validate method

@override ValidationResult<String> validate(String key, covariant String input)

Performs type coercion against an input value, and returns a list of errors if the validation was unsuccessful.

Implementation

@override
ValidationResult<String> validate(String key, String input) {
  if (!values.any((v) => v.name == input)) {
    //if (input == null) {
    //  return new ValidationResult<String>._failure(
    //      ['The enum "$name" does not accept null values.']);
    //}

    return ValidationResult<String>._failure(
        ['"$input" is not a valid value for the enum "$name".']);
  }

  return ValidationResult<String>._ok(input);
}