Extract creation of form into a formHandler

Gemfile

@@ -21,6 +21,7 @@ gem "bootsnap", ">= 1.4.4", require: false
 gem "govuk-components"
 gem "govuk_design_system_formbuilder"
 gem "hotwire-rails"
+gem "singleton"
 
 group :development, :test do
   # Call 'byebug' anywhere in the code to stop execution and get a debugger console

Gemfile.lock

@@ -287,6 +287,7 @@ GEM
       simplecov_json_formatter (~> 0.1)
     simplecov-html (0.12.3)
     simplecov_json_formatter (0.1.3)
+    singleton (0.1.1)
     sprockets (4.0.2)
       concurrent-ruby (~> 1.0)
       rack (> 1, < 3)
@@ -355,6 +356,7 @@ DEPENDENCIES
   scss_lint-govuk
   selenium-webdriver
   simplecov
+  singleton
   tzinfo-data
   web-console (>= 4.1.0)
   webpacker (~> 5.0)

app/controllers/case_logs_controller.rb

@@ -1,6 +1,7 @@
 class CaseLogsController < ApplicationController
   skip_before_action :verify_authenticity_token, if: :json_create_request?
   before_action :authenticate, if: :json_create_request?
+  @@form_handler = FormHandler.instance
 
   def index
     @submitted_case_logs = CaseLog.where(status: 1)
@@ -56,7 +57,7 @@ class CaseLogsController < ApplicationController
     render "form/check_answers", locals: { case_log: @case_log, subsection: subsection, form: form }
   end
 
-  form = ENV["RAILS_ENV"] == "test" ? Form.new("test", "form") : Form.new(2021, 2022)
+  form = ENV["RAILS_ENV"] == "test" ? @@form_handler.get_form("test_form") : @@form_handler.get_form("2021_2022")
   form.all_pages.map do |page_key, page_info|
     define_method(page_key) do |_errors = {}|
       @case_log = CaseLog.find(params[:case_log_id])
@@ -95,6 +96,6 @@ private
   end 
   
   def use_form
-    ENV["RAILS_ENV"] == "test" ? Form.new("test", "form") : Form.new(2021, 2022)
+    ENV["RAILS_ENV"] == "test" ? @@form_handler.get_form("test_form") : @@form_handler.get_form("2021_2022")
   end
 end

app/models/form.rb

@@ -1,10 +1,11 @@
 class Form
   attr_reader :form_definition
 
-  def initialize(start_year, end_year)
+  def initialize(filename)
-    form_json = "config/forms/#{start_year}_#{end_year}.json"
+    form_json = "config/forms/#{filename}.json"
     raise "No form definition file exists for given year".freeze unless File.exist?(form_json)
 
+
     @form_definition = JSON.parse(File.open(form_json).read)
   end
 

app/models/form_handler.rb

@@ -0,0 +1,22 @@
+class FormHandler
+  include Singleton
+
+  def initialize
+    @forms = {}
+  end
+
+  def get_form(form)
+    # binding.pry
+    @forms[form] ||= Form.new(form)
+  end
+
+  def get_all_forms
+    Dir.foreach("config/forms") do |filename|
+      next if (filename == ".") || (filename == "..")
+
+      form_name = filename.sub(".json", "")
+      @forms[form_name] = Form.new(form_name)
+    end
+    @forms
+  end
+end

config/routes.rb

@@ -5,7 +5,8 @@ Rails.application.routes.draw do
 
   post "/case_logs/:id", to: "case_logs#submit_form"
 
-  form = ENV["RAILS_ENV"] == "test" ? Form.new("test", "form") : Form.new(2021, 2022)
+  form_handler = FormHandler.instance
+  form = ENV["RAILS_ENV"] == "test" ? form_handler.get_form("test_form") : form_handler.get_form("2021_2022")
   resources :case_logs do
     form.all_pages.keys.map do |page|
       get page.to_s, to: "case_logs##{page}"

spec/helpers/check_answers_helper_spec.rb

@@ -16,7 +16,8 @@ RSpec.describe CheckAnswersHelper do
   let(:subsection) { "income_and_benefits" }
   let(:subsection_with_numeric_conditionals) { "household_characteristics" }
   let(:subsection_with_radio_conditionals) { "household_needs" }
-  let(:form) { Form.new("test", "form") }
+  form_handler = FormHandler.instance
+  let(:form) { form_handler.get_form("test_form") }
 
   describe "Get answered questions total" do
     it "returns 0 if no questions are answered" do

spec/helpers/conditional_questions_helper_spec.rb

@@ -1,7 +1,8 @@
 require "rails_helper"
 
 RSpec.describe ConditionalQuestionsHelper do
-  let(:form) { Form.new("test", "form") }
+  form_handler = FormHandler.instance
+  let(:form) { form_handler.get_form("test_form") }
   let(:page_key) { "armed_forces" }
   let(:page) { form.all_pages[page_key] }
 

spec/helpers/question_attribute_helper_spec.rb

@@ -1,7 +1,8 @@
 require "rails_helper"
 
 RSpec.describe QuestionAttributeHelper do
-  let(:form) { Form.new("test", "form") }
+  form_handler = FormHandler.instance
+  let(:form) { form_handler.get_form("test_form") }
   let(:questions) { form.questions_for_page("rent") }
 
   describe "html attributes" do

spec/helpers/tasklist_helper_spec.rb

@@ -3,7 +3,8 @@ require "rails_helper"
 RSpec.describe TasklistHelper do
   let!(:empty_case_log) { FactoryBot.create(:case_log) }
   let!(:case_log) { FactoryBot.create(:case_log, :in_progress) }
-  let(:form) { Form.new("test", "form") }
+  form_handler = FormHandler.instance
+  let(:form) { form_handler.get_form("test_form") }
 
   describe "get subsection status" do
     let(:section) { "income_and_benefits" }

spec/models/form_handler_spec.rb

@@ -0,0 +1,27 @@
+require "rails_helper"
+
+RSpec.describe FormHandler do
+  describe "Get all forms" do
+    it "should be able to load all the forms" do
+      form_handler = FormHandler.instance
+      all_forms = form_handler.get_all_forms
+      expect(all_forms.count).to be >= 1
+      expect(all_forms["2021_2022"]).to be_a(Form)
+    end
+  end
+
+  describe "Get specific form" do
+    it "should be able to load a specific form" do
+      form_handler = FormHandler.instance
+      form = form_handler.get_form("2021_2022")
+      expect(form).to be_a(Form)
+      expect(form.all_pages.count).to eq(43)
+    end
+  end
+
+  it "should only load the form once at boot time" do
+    form_handler = FormHandler.instance
+    expect(Form).not_to receive(:new).with("test_form")
+    expect(form_handler.get_form("test_form")).to be_a(Form)
+  end
+end

spec/models/form_spec.rb

@@ -1,7 +1,8 @@
 require "rails_helper"
 
 RSpec.describe Form, type: :model do
-  let(:form) { Form.new("test", "form") }
+  form_handler = FormHandler.instance
+  let(:form) { form_handler.get_form("test_form") }
 
   describe ".next_page" do
     let(:previous_page) { "tenant_age" }