Proof-of-concept showing how to use GitHub's v4 GraphQL API to look up the pull request associated with an arbitrary commit

lookup-pull-request

#!/usr/bin/env python3

import os
import sys

import requests


def run_query(api_token, query):
    url = 'https://api.github.com/graphql'
    headers = {'Authorization': f'bearer {api_token}'}
    body = {'query': query}
    resp = requests.post(url, json=body, headers=headers)
    if resp.status_code != 200:
        raise Exception(f'Query failed: HTTP {resp.status_code}: {resp.content}')
    return resp.json()


def lookup_pull_requests(api_token, commit, limit):
    results = run_query(api_token, """
        {
          repository(name: "mono", owner: "buzzfeed") {
            commit: object(expression: "%(commit)s") {
              ... on Commit {
                associatedPullRequests(first:%(limit)d){
                  edges{
                    node{
                      number
                    }
                  }
                }
              }
            }
          }
        }
    """ % dict(commit=commit, limit=limit))

    return [
        edge['node']['number'] for edge in
        results['data']['repository']['commit']['associatedPullRequests']['edges']
    ]


def main(api_token, commit):
    pull_request = lookup_pull_requests(api_token, commit, 1)[0]
    print(pull_request)


if __name__ == '__main__':
    if len(sys.argv) < 2:
        print(f'Usage: {sys.argv[0]} COMMIT_HASH', file=sys.stderr)
        sys.exit(1)

    commit = sys.argv[1]
    api_token = os.environ.get('GITHUB_API_TOKEN')
    if not api_token:
        print('Error: GITHUB_API_TOKEN env var required', file=sys.stderr)
        sys.exit(1)

    main(api_token, commit)