Custom error responses

Author: andrew

app/controllers/errors_controller.rb

@@ -0,0 +1,25 @@
+class ErrorsController < ApplicationController
+  def not_found
+    respond_to do |format|
+      format.html { render status: :not_found }
+      format.json { render json: { error: "not found" }, status: :not_found }
+      format.any { head :not_found }
+    end
+  end
+
+  def unprocessable
+    respond_to do |format|
+      format.html { render status: :unprocessable_entity }
+      format.json { render json: { error: "unprocessable" }, status: :unprocessable_entity }
+      format.any { head :unprocessable_entity }
+    end
+  end
+
+  def internal
+    respond_to do |format|
+      format.html { render status: :internal_server_error }
+      format.json { render json: { error: "internal server error" }, status: :internal_server_error }
+      format.any { head :internal_server_error }
+    end
+  end
+end

app/views/errors/internal.html.erb

@@ -0,0 +1,4 @@
+<div class="container-sm text-center">
+  <h2>Oops, We've had a problem at our end.</h2>
+  <p>Hopefully this a temporary setback.  Try again in a few moments.</p>
+</div>

app/views/errors/not_found.html.erb

@@ -0,0 +1,4 @@
+<div class="container-sm text-center">
+  <h2>We can't find whatever it was you were looking for.</h2>
+  <p>It may have been deleted, or might not even exist.</p>
+</div>

app/views/errors/unprocessable.html.erb

@@ -0,0 +1,4 @@
+<div class="container-sm text-center">
+  <h2>Unprocessable request</h2>
+  <p>Check your request parameters and try again.</p>
+</div>

config/application.rb

@@ -23,6 +23,7 @@ module Diff
   class Application < Rails::Application
     # Initialize configuration defaults for originally generated Rails version.
     config.load_defaults 7.0
+    config.exceptions_app = routes
 
     # Configuration for the application, engines, and railties goes here.
     #

config/routes.rb

@@ -24,5 +24,9 @@
 
   get '/diff', to: 'jobs#diff', as: :diff
 
+  get '/404', to: 'errors#not_found'
+  get '/422', to: 'errors#unprocessable'
+  get '/500', to: 'errors#internal'
+  
   root "home#index"
 end

public/404.html

@@ -0,0 +1,21 @@
+require 'test_helper'
+
+class ErrorsControllerTest < ActionDispatch::IntegrationTest
+  test 'renders 404' do
+    get '/404'
+    assert_response :not_found
+    assert_template 'errors/not_found'
+  end
+
+  test 'renders 422' do
+    get '/422'
+    assert_response :unprocessable_entity
+    assert_template 'errors/unprocessable'
+  end
+
+  test 'renders 500' do
+    get '/500'
+    assert_response :internal_server_error
+    assert_template 'errors/internal'
+  end
+end