Changes poll.js to keep polling on any 2xx http status code

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

@@ -2,11 +2,34 @@
  * exports HTTP status codes
  */
 
-export default {
+const httpStatusCodes = {
   ABORTED: 0,
-  NO_CONTENT: 204,
   OK: 200,
+  CREATED: 201,
+  ACCEPTED: 202,
+  NON_AUTHORITATIVE_INFORMATION: 203,
+  NO_CONTENT: 204,
+  RESET_CONTENT: 205,
+  PARTIAL_CONTENT: 206,
+  MULTI_STATUS: 207,
+  ALREADY_REPORTED: 208,
+  IM_USED: 226,
   MULTIPLE_CHOICES: 300,
   BAD_REQUEST: 400,
   NOT_FOUND: 404,
 };
+
+export const successCodes = [
+  httpStatusCodes.OK,
+  httpStatusCodes.CREATED,
+  httpStatusCodes.ACCEPTED,
+  httpStatusCodes.NON_AUTHORITATIVE_INFORMATION,
+  httpStatusCodes.NO_CONTENT,
+  httpStatusCodes.RESET_CONTENT,
+  httpStatusCodes.PARTIAL_CONTENT,
+  httpStatusCodes.MULTI_STATUS,
+  httpStatusCodes.ALREADY_REPORTED,
+  httpStatusCodes.IM_USED,
+];
+
+export default httpStatusCodes;

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

-import httpStatusCodes from './http_status';
+import httpStatusCodes, { successCodes } from './http_status';
 import { normalizeHeaders } from './common_utils';
 
 /**
@@ -62,7 +62,7 @@ export default class Poll {
   checkConditions(response) {
     const headers = normalizeHeaders(response.headers);
     const pollInterval = parseInt(headers[this.intervalHeader], 10);
-    if (pollInterval > 0 && response.status === httpStatusCodes.OK && this.canPoll) {
+    if (pollInterval > 0 && successCodes.indexOf(response.status) !== -1 && this.canPoll) {
       clearTimeout(this.timeoutID);
       this.timeoutID = setTimeout(() => {
         this.makeRequest();

changelogs/unreleased/49747-update-poll-2xx.yml

+---
+title: Changes poll.js to keep polling on any 2xx http status code
+merge_request: 20904
+author:
+type: other

doc/development/fe_guide/performance.md

@@ -15,7 +15,7 @@ Use the following rules when creating realtime solutions.
 Use that as your polling interval. This way it is [easy for system administrators to change the
 polling rate](../../administration/polling.md).
 A `Poll-Interval: -1` means you should disable polling, and this must be implemented.
-1. A response with HTTP status `4XX` or `5XX` should disable polling as well.
+1. A response with HTTP status different from 2XX should disable polling as well.
 1. Use a common library for polling.
 1. Poll on active tabs only. Please use [Visibility](https://github.com/ai/visibilityjs).
 1. Use regular polling intervals, do not use backoff polling, or jitter, as the interval will be

spec/javascripts/lib/utils/poll_spec.js

 import Poll from '~/lib/utils/poll';
+import { successCodes } from '~/lib/utils/http_status';
 
 const waitForAllCallsToFinish = (service, waitForCount, successCallback) => {
   const timer = () => {
@@ -91,8 +92,10 @@ describe('Poll', () => {
     }).catch(done.fail);
   });
 
-  it('starts polling when http status is 200 and interval header is provided', (done) => {
-    mockServiceCall(service, { status: 200, headers: { 'poll-interval': 1 } });
+  describe('for 2xx status code', () => {
+    successCodes.forEach(httpCode => {
+      it(`starts polling when http status is ${httpCode} and interval header is provided`, (done) => {
+        mockServiceCall(service, { status: httpCode, headers: { 'poll-interval': 1 } });
 
         const Polling = new Poll({
           resource: service,
@@ -115,6 +118,8 @@ describe('Poll', () => {
           done();
         });
       });
+    });
+  });
 
   describe('stop', () => {
     it('stops polling when method is called', (done) => {