validate method
Implementation
@override
ValidationResult validate(String phoneNumber, Country country) {
final pattern = countryPatterns[country.code];
if (pattern == null) {
// No pattern defined, skip validation
return const ValidationResult.valid();
}
final digitsOnly = phoneNumber.replaceAll(RegExp(r'\D'), '');
if (pattern.hasMatch(digitsOnly)) {
return const ValidationResult.valid();
}
return ValidationResult.invalid(
'Invalid phone number format for ${country.name}',
);
}