Code button in the demo not working properly

[tompazourek]

Hi Guardian team!

Using Chrome 51 on Windows.

When I try your current demo, the Code button is not working correctly. It is like the editor did't recognize that some text was already wrapped in <code>, so it keeps wrapping it over and over instead of removing the code formatting after second click.

How to reproduce:

1. Open the demo
2. Select the word World
3. Press Code button
4. Press Code button again

Expected: The selected word would be wrapped in <code> and then unwrapped.
Actual: The selected word is wrapped twice (<code><code>World</code></code>)

[danburzo]

I believe this is a bug with https://github.com/guardian/scribe-plugin-code-command/, specifically that the queryState does not return the correct value in Chrome. Seems like https://github.com/guardian/scribe-plugin-code-command/blob/master/src/scribe-plugin-code-command.js#L42 should read this._nodeName instead.

[shaundillon]

@tompazourek, I'm looking in to this now. @danburzo, your assertion that this._nodeName contains the correct value is right, but node.nodeName is still returning the original ancestor node, not the new <code> node, leading to the same problem.