fix(ChatView): React crash from malformed follow-up suggestion mode

packages/types/src/followup.ts

@@ -22,6 +22,19 @@ export interface SuggestionItem {
 	mode?: string
 }
 
+export const getSuggestionMode = (mode: unknown): string | undefined => {
+	if (typeof mode === "string" && mode.trim().length > 0) {
+		return mode.trim()
+	}
+
+	if (mode && typeof mode === "object" && "mode_slug" in mode) {
+		const modeSlug = (mode as { mode_slug?: unknown }).mode_slug
+		return typeof modeSlug === "string" && modeSlug.trim().length > 0 ? modeSlug.trim() : undefined
+	}
+
+	return undefined
+}
+
 /**
  * Zod schema for SuggestionItem
  */

src/core/tools/AskFollowupQuestionTool.ts

@@ -1,12 +1,13 @@
 import { Task } from "../task/Task"
 import { formatResponse } from "../prompts/responses"
 import type { ToolUse } from "../../shared/tools"
+import { getSuggestionMode } from "@roo-code/types"
 
 import { BaseTool, ToolCallbacks } from "./BaseTool"
 
 interface Suggestion {
 	text: string
-	mode?: string
+	mode?: unknown
 }
 
 interface AskFollowupQuestionParams {
@@ -42,7 +43,7 @@ export class AskFollowupQuestionTool extends BaseTool<"ask_followup_question"> {
 			// Transform follow_up suggestions to the format expected by task.ask
 			const follow_up_json = {
 				question,
-				suggest: follow_up.map((s) => ({ answer: s.text, mode: s.mode })),
+				suggest: follow_up.map((s) => ({ answer: s.text, mode: getSuggestionMode(s.mode) })),
 			}
 
 			task.consecutiveMistakeCount = 0

src/core/tools/__tests__/askFollowupQuestionTool.spec.ts

@@ -137,6 +137,22 @@ describe("AskFollowupQuestionTool", () => {
 		expect(mockTask.ask).toHaveBeenCalledWith("followup", expectedJson, false)
 	})
 
+	it("should normalize malformed object mode values", async () => {
+		const params = {
+			question: "Switch mode?",
+			follow_up: [{ text: "Use code mode", mode: { mode_slug: "code" } }],
+		} as any
+
+		await tool.execute(params, mockTask, mockCallbacks)
+
+		const expectedJson = JSON.stringify({
+			question: "Switch mode?",
+			suggest: [{ answer: "Use code mode", mode: "code" }],
+		})
+
+		expect(mockTask.ask).toHaveBeenCalledWith("followup", expectedJson, false)
+	})
+
 	it("should say user_feedback and push tool result after user answers", async () => {
 		const params = {
 			question: "Which approach?",

webview-ui/src/components/chat/ChatView.tsx

@@ -10,11 +10,10 @@ import { appendImages } from "@src/utils/imageUtils"
 import { getCostBreakdownIfNeeded } from "@src/utils/costFormatting"
 import { batchConsecutive } from "@src/utils/batchConsecutive"
 
-import type { ClineAsk, ClineSayTool, ClineMessage, ExtensionMessage, AudioType } from "@roo-code/types"
-import { isRetiredProvider } from "@roo-code/types"
+import type { ClineAsk, ClineSayTool, ClineMessage, ExtensionMessage, AudioType, SuggestionItem } from "@roo-code/types"
+import { getSuggestionMode, isRetiredProvider } from "@roo-code/types"
 
 import { findLast } from "@roo/array"
-import { SuggestionItem } from "@roo-code/types"
 import { combineApiRequests } from "@roo/combineApiRequests"
 import { combineCommandSequences } from "@roo/combineCommandSequences"
 import { getApiMetrics } from "@roo/getApiMetrics"
@@ -1336,13 +1335,17 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 
 	const switchToMode = useCallback(
 		(modeSlug: string): void => {
+			if (!getAllModes(customModes).some((modeConfig) => modeConfig.slug === modeSlug)) {
+				return
+			}
+
 			// Update local state and notify extension to sync mode change.
 			setMode(modeSlug)
 
