title: JSON-Schema draft-04 - OneOf with required
body: <p>I have an API route that validate the json schema before to handle the logic.</p>
  
  <p>This route can create 2 types of <strong>"articles"</strong> based on the JSON sent. I used OneOf to check if the schema correspond to one of this 2 types.</p>
  
  <pre><code>{
      "type": "object",
      "oneOf": [{
          "properties": {
              "name": {
                  "type": "string",
              },
              "description": {
                  "type": "string"
              }
          }
      }, {
          "properties": {
              "author": {
                  "type": "string",
              },
              "editor": {
                  "type": "string"
              }
          },
          "required":["author", "editor"]
      }]
  } 
  </code></pre>
  
  <hr>
  
  <ul>
  <li><p>So the first type can have a name and description, but this fields are not required.</p></li>
  <li><p>The second type required to have an <strong>author</strong> and <strong>editor</strong>.</p></li>
  </ul>
  
  <p>What happend if a JSON schema is sent with only <strong>author</strong> field? (<strong>editor</strong> is empty)</p>
  
  <p>Thanks for your responses.</p>