Eagerly find all features gated by Flipper

[synth]

FlipperUI is great! However, in my case, I want to be able to flip features at an organizational level. So I need a UI to flip features that is baked into our existing site admin for each org.

I want to display a multi-select box for each available feature in the app. The feature list is a combination of deployment features as well as canary features. I don't want to burden developers with having to maintain a list or do migrations for each feature.

This could be done with a custom rubocop cop, but I found a simpler way to scan the entire app directory for Flipper.enabled? lines and parse an AST to get the first argument.

The entire scan takes 0.07s (and we have a fairly large app), so I can put this into a remote endpoint for dynamically populating the select box. It's only a site admin for a particular org, so its not frequently visited. Easy solution instead of building a cop or maintaining a file or redis set.

Here's the oneliner (broken out for readability):

Dir.glob('./app/**/*.rb').map{|f| 
  File.read(f).scan(/Flipper.enabled\?.*/)}.reject{|a| a.length == 0}.map{|d| d[0]}.map{|line| 
  Parser::CurrentRuby.parse(line).children.detect{|c| c.respond_to?(:type) && c.type == :sym}.children.first}