generate strong params hash rule by real request hash

strong_params_generator.rb

def to_permit_rule(h)
  scalar = []
  complex = {}
  h.each do |k,v|
    if v.is_a? Array
      complex[k.to_sym] = []
    elsif v.is_a? Hash
      if v.keys.all?{|vk| vk =~ /\A\d+\z/ }
        complex[k.to_sym] = to_permit_rule(v.values.first)
      else
        complex[k.to_sym] = to_permit_rule(v)
      end
    else
      scalar << k.to_sym
    end
  end
  scalar.delete(:_destroy)
  scalar.sort!
  if !complex.empty? && scalar.empty?
    complex
  elsif !complex.empty? && !scalar.empty?
    scalar << complex
  else
    scalar
  end
end

require 'pp'

#pp to_permit_rule(h)


pp to_permit_rule(post: {title: 'tt', author: 'au', comments: {
  '0' => {comment: 'C1', id: 1},
  '1' => {comment: 'C2', id: 1},
}})