fix: prevent enhance prompt from overwriting both edit and new message boxes

- Add context parameter to enhance prompt messages to distinguish between main and edit mode
- Update ChatTextArea to only respond to enhance prompt messages matching its context
- Add comprehensive test coverage for context-specific behavior

Fixes #8553

src/core/webview/webviewMessageHandler.ts

@@ -1694,7 +1694,12 @@ export const webviewMessageHandler = async (
 					if (result.success && result.enhancedText) {
 						// Capture telemetry for prompt enhancement
 						MessageEnhancer.captureTelemetry(currentCline?.taskId, includeTaskHistoryInEnhance)
-						await provider.postMessageToWebview({ type: "enhancedPrompt", text: result.enhancedText })
+						// Include the context from the original request in the response
+						await provider.postMessageToWebview({
+							type: "enhancedPrompt",
+							text: result.enhancedText,
+							context: message.context,
+						})
 					} else {
 						throw new Error(result.error || "Unknown error")
 					}
@@ -1704,7 +1709,11 @@ export const webviewMessageHandler = async (
 					)
 
 					vscode.window.showErrorMessage(t("common:errors.enhance_prompt"))
-					await provider.postMessageToWebview({ type: "enhancedPrompt" })
+					// Include context even in error response
+					await provider.postMessageToWebview({
+						type: "enhancedPrompt",
+						context: message.context,
+					})
 				}
 			}
 			break

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

@@ -124,28 +124,33 @@ export const ChatTextArea = forwardRef<HTMLTextAreaElement, ChatTextAreaProps>(
 				const message = event.data
 
 				if (message.type === "enhancedPrompt") {
-					if (message.text && textAreaRef.current) {
-						try {
-							// Use execCommand to replace text while preserving undo history
-							if (document.execCommand) {
-								// Use native browser methods to preserve undo stack
-								const textarea = textAreaRef.current
+					// Only handle the enhanced prompt if it's for this specific textarea instance
+					// Edit mode textareas have context "edit", main textarea has context "main"
+					const expectedContext = isEditMode ? "edit" : "main"
+					if (message.context === expectedContext) {
+						if (message.text && textAreaRef.current) {
+							try {
+								// Use execCommand to replace text while preserving undo history
+								if (document.execCommand) {
+									// Use native browser methods to preserve undo stack
+									const textarea = textAreaRef.current
 
-								// Focus the textarea to ensure it's the active element
-								textarea.focus()
+									// Focus the textarea to ensure it's the active element
+									textarea.focus()
 
-								// Select all text first
-								textarea.select()
-								document.execCommand("insertText", false, message.text)
-							} else {
+									// Select all text first
+									textarea.select()
+									document.execCommand("insertText", false, message.text)
+								} else {
+									setInputValue(message.text)
+								}
+							} catch {
 								setInputValue(message.text)
 							}
-						} catch {
-							setInputValue(message.text)
 						}
-					}
 
-					setIsEnhancingPrompt(false)
+						setIsEnhancingPrompt(false)
+					}
 				} else if (message.type === "insertTextIntoTextarea") {
 					if (message.text && textAreaRef.current) {
 						// Insert the command text at the current cursor position
@@ -196,7 +201,7 @@ export const ChatTextArea = forwardRef<HTMLTextAreaElement, ChatTextAreaProps>(
 
 			window.addEventListener("message", messageHandler)
 			return () => window.removeEventListener("message", messageHandler)
-		}, [setInputValue, searchRequestId, inputValue])
+		}, [setInputValue, searchRequestId, inputValue, isEditMode])
 
 		const [isDraggingOver, setIsDraggingOver] = useState(false)
 		const [textAreaBaseHeight, setTextAreaBaseHeight] = useState<number | undefined>(undefined)
@@ -239,11 +244,13 @@ export const ChatTextArea = forwardRef<HTMLTextAreaElement, ChatTextAreaProps>(
 
 			if (trimmedInput) {
 				setIsEnhancingPrompt(true)
-				vscode.postMessage({ type: "enhancePrompt" as const, text: trimmedInput })
+				// Include context to identify which textarea is requesting enhancement
+				const context = isEditMode ? "edit" : "main"
+				vscode.postMessage({ type: "enhancePrompt" as const, text: trimmedInput, context })
 			} else {
 				setInputValue(t("chat:enhancePromptDescription"))
 			}
-		}, [inputValue, setInputValue, t])
+		}, [inputValue, setInputValue, t, isEditMode])
 
 		const allModes = useMemo(() => getAllModes(customModes), [customModes])
 

