FormatCheck.yml

name: "FormatCheck"

# Parse phase of the format-check pipeline. Designed to run on
# `pull_request:` (no secrets, read-only `GITHUB_TOKEN` for fork PRs)
# so that PR-controlled content the formatter touches can never reach
# secrets. The check status this workflow emits is what branch
# protection should require.
#
# Companion: FormatCheckComment.yml runs on `workflow_run:` after this
# workflow finishes, downloads the artifact uploaded here, and posts /
# updates the format-suggestion comment. The comment workflow runs in the base
# repo's trusted context so it can use `FORMATPULLREQUEST_PAT` without
# exposing it to the parse phase.

on:
  workflow_call:
    inputs:
      directory:
        description: "The directory on which ITensorFormatter needs to be run"
        default: "."
        required: false
        type: string
      julia-version:
        description: "Julia version"
        default: "1"
        required: false
        type: string
      concurrent-jobs:
        description: "Run jobs concurrently"
        default: false
        required: false
        type: boolean
      cancel-in-progress:
        description: "Cancel jobs in-progress in favor of a new one in the same concurrency group"
        default: true
        required: false
        type: boolean

concurrency:
  # Key on the PR number so each PR has its own concurrency group;
  # falling back to `github.ref` for non-PR triggers.
  group: "${{ inputs.concurrent-jobs && github.run_id || github.event.pull_request.number || github.ref }}:${{ github.workflow }}"
  cancel-in-progress: ${{ !inputs.concurrent-jobs && inputs.cancel-in-progress }}

jobs:
  format-check:
    name: "FormatCheck"
    runs-on: ubuntu-latest
    permissions:
      contents: read

    steps:
      - name: "Check out PR head"
        uses: actions/checkout@v6
        with:
          repository: ${{ github.event.pull_request.head.repo.full_name }}
          ref: ${{ github.event.pull_request.head.sha }}
          fetch-depth: 0

      - name: "Setup Julia"
        uses: julia-actions/setup-julia@v3
        with:
          version: "${{ inputs.julia-version }}"
          arch: "x64"

      - uses: julia-actions/cache@v2

      - name: "Install ITensorFormatter"
        run: |
          julia -e '
            using Pkg
            Pkg.Registry.add("General")
            Pkg.Registry.add(; url = "https://github.com/ITensor/ITensorRegistry")
            Pkg.Apps.add("ITensorFormatter")
          '
          echo "$HOME/.julia/bin" >> $GITHUB_PATH

      - name: "Run ITensorFormatter"
        id: format
        env:
          DIRECTORY: ${{ inputs.directory }}
        run: |
          set +e
          echo "Formatter will run on: $DIRECTORY"
          itpkgfmt "$DIRECTORY"
          FORMAT_EXIT=$?
          if [ $FORMAT_EXIT -ne 0 ]; then
            : > diff.patch
            echo "exit_code=2" >> "$GITHUB_OUTPUT"
            exit 0
          fi
          # `git add -N .` makes new (untracked) files visible to `git diff`
          # so the diff captured below covers added files as well.
          git add -N .
          git diff > diff.patch
          if [ -s diff.patch ]; then
            echo "exit_code=1" >> "$GITHUB_OUTPUT"
          else
            echo "exit_code=0" >> "$GITHUB_OUTPUT"
          fi

      - name: "Save metadata for comment workflow"
        if: ${{ always() }}
        env:
          PR_NUMBER: ${{ github.event.pull_request.number }}
          PR_HEAD_SHA: ${{ github.event.pull_request.head.sha }}
          EXIT_CODE: ${{ steps.format.outputs.exit_code }}
        run: |
          {
            echo "pr_number=$PR_NUMBER"
            echo "pr_head_sha=$PR_HEAD_SHA"
            echo "exit_code=${EXIT_CODE:-2}"
          } > metadata.txt

      - name: "Upload artifact for comment workflow"
        if: ${{ always() }}
        uses: actions/upload-artifact@v7
        with:
          name: "format-check"
          path: |
            metadata.txt
            diff.patch
          if-no-files-found: ignore

      - name: "Propagate exit code"
        run: |
          # exit 0 -> already formatted; exit 1 -> formatting needed;
          # exit 2 -> formatter itself errored. The check status reflects
          # this directly so branch protection can require it.
          exit ${{ steps.format.outputs.exit_code }}