Fix counting of pending AJAX requests

@rails/ujs uses native XHR rather than jQuery AJAX. Thus we add event
listeners to count pending Rails UJS requests. This uses the same
methodology as our request counting for axios.

app/assets/javascripts/lib/utils/rails_ujs.js

@@ -5,6 +5,16 @@ export const initRails = () => {
   // eslint-disable-next-line no-underscore-dangle
   if (!window._rails_loaded) {
     Rails.start();
+
+    // Count XHR requests for tests. See spec/support/helpers/wait_for_requests.rb
+    window.pendingRailsUJSRequests = 0;
+    document.body.addEventListener('ajax:complete', () => {
+      window.pendingRailsUJSRequests -= 1;
+    });
+
+    document.body.addEventListener('ajax:beforeSend', () => {
+      window.pendingRailsUJSRequests += 1;
+    });
   }
 };
 

qa/qa/support/wait_for_requests.rb

@@ -9,20 +9,14 @@ module QA
 
       def wait_for_requests(skip_finished_loading_check: false)
         Waiter.wait_until(log: false) do
-          finished_all_ajax_requests? && finished_all_axios_requests? && (!skip_finished_loading_check ? finished_loading?(wait: 1) : true)
+          finished_all_ajax_requests? && (!skip_finished_loading_check ? finished_loading?(wait: 1) : true)
         end
       rescue Repeater::WaitExceededError
         raise $!, 'Page did not fully load. This could be due to an unending async request or loading icon.'
       end
 
-      def finished_all_axios_requests?
-        Capybara.page.evaluate_script('window.pendingRequests || 0').zero? # rubocop:disable Style/NumericPredicate
-      end
-
       def finished_all_ajax_requests?
-        return true if Capybara.page.evaluate_script('typeof jQuery === "undefined"')
-
-        Capybara.page.evaluate_script('jQuery.active').zero? # rubocop:disable Style/NumericPredicate
+        Capybara.page.evaluate_script('window.pendingRequests || window.pendingRailsUJSRequests || 0').zero? # rubocop:disable Style/NumericPredicate
       end
 
       def finished_loading?(wait: DEFAULT_MAX_WAIT_TIME)

qa/spec/support/wait_for_requests_spec.rb

@@ -3,7 +3,6 @@
 describe QA::Support::WaitForRequests do
   describe '.wait_for_requests' do
     before do
-      allow(subject).to receive(:finished_all_axios_requests?).and_return(true)
       allow(subject).to receive(:finished_all_ajax_requests?).and_return(true)
       allow(subject).to receive(:finished_loading?).and_return(true)
     end

spec/support/helpers/wait_for_requests.rb

@@ -48,17 +48,10 @@ module WaitForRequests
   def finished_all_js_requests?
     return true unless javascript_test?
 
-    finished_all_ajax_requests? &&
-      finished_all_axios_requests?
-  end
-
-  def finished_all_axios_requests?
-    Capybara.page.evaluate_script('window.pendingRequests || 0').zero? # rubocop:disable Style/NumericPredicate
+    finished_all_ajax_requests?
   end
 
   def finished_all_ajax_requests?
-    return true if Capybara.page.evaluate_script('typeof jQuery === "undefined"')
-
-    Capybara.page.evaluate_script('jQuery.active').zero? # rubocop:disable Style/NumericPredicate
+    Capybara.page.evaluate_script('window.pendingRequests || window.pendingRailsUJSRequests || 0').zero? # rubocop:disable Style/NumericPredicate
   end
 end