fix(core): use setTimeout when coalescing tasks in Node.js (#50820)

This commit updates the implementation of the `getNativeRequestAnimationFrame`
and checks whether the current code runs in the browser before retrieving
`requestAnimationFrame`. `requestAnimationFrame` is not available when the code
is running in the Node.js environment. We have to fallback to `setTimeout` for
delaying the change detection.

PR Close #50820

Author: arturovt

packages/core/src/util/raf.ts

@@ -5,15 +5,35 @@
  * Use of this source code is governed by an MIT-style license that can be
  * found in the LICENSE file at https://angular.io/license
  */
+
 import {global} from './global';
 
 export function getNativeRequestAnimationFrame() {
+  // Note: the `getNativeRequestAnimationFrame` is used in the `NgZone` class, but we cannot use the
+  // `inject` function. The `NgZone` instance may be created manually, and thus the injection
+  // context will be unavailable. This might be enough to check whether `requestAnimationFrame` is
+  // available because otherwise, we'll fall back to `setTimeout`.
+  const isBrowser = typeof global['requestAnimationFrame'] === 'function';
+
+  // Note: `requestAnimationFrame` is unavailable when the code runs in the Node.js environment. We
+  // use `setTimeout` because no changes are required other than checking if the current platform is
+  // the browser. `setTimeout` is a well-established API that is available in both environments.
+  // `requestAnimationFrame` is used in the browser to coalesce event tasks since event tasks are
+  // usually executed within the same rendering frame (but this is more implementation details of
+  // browsers).
   let nativeRequestAnimationFrame: (callback: FrameRequestCallback) => number =
-      global['requestAnimationFrame'];
-  let nativeCancelAnimationFrame: (handle: number) => void = global['cancelAnimationFrame'];
+      global[isBrowser ? 'requestAnimationFrame' : 'setTimeout'];
+
+  let nativeCancelAnimationFrame: (handle: number) => void =
+      global[isBrowser ? 'cancelAnimationFrame' : 'clearTimeout'];
+
   if (typeof Zone !== 'undefined' && nativeRequestAnimationFrame! && nativeCancelAnimationFrame!) {
-    // use unpatched version of requestAnimationFrame(native delegate) if possible
-    // to avoid another Change detection
+    // Note: zone.js sets original implementations on patched APIs behind the
+    // `__zone_symbol__OriginalDelegate` key (see `attachOriginToPatched`). Given the following
+    // example: `window.requestAnimationFrame.__zone_symbol__OriginalDelegate`; this would return an
+    // unpatched implementation of the `requestAnimationFrame`, which isn't intercepted by the
+    // Angular zone. We use the unpatched implementation to avoid another change detection when
+    // coalescing tasks.
     const unpatchedRequestAnimationFrame =
         (nativeRequestAnimationFrame as any)[(Zone as any).__symbol__('OriginalDelegate')];
     if (unpatchedRequestAnimationFrame) {