title: "TypeError: Cannot assign to read only property" when rendering Expressjs view
body: <p>I am building an app in node.js and encountered an error when I tried to send data from my server to my view:</p>
  
  <pre><code>module.exports = function (req, res) {
  
  var cookie = parseCookie.parseCookie(req.headers.cookie);
  
  user.returnUser(cookie, function(result) {
  
      var context = result[0].first_name;
      console.log(context); //console logs properly
      res.render('../views/home', context); //errors out at 'context'
  });
  };
  </code></pre>
  
  <p>The error returned is:</p>
  
  <pre><code>Unhandled rejection TypeError: Cannot assign to read only property '_locals' of Josh
  at ServerResponse.render (/Users/tinzors/Documents/portal/node_modules/express/lib/response.js:952:16)
  at /Users/tinzors/Documents/portal/controllers/home.js:27:7
  at /Users/tinzors/Documents/portal/methods/returnUser.js:8:5
  at tryCatcher (/Users/tinzors/Documents/portal/node_modules/knex/node_modules/bluebird/js/main/util.js:26:23)
  at Promise._settlePromiseFromHandler (/Users/tinzors/Documents/portal/node_modules/knex/node_modules/bluebird/js/main/promise.js:507:31)
  at Promise._settlePromiseAt (/Users/tinzors/Documents/portal/node_modules/knex/node_modules/bluebird/js/main/promise.js:581:18)
  at Promise._settlePromises (/Users/tinzors/Documents/portal/node_modules/knex/node_modules/bluebird/js/main/promise.js:697:14)
  at Async._drainQueue (/Users/tinzors/Documents/portal/node_modules/knex/node_modules/bluebird/js/main/async.js:123:16)
  at Async._drainQueues (/Users/tinzors/Documents/portal/node_modules/knex/node_modules/bluebird/js/main/async.js:133:10)
  at Immediate.Async.drainQueues [as _onImmediate] (/Users/tinzors/Documents/portal/node_modules/knex/node_modules/bluebird/js/main/async.js:15:14)
  at processImmediate [as _immediateCallback] (timers.js:374:17)
  </code></pre>
  
  <p>My view:</p>
  
  <pre><code>&lt;!DOCTYPE HTML&gt;
  &lt;html&gt;
  
  {{&gt; header}}
  &lt;script type="text/javascript" src="/js/home.js"&gt;&lt;/script&gt;
  
      &lt;div class="container"&gt;
        &lt;h1&gt;Welcome home, {{first_name}}.&lt;/h1&gt;
      &lt;/div&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>I'm not sure if it helps, but <code>user.returnUser</code> calls a method that returns data from a DB query.</p>
  
  <p>Can someone help?</p>
  
  <p>Thanks in advance!!</p>