title: sails js model 'array' type validation and multiple select
body: <p>I'm adding a type validation for my model, example: </p>
  
  <pre><code>selectList: {
        type: 'array'
    }
  </code></pre>
  
  <p>The selectList input comes from HTML Form's Multiple Select.</p>
  
  <p><strong>Problem</strong>
  When user selects zero or one option only, in the case of zero, we get undefined/object type, in case of 1 selection we get 'string' type. Saving it to the selectList will fail.</p>
  
  <p>What is the best solution to handle this issue?
  <strong>Any ideas?</strong> using beforeValidation doesn't sound a good solution to me.</p>