bot.yml

# This workflow must be kept in sync to some extent with bot-proxy.yml
name: GitHub Bot

on:
  # Watch for changes on PR state, assignees, labels, head branch and draft/ready status
  pull_request_target:
    types:
      - assigned
      - unassigned
      - labeled
      - unlabeled
      - opened
      - reopened
      - synchronize # PR head updated
      - converted_to_draft
      - ready_for_review

  # Watch for changes on PR reviews
  pull_request_review:
    types: [submitted, edited, dismissed]

  # Watch for changes on PR comment
  issue_comment:
    types: [created, edited, deleted]

  # Manual run from GitHub Actions interface
  workflow_dispatch:
    inputs:
      pull-request-list:
        description: "PR(s) to process: specify 'all' or a comma separated list of PR numbers, e.g. '42,1337,7890'"
        required: true
        default: all
        type: string

jobs:
  # This job creates a matrix of PR numbers based on the inputs from the various
  # events that can trigger this workflow so that the process-pr job below can
  # handle the parallel processing of the pull-requests
  define-prs-matrix:
    name: Define PRs matrix
    # Skip this workflow if:
    #   - the bot is retriggering itself
    #   - the event is emitted by codecov
    #   - the event is a review on a pull request from a fork (see save-pr-number job below)
    if: |
      github.actor != vars.GH_BOT_LOGIN &&
      github.actor != 'codecov[bot]' &&
      (github.event_name != 'pull_request_review' || github.event.pull_request.base.repo.full_name == github.event.pull_request.head.repo.full_name)
    runs-on: ubuntu-latest
    permissions:
      pull-requests: read
    outputs:
      pr-numbers: ${{ steps.pr-numbers.outputs.pr-numbers }}

    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Install Go
        uses: actions/setup-go@v5
        with:
          go-version-file: contribs/github-bot/go.mod

      - name: Generate matrix from event
        id: pr-numbers
        working-directory: contribs/github-bot
        env:
          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: go run . matrix -matrix-key 'pr-numbers' -verbose

  # This job is executed if an event with read-only permission has triggered this
  # workflow (e.g 'pull_request_review' on a pull request opened from a fork).
  # In this case, this job persists the PR number in an artifact so that the
  # proxy workflow can use it to rerun the current workflow with write permission.
  # See bot-proxy.yml for more info.
  save-pr-number:
    name: Persist PR number for proxy
    # Run this job if the event is a review on a pull request opened from a fork
    if: github.event_name == 'pull_request_review' && github.event.pull_request.base.repo.full_name != github.event.pull_request.head.repo.full_name
    runs-on: ubuntu-latest

    steps:
      - name: Write PR number to a file
        env:
          PR_NUMBER: ${{ github.event.pull_request.number }}
        run: echo $PR_NUMBER > pr-number

      - name: Upload it as an artifact
        uses: actions/upload-artifact@v4
        with:
          name: pr-number
          path: pr-number

  # This job processes each pull request in the matrix individually while ensuring
  # that a same PR cannot be processed concurrently by mutliple runners
  process-pr:
    name: Process PR
    needs: define-prs-matrix
    # Just skip this job if PR numbers matrix is empty (prevent failed state)
    if: needs.define-prs-matrix.outputs.pr-numbers != '[]' && needs.define-prs-matrix.outputs.pr-numbers != ''
    runs-on: ubuntu-latest
    strategy:
      matrix:
        # Run one job for each PR to process
        pr-number: ${{ fromJSON(needs.define-prs-matrix.outputs.pr-numbers) }}
    concurrency:
      # Prevent running concurrent jobs for a given PR number
      group: ${{ matrix.pr-number }}

    steps:
      - name: Checkout code
        uses: actions/checkout@v4

      - name: Install Go
        uses: actions/setup-go@v5
        with:
          go-version-file: contribs/github-bot/go.mod

      - name: Run GitHub Bot
        working-directory: contribs/github-bot
        env:
          GITHUB_TOKEN: ${{ secrets.GH_BOT_PAT }}
        run: go run . check -pr-numbers '${{ matrix.pr-number }}' -verbose