module ActionController::Helpers::ClassMethods

def all_helpers_from_path(path)

# => ["application", "chart", "rubygems"]
ActionController::Base.all_helpers_from_path 'app/helpers'

Returns a list of helper names in a given path. 
def all_helpers_from_path(path)
  helpers = Array(path).flat_map do |_path|
    names = Dir["#{_path}/**/*_helper.rb"].map { |file| file[_path.to_s.size + 1..-"_helper.rb".size - 1] }
    names.sort!
  end
  helpers.uniq!
  helpers
end