mark-metrics-stale.yml

name: Mark Metrics Comment Stale

# Runs on pull_request_target so it gets write permissions even for PRs
# from forks (the original placement under `pull_request` in
# build-package.yml silently lost write perms for fork PRs and 403'd).
#
# This workflow does NOT check out the PR's code — it only calls the
# GitHub API — so pull_request_target is safe here.

on:
  pull_request_target:
    types: [opened, synchronize, reopened]
    branches: [ "main" ]

permissions:
  pull-requests: write

jobs:
  mark-stale:
    runs-on: ubuntu-latest
    steps:
      - name: Mark metrics comment as stale
        uses: actions/github-script@v7
        with:
          github-token: ${{ secrets.GITHUB_TOKEN }}
          script: |
            const allComments = await github.paginate(github.rest.issues.listComments, {
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
              per_page: 100,
            });

            const existing = allComments.find(c => c.body &&
              (c.body.includes('<!-- build-metrics-report -->') || c.body.includes('<!-- binary-size-report -->')));

            if (!existing) {
              core.info('No existing metrics comment found, nothing to mark stale.');
              return;
            }

            // Skip if already marked stale
            if (existing.body.includes('<!-- build-metrics-stale -->')) {
              core.info('Comment is already marked stale.');
              return;
            }

            const staleBanner = '> :hourglass_flowing_sand: **Build in progress** — metrics below are from a previous commit and will update when the current build finishes.\n>\n<!-- build-metrics-stale -->\n\n';
            const updatedBody = staleBanner + existing.body;

            await github.rest.issues.updateComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              comment_id: existing.id,
              body: updatedBody,
            });
            core.info(`Marked comment ${existing.id} as stale.`);