autoformat.yml

name: Auto-format & Auto-fix

# On every push (master AND PR branches), run `cargo fmt` and
# `cargo clippy --fix`, then commit any changes back to the same branch.
# Skips itself on bot-authored commits to avoid infinite loops, and on
# commits that are already CI-clean. Forked-repo PRs aren't covered — the
# default token can't push to forks.
on:
  push:
    branches: ['**']

permissions:
  contents: write

# One run per branch at a time; a fix-commit superseding the triggering push
# cancels the now-stale run instead of racing it.
concurrency:
  group: autofix-${{ github.ref }}
  cancel-in-progress: true

jobs:
  autofix:
    # Skip when the previous commit was the bot itself (prevents loops) and
    # when the commit message contains [skip autofmt].
    if: |
      github.event.head_commit.author.email != 'noreply@github.com' &&
      !contains(github.event.head_commit.message, '[skip autofmt]') &&
      !contains(github.event.head_commit.message, 'chore(autofmt)')
    runs-on: blacksmith-4vcpu-ubuntu-2404
    steps:
      - uses: actions/checkout@v4
        with:
          # Need write access via the default token; fetch full history so we
          # can push the resulting commit cleanly.
          fetch-depth: 0
          token: ${{ secrets.GITHUB_TOKEN }}

      - name: Install nightly + stable toolchains
        run: |
          rustup toolchain install nightly --component rustfmt
          rustup toolchain install stable --component clippy

      - name: Install protoc
        run: sudo apt-get update && sudo apt-get install -y protobuf-compiler

      - uses: Swatinem/rust-cache@v2

      # rustfmt.toml uses nightly-only options — must invoke +nightly explicitly
      # so it matches the CI fmt-check job.
      - name: Run cargo fmt
        run: cargo +nightly fmt --all

      - name: Run cargo clippy --fix
        # --allow-dirty because fmt may have already produced uncommitted changes.
        # --allow-staged for the same reason in case any pre-stage runs.
        # Intentionally non-fatal: clippy autofixes are best-effort. If a fix
        # introduces a compile error, we revert and only push the fmt changes.
        run: |
          set +e
          cargo clippy --fix --all-targets --all-features --allow-dirty --allow-staged -- -D warnings
          rc=$?
          if [ $rc -ne 0 ]; then
            echo "clippy --fix failed (likely couldn't auto-fix every warning); reverting clippy hunks only"
            # Re-apply fmt result on top of HEAD without clippy's partial changes.
            git checkout -- .
            cargo +nightly fmt --all
          fi
          exit 0

      - name: Commit & push if changed
        run: |
          if [ -z "$(git status --porcelain)" ]; then
            echo "No formatting / clippy changes — nothing to push."
            exit 0
          fi
          git config user.name 'github-actions[bot]'
          git config user.email 'github-actions[bot]@users.noreply.github.com'
          git add -A
          git commit -m "chore(autofmt): apply cargo fmt + clippy --fix [skip autofmt]"
          git push origin "HEAD:${{ github.ref_name }}"