check-milestone.yml

name: Milestone Reminder

on:
  pull_request:
    types: [closed]
    branches:
      - "master"

jobs:
  milestone-reminder:
    if: github.event.pull_request.merged == true
    name: Remind to set milestone
    runs-on: ubuntu-22.04
    timeout-minutes: 5
    permissions:
      pull-requests: write
      issues: read
    steps:
      - uses: actions/github-script@v6
        with:
          script: | # js
            const owner = context.repo.owner;
            const repo = context.repo.repo;

            const pullNumber = '${{ github.event.pull_request.number }}';

            // the github API doesn't expose linked issues, so we have to parse the body ourselves
            function getLinkedIssueId(pull) {
              // https://regexr.com/7mjnp
              const match = pull.data.body.match(/(\/issues\/|#)(\d+)/);
              return match && match?.[2];
            }

            function getMilestone(pullOrIssue) {
              // pull has pull.data.milestone, issue has issue.milestone
              return pullOrIssue?.data?.milestone || pullOrIssue?.milestone;
            }

            const pull = await github.rest.pulls.get({
              owner,
              repo,
              pull_number: pullNumber,
            });

            if (getMilestone(pull)) {
              console.log("Pull request has milestone", pull.data.milestone?.title);
              process.exit(0);
            }

            const issueId = getLinkedIssueId(pull);

            if (issueId) {
              console.log('linked issue found', issueId);

              const issue = await github.rest.issues.get({
                owner,
                repo,
                issue_number: issueId,
              });

              const milestone = getMilestone(issue);

              if (milestone) {
                console.log("Linked issue has milestone", milestone.title);
                process.exit(0);
              }
            }

            console.log("No milestone found");

            const author = pull.data.user.login;
            const guideLink = "https://www.notion.so/metabase/Metabase-Branching-Strategy-6eb577d5f61142aa960a626d6bbdfeb3?pvs=4#3dea255ffa3b4f74942a227844e889fa";
            const message = `@${author} Did you forget to add a milestone to the issue for this PR? _[When and where should I add a milestone?](${guideLink})_`;

            await github.rest.issues.createComment({
              owner,
              repo,
              issue_number: pullNumber,
              body: message,
            });