name: Diff completeness check
on: pull_request

env:
  # Force colored output (see https://bixense.com/clicolors/ and https://force-color.org/)
  TERM: xterm-256color
  CLICOLOR: 1
  CLICOLOR_FORCE: 1

jobs:
  checkdiff:
    runs-on: ubuntu-slim
    steps:
      - name: Clone repo
        uses: actions/checkout@v6
        with:
          ref: ${{ github.event.pull_request.head.sha }}
      - name: Check diff
        shell: bash # Bash is the default, but specifying it explicitly enables `-o pipefail`.
        run: |
          MERGE_BASE=$(gh api "/repos/{owner}/{repo}/compare/$BASE_SHA...$HEAD_SHA" --jq '.merge_base_commit.sha')
          git fetch origin "$MERGE_BASE"
          contrib/checkdiff.bash "$MERGE_BASE" | sed -E 's/^/::warning::/'
        env:
          BASE_SHA: ${{ github.event.pull_request.base.sha }}
          HEAD_SHA: ${{ github.event.pull_request.head.sha }}
          GH_TOKEN: ${{ github.token }}