routes_with_constraints.rake

namespace :routes do
  desc 'Print out all defined routes in match order, with names, per constraint class. Target specific constraint class with CONSTRAINT=x. Target specific controller with CONTROLLER=x.'
  task :constrained => :environment do
    Rails.application.reload_routes!

    constraints_routes = Hash.new

    Rails.application.routes.routes.each do |route|
      group = (route.app.class == ActionDispatch::Routing::Mapper::Constraints ? route.app.constraints.to_s : 'No constraint class')
      constraints_routes[group] ||= []
      constraints_routes[group] << route
    end

    requested_constraint = ENV['CONSTRAINT']

    constraints_routes.each do |group, all_routes|
      if requested_constraint.nil? or group == requested_constraint
        puts "\n\nConstraint class : #{group}\n\n"

        if ENV['CONTROLLER']
          all_routes = all_routes.select{ |route| route.defaults[:controller] == ENV['CONTROLLER'] }
        end

        routes = all_routes.collect do |route|

          reqs = route.requirements.dup
          reqs[:to] = route.app unless route.app.class.name.to_s =~ /^ActionDispatch::Routing/
          reqs = reqs.empty? ? "" : reqs.inspect

          {:name => route.name.to_s, :verb => route.verb.to_s, :path => route.path, :reqs => reqs}
        end

        routes.reject! { |r| r[:path] =~ %r{/rails/info/properties} } # Skip the route if it's internal info route

        name_width = routes.map{ |r| r[:name].length }.max
        verb_width = routes.map{ |r| r[:verb].length }.max
        path_width = routes.map{ |r| r[:path].length }.max

        routes.each do |r|
          puts "#{r[:name].rjust(name_width)} #{r[:verb].ljust(verb_width)} #{r[:path].ljust(path_width)} #{r[:reqs]}"
        end
      end
    end
  end
end