'undefined' inputs throw a deprecation warning from Validator.js

[chronosis]

If an input from a React component is returned to Winterfell with an undefined value. A deprecation warning is thrown.

validator deprecated you tried to validate an undefined but this library (validator.js) validates strings only. Please update your code as this will be an error soon. node_modules/winterfell/dist/lib/validation.js:70:27

The simplest fix would be to coerce the value to an empty string in /src/lib/validation.js. So that lines 36 and 37 change from this:

var validateAnswer = (value, validationItem, questionAnswers) => {
  var validationMethod = typeof extraValidators[validationItem.type] !== 'undefined'
                           ? extraValidators[validationItem.type]
                           : Validator.hasOwnProperty(validationItem.type)
                               && typeof Validator[validationItem.type] === 'function'
                               ? Validator[validationItem.type]
                               : undefined;

To this:

var validateAnswer = (value, validationItem, questionAnswers) => {
  value = (value === undefined) ? '' : value;
  var validationMethod = typeof extraValidators[validationItem.type] !== 'undefined'
                           ? extraValidators[validationItem.type]
                           : Validator.hasOwnProperty(validationItem.type)
                               && typeof Validator[validationItem.type] === 'function'
                               ? Validator[validationItem.type]
                               : undefined;

[andrewhathaway]

Yeah for sure. This entire set of logic is awful and should be split out ideally. Also, it's ideal to not use the built in validator if you're validating against other types, when using selects etc.

Happy to accept a PR for this, from anyone, or will keep it open until it's something I can look at!

Thanks!