Demonstrate testing OPTIONS requests for CORS

[eliotsykes]

Notes:

diff --git a/spec/api/events_api_spec.rb b/spec/api/events_api_spec.rb
index 7f1c1d0..3f4f2ef 100644
--- a/spec/api/events_api_spec.rb
+++ b/spec/api/events_api_spec.rb
@@ -1,15 +1,32 @@
 require 'rails_helper'

 RSpec.describe '/api/events' do
+  
+  context 'OPTIONS#preflight' do
+    it 'responds with CORS headers' do
+      options '/api/events/'
+      
+      expect(response).to have_http_status(:ok)
+      expect(response.headers['Access-Control-Allow-Headers']).to eq 'Content-Type'
+      # More like this expect(response.headers[...]).to eq ...
+      expect(response.body).to eq ''
+    end
+  end
+  
   context 'POST#create' do

     context 'with correct paramaters' do
-      xit 'creates a new event for the registered application' do
+      it 'creates a new event for the registered application' do
           user = create(:user)
           application = create(:application)
           params = { name: "the name of the event" }
+          headers = {
+            'Content-Type' => 'application/json',
+            'Accept' => 'application/json',
+            'Origin' => application.url
+          }

-          post '/api/events/', params.to_json
+          post '/api/events/', params.to_json, headers
           json = JSON.parse(response.body)

           expect(json).to eq("")
diff --git a/spec/controllers/api/events_controller_spec.rb b/spec/controllers/api/events_controller_spec.rb
index 345168b..cfb9d5f 100644
--- a/spec/controllers/api/events_controller_spec.rb
+++ b/spec/controllers/api/events_controller_spec.rb
@@ -3,7 +3,7 @@ require 'rails_helper'
 RSpec.describe API::EventsController, type: :controller do
   describe "OPTIONS#preflight" do
     it "returns status 200" do
-      get :preflight
+      process :preflight, 'OPTIONS'
       expect(response).to have_http_status(200)
       expect(response.headers["Access-Control-Allow-Headers"]).to eq("Content-Type")
     end
diff --git a/spec/support/request_helper.rb b/spec/support/request_helper.rb
new file mode 100644
index 0000000..d63928b
--- /dev/null
+++ b/spec/support/request_helper.rb
@@ -0,0 +1,14 @@
+module RequestHelper
+  # Add support for testing `options` requests in RSpec.
+  # See: https://github.com/rspec/rspec-rails/issues/925
+  def options(*args)
+    reset! unless integration_session
+    integration_session.__send__(:process, :options, *args).tap do
+      copy_session_variables!
+    end
+  end
+end
+
+RSpec.configure do |config|
+  config.include RequestHelper, type: :request
+end
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