fix: show preparing message before file path stabilizes

This change implements a two-phase UX for file editing operations:
1. Show "Roo is preparing to edit a file..." immediately when a file edit starts
2. Update to "Roo wants to edit this file" with the actual filename once path stabilizes

The issue was that file paths arrive character-by-character during streaming, and
the UI waited for path stabilization before showing anything, creating the appearance
of a frozen UI.

Changes:
- Added preparingToEdit translation string to all 18 locale files
- Modified ChatRow.tsx to show preparing message when tool.path is undefined
- Updated CodeAccordian.tsx to show loading placeholder for undefined paths
- Added hasSentInitialMessage flag to BaseTool.ts
- Updated ApplyDiffTool, EditFileTool, WriteToFileTool, SearchAndReplaceTool,
  and SearchReplaceTool to send initial "preparing" message immediately
- Updated writeToFileTool test to reflect new behavior

Addresses issue #10855

src/core/tools/ApplyDiffTool.ts

@@ -271,7 +271,18 @@ export class ApplyDiffTool extends BaseTool<"apply_diff"> {
 		const relPath: string | undefined = block.params.path
 		const diffContent: string | undefined = block.params.diff
 
-		// Wait for path to stabilize before showing UI (prevents truncated paths)
+		// Send initial "preparing" message immediately (before path stabilizes)
+		if (!this.hasSentInitialMessage) {
+			this.hasSentInitialMessage = true
+			const initialMessageProps: ClineSayTool = {
+				tool: "appliedDiff",
+				path: undefined as any, // Undefined path triggers "preparing to edit" message in frontend
+				diff: diffContent,
+			}
+			await task.ask("tool", JSON.stringify(initialMessageProps), block.partial).catch(() => {})
+		}
+
+		// Wait for path to stabilize before showing the full UI with filename
 		if (!this.hasPathStabilized(relPath)) {
 			return
 		}

src/core/tools/BaseTool.ts

@@ -38,6 +38,12 @@ export abstract class BaseTool<TName extends ToolName> {
 	 */
 	protected lastSeenPartialPath: string | undefined = undefined
 
+	/**
+	 * Track whether the initial "preparing" message has been sent for this tool invocation.
+	 * Used by file editing tools to show immediate feedback before the path stabilizes.
+	 */
+	protected hasSentInitialMessage: boolean = false
+
 	/**
 	 * Execute the tool with typed parameters.
 	 *
@@ -96,6 +102,7 @@ export abstract class BaseTool<TName extends ToolName> {
 	 */
 	resetPartialState(): void {
 		this.lastSeenPartialPath = undefined
+		this.hasSentInitialMessage = false
 	}
 
 	/**

src/core/tools/EditFileTool.ts

@@ -488,7 +488,18 @@ export class EditFileTool extends BaseTool<"edit_file"> {
 		const filePath: string | undefined = block.params.file_path
 		const oldString: string | undefined = block.params.old_string
 
-		// Wait for path to stabilize before showing UI (prevents truncated paths)
+		// Send initial "preparing" message immediately (before path stabilizes)
+		if (!this.hasSentInitialMessage) {
+			this.hasSentInitialMessage = true
+			const initialMessageProps: ClineSayTool = {
+				tool: "appliedDiff",
+				path: undefined as any, // Undefined path triggers "preparing to edit" message in frontend
+				diff: undefined,
+			}
+			await task.ask("tool", JSON.stringify(initialMessageProps), block.partial).catch(() => {})
+		}
+
+		// Wait for path to stabilize before showing the full UI with filename
 		if (!this.hasPathStabilized(filePath)) {
 			return
 		}

src/core/tools/SearchAndReplaceTool.ts

@@ -257,7 +257,18 @@ export class SearchAndReplaceTool extends BaseTool<"search_and_replace"> {
 	override async handlePartial(task: Task, block: ToolUse<"search_and_replace">): Promise<void> {
 		const relPath: string | undefined = block.params.path
 
