use undo-loop instead of undo-edit when discarding chat session (microsoft#184063)

* use undo-loop instead of undo-edit when discarding chat session

fixes microsoft/vscode-internalbacklog#4118

* fix tests, wait for correct state

Author: jrieken

src/vs/workbench/contrib/interactiveEditor/browser/interactiveEditorSession.ts

@@ -8,7 +8,7 @@ import { URI } from 'vs/base/common/uri';
 import { Event } from 'vs/base/common/event';
 import { ResourceEdit, ResourceFileEdit, ResourceTextEdit } from 'vs/editor/browser/services/bulkEditService';
 import { TextEdit } from 'vs/editor/common/languages';
-import { ITextModel, ITextSnapshot } from 'vs/editor/common/model';
+import { ITextModel } from 'vs/editor/common/model';
 import { EditMode, IInteractiveEditorSessionProvider, IInteractiveEditorSession, IInteractiveEditorBulkEditResponse, IInteractiveEditorEditResponse, IInteractiveEditorMessageResponse, IInteractiveEditorResponse, IInteractiveEditorService } from 'vs/workbench/contrib/interactiveEditor/common/interactiveEditor';
 import { IRange, Range } from 'vs/editor/common/core/range';
 import { IActiveCodeEditor, ICodeEditor } from 'vs/editor/browser/editorBrowser';
@@ -60,12 +60,14 @@ export class Session {
 	private _lastInput: string | undefined;
 	private _lastExpansionState: boolean | undefined;
 	private _lastTextModelChanges: LineRangeMapping[] | undefined;
-	private _lastSnapshot: ITextSnapshot | undefined;
 	private _isUnstashed: boolean = false;
 	private readonly _exchange: SessionExchange[] = [];
 	private readonly _startTime = new Date();
 	private readonly _teldata: Partial<TelemetryData>;
 
+	readonly textModelNAltVersion: number;
+	private _textModelNSnapshotAltVersion: number | undefined;
+
 	constructor(
 		readonly editMode: EditMode,
 		readonly editor: ICodeEditor,
@@ -75,6 +77,7 @@ export class Session {
 		readonly session: IInteractiveEditorSession,
 		private readonly _wholeRangeMarkerId: string
 	) {
+		this.textModelNAltVersion = textModelN.getAlternativeVersionId();
 		this._teldata = {
 			extension: provider.debugName,
 			startTime: this._startTime.toISOString(),
@@ -109,8 +112,8 @@ export class Session {
 		this._lastExpansionState = state;
 	}
 
-	get lastSnapshot(): ITextSnapshot | undefined {
-		return this._lastSnapshot;
+	get textModelNSnapshotAltVersion(): number | undefined {
+		return this._textModelNSnapshotAltVersion;
 	}
 
 	get wholeRange(): Range {
@@ -119,7 +122,7 @@ export class Session {
 	}
 
 	createSnapshot(): void {
-		this._lastSnapshot = this.textModelN.createSnapshot();
+		this._textModelNSnapshotAltVersion = this.textModelN.getAlternativeVersionId();
 	}
 
 	addExchange(exchange: SessionExchange): void {

src/vs/workbench/contrib/interactiveEditor/browser/interactiveEditorStrategies.ts

@@ -24,7 +24,6 @@ import { IStorageService, StorageScope, StorageTarget } from 'vs/platform/storag
 import { InteractiveEditorFileCreatePreviewWidget, InteractiveEditorLivePreviewWidget } from 'vs/workbench/contrib/interactiveEditor/browser/interactiveEditorLivePreviewWidget';
 import { EditResponse, Session } from 'vs/workbench/contrib/interactiveEditor/browser/interactiveEditorSession';
 import { InteractiveEditorWidget } from 'vs/workbench/contrib/interactiveEditor/browser/interactiveEditorWidget';
-import { getValueFromSnapshot } from 'vs/workbench/contrib/interactiveEditor/browser/utils';
 import { CTX_INTERACTIVE_EDITOR_SHOWING_DIFF, CTX_INTERACTIVE_EDITOR_DOCUMENT_CHANGED } from 'vs/workbench/contrib/interactiveEditor/common/interactiveEditor';
 import { IEditorService, SIDE_GROUP } from 'vs/workbench/services/editor/common/editorService';
 
@@ -278,19 +277,13 @@ export class LiveStrategy extends EditModeStrategy {
 	}
 
 	async cancel() {
-		const { textModelN: modelN, textModel0: model0, lastSnapshot } = this._session;
-		if (modelN.isDisposed() || (model0.isDisposed() && !lastSnapshot)) {
+		const { textModelN: modelN, textModelNAltVersion, textModelNSnapshotAltVersion } = this._session;
+		if (modelN.isDisposed()) {
 			return;
 		}
-
-		const newText = lastSnapshot
-			? getValueFromSnapshot(lastSnapshot)
-			: model0.getValue();
-
-		const edits = await this._editorWorkerService.computeMoreMinimalEdits(modelN.uri, [{ range: modelN.getFullModelRange(), text: newText }]);
-		if (edits) {
-			const operations = edits.map(e => EditOperation.replace(Range.lift(e.range), e.text));
-			modelN.pushEditOperations(null, operations, () => null);
+		const targetAltVersion = textModelNSnapshotAltVersion ?? textModelNAltVersion;
+		while (targetAltVersion < modelN.getAlternativeVersionId() && modelN.canUndo()) {
+			modelN.undo();
 		}
 	}
 

src/vs/workbench/contrib/interactiveEditor/browser/utils.ts

@@ -5,7 +5,7 @@
 
 import { LineRange } from 'vs/editor/common/core/lineRange';
 import { Range } from 'vs/editor/common/core/range';
-import { ITextModel, ITextSnapshot } from 'vs/editor/common/model';
+import { ITextModel } from 'vs/editor/common/model';
 
 export function invertLineRange(range: LineRange, model: ITextModel): LineRange[] {
 	if (range.isEmpty) {
@@ -20,15 +20,3 @@ export function invertLineRange(range: LineRange, model: ITextModel): LineRange[
 export function lineRangeAsRange(r: LineRange): Range {
 	return new Range(r.startLineNumber, 1, r.endLineNumberExclusive - 1, 1);
 }
-
-export function getValueFromSnapshot(snapshot: ITextSnapshot): string {
-	let result = '';
-	while (true) {
-		const chunk = snapshot.read();
-		if (chunk === null) {
-			break;
-		}
-		result += chunk;
-	}
-	return result;
-}

src/vs/workbench/contrib/interactiveEditor/test/browser/interactiveEditorController.test.ts

@@ -115,9 +115,8 @@ suite('InteractiveEditorController', function () {
 		ctrl = instaService.createInstance(TestController, editor);
 		const run = ctrl.run({ message: 'Hello', autoSend: true });
 
-		await Event.toPromise(Event.filter(ctrl.onDidChangeState, e => e === State.SHOW_RESPONSE));
+		await Event.toPromise(Event.filter(ctrl.onDidChangeState, e => e === State.WAIT_FOR_INPUT));
 		assert.ok(ctrl.getWidgetPosition() !== undefined);
-
 		await ctrl.cancelSession();
 
 		await run;