gstack/.github/workflows/version-gate.yml

name: Version Gate

# Every PR: under changelog_fragments a PR that touches no release file must
# still prove it carries a fragment (docs/ship-policy.md#changelog-fragments).
on:
  pull_request:
    branches: [main]

concurrency:
  group: version-gate-${{ github.event.pull_request.number }}
  cancel-in-progress: true

jobs:
  check:
    name: Check VERSION is not stale vs queue
    runs-on: ubuntu-24.04
    timeout-minutes: 10
    permissions:
      contents: read
      pull-requests: read
    steps:
      - name: Checkout PR head
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
        with:
          fetch-depth: 0
          # Blobless: full history with file contents fetched on demand; the
          # reads below fail loudly when a fetch fails (.github/scripts/history-read.sh).
          filter: blob:none
          ref: ${{ github.event.pull_request.head.sha }}
          # The head's release_tool runs inside the gate (lib/version-gate-train.ts);
          # no token may sit in the checkout it stages. The base fetch below is public.
          persist-credentials: false

      # The gate's own code comes from the PR's merge commit (github.sha): a PR
      # that edits the gate runs its edit, and an open PR picks up a gate fix
      # on main at its next pull_request event (reopen or push), not on a re-run.
      - name: Checkout gate code (merge commit)
        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7
        with:
          ref: ${{ github.sha }}
          path: .version-gate
          persist-credentials: false

      - name: Setup Bun
        uses: oven-sh/setup-bun@0c5077e51419868618aeaa5fe8019c62421857d6 # v2
        with:
          bun-version: 1.4.2

      - name: Read versions
        id: versions
        run: |
          set -euo pipefail
          PR_VERSION=$(cat VERSION | tr -d '[:space:]')
          BASE_REF="${{ github.event.pull_request.base.ref }}"
          for try in 1 2 3; do
            git fetch origin "$BASE_REF" --quiet && break
            if [ "$try" = 3 ]; then echo "::error::git fetch origin $BASE_REF failed 3 times ($(git --version)). Fix: see docs/troubleshooting.md#history-read-failed (HISTORY_READ_FAILED)"; exit 1; fi
            sleep $((try * 2))
          done
          BASE_VERSION=$(bash .version-gate/.github/scripts/history-read.sh "origin/$BASE_REF" VERSION --absent 0.0.0.0 | tr -d '[:space:]')
          {
            echo "pr_version=$PR_VERSION"
            echo "base_version=$BASE_VERSION"
            echo "base_ref=$BASE_REF"
          } >> "$GITHUB_OUTPUT"

      - name: Detect bump level
        id: bump
        run: |
          LEVEL=$(bun run scripts/detect-bump.ts "${{ steps.versions.outputs.base_version }}" "${{ steps.versions.outputs.pr_version }}")
          echo "level=$LEVEL" >> "$GITHUB_OUTPUT"

      - name: Query queue (util) — fail-open on error
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          set +e
          bun run bin/gstack-next-version \
            --base "${{ steps.versions.outputs.base_ref }}" \
            --bump "${{ steps.bump.outputs.level }}" \
            --current-version "${{ steps.versions.outputs.base_version }}" \
            --workspace-root null \
            --exclude-pr "${{ github.event.pull_request.number }}" \
            > next.json 2> next.err
          RC=$?
          if [ "$RC" != "0" ] || [ ! -s next.json ]; then
            echo '{"offline":true}' > next.json
            echo "::warning::util exit=$RC — failing open. stderr:"
            cat next.err || true
          fi

      - name: Compare PR VERSION to next free slot
        env:
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
          PR_VERSION: ${{ steps.versions.outputs.pr_version }}
          PR_AUTHOR: ${{ github.event.pull_request.user.login }}
          BASE_REF: ${{ steps.versions.outputs.base_ref }}
          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
        run: |
          if ! PR_CHANGED_FILES=$(gh api --paginate "repos/${{ github.repository }}/pulls/${{ github.event.pull_request.number }}/files" --jq '.[].filename'); then PR_CHANGED_FILES=""; fi
          export PR_CHANGED_FILES
          bun --no-env-file --config=/dev/null run .version-gate/scripts/compare-pr-version.ts next.json "${{ github.event.pull_request.number }}"