create-replacement-pr.yml

name: Create replacement pull request
run-name: "Replace PR #${{ inputs.pull_request }}"

concurrency:
  group: ${{ github.workflow }}-${{ github.event.inputs.pull_request }}-${{ github.event.inputs.upload }}
  cancel-in-progress: ${{ !fromJson(github.event.inputs.upload) }}

on:
  workflow_dispatch:
    inputs:
      pull_request:
        description: Pull request number
        required: true
      autosquash:
        description: "Squash pull request commits according to Homebrew style? (default: true)"
        type: boolean
        required: false
        default: true
      upload:
        description: >
          Upload bottles built from original pull request? (default: false)
          Warning: This destroys status check information when used with autosquash!
        type: boolean
        required: false
        default: false
      warn_on_upload_failure:
        description: "Pass `--warn-on-upload-failure` to `brew pr-pull`? (default: false)"
        type: boolean
        required: false
        default: false
      message:
        description: "Message to include when autosquashing revision bumps, deletions, and rebuilds (requires autosquash)"
        required: false

env:
  PR: ${{ inputs.pull_request }}
  GNUPGHOME: /tmp/gnupghome
  HOMEBREW_DEVELOPER: 1
  HOMEBREW_NO_AUTO_UPDATE: 1
  HOMEBREW_NO_INSTALL_FROM_API: 1
  GH_REPO: ${{ github.repository }}
  GH_NO_UPDATE_NOTIFIER: 1
  GH_PROMPT_DISABLED: 1
  RUN_URL: ${{ github.event.repository.html_url }}/actions/runs/${{ github.run_id }}
  REPLACEMENT_BRANCH: PR/${{ inputs.pull_request }}

jobs:
  create:
    runs-on: ubuntu-latest
    container:
      image: ghcr.io/homebrew/ubuntu22.04:master
    permissions:
      contents: read
      pull-requests: write # for `post-comment`, `gh api`, `gh pr edit`
      repository-projects: write # for `gh pr edit`
    defaults:
      run:
        shell: bash
    steps:
      - name: Post comment once started
        uses: Homebrew/actions/post-comment@master
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          issue: ${{ env.PR }}
          body: ":shipit: @${{ github.actor }} has [requested creation of a replacement PR](${{ env.RUN_URL }})."
          bot_body: ":robot: An automated task has [requested creation of a replacement PR](${{ env.RUN_URL }})."
          bot: github-actions[bot]

      - name: Set up Homebrew
        id: set-up-homebrew
        uses: Homebrew/actions/setup-homebrew@master
        with:
          core: true
          cask: false
          test-bot: false

      - name: Get reviewers
        id: reviewers
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          review_data="$(
            gh api \
              --header 'Accept: application/vnd.github+json' \
              --header 'X-GitHub-Api-Version: 2022-11-28' \
              "repos/{owner}/{repo}/pulls/$PR/reviews"
          )"

          reviewers="$(jq --compact-output '[.[].user.login]' <<< "$review_data")"
          approved="$(jq --raw-output 'any(.[].state; .== "APPROVED")' <<< "$review_data")"

          # See https://github.com/octokit/octokit.net/issues/1763 for possible `mergeable_state` values.
          mergeable="$(
            gh api \
              --header 'Accept: application/vnd.github+json' \
              --header 'X-GitHub-Api-Version: 2022-11-28' \
              "repos/{owner}/{repo}/pulls/$PR" \
              --jq '(.mergeable_state == "clean") and (.draft | not)'
          )"

          {
            echo "reviewers=$reviewers"
            echo "approved=$approved"
            echo "mergeable=$mergeable"
          } >> "$GITHUB_OUTPUT"

      - name: Check approval if needed
        if: >
          inputs.upload &&
          !(fromJson(steps.reviewers.outputs.approved) && fromJson(steps.reviewers.outputs.mergeable))
        run: |
          echo "::error ::Refusing to upload bottles because PR #$PR is not mergeable!"
          exit 1

      - name: Configure Git user
        id: git-user-config
        uses: Homebrew/actions/git-user-config@master
        with:
          username: BrewTestBot

      - name: Checkout PR branch
        if: ${{ !inputs.autosquash }}
        working-directory: ${{steps.set-up-homebrew.outputs.repository-path}}
        env:
          GH_TOKEN: ${{secrets.GITHUB_TOKEN}}
        run: gh pr checkout "$PR"

      - name: Checkout replacement PR branch
        working-directory: ${{ steps.set-up-homebrew.outputs.repository-path }}
        env:
          START_POINT: ${{ inputs.autosquash && 'origin/master' || 'HEAD' }}
        run: |
          if git ls-remote --exit-code --heads origin "$REPLACEMENT_BRANCH"
          then
            echo "::error ::Branch $REPLACEMENT_BRANCH already exists!"
            exit 1
          fi
          git checkout -b "$REPLACEMENT_BRANCH" "$START_POINT"

      - name: Dismiss approvals
        if: fromJson(steps.reviewers.outputs.approved)
        uses: Homebrew/actions/dismiss-approvals@master
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          pr: ${{ env.PR }}
          message: Replacement PR dispatched

      - name: Set up commit signing
        uses: Homebrew/actions/setup-commit-signing@master
        with:
          signing_key: ${{ secrets.BREWTESTBOT_GPG_SIGNING_SUBKEY }}

