check-extension-case.yml

name: CheckExtensionCase

on:
  pull_request:
    branches: [ main ]

jobs:
  build:
    runs-on: ubuntu-latest

    steps:
      - uses: actions/checkout@v2
          
      - id: file_changes
        uses: trilom/file-changes-action@v1.2.4

      - name: test
        run: |
          FILES=${{steps.file_changes.outputs.files_added}}

          if [ ${#FILES} -ge 3 ];
          then
              IFS=", " read -a myarray <<< $FILES

              for filename in "${myarray[@]}" 
              do
                  fileExtension=$(echo $filename | sed 's/"//g' | sed 's/]//g' | grep -o '...$')
                  lowercaseFileExtension=$(echo "$fileExtension" | tr '[:upper:]' '[:lower:]')
                  if [ $lowercaseFileExtension == 'gif' ] || [ $lowercaseFileExtension == 'svg' ]
                  then
                      if ! [[ $fileExtension =~ ^[[:lower:]]+$ ]];
                      then
                          echo "Use lowercase file extensions"
                          exit 1
                      fi
                  fi
              done
          fi