code: function strictString(value, notSet) {
    if (Array.isArray(value)) return strictString(value[0], notSet)
    if (typeof value !== 'string') return notSet
  
    value = value.trim()
    return value === '' ? notSet : value
  }
docs: Yeoman's option parsing is not strict enough for our purposes. Don't allow empty strings, and take the first of "--name a --name b".