title: Unit testing JSON Swift
body: <p>I am working on an iOS application written in Swift which parse a lot of  JSON files.
  The JSON structures are sophisticated and I would to test them before to map JSON to object.</p>
  
  <p>For example test if the key 'users' exists and for each user the structure('name', 'first', 'last').</p>
  
  <pre><code>{
    "users": [
      {
        "name": {
          "first": "emmi",
          "last": "wiita"
        }
      },
      {
        "name": {
          "first": "erdi",
          "last": "nielen"
        }
      },
      {
        "name": {
          "first": "daniel",
          "last": "beck"
        }
      }
   ]
  }
  </code></pre>
  
  <p>Are there any good way to do this?</p>
  
  <p>Thanks.</p>