-		// Wait for path to stabilize before showing UI (prevents truncated paths)
+		// Send initial "preparing" message immediately (before path stabilizes)
+		if (!this.hasSentInitialMessage) {
+			this.hasSentInitialMessage = true
+			const initialMessageProps: ClineSayTool = {
+				tool: "appliedDiff",
+				path: undefined as any, // Undefined path triggers "preparing to edit" message in frontend
+				diff: "",
+			}
+			await task.ask("tool", JSON.stringify(initialMessageProps), block.partial).catch(() => {})
+		}
+
+		// Wait for path to stabilize before showing the full UI with filename
 		if (!this.hasPathStabilized(relPath)) {
 			return
 		}

src/core/tools/SearchReplaceTool.ts

@@ -243,7 +243,18 @@ export class SearchReplaceTool extends BaseTool<"search_replace"> {
 		const filePath: string | undefined = block.params.file_path
 		const oldString: string | undefined = block.params.old_string
 
-		// Wait for path to stabilize before showing UI (prevents truncated paths)
+		// Send initial "preparing" message immediately (before path stabilizes)
+		if (!this.hasSentInitialMessage) {
+			this.hasSentInitialMessage = true
+			const initialMessageProps: ClineSayTool = {
+				tool: "appliedDiff",
+				path: undefined as any, // Undefined path triggers "preparing to edit" message in frontend
+				diff: "",
+			}
+			await task.ask("tool", JSON.stringify(initialMessageProps), block.partial).catch(() => {})
+		}
+
+		// Wait for path to stabilize before showing the full UI with filename
 		if (!this.hasPathStabilized(filePath)) {
 			return
 		}

src/core/tools/WriteToFileTool.ts

@@ -197,7 +197,18 @@ export class WriteToFileTool extends BaseTool<"write_to_file"> {
 		const relPath: string | undefined = block.params.path
 		let newContent: string | undefined = block.params.content
 
-		// Wait for path to stabilize before showing UI (prevents truncated paths)
+		// Send initial "preparing" message immediately (before path stabilizes)
+		if (!this.hasSentInitialMessage) {
+			this.hasSentInitialMessage = true
+			const initialMessageProps: ClineSayTool = {
+				tool: "newFileCreated",
+				path: undefined as any, // Undefined path triggers "preparing to edit" message in frontend
+				content: "",
+			}
+			await task.ask("tool", JSON.stringify(initialMessageProps), block.partial).catch(() => {})
+		}
+
+		// Wait for path to stabilize before showing the full UI with filename
 		if (!this.hasPathStabilized(relPath) || newContent === undefined) {
 			return
 		}

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

@@ -400,12 +400,16 @@ describe("writeToFileTool", () => {
 		})
 
 		it("streams content updates during partial execution after path stabilizes", async () => {
-			// First call - path not yet stabilized, early return (no file operations)
+			// First call - path not yet stabilized, sends initial "preparing" message but no file operations
 			await executeWriteFileTool({}, { isPartial: true })
-			expect(mockCline.ask).not.toHaveBeenCalled()
+			// Initial "preparing" message is sent with undefined path to show UI immediately
+			expect(mockCline.ask).toHaveBeenCalledWith("tool", expect.stringContaining('"tool":"newFileCreated"'), true)
 			expect(mockCline.diffViewProvider.open).not.toHaveBeenCalled()
 
-			// Second call with same path - path is now stabilized, file operations proceed
+			// Clear mocks to track subsequent calls
+			vi.clearAllMocks()
+
+			// Second call with same path - path is now stabilized, full file operations proceed
 			await executeWriteFileTool({}, { isPartial: true })
 			expect(mockCline.ask).toHaveBeenCalled()
 			expect(mockCline.diffViewProvider.open).toHaveBeenCalledWith(testFilePath)
@@ -455,11 +459,11 @@ describe("writeToFileTool", () => {
 		it("handles partial streaming errors after path stabilizes", async () => {
 			mockCline.diffViewProvider.open.mockRejectedValue(new Error("Open failed"))
 
-			// First call - path not yet stabilized, no error yet
+			// First call - path not yet stabilized, sends initial message but no error (ask catches errors)
 			await executeWriteFileTool({}, { isPartial: true })
 			expect(mockHandleError).not.toHaveBeenCalled()
 
-			// Second call with same path - path is now stabilized, error occurs
+			// Second call with same path - path is now stabilized, error occurs during file operations
 			await executeWriteFileTool({}, { isPartial: true })
 			expect(mockHandleError).toHaveBeenCalledWith("handling partial write_to_file", expect.any(Error))
 		})

