title: CouchDB "[Circular]" when writing to an array
body: <p>In CouchDB, I am writing to an array and keep getting the message "[Circular]".  I am using Node.js to create the data to be written like this.</p>
  
  <p>Say I have an two email objects in the same document in CouchDB:</p>
  
  <pre><code>unverifiedEmail = [{"address":"john@example.com","dateAdded":"1389215329484"}]
  verifiedEmail = []
  </code></pre>
  
  <p>Now in Node.js I do this before writing.</p>
  
  <pre><code>var oldData = readFromCouchDb();
  var newData = oldData;
  newData.verifiedEmail.unshift(newData.unverifiedEmail[0]);
  writeToCouchDb(newData);
  </code></pre>
  
  <p>Then when I view the document in Futon I see this:</p>
  
  <pre><code>unverifiedEmail = [{"address":"john@example.com","dateAdded":"1389215329484"}]
  verifiedEmail = "[Circular]"
  </code></pre>
  
  <p>What's going on here?</p>