Fix collections wrapped in suspense updating incorrectly

Author: devongovett

packages/@react-aria/collections/src/CollectionBuilder.tsx

@@ -19,7 +19,6 @@ import {forwardRefType, Key, Node} from '@react-types/shared';
 import {Hidden} from './Hidden';
 import React, {createContext, ForwardedRef, forwardRef, JSX, ReactElement, ReactNode, useCallback, useContext, useMemo, useRef, useState} from 'react';
 import {useIsSSR} from '@react-aria/ssr';
-import {useLayoutEffect} from '@react-aria/utils';
 import {useSyncExternalStore as useSyncExternalStoreShim} from 'use-sync-external-store/shim/index.js';
 
 const ShallowRenderContext = createContext(false);
@@ -114,14 +113,6 @@ function useCollectionDocument<T extends object, C extends BaseCollection<T>>(cr
     return document.getCollection();
   }, [document]);
   let collection = useSyncExternalStore(subscribe, getSnapshot, getServerSnapshot);
-  useLayoutEffect(() => {
-    document.isMounted = true;
-    return () => {
-      // Mark unmounted so we can skip all of the collection updates caused by
-      // React calling removeChild on every item in the collection.
-      document.isMounted = false;
-    };
-  }, [document]);
   return {collection, document};
 }
 

packages/@react-aria/collections/src/Document.ts

@@ -179,7 +179,7 @@ export class BaseNode<T> {
   }
 
   removeChild(child: ElementNode<T>): void {
-    if (child.parentNode !== this || !this.ownerDocument.isMounted) {
+    if (child.parentNode !== this) {
       return;
     }
 
@@ -411,7 +411,6 @@ export class Document<T, C extends BaseCollection<T> = BaseCollection<T>> extend
   isSSR = false;
   nodeId = 0;
   nodesByProps: WeakMap<object, ElementNode<T>> = new WeakMap<object, ElementNode<T>>();
-  isMounted = true;
   private collection: C;
   private nextCollection: C | null = null;
   private subscriptions: Set<() => void> = new Set();
@@ -426,7 +425,7 @@ export class Document<T, C extends BaseCollection<T> = BaseCollection<T>> extend
   }
 
   get isConnected(): boolean {
-    return this.isMounted;
+    return true;
   }
 
   createElement(type: string): ElementNode<T> {