I created a controller file by hand in Rubymine named businesses_controller.rb. While creating the file, I created it as a text file, and not a Ruby file. I also did not use any of the generators to create this controller.
Syntax highlighting did not work, so I deleted that file and recreated it using the controller generator. Unfortunately, the file still shows up as a text file, and since Rubymine does not recognize it as a Ruby file, autocompletion does not work for this controller either.
I tried Invalidating Caches, and Reloading from Disk but unfortunately that didn't work. I also removed the entire directory, and downloaded a fresh copy from our subversion project, and tried creating the controller again in a completely separate directory. But Rubymine still did not recognize it as a Ruby file.
Also tried creating a completely new project from scratch with a controller named businesses_controller.rb and it still showed up as a text file. I think this particular filename has been permanently cached somewhere as a non-Ruby file. Is there some other configuration that we are supposed to clear besides invalidating caches, or reloading from disk? Could this be a bug? My version of Rubymine is 3.1.1, Build RM# 103.260 running on OSX (Snow Leopard).