detect-conflicting-prs.yml

name: "Detect conflicting PRs"

on:
  workflow_dispatch:              # manually
  # So that PRs touching the same files as the push are updated
  push:
  # So that the `dirtyLabel` is removed if conflicts are resolved
  pull_request_target:            # - A pull request (even with conflicts)
    types:
      - synchronize               #   pushing more commits

permissions:
  # no checkouts/branching needed
  contents: none
  # need by "eps1lon/actions-label-merge-conflict" to manage PR label/comments
  pull-requests: write

# This allows a subsequently queued workflow run to interrupt/wait for previous runs
concurrency:
  group: '${{ github.workflow }}'
  cancel-in-progress: false  # true: interrupt, false = wait for

jobs:
  detect-prs:
    name: Detect
    if: ${{ github.actor != 'dependabot[bot]' }} # avoid dependabot PRs
    runs-on: ubuntu-latest
    steps:

      - name: Label conflicting PRs that are open
        id: pr-labeler
        uses: eps1lon/actions-label-merge-conflict@v3.0.2
        with:
          repoToken:  ${{ secrets.GITHUB_TOKEN }}
          retryAfter: 30 # seconds
          retryMax:   5  # atemps
          dirtyLabel: conflicts
          commentOnDirty: |
            Oh no 😟! Conflicts have been found.

            Please 🙏, take a moment and [address the merge conflicts](https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/addressing-merge-conflicts) of your pull request before we can evaluate it again.

            Thanks in advance for your effort and patience ❤️!
          continueOnMissingPermissions: true

      - name: Print outputs
        run: echo ${{ join(steps.pr-labeler.outputs.*, ',') }}

      - name: Set PRs outputs
        id: set-prs
        run: |
          echo "$INPUT_PRS"  \
            | jq --compact-output --raw-output 'to_entries | map({number: .key, dirty: .value})'  \
            | sed -e 's/^/prs=/'  \
            >> $GITHUB_OUTPUT
          echo "$INPUT_PRS"  \
            | jq --raw-output 'to_entries | length'  \
            | sed -e 's/^/prs-len=/'  \
            >> $GITHUB_OUTPUT
        env:
          INPUT_PRS: ${{ steps.pr-labeler.outputs.prDirtyStatuses }}

      - name: Write job summary
        run: |
          echo "### Pull Request statuses"  \
            >> $GITHUB_STEP_SUMMARY
          # render json array to a Markdown table with an optional "No records" message if empty
          echo "$INPUT_PRS"  \
            | jq --raw-output 'map("| [#\(.number)](\(env.GITHUB_PUBLIC_URL)/\(.number)) | \(if (.dirty) then "❌" else "✔️" end) |") | join("\n") | if (. == "") then "\nNo records.\n" else "\n| PR | Mergeable? |\n|---:|:----------:|\n\(.)\n" end'  \
            >> $GITHUB_STEP_SUMMARY
        env:
          GITHUB_PUBLIC_URL:   ${{ format('{0}/{1}/pull', github.server_url, github.repository) }}
          INPUT_PRS: ${{ steps.set-prs.outputs.prs }}