title: webdriverio browser.execute returns null
body: <p>I have a meteor app and want to retrieve some data inside a unit test from the client via a headless browser from webdriver.io.</p>
  
  <p>The data I want is from this function: </p>
  
  <p><code>Session.get()</code> -> <a href="http://meteortips.com/first-meteor-tutorial/sessions/" rel="nofollow noreferrer">http://meteortips.com/first-meteor-tutorial/sessions/</a></p>
  
  <p>The headless browser I use is from below URL:</p>
  
  <p><a href="http://webdriver.io/" rel="nofollow noreferrer">http://webdriver.io/</a></p>
  
  <p>My test looks like this:</p>
  
  <pre><code>describe('[Check Boards]', () =&gt; {
    it('should exist', () =&gt; {
      const board = browser.execute('Session.get(\'currentBoard\')');
      ...
    }
  }
  </code></pre>
  
  <p>When i run this command <code>Session.get('currentBoard')</code> inside a real browser console, I get the board as expected. </p>
  
  <p>But when I run it from the code like described above inside a mocha test, I get this result:</p>
  
  <pre><code>{
    "state": "success",
    "sessionId": "12345",
    "hCode": 12345,
    "value": null,
    "class": "org.openqa.selenium.remote.Response",
    "_status": 0
  }
  </code></pre>
  
  <p>The value is null, but there should be the board.</p>