fix: angular wrapped mutationobserver detection

.changeset/moody-experts-build.md

@@ -0,0 +1,5 @@
+---
+"@rrweb/record": patch
+---
+
+correctly detect when angular has wrapped mutation observer"

packages/utils/src/index.ts

@@ -28,6 +28,25 @@ const testableMethods = {
 
 const untaintedBasePrototype: Partial<BasePrototypeCache> = {};
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+const isFunction = (x: unknown): x is (...args: any[]) => any => {
+  return typeof x === 'function';
+};
+
+/*
+ When angular patches things they pass the above `isNativeFunction` check
+ That then causes performance issues
+ because angular's change detection
+ doesn't like sharing a mutation observer
+ */
+export const isAngularZonePatchedFunction = (x: unknown): boolean => {
+  if (!isFunction(x)) {
+    return false;
+  }
+  const prototypeKeys = Object.getOwnPropertyNames(x.prototype || {});
+  return prototypeKeys.some((key) => key.indexOf('__zone'));
+};
+
 export function getUntaintedPrototype<T extends keyof BasePrototypeCache>(
   key: T,
 ): BasePrototypeCache[T] {
@@ -63,7 +82,11 @@ export function getUntaintedPrototype<T extends keyof BasePrototypeCache>(
       ),
   );
 
-  if (isUntaintedAccessors && isUntaintedMethods) {
+  if (
+    isUntaintedAccessors &&
+    isUntaintedMethods &&
+    !isAngularZonePatchedFunction(defaultObj)
+  ) {
     untaintedBasePrototype[key] = defaultObj.prototype as BasePrototypeCache[T];
     return defaultObj.prototype as BasePrototypeCache[T];
   }