      - name: Pull PR${{ inputs.upload && ' and upload bottles to GitHub Packages' || '' }}
        working-directory: ${{ steps.set-up-homebrew.outputs.repository-path }}
        env:
          BREWTESTBOT_NAME_EMAIL: "${{ steps.git-user-config.outputs.name }} <${{ steps.git-user-config.outputs.email }}>"
          HOMEBREW_GPG_PASSPHRASE: ${{ secrets.BREWTESTBOT_GPG_SIGNING_SUBKEY_PASSPHRASE }}
          HOMEBREW_GITHUB_API_TOKEN: ${{ secrets.HOMEBREW_CORE_PUBLIC_REPO_EMAIL_TOKEN }}
          HOMEBREW_GITHUB_PACKAGES_USER: brewtestbot
          HOMEBREW_GITHUB_PACKAGES_TOKEN: ${{ secrets.HOMEBREW_CORE_GITHUB_PACKAGES_TOKEN }}
          MESSAGE: ${{ inputs.message }}
        run: |
          # Don't quote arguments that might be empty; this causes errors.
          brew pr-pull \
            --debug \
            --branch-okay \
            --workflows=tests.yml \
            --committer="$BREWTESTBOT_NAME_EMAIL" \
            --root-url="https://ghcr.io/v2/homebrew/core" \
            ${{ inputs.autosquash && '--autosquash' || '--clean --no-cherry-pick' }} \
            ${{ !inputs.upload && '--no-upload' || '' }} \
            ${{ inputs.warn_on_upload_failure && '--warn-on-upload-failure' || '' }} \
            ${{ inputs.message && '--message="$MESSAGE"' || '' }} \
            "$PR"

      - name: Push commits
        uses: Homebrew/actions/git-try-push@master
        with:
          token: ${{ secrets.HOMEBREW_GITHUB_PUBLIC_REPO_TOKEN }}
          directory: ${{ steps.set-up-homebrew.outputs.repository-path }}
          branch: ${{ env.REPLACEMENT_BRANCH }}
        env:
          GIT_COMMITTER_NAME: ${{ steps.git-user-config.outputs.name }}
          GIT_COMMITTER_EMAIL: ${{ steps.git-user-config.outputs.email }}
          HOMEBREW_GPG_PASSPHRASE: ${{ secrets.BREWTESTBOT_GPG_SIGNING_SUBKEY_PASSPHRASE }}

      - name: Open replacement pull request
        id: create-pr
        working-directory: ${{ steps.set-up-homebrew.outputs.repository-path }}
        env:
          GH_TOKEN: ${{ secrets.HOMEBREW_GITHUB_PUBLIC_REPO_TOKEN }}
          REVIEWERS: ${{ join(fromJson(steps.reviewers.outputs.reviewers)) }}
          LABELS: ${{ inputs.upload && 'CI-published-bottle-commits' || '' }}
        run: |
          cat <<MESSAGE > body.txt
          Created by [\`create-replacement-pr.yml\`]($RUN_URL)

          -----

          Closes #$PR
          MESSAGE

          gh pr create \
            --base "$GITHUB_REF" \
            --title "Replacement for #$PR"\
            --body-file body.txt \
            --head "$REPLACEMENT_BRANCH" \
            --reviewer "$REVIEWERS" \
            --label "$LABELS"

          pull_number="$(gh pr list --head "$REPLACEMENT_BRANCH" --limit 1 --json number --jq '.[].number')"
          echo "pull_number=$pull_number" >> "$GITHUB_OUTPUT"

      - name: Approve replacement PR if applicable
        if: >
          fromJson(steps.reviewers.outputs.approved) &&
          fromJson(steps.reviewers.outputs.mergeable)
        working-directory: ${{ steps.set-up-homebrew.outputs.repository-path }}
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          REPLACEMENT_PR: ${{ steps.create-pr.outputs.pull_number }}
        run: gh pr review --approve "$REPLACEMENT_PR"

      - name: Enable automerge for replacement PR if applicable
        if: inputs.upload
        working-directory: ${{ steps.set-up-homebrew.outputs.repository-path }}
        env:
          GH_TOKEN: ${{ secrets.HOMEBREW_GITHUB_PUBLIC_REPO_TOKEN }}
          REPLACEMENT_PR: ${{ steps.create-pr.outputs.pull_number }}
        run: |
          gh pr merge "$REPLACEMENT_PR" \
            --auto \
            --merge \
            --delete-branch \
            --match-head-commit "$(git rev-parse HEAD)"

      - name: Label replaced PR
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: gh pr edit --add-label automerge-skip --add-label superseded "$PR"

      - name: Mark replaced PR as draft
        env: # We need a PAT here. https://github.com/github/docs/issues/8925#issuecomment-970255180
          GH_TOKEN: ${{ secrets.HOMEBREW_GITHUB_PUBLIC_REPO_TOKEN  }}
        run: gh pr ready --undo "$PR"

      - name: Post comment on success
        uses: Homebrew/actions/post-comment@master
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          issue: ${{ env.PR }}
          body: ":white_check_mark: @${{ github.actor }} replacement PR created at #${{ steps.create-pr.outputs.pull_number }}."
          bot_body: ":white_check_mark: Replacement PR created at #${{ steps.create-pr.outputs.pull_number }}."
          bot: github-actions[bot]

      - name: Post comment on failure
        if: ${{ !success() }}
        uses: Homebrew/actions/post-comment@master
        with:
          token: ${{ secrets.GITHUB_TOKEN }}
          issue: ${{ env.PR }}
          body: ":warning: @${{ github.actor }} replacement PR creation [failed](${{ env.RUN_URL }})."
          bot_body: ":warning: Replacement PR creation [failed](${{ env.RUN_URL }})."
          bot: github-actions[bot]