Extend request helpers for rspec-rails request specs

Session-based API authentication requires the X-requested-with header to be present.
Since Integration tests of Rails do not offer adding a header to all requests as
Capybara or Rack::Test does, we simply extend the request helpers to do
so.

spec/support/request_with_header.rb

@@ -1,8 +1,55 @@
-RSpec.configure do |c|
-  c.before(:each, type: :request) do |ex|
-    header('X-Requested-With', 'XMLHttpRequest') unless ex.metadata[:skip_xhr_header]
+module APISessionAuthentication
+  def merge_with_header(args = {})
+    # Can't get example. in here
+    metadata = self.class.metadata
+    headers = args.fetch(:headers) { {} }
+
+    unless metadata[:skip_xhr_header]
+      headers.merge!('X-Requested-With' => 'XMLHttpRequest')
+    end
+
+    headers
+  end
+
+  def get(path, args = {})
+    args[:headers] = merge_with_header args
+    super
+  end
+
+  def post(path, args = {})
+    args[:headers] = merge_with_header args
+    super
+  end
+
+  def put(path, args = {})
+    args[:headers] = merge_with_header args
+    super
   end
 
+  def delete(path, args = {})
+    args[:headers] = merge_with_header args
+    super
+  end
+
+  def patch(path, args = {})
+    args[:headers] = merge_with_header args
+    super
+  end
+
+  def head(path, args = {})
+    args[:headers] = merge_with_header args
+    super
+  end
+end
+
+
+RSpec.configure do |c|
+  ##
+  # Session-based API authentication requires the X-requested-with header to be present.
+  # Since Integration tests of Rails do not offer adding a header to all requests as
+  # Capybara or Rack::Test does, we simply extend the request helpers to do so.
+  c.include APISessionAuthentication, type: :request
+
   c.before(:each, type: :feature) do |ex|
     unless ex.metadata[:skip_xhr_header] || ex.metadata[:js]
       page.driver.header('X-Requested-With', 'XMLHttpRequest')