api-check.yml

name: Public API Check

on:
  pull_request:
    branches:
      - master

concurrency:
  # Cancels pending runs when a PR gets updated.
  group: ${{ github.workflow }}-${{ github.head_ref || github.run_id }}
  cancel-in-progress: true

# The workflow may fail if we change the public API in a pull request.
# We allow fail on this action. But we should manually check if the changes are reasonable when we see a failed action.
# It would be good if the workflow returns a neutral status when we find API changes. But it is currently not
# possible with Github actions.
jobs:
  check-public-api-changes:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout mmtk-core
        uses: actions/checkout@v4
        with:
          # Full git history needed
          fetch-depth: 0

      # cargo-public-api needs a nightly toolchain installed in order to work.
      # It does not have to be the active toolchain.
      - name: Install nightly Rust toolchain
        run: rustup toolchain install nightly

      # Show the Rust toolchain we are actually using
      - run: rustup show
      - run: cargo --version
      - run: cargo +nightly --version

      - name: Install cargo-public-api
        run: cargo +nightly install cargo-public-api
      - name: API Diff
        run: cargo +nightly public-api diff origin/${GITHUB_BASE_REF}..${{ github.event.pull_request.head.sha }} --deny=all

  check-api-migration-update:
    needs: check-public-api-changes
    runs-on: ubuntu-latest
    if: ${{ always() && needs.check-public-api-changes.result == 'failure'}}
    env:
      MIGRATION_GUIDE_PATH: 'docs/userguide/src/migration/**'
    steps:
      # Check if migration guide is updated.
      - name: Get the update status for the migration guide.
        uses: tj-actions/changed-files@v44
        id: migration-guide-status
        with:
          files: ${{ env.MIGRATION_GUIDE_PATH }}
      # If the api check failed but the migration is not updated, we fail here
      - name: Report if the migration guide is not updated.
        if: ${{ steps.migration-guide-status.outputs.any_changed == 'false' }}
        uses: actions/github-script@v7
        with:
          script: |
            core.setFailed('Public API is changed, but the migration guide (${{ env.MIGRATION_GUIDE_PATH }}) is not updated. If the bindings need to be updated for the API change, the migration guide needs to be updated as well.')