Revert "Merge branch 'nfriend-dont-show-error-messages-on-browser-navigation-2' into 'master'"

This reverts merge request !16545

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

 import axios from 'axios';
 import csrf from './csrf';
-import suppressAjaxErrorsDuringNavigation from './suppress_ajax_errors_during_navigation';
 
 axios.defaults.headers.common[csrf.headerKey] = csrf.token;
 // Used by Rails to check if it is a valid XHR request
@@ -26,20 +25,6 @@ axios.interceptors.response.use(
   },
 );
 
-let isUserNavigating = false;
-window.addEventListener('beforeunload', () => {
-  isUserNavigating = true;
-});
-
-// Ignore AJAX errors caused by requests
-// being cancelled due to browser navigation
-const { gon } = window;
-const featureFlagEnabled = gon && gon.features && gon.features.suppressAjaxNavigationErrors;
-axios.interceptors.response.use(
-  response => response,
-  err => suppressAjaxErrorsDuringNavigation(err, isUserNavigating, featureFlagEnabled),
-);
-
 export default axios;
 
 /**

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

-/**
- * An Axios error interceptor that suppresses AJAX errors caused
- * by the request being cancelled when the user navigates to a new page
- */
-export default (err, isUserNavigating, featureFlagEnabled) => {
-  if (featureFlagEnabled && isUserNavigating && err.code === 'ECONNABORTED') {
-    // If the user is navigating away from the current page,
-    // prevent .then() and .catch() handlers from being
-    // called by returning a Promise that never resolves
-    return new Promise(() => {});
-  }
-
-  // The error is not related to browser navigation,
-  // so propagate the error
-  return Promise.reject(err);
-};

ee/changelogs/unreleased/nfriend-dont-show-error-messages-on-browser-navigation.yml

----
-title: Suppress error messages shown when navigating to a new page
-merge_request: 16545
-author:
-type: fixed

lib/gitlab/gon_helper.rb

@@ -38,10 +38,6 @@ module Gitlab
         gon.current_user_fullname = current_user.name
         gon.current_user_avatar_url = current_user.avatar_url
       end
-
-      # Initialize gon.features with any flags that should be
-      # made globally available to the frontend
-      push_frontend_feature_flag(:suppress_ajax_navigation_errors, default_enabled: true)
     end
 
     # Exposes the state of a feature flag to the frontend code.

spec/frontend/lib/utils/suppress_ajax_errors_during_navigation_spec.js

-import suppressAjaxErrorsDuringNavigation from '~/lib/utils/suppress_ajax_errors_during_navigation';
-import waitForPromises from 'helpers/wait_for_promises';
-
-describe('suppressAjaxErrorsDuringNavigation', () => {
-  const OTHER_ERR_CODE = 'foo';
-  const NAV_ERR_CODE = 'ECONNABORTED';
-
-  it.each`
-    isFeatureFlagEnabled | isUserNavigating | code
-    ${false}             | ${false}         | ${OTHER_ERR_CODE}
-    ${false}             | ${false}         | ${NAV_ERR_CODE}
-    ${false}             | ${true}          | ${OTHER_ERR_CODE}
-    ${false}             | ${true}          | ${NAV_ERR_CODE}
-    ${true}              | ${false}         | ${OTHER_ERR_CODE}
-    ${true}              | ${false}         | ${NAV_ERR_CODE}
-    ${true}              | ${true}          | ${OTHER_ERR_CODE}
-  `('should return a rejected Promise', ({ isFeatureFlagEnabled, isUserNavigating, code }) => {
-    const err = { code };
-    const actual = suppressAjaxErrorsDuringNavigation(err, isUserNavigating, isFeatureFlagEnabled);
-
-    return expect(actual).rejects.toBe(err);
-  });
-
-  it('should return a Promise that never resolves', () => {
-    const err = { code: NAV_ERR_CODE };
-    const actual = suppressAjaxErrorsDuringNavigation(err, true, true);
-
-    const thenCallback = jest.fn();
-    const catchCallback = jest.fn();
-    actual.then(thenCallback).catch(catchCallback);
-
-    return waitForPromises().then(() => {
-      expect(thenCallback).not.toHaveBeenCalled();
-      expect(catchCallback).not.toHaveBeenCalled();
-    });
-  });
-});

spec/javascripts/frequent_items/components/app_spec.js

@@ -236,15 +236,8 @@ describe('Frequent Items App Component', () => {
         .then(() => {
           expect(vm.$el.querySelector('.loading-animation')).toBeDefined();
         })
-
-        // This test waits for multiple ticks in order to allow the responses to
-        // propagate through each interceptor installed on the Axios instance.
-        // This shouldn't be necessary; this test should be refactored to avoid this.
-        // https://gitlab.com/gitlab-org/gitlab/issues/32479
-        .then(vm.$nextTick)
         .then(vm.$nextTick)
         .then(vm.$nextTick)
-
         .then(() => {
           expect(vm.$el.querySelectorAll('.frequent-items-list-container li').length).toBe(
             mockSearchedProjects.length,