run

# map pylint categories to CodeClimate severity
PYLINT_CATEGORY_TO_SEVERITY = {
    "fatal": "blocker",
    "error": "critical",
    "warning": "major",
    "refactor": "minor",
    "convention": "minor",
}


class GitlabCodeClimateReporter(JSONReporter):
    """
    Custom pylint reporter to convert pylint messages into a reduced CodeClimate JSON report
    suitable for Gitlab's Code Quality. Only reports `description`, `fingerprint`, `severity`,
    `location`.

    See:
    1. https://docs.gitlab.com/ee/user/project/merge_requests/code_quality.html#implementing-a-custom-tool.
    2. https://github.com/PyCQA/pylint/blob/master/pylint/reporters/json_reporter.py
    """

    name = "gitlabcodeclimate"

    def display_messages(self, layout: Optional["Section"]) -> None:
        """
        Convert the pylint messages into a reduced CodeClimate report dictionary and dump as JSON.
        """
        codeclimate_dict = [
            {
                "description": html.escape(f"{msg.msg_id}: {msg.msg or ''}", quote=False),
                "severity": PYLINT_CATEGORY_TO_SEVERITY[msg.category],
                "location": {"path": msg.path, "lines": {"begin": msg.line}},
                "fingerprint": hashlib.sha1(
                    (msg.symbol + msg.path + str(msg.line)).encode()
                ).hexdigest(),
            }
            for msg in self.messages
        ]

        print(json.dumps(codeclimate_dict, indent=4), file=self.out)


if __name__ == "__main__":
    Run(sys.argv[1:], reporter=GitlabCodeClimateReporter())

Thanks for the reports and suggestions @nyue, @quanterium and @ahogen. pylint-gitlab indeed looks like the easiest option but for a lightweight option I've updated the gist so that it now works with Python 3.10 and pylint==2.12.2. As @nyue noted it's easiest now to just override display_messages because this commit makes it now assume messages contains a list of Message.