Add cors files and tests

Gemfile

@@ -41,3 +41,5 @@ end
 
 # Windows does not include zoneinfo files, so bundle the tzinfo-data gem
 gem 'tzinfo-data', platforms: %i[mingw mswin x64_mingw jruby]
+
+gem "rack-cors", "~> 1.1"

Gemfile.lock

@@ -122,6 +122,8 @@ GEM
     puma (4.3.1)
       nio4r (~> 2.0)
     rack (2.2.2)
+    rack-cors (1.1.1)
+      rack (>= 2.0.0)
     rack-proxy (0.6.5)
       rack
     rack-test (1.1.0)
@@ -255,6 +257,7 @@ DEPENDENCIES
   mdl_form!
   pg
   puma (~> 4.1)
+  rack-cors (~> 1.1)
   rails (~> 6.0.1)
   rspec-rails (= 4.0.0.beta3)
   rswag-api

config/initializers/cors.rb

+Rails.application.config.middleware.insert_before 0, Rack::Cors do
+    allow do
+      origins '*'
+      resource '/*', headers: :any, methods: :get
+    end
+   
+    allow do
+      origins 'localhost:3000', '127.0.0.1:3000', 'http://www.kuhn4sports.eu/test-cors/cors.html'
+      resource '/api/v1/*',
+        methods: %i(get post put patch delete options head)
+    end
+  end
\ No newline at end of file

spec/api_spec.rb

+# frozen_string_literal: true
+# file /spec/requests/api_spec.rb
+
+require 'swagger_helper'
+
+RSpec.describe 'Stand Alone API', type: :request do
+  fixtures :users
+  before { @user = users(:mando) }
+  path '/api/v1/users' do
+    get 'list all the users' do
+      produces 'abpplication/json'
+
+      response(200, 'successful') do
+        schema type: :object,
+            properties: {
+                data: { 
+                    type: :array,
+                    items: {
+                        type: :object, 
+                        properties: {
+                            id: { type: :string },
+                            type: { type: :string },
+                            attributes: { 
+                                type: :object, 
+                                properties: {
+                                    name: { type: :string },
+                                    email: { type: :string }
+                                },
+                                required: %w[name email]
+                            }
+                        },
+                        required: %w[id type attributes]
+                    }
+                }
+            }
+
+        run_test!
+      end
+    end
+  end
+
+  path '/api/v1/users/{id}' do
+    get 'show user' do
+      produces 'application/json'
+      parameter name: 'id', in: :path, type: :string
+
+      response 200, 'successful' do
+        schema type: :object,
+            properties: {
+                data: { 
+                    type: :object, 
+                    properties: {
+                        id: { type: :string },
+                        type: { type: :string },
+                        attributes: { 
+                            type: :object, 
+                            properties: {
+                                name: { type: :string },
+                                email: { type: :string }
+                            },
+                            required: %w[name email]
+                        }
+                    },
+                    required: %w[id type attributes]
+                }
+            }
+        let(:id) do
+          u = User.create!(name: 'Luke', email: 'luke@skywalker.net', password: '1234567', password_confirmation: '1234567')
+          u.id
+        end
+
+        run_test!
+      end
+    end
+  end
+end