From 0b776c15f202e9355cce919d94ed27b12957bc2b Mon Sep 17 00:00:00 2001
From: Timmy Willison <timmywil@users.noreply.github.com>
Date: Thu, 8 Feb 2024 08:21:43 -0500
Subject: [PATCH] Core: Fix IE 10 and IE 11 compatibility of internal Promise
 with sinon.useFakeTimers

The Promise polyfill needs to save the unmodified reference to the
`setImmediate` function in IE, for use in `Promise._immediateFn`.

This broke in QUnit 2.14.0, with the introduction of internal Promise usage
as part of https://github.com/qunitjs/qunit/issues/1535.

Closes https://github.com/qunitjs/qunit/pull/1738.
---
 lib/promise-polyfill.js | 18 +++++++++-------
 test/main/promise.js    | 46 +++++++++++++++++++++++++++++++++++++++++
 2 files changed, 57 insertions(+), 7 deletions(-)

diff --git a/lib/promise-polyfill.js b/lib/promise-polyfill.js
index 0513c4a0b..d144ac46d 100644
--- a/lib/promise-polyfill.js
+++ b/lib/promise-polyfill.js
@@ -36,6 +36,8 @@ Patches for use in QUnit:
 
 - 2021-01-10: Add 'globalThis' to globalNS implementation to support SpiderMonkey.
 
+- 2024-02-07: Save unmodified setImmediate to avoid conflicts with Sinon fake timers.
+
 */
 
 (function () { 'use strict';
@@ -373,16 +375,18 @@ Promise.race = function(arr) {
 };
 
 // Use polyfill for setImmediate for performance gains
-Promise._immediateFn =
+// @ts-ignore
+if (typeof setImmediate === 'function') {
   // @ts-ignore
-  (typeof setImmediate === 'function' &&
-    function(fn) {
-      // @ts-ignore
-      setImmediate(fn);
-    }) ||
-  function(fn) {
+  var setImmediateFunc = setImmediate;
+  Promise._immediateFn = function(fn) {
+    setImmediateFunc(fn);
+  };
+} else {
+  Promise._immediateFn = function(fn) {
     setTimeoutFunc(fn, 0);
   };
+}
 
 Promise._unhandledRejectionFn = function _unhandledRejectionFn(err) {
   if (typeof console !== 'undefined' && console) {
diff --git a/test/main/promise.js b/test/main/promise.js
index 8745e7da9..a828bb331 100644
--- a/test/main/promise.js
+++ b/test/main/promise.js
@@ -8,6 +8,27 @@ var defer = typeof setTimeout !== 'undefined'
     Promise.resolve().then(fn);
   };
 
+// Get the global namespace the same way as the Promise polyfill.
+var globalNS = (function () {
+  if (typeof globalThis !== 'undefined') {
+    // eslint-disable-next-line no-undef
+    return globalThis;
+  }
+  if (typeof self !== 'undefined') {
+    // eslint-disable-next-line no-undef
+    return self;
+  }
+  if (typeof window !== 'undefined') {
+    // eslint-disable-next-line no-undef
+    return window;
+  }
+  if (typeof global !== 'undefined') {
+    // eslint-disable-next-line no-undef
+    return global;
+  }
+  throw new Error('unable to locate global object');
+})();
+
 // NOTE: Adds 1 assertion
 function createMockPromise (assert, reject, value) {
   if (arguments.length < 3) {
@@ -247,4 +268,29 @@ QUnit.module('Support for Promise', function () {
 
     return createMockPromise(assert, true, new Error('this is an error'));
   });
+
+  QUnit.module('compatible with fake timers', {
+    beforeEach: function (assert) {
+      this.setTimeout = globalNS.setTimeout;
+      globalNS.setTimeout = function () {};
+      if (globalNS.setImmediate) {
+        this.setImmediate = globalNS.setImmediate;
+        globalNS.setImmediate = function () {};
+      }
+      // Adds 1 assertion
+      return createMockPromise(assert);
+    },
+    afterEach: function (assert) {
+      globalNS.setTimeout = this.setTimeout;
+      if (this.setImmediate) {
+        globalNS.setImmediate = this.setImmediate;
+      }
+      // Adds 1 assertion
+      return createMockPromise(assert);
+    }
+  });
+
+  QUnit.test('test', function (assert) {
+    assert.expect(2);
+  });
 });