date static method
📅 Date Validator (yyyy-mm-dd)
Implementation
static String? date(
String? value, {
String errorMsg = 'Enter a valid date (yyyy-mm-dd)',
}) {
if (value == null || value.isEmpty) return 'Date is required';
final regex = RegExp(r'^\d{4}-\d{2}-\d{2}$');
return regex.hasMatch(value) ? null : errorMsg;
}