check-size.yml

name: Check binary size

on:
  pull_request:
    types: [opened, reopened, synchronize, labeled, unlabeled, ready_for_review]

permissions:
  contents: read

jobs:
  check_size:
    runs-on: ubuntu-latest
    # Check if pull request does not have label "bloat-ok".
    if: "!contains(github.event.pull_request.labels.*.name, 'bloat-ok')"
    steps:
    - uses: actions/checkout@v4
      with:
        # Needed to rebase against the base branch
        fetch-depth: 0
        # Checkout pull request HEAD commit instead of merge commit
        ref: ${{ github.event.pull_request.head.sha }}
    - name: Configure git user details
      run: |
        git config --global user.email "checkpoint-restore@users.noreply.github.com"
        git config --global user.name "checkpoint-restore"
    - name: Configure base branch without switching current branch
      run: git fetch origin ${GITHUB_BASE_REF}:${GITHUB_BASE_REF}
    - name: Save PR context
      env:
        EVENT_JSON: ${{ toJSON(github.event) }}
      run: |
        mkdir -p artifacts
        printenv EVENT_JSON > artifacts/event.json
    - name: Compare binary size change across each commit
      id: size-check
      # Use the last non-merge commit from the base branch as the baseline
      run: |
        set +e
        OUTPUT=$(git rebase -v $(git rev-list --no-merges -n 1 ${GITHUB_BASE_REF})^ -x test/check-size.sh 2>&1)
        EXIT_CODE=$?
        echo "$OUTPUT"
        echo "$OUTPUT" > artifacts/output.txt
        echo "exit_code=${EXIT_CODE}" >> $GITHUB_OUTPUT
        exit $EXIT_CODE
    - name: Generate size check comment
      if: failure()
      run: |
        cat > artifacts/comment.md << 'EOF'
        ## Binary Size Check Failed

        The binary size increase exceeds the allowed threshold.

        ### Size Check Output
        ```
        EOF
        cat artifacts/output.txt >> artifacts/comment.md
        cat >> artifacts/comment.md << 'EOF'
        ```

        ### How to resolve

        If this size increase is expected and acceptable, a maintainer can add
        the `bloat-ok` label to this PR to bypass the size check.

        ---
        *Binary size check performed by CI*
        EOF
    - name: Upload size check results
      if: always()
      uses: actions/upload-artifact@v4
      with:
        name: size-check-results
        retention-days: 5
        path: artifacts/