fix microsoft/vscode-copilot#7519 (microsoft#226444)

* don't filter responses with errors
* use list error rendering and not status message
* on error, don't cancel but undo till request

Author: jrieken

src/vs/workbench/contrib/inlineChat/browser/inlineChatController.ts

@@ -752,18 +752,15 @@ export class InlineChatController implements IEditorContribution {
 
 		let newPosition: Position | undefined;
 
-		if (response.response.value.length === 0) {
+		if (response.result?.errorDetails) {
+			//
+			await this._session.undoChangesUntil(response.requestId);
+
+		} else if (response.response.value.length === 0) {
 			// empty -> show message
 			const status = localize('empty', "No results, please refine your input and try again");
 			this._ui.value.zone.widget.updateStatus(status, { classes: ['warn'] });
 
-		} else if (response.result?.errorDetails) {
-			// error -> show error
-			if (!response.isCanceled) {
-				this._ui.value.zone.widget.updateStatus(response.result.errorDetails.message, { classes: ['error'] });
-			}
-			this._strategy?.cancel();
-
 		} else {
 			// real response -> complex...
 			this._ui.value.zone.widget.updateStatus('');

src/vs/workbench/contrib/inlineChat/browser/inlineChatWidget.ts

@@ -148,7 +148,7 @@ export class InlineChatWidget {
 						// filter welcome messages
 						return false;
 					}
-					if (isResponseVM(item) && item.isComplete) {
+					if (isResponseVM(item) && item.isComplete && !item.errorDetails) {
 						// filter responses that
 						// - are just text edits(prevents the "Made Edits")
 						// - are all empty

src/vs/workbench/contrib/inlineChat/test/browser/inlineChatController.test.ts

@@ -859,4 +859,54 @@ suite('InteractiveChatController', function () {
 		assert.strictEqual(model.getValue(), 'Existing');
 
 	});
+
+	test('Undo on error (2 rounds)', async function () {
+
+		return runWithFakedTimers({}, async () => {
+
+
+			store.add(chatAgentService.registerDynamicAgent({ id: 'testEditorAgent', ...agentData, }, {
+				async invoke(request, progress, history, token) {
+
+					progress({
+						kind: 'textEdit',
+						uri: model.uri,
+						edits: [{
+							range: new Range(1, 1, 1, 1),
+							text: request.message
+						}]
+					});
+
+					if (request.message === 'two') {
+						await timeout(100); // give edit a chance
+						return {
+							errorDetails: { message: 'FAILED' }
+						};
+					}
+					return {};
+				},
+			}));
+
+			model.setValue('');
+
+			// ROUND 1
+
+			ctrl = instaService.createInstance(TestController, editor);
+			const p = ctrl.awaitStates([...TestController.INIT_SEQUENCE, State.SHOW_REQUEST, State.WAIT_FOR_INPUT]);
+			ctrl.run({ autoSend: true, message: 'one' });
+			assert.strictEqual(await p, undefined);
+			assert.strictEqual(model.getValue(), 'one');
+
+
+			// ROUND 2
+
+			const p2 = ctrl.awaitStates([State.SHOW_REQUEST, State.WAIT_FOR_INPUT]);
+			const values = new Set<string>();
+			store.add(model.onDidChangeContent(() => values.add(model.getValue())));
+			ctrl.chatWidget.acceptInput('two'); // WILL Trigger a failure
+			assert.strictEqual(await p2, undefined);
+			assert.strictEqual(model.getValue(), 'one'); // undone
+			assert.ok(values.has('twoone')); // we had but the change got undone
+		});
+	});
 });