chat: mark streaming tool calls as skipped when request completes (#297130)

* chat: mark streaming tool calls as skipped when request completes

When a steering message causes the extension to yield after handleToolStream
has been received but before invokeTool is called, the streaming tool call
should be marked as skipped instead of being silently deleted.

- Call cancelToolCallsForRequest in CancellableRequest.dispose() to ensure
  streaming tool calls are marked as skipped when requests complete naturally
- Update cancelToolCallsForRequest to call invocation.cancelFromStreaming()
  before deleting pending tool calls from the map

Fixes #294224

(Commit message generated by Copilot)

* tests

Author: connor4312

src/vs/workbench/contrib/chat/browser/tools/languageModelToolsService.ts

@@ -1150,6 +1150,7 @@ export class LanguageModelToolsService extends Disposable implements ILanguageMo
 		// Clean up any pending tool calls that belong to this request
 		for (const [toolCallId, invocation] of this._pendingToolCalls) {
 			if (invocation.chatRequestId === requestId) {
+				invocation.cancelFromStreaming(ToolConfirmKind.Skipped);
 				this._pendingToolCalls.delete(toolCallId);
 			}
 		}

src/vs/workbench/contrib/chat/common/chatService/chatServiceImpl.ts

@@ -70,6 +70,9 @@ class CancellableRequest implements IDisposable {
 	) { }
 
 	dispose() {
+		if (this.requestId) {
+			this.toolsService.cancelToolCallsForRequest(this.requestId);
+		}
 		this.cancellationTokenSource.dispose();
 	}
 

src/vs/workbench/contrib/chat/test/common/chatService/chatService.test.ts

@@ -50,6 +50,8 @@ import { MockChatVariablesService } from '../mockChatVariables.js';
 import { IPromptsService } from '../../../common/promptSyntax/service/promptsService.js';
 import { MockPromptsService } from '../promptSyntax/service/mockPromptsService.js';
 import { CancellationToken } from '../../../../../../base/common/cancellation.js';
+import { ILanguageModelToolsService } from '../../../common/tools/languageModelToolsService.js';
+import { MockLanguageModelToolsService } from '../tools/mockLanguageModelToolsService.js';
 
 const chatAgentWithUsedContextId = 'ChatProviderWithUsedContext';
 const chatAgentWithUsedContext: IChatAgent = {
@@ -163,6 +165,7 @@ suite('ChatService', () => {
 			[IWorkbenchAssignmentService, new NullWorkbenchAssignmentService()],
 			[IMcpService, new TestMcpService()],
 			[IPromptsService, new MockPromptsService()],
+			[ILanguageModelToolsService, testDisposables.add(new MockLanguageModelToolsService())]
 		)));
 		instantiationService.stub(IStorageService, testDisposables.add(new TestStorageService()));
 		instantiationService.stub(IChatEntitlementService, new TestChatEntitlementService());