nixpkgs/.github/workflows/merge-group.yml

name: Merge Group

on:
  merge_group:
  workflow_call:
    inputs:
      artifact-prefix:
        required: true
        type: string
      mergedSha:
        required: true
        type: string
      targetSha:
        required: true
        type: string

permissions: {}

jobs:
  prepare:
    runs-on: ubuntu-24.04-arm
    outputs:
      baseBranch: ${{ steps.prepare.outputs.base }}
      mergedSha: ${{ steps.prepare.outputs.mergedSha }}
      targetSha: ${{ steps.prepare.outputs.targetSha }}
      systems: ${{ steps.prepare.outputs.systems }}
    steps:
      - uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
        with:
          persist-credentials: false
          sparse-checkout: |
            ci/supportedSystems.json

      - id: prepare
        uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
        env:
          MERGED_SHA: ${{ inputs.mergedSha }}
          TARGET_SHA: ${{ inputs.targetSha }}
        with:
          script: |
            const { classify } = require('./ci/supportedBranches.js')
            const baseBranch = (
              context.payload.merge_group?.base_ref ??
              context.payload.pull_request.base.ref
            ).replace(/^refs\/heads\//, '')
            const baseClassification = classify(baseBranch)
            core.setOutput('base', baseClassification)
            core.info('base classification:', baseClassification)

            core.setOutput('mergedSha', context.payload.merge_group?.head_sha ?? process.env.MERGED_SHA)
            core.info(`mergedSha: ${context.payload.merge_group?.head_sha ?? process.env.MERGED_SHA}`)
            core.setOutput('targetSha', context.payload.merge_group?.base_sha ?? process.env.TARGET_SHA)
            core.info(`targetSha: ${context.payload.merge_group?.base_sha ?? process.env.TARGET_SHA}`)
            core.setOutput('systems', require('./ci/supportedSystems.json'))

  check:
    name: Check
    needs: [prepare]
    uses: ./.github/workflows/check.yml
    permissions:
      # cherry-picks; formality right now, but unused
      pull-requests: write
    secrets:
      CACHIX_AUTH_TOKEN_GHA: ${{ secrets.CACHIX_AUTH_TOKEN_GHA }}
    with:
      mergedSha: ${{ needs.prepare.outputs.mergedSha }}
      targetSha: ${{ needs.prepare.outputs.targetSha }}

  lint:
    name: Lint
    needs: [prepare]
    uses: ./.github/workflows/lint.yml
    secrets:
      CACHIX_AUTH_TOKEN_GHA: ${{ secrets.CACHIX_AUTH_TOKEN_GHA }}
    with:
      mergedSha: ${{ needs.prepare.outputs.mergedSha }}
      targetSha: ${{ needs.prepare.outputs.targetSha }}

  eval:
    name: Eval
    needs: [prepare]
    uses: ./.github/workflows/eval.yml
    # The eval workflow requests these permissions so we must explicitly allow them,
    # even though they are unused when working with the merge queue.
    permissions:
      # compare
      statuses: write
    secrets:
      CACHIX_AUTH_TOKEN_GHA: ${{ secrets.CACHIX_AUTH_TOKEN_GHA }}
    with:
      artifact-prefix: ${{ inputs.artifact-prefix }}
      mergedSha: ${{ needs.prepare.outputs.mergedSha }}
      targetSha: ${{ needs.prepare.outputs.targetSha }}
      systems: ${{ needs.prepare.outputs.systems }}

  build:
    name: Build
    needs: [prepare]
    uses: ./.github/workflows/build.yml
    secrets:
      CACHIX_AUTH_TOKEN_GHA: ${{ secrets.CACHIX_AUTH_TOKEN_GHA }}
    with:
      artifact-prefix: ${{ inputs.artifact-prefix }}
      baseBranch: ${{ needs.prepare.outputs.baseBranch }}
      mergedSha: ${{ needs.prepare.outputs.mergedSha }}
      targetSha: ${{ needs.prepare.outputs.targetSha }}

  # This job's only purpose is to create the target for the "Required Status Checks" branch ruleset.
  # It "needs" all the jobs that should block the Merge Queue.
  unlock:
    if: github.event_name != 'pull_request' && always()
    # Modify this list to add or remove jobs from required status checks.
    needs:
      - lint
      - eval
    runs-on: ubuntu-24.04-arm
    permissions:
      statuses: write
    steps:
      - uses: actions/github-script@ed597411d8f924073f98dfc5c65a23a2325f34cd # v8.0.0
        env:
          RESULTS: ${{ toJSON(needs.*.result) }}
        with:
          script: |
            const { serverUrl, repo, runId, payload } = context
            const target_url =
              `${serverUrl}/${repo.owner}/${repo.repo}/actions/runs/${runId}`
            await github.rest.repos.createCommitStatus({
              ...repo,
              sha: payload.merge_group.head_sha,
              // WARNING:
              // Do NOT change the name of this, otherwise the rule will not catch it anymore.
              // This would prevent all PRs from merging.
              context: 'no PR failures',
              state: JSON.parse(process.env.RESULTS).every(result => result == 'success') ? 'success' : 'error',
              target_url,
            })