 			// Send the mode switch message.
 			vscode.postMessage({ type: "mode", text: modeSlug })
 		},
-		[setMode],
+		[customModes, setMode],
 	)
 
 	const handleSuggestionClickInRow = useCallback(
@@ -1358,12 +1361,13 @@ const ChatViewComponent: React.ForwardRefRenderFunction<ChatViewRef, ChatViewPro
 			}
 
 			// Check if we need to switch modes
-			if (suggestion.mode) {
+			const suggestionMode = getSuggestionMode(suggestion.mode)
+			if (suggestionMode) {
 				// Only switch modes if it's a manual click (event exists) or auto-approval is allowed
 				const isManualClick = !!event
 				if (isManualClick || alwaysAllowModeSwitch) {
 					// Switch mode without waiting
-					switchToMode(suggestion.mode)
+					switchToMode(suggestionMode)
 				}
 			}
 

webview-ui/src/components/chat/FollowUpSuggest.tsx

@@ -5,7 +5,7 @@ import { Button, StandardTooltip } from "@/components/ui"
 
 import { useAppTranslation } from "@src/i18n/TranslationContext"
 import { useExtensionState } from "@src/context/ExtensionStateContext"
-import { SuggestionItem } from "@roo-code/types"
+import { getSuggestionMode, type SuggestionItem } from "@roo-code/types"
 import { cn } from "@/lib/utils"
 
 const DEFAULT_FOLLOWUP_TIMEOUT_MS = 60000
@@ -111,6 +111,7 @@ export const FollowUpSuggest = ({
 		<div className="flex mb-2 flex-col h-full gap-2">
 			{suggestions.map((suggestion, index) => {
 				const isFirstSuggestion = index === 0
+				const suggestionMode = getSuggestionMode(suggestion.mode)
 
 				return (
 					<div key={`${suggestion.answer}-${ts}`} className="w-full relative group">
@@ -134,10 +135,10 @@ export const FollowUpSuggest = ({
 								{t("chat:followUpSuggest.timerPrefix", { seconds: countdown })}
 							</p>
 						)}
-						{suggestion.mode && (
+						{suggestionMode && (
 							<div className="absolute bottom-0 right-0 text-[10px] text-vscode-badge-foreground pl-1 pr-2.5 pt-0.5 pb-1.5 flex items-center gap-0.5 bg-transparent rounded-xl">
 								<span className="codicon codicon-arrow-right" style={{ fontSize: "8px" }} />
-								{suggestion.mode}
+								{suggestionMode}
 							</div>
 						)}
 						<StandardTooltip content={t("chat:followUpSuggest.copyToInput")}>

webview-ui/src/components/chat/__tests__/ChatView.spec.tsx

@@ -6,6 +6,7 @@ import { QueryClient, QueryClientProvider } from "@tanstack/react-query"
 
 import { ExtensionStateContextProvider } from "@src/context/ExtensionStateContext"
 import { vscode } from "@src/utils/vscode"
+import type { SuggestionItem } from "@roo-code/types"
 
 import ChatView, { ChatViewProps } from "../ChatView"
 
@@ -46,7 +47,33 @@ vi.mock("use-sound", () => ({
 
 // Mock components that use ESM dependencies
 vi.mock("../ChatRow", () => ({
-	default: function MockChatRow({ message }: { message: ClineMessage }) {
+	default: function MockChatRow({
+		message,
+		onSuggestionClick,
+	}: {
+		message: ClineMessage
+		onSuggestionClick?: (suggestion: SuggestionItem, event?: React.MouseEvent) => void
+	}) {
+		if (message.type === "ask" && message.ask === "followup" && message.text) {
+			try {
+				const followUp = JSON.parse(message.text) as { suggest?: SuggestionItem[] }
+				return (
+					<div data-testid="chat-row">
+						{followUp.suggest?.map((suggestion) => (
+							<button
+								key={suggestion.answer}
+								type="button"
+								onClick={(event) => onSuggestionClick?.(suggestion, event)}>
+								{suggestion.answer}
+							</button>
+						))}
+					</div>
+				)
+			} catch {
+				// Fall through to the generic row renderer.
+			}
+		}
+
 		return <div data-testid="chat-row">{JSON.stringify(message)}</div>
 	},
 }))
@@ -1050,6 +1077,97 @@ describe("ChatView - Message Queueing Tests", () => {
 	})
 })
 
