Convert shared helper to a class

TODO figure out what should be class method; at the moment everything is
instance except for the ones that have a .skip because that wasn't
implementable for an instance method, and also because these clearly
aren’t going to be called at a per-test level. But there may well be
other stuff (e.g. stuff that's used at a non-test level, or it might
just be that the instance doesn't always have a test)

test/browser/connection.test.js

@@ -1,6 +1,8 @@
 'use strict';
 
-define(['shared_helper', 'chai'], function (helper, chai) {
+define(['shared_helper', 'chai'], function (Helper, chai) {
+  const helper = new Helper();
+
   var { expect, assert } = chai;
   var transportPreferenceName = 'ably-transport-preference';
 

test/browser/http.test.js

@@ -1,6 +1,8 @@
 'use strict';
 
-define(['ably', 'shared_helper', 'chai'], function (Ably, helper, chai) {
+define(['ably', 'shared_helper', 'chai'], function (Ably, Helper, chai) {
+  const helper = new Helper();
+
   var rest;
   var expect = chai.expect;
 

test/browser/modular.test.js

@@ -21,9 +21,10 @@ import {
   MessageInteractions,
 } from '../../build/modular/index.mjs';
 
-function registerAblyModularTests(helper) {
+function registerAblyModularTests(Helper) {
   describe('browser/modular', function () {
     this.timeout(10 * 1000);
+    const helper = new Helper();
     const expect = chai.expect;
     const BufferUtils = BaseRest.Platform.BufferUtils;
     const loadTestData = async (dataPath) => {
@@ -885,8 +886,8 @@ function registerAblyModularTests(helper) {
 // This function is called by browser_setup.js once `require` is available
 window.registerAblyModularTests = async () => {
   return new Promise((resolve) => {
-    require(['shared_helper'], (helper) => {
-      registerAblyModularTests(helper);
+    require(['shared_helper'], (Helper) => {
+      registerAblyModularTests(Helper);
       resolve();
     });
   });

test/browser/simple.test.js

@@ -1,6 +1,8 @@
 'use strict';
 
-define(['ably', 'shared_helper', 'chai'], function (Ably, helper, chai) {
+define(['ably', 'shared_helper', 'chai'], function (Ably, Helper, chai) {
+  const helper = new Helper();
+
   var expect = chai.expect;
 
   describe('browser/simple', function () {