gate.yml

name: gate

# Sets the gate/gpu commit status of a pull request from the GPU gate
# results that scripts/gate.py records on a Mac and pushes to origin as
# refs/gmlx-gate/<tree>/<run>. It runs when the pull request is pushed,
# and test.yml calls it again when its test legs end. Pushing results
# alone starts no workflow, so after a push of results that comes later,
# refresh the status with:
#
#   gh workflow run gate.yml -f pr=<number>
#
# The results come from this repository's refs, never a fork's, and the
# decision is scripts/gate.py decide, which docs/internals/testing.md
# describes.

on:
  pull_request:
  workflow_call:
  workflow_dispatch:
    inputs:
      pr:
        description: The pull request whose gate/gpu status to refresh
        required: true

jobs:
  gate-status:
    runs-on: ubuntu-latest
    permissions:
      contents: read
      statuses: write
      pull-requests: read
    steps:
      - uses: actions/checkout@v6
        with:
          fetch-depth: 0
      - name: The pull request and its results
        id: pr
        env:
          GH_TOKEN: ${{ github.token }}
          GH_REPO: ${{ github.repository }}
          PR: ${{ inputs.pr || github.event.pull_request.number }}
        run: |
          gh api "repos/$GH_REPO/pulls/$PR" --jq '"head=\(.head.sha)", "base=\(.base.sha)", "repo=\(.head.repo.full_name)"' >> "$GITHUB_OUTPUT"
          git fetch --quiet origin "+refs/pull/$PR/head:refs/remotes/pr/head" "+refs/gmlx-gate/*:refs/gmlx-gate/*"
      - name: Decide
        env:
          HEAD_SHA: ${{ steps.pr.outputs.head }}
          BASE: ${{ steps.pr.outputs.base }}
        run: |
          python3 scripts/gate.py decide --head "$HEAD_SHA" --base "$BASE" | tee status.json
      - name: Post
        # A fork's token is read-only, so a fork pull request gets no status
        # and its required check blocks the merge.
        if: github.event_name == 'workflow_dispatch' || github.event.pull_request.head.repo.full_name == github.repository
        env:
          GH_TOKEN: ${{ github.token }}
          GH_REPO: ${{ github.repository }}
          HEAD_SHA: ${{ steps.pr.outputs.head }}
          HEAD_REPO: ${{ steps.pr.outputs.repo }}
          RUN_URL: ${{ github.server_url }}/${{ github.repository }}/actions/runs/${{ github.run_id }}
        run: |
          if [ "$HEAD_REPO" != "$GH_REPO" ]; then
            echo "::notice::$HEAD_REPO is a fork; no status posted"
            exit 0
          fi
          python3 - <<'EOF'
          import json, os, subprocess
          s = json.load(open("status.json"))
          subprocess.run(["gh", "api", f"repos/{os.environ['GH_REPO']}/statuses/{os.environ['HEAD_SHA']}",
                          "-f", f"state={s['state']}", "-f", f"context={s['context']}",
                          "-f", f"description={s['description']}", "-f", f"target_url={os.environ['RUN_URL']}"],
                         check=True, stdout=subprocess.DEVNULL)
          print(f"{s['context']}: {s['state']}, {s['description']}")
          EOF