Use MoneyHelper branded error pages

app/controllers/errors_controller.rb

@@ -0,0 +1,13 @@
+class ErrorsController < ApplicationController
+  def not_found
+    render status: :not_found
+  end
+
+  def internal_server_error
+    render status: :internal_server_error
+  end
+
+  def unprocessable_entity
+    render status: :unprocessable_entity
+  end
+end

app/views/errors/internal_server_error.html.erb

@@ -0,0 +1,12 @@
+<div class="l-constrained l-error">
+  <h1>We're sorry. Something seems to have gone wrong.</h1>
+  <p class="l-error__description">This is a problem at our end. Try again later and we will hope to have fixed it.</p>
+
+  <section class="l-error__useful-links">
+    <h2 class="l-error__useful-links-heading">Useful links</h2>
+    <ul class="l-error__list">
+      <li class="l-error__list-item"><a class="l-error__link" href="/">Return to the Retirement Advice Directory homepage</a></li>
+      <li class="l-error__list-item"><a class="l-error__link" href="https://www.moneyhelper.org.uk">Go to the MoneyHelper homepage</a></li>
+    </ul>
+  </section>
+</div>

app/views/errors/not_found.html.erb

@@ -0,0 +1,12 @@
+<div class="l-constrained l-error">
+  <h1>We're sorry. We can't find that page.</h1>
+  <p class="l-error__description">Please check the address you entered or try again later and you should be able to find it.</p>
+
+  <section class="l-error__useful-links">
+    <h2 class="l-error__useful-links-heading">Useful links</h2>
+    <ul class="l-error__list">
+      <li class="l-error__list-item"><a class="l-error__link" href="/">Return to the Retirement Advice Directory homepage</a></li>
+      <li class="l-error__list-item"><a class="l-error__link" href="https://www.moneyhelper.org.uk">Go to the MoneyHelper homepage</a></li>
+    </ul>
+  </section>
+</div>

app/views/errors/unprocessable_entity.html.erb

@@ -0,0 +1,12 @@
+<div class="l-constrained l-error">
+  <h1>We're sorry. We can't process that data.</h1>
+  <p class="l-error__description">You have entered data that we don't know what to do with, or that we can't process. Please go back and try again later.</p>
+
+  <section class="l-error__useful-links">
+    <h2 class="l-error__useful-links-heading">Useful links</h2>
+    <ul class="l-error__list">
+      <li class="l-error__list-item"><a class="l-error__link" href="/">Return to the Retirement Advice Directory homepage</a></li>
+      <li class="l-error__list-item"><a class="l-error__link" href="https://www.moneyhelper.org.uk">Go to the MoneyHelper homepage</a></li>
+    </ul>
+  </section>
+</div>

config/application.rb

@@ -10,6 +10,8 @@ module Rad
   class Application < Rails::Application
     config.load_defaults 5.1
 
+    config.exceptions_app = self.routes
+
     config.action_mailer.delivery_job = "ActionMailer::MailDeliveryJob"
 
     config.active_record.belongs_to_required_by_default = false

config/routes.rb

@@ -3,6 +3,10 @@
 Rails.application.routes.draw do
   devise_for :users
 
+  get '/404', to: 'errors#not_found'
+  get '/500', to: 'errors#internal_server_error'
+  get '/422', to: 'errors#unprocessable_entity'
+
   if Rails.env.staging?
     mount Lockup::Engine, at: '/lockup'
   end