validateExtension method

String? validateExtension(
  1. List<String> allowedExtensions
)

Validates file extension.

Implementation

String? validateExtension(List<String> allowedExtensions) {
  final ext = path.split('.').last.toLowerCase();
  if (!allowedExtensions.contains(ext)) {
    return "Unsupported file extension: .\$ext.";
  }
  return null;
}