Parent controller path through recognize_path

parent_controller_path.rb

class ParentControllerPath
  SEGMENT = '/'

  attr_reader :path, :found

  class << self
    def routes
      Rails.application.routes
    end
  end

  def initialize(path)
    @uri = URI(path)
    @path = @uri.path

    names = path_to_controller_names

    last_name = names.last[:name]

    @found = names.reverse[1..-1].find do |v|
      v[:name] != last_name
    end
  end

  def generate(actions = nil, options = nil)
    ([@found[:path]] + Array(actions)).compact.join(ParentControllerPath::SEGMENT).tap do |s|
      uri = URI(s)

      if @uri.scheme && @uri.host
        uri.scheme = @uri.scheme
        uri.host = @uri.host
      end

      if options
        if options[:query]
          uri.query = "#{Rack::Utils.build_query(options[:query])}"
        end

        if options[:params]
          options[:params].each do |k, v|
            uri.send("#{k}=", v)
          end
        end
      end

      s.replace(uri.to_s)
    end
  end

  private

  def path_to_controller_names
    path_segments = @path.split(SEGMENT)

    (0..(path_segments.size - 1)).map do |i|
      path = path_segments[0..i].join(SEGMENT)

      {
        path: path,
        name: recognized_path(path)[:controller]
      }
    end
  end

  def recognized_path(path)
    rp = nil

    [:get, :post, :put, :patch].find do |method|
      begin
        rp = self.class.routes.recognize_path(path, method: method)
      rescue ActionController::RoutingError
      end
    end

    rp
  end
end

parent_controller_path_test.rb

# encoding: utf-8
require 'test_helper'

class ParentControllerPathTest < ActiveSupport::TestCase
  should 'find correct parent path' do
    assert_equal '', ParentControllerPath.new('/bookings').generate
    assert_equal '', ParentControllerPath.new('/bookings/1').generate
    assert_equal '/accommodations/1/cancellation', ParentControllerPath.new('/accommodations/1/cancellation/paypal/cancel').generate
    assert_equal '/accommodations/1/cancellation/success', ParentControllerPath.new('/accommodations/1/cancellation/paypal/cancel').generate('success')
    assert_equal '/accommodations/1/cancellation/payment/success', ParentControllerPath.new('/accommodations/1/cancellation/paypal/cancel').generate(['payment', 'success'])
  end

  should 'add options and params to parent path' do
    url = ParentControllerPath.
      new('http://9flats.com/accommodations/1/cancellation/paypal/cancel').
      generate(nil, query: {a: 2, b: 3}, params: {host: '9flats.ngrok.com'})
    assert_equal 'http://9flats.ngrok.com/accommodations/1/cancellation?a=2&b=3', url

    url = ParentControllerPath.
      new('http://9flats.com/accommodations/1/cancellation/heidelpay/callback').
      generate(nil, query: {a: 2, b: 3}, params: {host: '9flats.ngrok.com'})
    assert_equal 'http://9flats.ngrok.com/accommodations/1/cancellation?a=2&b=3', url

    url = ParentControllerPath.
      new('http://9flats.com/accommodations/1/cancellation/heidelpay/callback').
      generate(nil, query: {a: 2, b: 3})
    assert_equal 'http://9flats.com/accommodations/1/cancellation?a=2&b=3', url

    url = ParentControllerPath.
      new('http://9flats.com/accommodations/1/cancellation/heidelpay/callback').
      generate
    assert_equal 'http://9flats.com/accommodations/1/cancellation', url
  end

  should 'works with locale' do
    url = ParentControllerPath.
      new('http://9flats.com/de/accommodations/1/cancellation/heidelpay/callback').
      generate
    assert_equal 'http://9flats.com/de/accommodations/1/cancellation', url
  end
end