Rails 4 - App works locally, but not on Heroku

Question

In my app, I'm using the cocoon gem to dynamically add/remove nested form fields. The problem I am experiencing is that it works perfectly in my development environment, but when I push to Heroku, that piece of functionality doesn't work. To clarify what I mean, the link to add a form field simply doesn't do anything.

<%= link_to_add_association "Add URL", f, :mozs %>

Now, I am making the assumption that since it works locally, that my code is correct and nothing is wrong there. What I would like to know is why might I experience this issue between dev and production? What could be different between the two environments that might cause this?

I know Heroku uses the rails_12factor gem, which I have set to use in production. Could this be a potential conflict with the cocoon gem that I am using?

(Note: I'm not sure what other useful information I can provide. Please let me know if there is anything else that would be useful for me to include.)

Answer 1

Don't forget rake assets:precompile. In the case of rake aborting from invalid css, check the bootstrap_and_overrides.css for any added less code. I've noticed that generating this from the twitter-bootstrap-rails gem has in the past done this to me.