Simplify the way we explain how to test cookies in controller

features/controller_specs/cookies.feature

@@ -0,0 +1,36 @@
+Feature: Cookies
+
+  There are different ways to make assertions on cookies from controller specs,
+  but we recommend using the `cookies` method as set out below.
+
+  You can use strings or symbols to fetch or set your cookies because the `cookies`
+  method supports indifferent access.
+
+  Scenario: Testing cookie's value cleared in controller
+    Given a file named "spec/controllers/application_controller_spec.rb" with:
+      """ruby
+      require "rails_helper"
+
+      RSpec.describe ApplicationController, :type => :controller do
+        controller do
+          def clear_cookie
+            cookies.delete(:user_name)
+            head :ok
+          end
+        end
+
+        before do
+          routes.draw { get "clear_cookie" => "anonymous#clear_cookie" }
+        end
+
+        it "clear cookie's value 'user_name'" do
+          cookies[:user_name] = "Sam"
+
+          get :clear_cookie
+
+          expect(cookies[:user_name]).to eq nil
+        end
+      end
+      """
+    When I run `rspec spec`
+    Then the example should pass