+describe("ChatView - Follow-up Suggestions", () => {
+	beforeEach(() => {
+		vi.clearAllMocks()
+		vi.mocked(vscode.postMessage).mockClear()
+	})
+
+	it("switches to a known mode from a malformed object mode suggestion", async () => {
+		const { getByRole } = renderChatView()
+
+		mockPostMessage({
+			mode: "ask",
+			customModes: [],
+			clineMessages: [
+				{
+					type: "say",
+					say: "task",
+					ts: Date.now() - 1000,
+					text: "Initial task",
+				},
+				{
+					type: "ask",
+					ask: "followup",
+					ts: Date.now(),
+					text: JSON.stringify({
+						question: "Switch mode?",
+						suggest: [{ answer: "Use code mode", mode: { mode_slug: "code" } }],
+					}),
+					partial: false,
+				},
+			],
+		})
+
+		const suggestion = await waitFor(() => getByRole("button", { name: "Use code mode" }))
+		vi.mocked(vscode.postMessage).mockClear()
+
+		fireEvent.click(suggestion)
+
+		await waitFor(() => {
+			expect(vscode.postMessage).toHaveBeenCalledWith({ type: "mode", text: "code" })
+		})
+		expect(vscode.postMessage).toHaveBeenCalledWith({
+			type: "askResponse",
+			askResponse: "messageResponse",
+			text: "Use code mode",
+			images: [],
+		})
+	})
+
+	it("does not switch modes for an unknown malformed object mode suggestion", async () => {
+		const { getByRole } = renderChatView()
+
+		mockPostMessage({
+			mode: "ask",
+			customModes: [],
+			clineMessages: [
+				{
+					type: "say",
+					say: "task",
+					ts: Date.now() - 1000,
+					text: "Initial task",
+				},
+				{
+					type: "ask",
+					ask: "followup",
+					ts: Date.now(),
+					text: JSON.stringify({
+						question: "Switch mode?",
+						suggest: [{ answer: "Use invalid mode", mode: { mode_slug: "not-a-mode" } }],
+					}),
+					partial: false,
+				},
+			],
+		})
+
+		const suggestion = await waitFor(() => getByRole("button", { name: "Use invalid mode" }))
+		vi.mocked(vscode.postMessage).mockClear()
+
+		fireEvent.click(suggestion)
+
+		await waitFor(() => {
+			expect(vscode.postMessage).toHaveBeenCalledWith({
+				type: "askResponse",
+				askResponse: "messageResponse",
+				text: "Use invalid mode",
+				images: [],
+			})
+		})
+		expect(vscode.postMessage).not.toHaveBeenCalledWith(expect.objectContaining({ type: "mode" }))
+	})
+})
+
 describe("ChatView - Context Condensing Indicator Tests", () => {
 	beforeEach(() => {
 		vi.clearAllMocks()

webview-ui/src/components/chat/__tests__/FollowUpSuggest.spec.tsx

@@ -243,6 +243,23 @@ describe("FollowUpSuggest", () => {
 		expect(container.firstChild).toBeNull()
 	})
 
+	it("should render malformed object mode values without crashing", () => {
+		const suggestions = [{ answer: "Use code mode", mode: { mode_slug: "code" } }] as any
+
+		renderWithTestProviders(
+			<FollowUpSuggest
+				suggestions={suggestions}
+				onSuggestionClick={mockOnSuggestionClick}
+				ts={123}
+				onCancelAutoApproval={mockOnCancelAutoApproval}
+			/>,
+			defaultTestState,
+		)
+
+		expect(screen.getByText("Use code mode")).toBeInTheDocument()
+		expect(screen.getByText("code")).toBeInTheDocument()
+	})
+
 	it("should stop countdown when user manually responds (isAnswered becomes true)", () => {
 		const { rerender } = renderWithTestProviders(
 			<FollowUpSuggest