I’ve been working with a developer who is putting together a Rails app to give other developers easy access to an in-browser Ruby development environment. You can <a href="http://rubyplex.com/">check it out here</a>.
One of the challenges we faced was how to test the Ace editor that users will enter their Ruby code into.
Here’s how we solved it:
This solution has been tested in Firefox 40.0.3 on Mac OS X.