serve frontend from rails through protected route

Procfile

@@ -0,0 +1,2 @@
+web: bundle exec rails s
+release: bundle exec rails db:migrate

app/controllers/application_controller.rb

@@ -1,7 +1,12 @@
 class ApplicationController < ActionController::API
   include Response
+  include ActionView::Layouts
 
   include ActionController::HttpAuthentication::Basic::ControllerMethods
   http_basic_authenticate_with name: ENV['BASIC_AUTH_USERNAME'],
                                password: ENV['BASIC_AUTH_PASSWORD']
+
+  def frontend_index_html
+    render file: 'protected_public/index.html'
+  end
 end

config/routes.rb

@@ -6,7 +6,12 @@ Rails.application.routes.draw do
         get 'cash'
       end
     end
-
   end
+
+  root to: 'application#frontend_index_html'
+
+  get '*path', to: 'application#frontend_index_html', constraints: lambda { |request|
+    !request.xhr? && request.format.html?
+  }
   # For details on the DSL available within this file, see http://guides.rubyonrails.org/routing.html
 end

package.json

@@ -1,4 +1,13 @@
 {
+  "engines": {
+    "node": "10.15.3",
+    "yarn": "1.15.2"
+  },
+  "scripts": {
+    "build": "yarn --cwd client install && yarn --cwd client build",
+    "deploy": "cp -a client/build/. protected_public/",
+    "heroku-postbuild": "yarn build && yarn deploy"
+  },
   "dependencies": {
     "react-router-dom": "^5.0.1"
   }