Add Cancel Review functionality to webview and backend

Co-authored-by: bamurtaugh <25310137+bamurtaugh@users.noreply.github.com>

Author: Copilot

src/github/pullRequestOverview.ts

@@ -387,6 +387,8 @@ export class PullRequestOverviewPanel extends IssueOverviewPanel<PullRequestMode
 				return this.cancelCodingAgent(message);
 			case 'pr.openCommitChanges':
 				return this.openCommitChanges(message);
+			case 'pr.delete-review':
+				return this.deleteReview(message);
 		}
 	}
 
@@ -850,6 +852,17 @@ export class PullRequestOverviewPanel extends IssueOverviewPanel<PullRequestMode
 		return this._item.deleteReviewComment(comment.id.toString());
 	}
 
+	private async deleteReview(message: IRequestMessage<void>) {
+		try {
+			const result = await this._item.deleteReview();
+			await this._replyMessage(message, result);
+		} catch (e) {
+			Logger.error(formatError(e), PullRequestOverviewPanel.ID);
+			vscode.window.showErrorMessage(vscode.l10n.t('Deleting review failed. {0}', formatError(e)));
+			this._throwError(message, `${formatError(e)}`);
+		}
+	}
+
 	override dispose() {
 		super.dispose();
 		disposeAll(this._prListeners);

webviews/common/context.tsx

@@ -145,6 +145,25 @@ export class PRContext {
 
 	public submit = (body: string) => this.submitReviewCommand('pr.submit', body);
 
+	public deleteReview = async () => {
+		try {
+			const result: { deletedReviewId: number; deletedReviewComments: IComment[] } = await this.postMessage({ command: 'pr.delete-review' });
+			// Update the PR state to reflect the deleted review
+			const state = this.pr;
+			state.busy = false;
+			state.pendingCommentText = '';
+			state.pendingCommentDrafts = {};
+			// Remove the deleted review from events
+			state.events = state.events.filter(event => 
+				!(event.event === EventType.Reviewed && event.id === result.deletedReviewId)
+			);
+			this.updatePR(state);
+			return result;
+		} catch (error) {
+			return this.updatePR({ busy: false });
+		}
+	};
+
 	public close = async (body?: string) => {
 		try {
 			const result: CloseResult = await this.postMessage({ command: 'pr.close', args: body });

webviews/components/timeline.tsx

@@ -267,7 +267,7 @@ function CommentThread({ thread, event }: { thread: IComment[]; event: ReviewEve
 }
 
 function AddReviewSummaryComment() {
-	const { requestChanges, approve, submit, pr } = useContext(PullRequestContext);
+	const { requestChanges, approve, submit, deleteReview, pr } = useContext(PullRequestContext);
 	const { isAuthor } = pr;
 	const comment = useRef<HTMLTextAreaElement>();
 	const [isBusy, setBusy] = useState(false);
@@ -289,6 +289,13 @@ function AddReviewSummaryComment() {
 		setBusy(false);
 	}
 
+	async function cancelReview(event: React.MouseEvent): Promise<void> {
+		event.preventDefault();
+		setBusy(true);
+		await deleteReview();
+		setBusy(false);
+	}
+
 	const onKeyDown = (event: React.KeyboardEvent<HTMLTextAreaElement>) => {
 		if ((event.ctrlKey || event.metaKey) && event.key === 'Enter') {
 			submitAction(event, ReviewType.Comment);
@@ -304,6 +311,14 @@ function AddReviewSummaryComment() {
 				onKeyDown={onKeyDown}
 			></textarea>
 			<div className="form-actions">
+				<button
+					id="cancel-review"
+					className='secondary'
+					disabled={isBusy || pr.busy}
+					onClick={cancelReview}
+				>
+					Cancel Review
+				</button>
 				{isAuthor ? null : (
 					<button
 						id="request-changes"