space-checker.yml

---
# Find bad spacing in modified text files
name: Space checker
on: [push, pull_request]
permissions: {}
env:
  MAIN_BRANCH: master
jobs:
  build:
    name: Space checker
    runs-on: ubuntu-latest
    steps:
      - name: Checkout Code
        uses: actions/checkout@v3
        with:
          fetch-depth: 0 # needed to get the full history
      - name: Fetch upstream
        run: |
          # Fetch the main upstream branch to find the common ancestor
          git config --global user.name "Nemo" # required on some servers
          git remote add upstream https://github.com/AliceO2Group/Run3Analysisvalidation.git || exit 1
          git fetch upstream ${{ env.MAIN_BRANCH }} || exit 1
      - name: Find bad spacing
        run: |
          # Find tabs and trailing whitespaces in modified text files and show where they are
          status_tab=0
          status_trail=0
          # Get the common ancestor of the current branch and the main upstream branch
          BASE_COMMIT=$(git merge-base HEAD upstream/${{ env.MAIN_BRANCH }})
          echo "Diffing against: $BASE_COMMIT"
          # loop over changed files
          for f in $(git diff --diff-filter d --name-only "$BASE_COMMIT"); do
            # ignore binary files
            file -bi "$f" | grep -q "charset=binary" && continue
            echo "Scanning file: $f"
            # find tabs
            if grep -q -P "\t" "$f"; then
              status_tab=1
              echo "::error::Found some tabs:"
              # print out where they are
              #grep -P -n "\t" "$f"
              awk 'i=index($0, "\t") {printf "%i (col. %i): %s\n", NR, i, $0}' "$f"
            fi
            # find trailing whitespaces
            if grep -q " $" "$f"; then
              status_trail=2
              echo "::error::Found some trailing whitespaces:"
              # print out where they are
              grep -n " $" "$f"
            fi
          done
          status=$((status_tab + status_trail))
          if [ "$status" -ne 0 ]; then
            # shellcheck disable=2028
            echo "::warning::Fix the errors in your editor (or with a command)
            Command tips:
            - Get list of files you changed: git diff --diff-filter d --name-only \$(git merge-base HEAD upstream/${{ env.MAIN_BRANCH }})
            - Replace each tab with two spaces: sed -i 's/\\t/  /g' <files>
            - Remove trailing whitespaces: sed -i 's/[[:space:]]*$//' <files>"
            echo "::warning::To avoid these errors, configure your editor to:
            - Emit spaces when the Tab key is pressed.
            - Display whitespace characters.
            - Replace tabs with spaces and remove trailing whitespaces when a file is saved."
          fi
          exit $status