Debounce chatWidget view model changes (microsoft#208120)

Currently we can end up updating the chat list multiple times per frame

With this change, we try to batch some of these updates to avoid this

Author: mjbvz

src/vs/workbench/contrib/chat/browser/chatWidget.ts

@@ -7,7 +7,7 @@ import * as dom from 'vs/base/browser/dom';
 import { ITreeContextMenuEvent, ITreeElement } from 'vs/base/browser/ui/tree/tree';
 import { disposableTimeout, timeout } from 'vs/base/common/async';
 import { toErrorMessage } from 'vs/base/common/errorMessage';
-import { Emitter } from 'vs/base/common/event';
+import { Emitter, Event } from 'vs/base/common/event';
 import { Disposable, DisposableStore, IDisposable, MutableDisposable, combinedDisposable, toDisposable } from 'vs/base/common/lifecycle';
 import { Schemas } from 'vs/base/common/network';
 import { isEqual } from 'vs/base/common/resources';
@@ -589,10 +589,15 @@ export class ChatWidget extends Disposable implements IChatWidget {
 
 		this.container.setAttribute('data-session-id', model.sessionId);
 		this.viewModel = this.instantiationService.createInstance(ChatViewModel, model, this._codeBlockModelCollection);
-		this.viewModelDisposables.add(this.viewModel.onDidChange(e => {
-			this.requestInProgress.set(this.viewModel!.requestInProgress);
+		this.viewModelDisposables.add(Event.accumulate(this.viewModel.onDidChange, 0)(events => {
+			if (!this.viewModel) {
+				return;
+			}
+
+			this.requestInProgress.set(this.viewModel.requestInProgress);
+
 			this.onDidChangeItems();
-			if (e?.kind === 'addRequest') {
+			if (events.some(e => e?.kind === 'addRequest')) {
 				revealLastElement(this.tree);
 				this.focusInput();
 			}