chore: cleanup usage of AsyncIterableObject (microsoft#256868)

refs microsoft#256854

Author: connor4312

src/vs/base/common/async.ts

@@ -2378,7 +2378,7 @@ class ProducerConsumer<T> {
 export class AsyncIterableProducer<T> implements AsyncIterable<T> {
 	private readonly _producerConsumer = new ProducerConsumer<IteratorResult<T>>();
 
-	constructor(executor: AsyncIterableExecutor<T>) {
+	constructor(executor: AsyncIterableExecutor<T>, private readonly _onReturn?: () => void) {
 		queueMicrotask(async () => {
 			const p = executor({
 				emitOne: value => this._producerConsumer.produce({ ok: true, value: { done: false, value: value } }),
@@ -2411,6 +2411,10 @@ export class AsyncIterableProducer<T> implements AsyncIterable<T> {
 
 	private readonly _iterator: AsyncIterator<T, void, void> = {
 		next: () => this._producerConsumer.consume(),
+		return: () => {
+			this._onReturn?.();
+			return Promise.resolve({ done: true, value: undefined });
+		},
 		throw: async (e) => {
 			this._finishError(e);
 			return { done: true, value: undefined };

src/vs/workbench/contrib/mcp/common/mcpServer.ts

@@ -3,7 +3,7 @@
  *  Licensed under the MIT License. See License.txt in the project root for license information.
  *--------------------------------------------------------------------------------------------*/
 
-import { AsyncIterableObject, raceCancellationError, Sequencer } from '../../../../base/common/async.js';
+import { AsyncIterableProducer, raceCancellationError, Sequencer } from '../../../../base/common/async.js';
 import { CancellationToken, CancellationTokenSource } from '../../../../base/common/cancellation.js';
 import { Iterable } from '../../../../base/common/iterator.js';
 import * as json from '../../../../base/common/json.js';
@@ -441,7 +441,7 @@ export class McpServer extends Disposable implements IMcpServer {
 
 	public resources(token?: CancellationToken): AsyncIterable<IMcpResource[]> {
 		const cts = new CancellationTokenSource(token);
-		return new AsyncIterableObject<IMcpResource[]>(async emitter => {
+		return new AsyncIterableProducer<IMcpResource[]>(async emitter => {
 			await McpServer.callOn(this, async (handler) => {
 				for await (const resource of handler.listResourcesIterable({}, cts.token)) {
 					emitter.emitOne(resource.map(r => new McpResource(this, r)));