pr-review-companion.yml

name: PR Review Companion

on:
  pull_request_target:

permissions:
  # Post comment in pull request.
  pull-requests: write

concurrency:
  group: pr-review-companion-${{ github.event.pull_request.number }}
  cancel-in-progress: true

jobs:
  diff:
    runs-on: ubuntu-latest

    env:
      PR_NUMBER: ${{ github.event.pull_request.number }}

    steps:
      - name: Checkout
        uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
        with:
          persist-credentials: false

      - name: Setup Node.js
        uses: actions/setup-node@53b83947a5a98c8d113130e565377fae1a50d02f # v6.3.0
        with:
          node-version-file: ".nvmrc"
          package-manager-cache: false

      - name: Install
        run: npm ci

      - name: Diff (by change)
        run: npm run diff:flat -- $PR_NUMBER
        env:
          FORCE_COLOR: 3

      - name: Diff (by change, mirroring applied)
        run: npm run diff:flat -- $PR_NUMBER --mirror
        env:
          FORCE_COLOR: 3

      - name: Diff (by feature)
        run: npm run diff:flat -- $PR_NUMBER --no-group
        env:
          FORCE_COLOR: 3

      - name: Diff (by feature, mirroring applied)
        run: npm run diff:flat -- $PR_NUMBER --no-group --mirror
        env:
          FORCE_COLOR: 3

      - name: Determine job url
        id: job
        run: |
          job_id=$(gh api repos/${{ github.repository }}/actions/runs/${{ github.run_id }}/jobs --jq '.jobs[0].id')
          echo "JOB_URL=https://github.com/${{ github.repository }}/actions/runs/${{ github.run_id }}/job/${job_id}?pr=$PR_NUMBER" >> "$GITHUB_OUTPUT"
        env:
          GITHUB_TOKEN: ${{ github.token }}

      - name: Post message in PR
        run: |
          AUTHOR="github-actions"
          MARKER="<!-- pr-review-companion -->"
          BODY="${MARKER}

          ${COMMENT}"

          COMMENT_ID=$(gh pr view "$PR_NUMBER" --repo "${{ github.repository }}" --comments --json comments \
            --jq ".comments | sort_by(.createdAt) | map(select(.author.login == \"$AUTHOR\" and (.body | contains(\"$MARKER\")))) | .[0].id")
          if [ -n "$COMMENT_ID" ]; then
            gh api graphql -f query='
                mutation($id:ID!, $body:String!) {
                  updateIssueComment(input:{id:$id, body:$body}) {
                    issueComment {
                      id
                    }
                  }
                }' -f id="$COMMENT_ID" -f body="$BODY"
          else
            gh pr comment "$PR_NUMBER" --repo "${{ github.repository }}" --body "$BODY"
          fi
        env:
          COMMENT: |
            _Tip_: Review these changes [grouped by change][1] (recommended for most PRs), or [grouped by feature][2] (for large PRs).

            [1]: ${{ steps.job.outputs.JOB_URL }}#step:5:1
            [2]: ${{ steps.job.outputs.JOB_URL }}#step:7:1
          GITHUB_TOKEN: ${{ github.token }}