Non-required rules give error on empty parameters

[asleire]

The following sample should pass:

const data = {
  title: 'This is a title'
}

const rules = {
  title: 'required|min:2',
  description: 'min:20',
}

validate(data, rules)

However the description rule gives an error { description: 'The description field must be at least 20 characters.' }