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

@@ -112,6 +112,7 @@ describe("ChatTextArea", () => {
 			expect(mockPostMessage).toHaveBeenCalledWith({
 				type: "enhancePrompt",
 				text: "Test prompt",
+				context: "main",
 			})
 		})
 
@@ -183,7 +184,7 @@ describe("ChatTextArea", () => {
 	})
 
 	describe("enhanced prompt response", () => {
-		it("should update input value using native browser methods when receiving enhanced prompt", () => {
+		it("should update input value using native browser methods when receiving enhanced prompt with matching context", () => {
 			const setInputValue = vi.fn()
 
 			// Mock document.execCommand
@@ -205,12 +206,13 @@ describe("ChatTextArea", () => {
 			textarea.select = mockSelect
 			textarea.focus = mockFocus
 
-			// Simulate receiving enhanced prompt message
+			// Simulate receiving enhanced prompt message with matching context
 			window.dispatchEvent(
 				new MessageEvent("message", {
 					data: {
 						type: "enhancedPrompt",
 						text: "Enhanced test prompt",
+						context: "main",
 					},
 				}),
 			)
@@ -221,6 +223,90 @@ describe("ChatTextArea", () => {
 			expect(mockExecCommand).toHaveBeenCalledWith("insertText", false, "Enhanced test prompt")
 		})
 
+		it("should ignore enhanced prompt with non-matching context", () => {
+			const setInputValue = vi.fn()
+
+			// Mock document.execCommand
+			const mockExecCommand = vi.fn().mockReturnValue(true)
+			Object.defineProperty(document, "execCommand", {
+				value: mockExecCommand,
+				writable: true,
+			})
+
+			const { container } = render(
+				<ChatTextArea {...defaultProps} setInputValue={setInputValue} inputValue="Original prompt" />,
+			)
+
+			const textarea = container.querySelector("textarea")!
+
+			// Mock textarea methods
+			const mockSelect = vi.fn()
+			const mockFocus = vi.fn()
+			textarea.select = mockSelect
+			textarea.focus = mockFocus
+
+			// Simulate receiving enhanced prompt message with non-matching context (edit instead of main)
+			window.dispatchEvent(
+				new MessageEvent("message", {
+					data: {
+						type: "enhancedPrompt",
+						text: "Enhanced test prompt",
+						context: "edit",
+					},
+				}),
+			)
+
+			// Verify native browser methods were NOT called
+			expect(mockFocus).not.toHaveBeenCalled()
+			expect(mockSelect).not.toHaveBeenCalled()
+			expect(mockExecCommand).not.toHaveBeenCalled()
+			expect(setInputValue).not.toHaveBeenCalled()
+		})
+
+		it("should handle enhanced prompt for edit mode", () => {
+			const setInputValue = vi.fn()
+
+			// Mock document.execCommand
+			const mockExecCommand = vi.fn().mockReturnValue(true)
+			Object.defineProperty(document, "execCommand", {
+				value: mockExecCommand,
+				writable: true,
+			})
+
+			const { container } = render(
+				<ChatTextArea
+					{...defaultProps}
+					setInputValue={setInputValue}
+					inputValue="Original prompt"
+					isEditMode={true}
+				/>,
+			)
+
+			const textarea = container.querySelector("textarea")!
+
+			// Mock textarea methods
+			const mockSelect = vi.fn()
+			const mockFocus = vi.fn()
+			textarea.select = mockSelect
+			textarea.focus = mockFocus
+
+			// Simulate receiving enhanced prompt message with edit context
+			window.dispatchEvent(
+				new MessageEvent("message", {
+					data: {
+						type: "enhancedPrompt",
+						text: "Enhanced test prompt",
+						context: "edit",
+					},
+				}),
+			)
+
+			// Verify native browser methods were called for edit mode
+			expect(mockFocus).toHaveBeenCalled()
+			expect(mockSelect).toHaveBeenCalled()
+			expect(mockExecCommand).toHaveBeenCalledWith("insertText", false, "Enhanced test prompt")
+		})
+
 		it("should fallback to setInputValue when execCommand is not available", () => {
 			const setInputValue = vi.fn()
 
@@ -238,6 +324,7 @@ describe("ChatTextArea", () => {
 					data: {
 						type: "enhancedPrompt",
 						text: "Enhanced test prompt",
+						context: "main",
 					},
 				}),
 			)
@@ -258,6 +345,7 @@ describe("ChatTextArea", () => {
 						data: {
 							type: "enhancedPrompt",
 							text: "Enhanced test prompt",
+							context: "main",
 						},
 					}),
 				)