basic preview controller

app/controllers/action_prompt/previews_controller.rb

@@ -0,0 +1,11 @@
+class ActionPrompt::PreviewsController < ApplicationController
+  # Note: if we were to fully copy the mailer pattern, we would have
+  # a line like this:
+  # before_action :require_local!
+
+  def index
+  end
+
+  def show
+  end
+end

app/views/action_prompt/previews/index.html.erb

@@ -0,0 +1 @@
+<h1>Action Prompt Previews</h1>

app/views/action_prompt/previews/show.html.erb

@@ -0,0 +1 @@
+<h1>Action Prompt Preview</h1>

lib/action_prompt.rb

@@ -1,5 +1,6 @@
 require "action_prompt/version"
 require "action_prompt/engine"
+require "action_prompt/railtie"
 
 module ActionPrompt
   def self.render(template_name, locals: {})

lib/action_prompt/engine.rb

@@ -1,4 +1,5 @@
 module ActionPrompt
   class Engine < ::Rails::Engine
+    isolate_namespace ActionPrompt
   end
 end

lib/action_prompt/railtie.rb

@@ -0,0 +1,14 @@
+require "rails/application_controller"
+
+module ActionPrompt
+  class Railtie < Rails::Railtie
+    config.after_initialize do |app|
+      if Rails.env.development? || Rails.env.test?
+        app.routes.prepend do
+          get "/action_prompt/previews", to: "action_prompt/previews#index", internal: true
+          get "/action_prompt/preview/:prompt_id", to: "action_prompt/previews#show", internal: true
+        end
+      end
+    end
+  end
+end

test/controllers/action_prompt/preview_controllers_test.rb

@@ -0,0 +1,8 @@
+require "test_helper"
+
+class ActionPrompt::PreviewControllerTest < ActionDispatch::IntegrationTest
+  test "should get index" do
+    get "/action_prompt/previews"
+    assert_response :success
+  end
+end