File cleanup/organization in controllers/concerns (#27846)

spec/controllers/concerns/api/rate_limit_headers_spec.rb

@@ -0,0 +1,56 @@
+# frozen_string_literal: true
+
+require 'rails_helper'
+
+describe Api::RateLimitHeaders do
+  controller(ApplicationController) do
+    include Api::RateLimitHeaders
+
+    def show
+      head 200
+    end
+  end
+
+  before do
+    routes.draw { get 'show' => 'anonymous#show' }
+  end
+
+  describe 'rate limiting' do
+    context 'when throttling is off' do
+      before do
+        request.env['rack.attack.throttle_data'] = nil
+      end
+
+      it 'does not apply rate limiting' do
+        get 'show'
+
+        expect(response.headers['X-RateLimit-Limit']).to be_nil
+        expect(response.headers['X-RateLimit-Remaining']).to be_nil
+        expect(response.headers['X-RateLimit-Reset']).to be_nil
+      end
+    end
+
+    context 'when throttling is on' do
+      let(:start_time) { DateTime.new(2017, 1, 1, 12, 0, 0).utc }
+
+      before do
+        request.env['rack.attack.throttle_data'] = { 'throttle_authenticated_api' => { limit: 100, count: 20, period: 10 } }
+        travel_to start_time do
+          get 'show'
+        end
+      end
+
+      it 'applies rate limiting limit header' do
+        expect(response.headers['X-RateLimit-Limit']).to eq '100'
+      end
+
+      it 'applies rate limiting remaining header' do
+        expect(response.headers['X-RateLimit-Remaining']).to eq '80'
+      end
+
+      it 'applies rate limiting reset header' do
+        expect(response.headers['X-RateLimit-Reset']).to eq (start_time + 10.seconds).iso8601(6)
+      end
+    end
+  end
+end