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

@@ -445,11 +445,13 @@ export const ChatRowContent = ({
 								toolIcon(tool.tool === "appliedDiff" ? "diff" : "edit")
 							)}
 							<span style={{ fontWeight: "bold" }}>
-								{tool.isProtected
-									? t("chat:fileOperations.wantsToEditProtected")
-									: tool.isOutsideWorkspace
-										? t("chat:fileOperations.wantsToEditOutsideWorkspace")
-										: t("chat:fileOperations.wantsToEdit")}
+								{!tool.path
+									? t("chat:fileOperations.preparingToEdit")
+									: tool.isProtected
+										? t("chat:fileOperations.wantsToEditProtected")
+										: tool.isOutsideWorkspace
+											? t("chat:fileOperations.wantsToEditOutsideWorkspace")
+											: t("chat:fileOperations.wantsToEdit")}
 							</span>
 						</div>
 						<div className="pl-6">
@@ -479,15 +481,17 @@ export const ChatRowContent = ({
 								toolIcon("insert")
 							)}
 							<span style={{ fontWeight: "bold" }}>
-								{tool.isProtected
-									? t("chat:fileOperations.wantsToEditProtected")
-									: tool.isOutsideWorkspace
-										? t("chat:fileOperations.wantsToEditOutsideWorkspace")
-										: tool.lineNumber === 0
-											? t("chat:fileOperations.wantsToInsertAtEnd")
-											: t("chat:fileOperations.wantsToInsertWithLineNumber", {
-													lineNumber: tool.lineNumber,
-												})}
+								{!tool.path
+									? t("chat:fileOperations.preparingToEdit")
+									: tool.isProtected
+										? t("chat:fileOperations.wantsToEditProtected")
+										: tool.isOutsideWorkspace
+											? t("chat:fileOperations.wantsToEditOutsideWorkspace")
+											: tool.lineNumber === 0
+												? t("chat:fileOperations.wantsToInsertAtEnd")
+												: t("chat:fileOperations.wantsToInsertWithLineNumber", {
+														lineNumber: tool.lineNumber,
+													})}
 							</span>
 						</div>
 						<div className="pl-6">
@@ -517,11 +521,13 @@ export const ChatRowContent = ({
 								toolIcon("replace")
 							)}
 							<span style={{ fontWeight: "bold" }}>
-								{tool.isProtected && message.type === "ask"
-									? t("chat:fileOperations.wantsToEditProtected")
-									: message.type === "ask"
-										? t("chat:fileOperations.wantsToSearchReplace")
-										: t("chat:fileOperations.didSearchReplace")}
+								{!tool.path && message.type === "ask"
+									? t("chat:fileOperations.preparingToEdit")
+									: tool.isProtected && message.type === "ask"
+										? t("chat:fileOperations.wantsToEditProtected")
+										: message.type === "ask"
+											? t("chat:fileOperations.wantsToSearchReplace")
+											: t("chat:fileOperations.didSearchReplace")}
 							</span>
 						</div>
 						<div className="pl-6">
@@ -580,9 +586,11 @@ export const ChatRowContent = ({
 								toolIcon("new-file")
 							)}
 							<span style={{ fontWeight: "bold" }}>
-								{tool.isProtected
-									? t("chat:fileOperations.wantsToEditProtected")
-									: t("chat:fileOperations.wantsToCreate")}
+								{!tool.path
+									? t("chat:fileOperations.preparingToEdit")
+									: tool.isProtected
+										? t("chat:fileOperations.wantsToEditProtected")
+										: t("chat:fileOperations.wantsToCreate")}
 							</span>
 						</div>
 						<div className="pl-6">

webview-ui/src/components/common/CodeAccordian.tsx

@@ -68,15 +68,19 @@ const CodeAccordian = ({
 								{isFeedback ? "User Edits" : "Console Logs"}
 							</span>
 						</div>
-					) : (
+					) : path ? (
 						<>
-							{path?.startsWith(".") && <span>.</span>}
+							{path.startsWith(".") && <span>.</span>}
 							<PathTooltip content={formatPathTooltip(path)}>
 								<span className="whitespace-nowrap overflow-hidden text-ellipsis text-left mr-2 rtl">
 									{formatPathTooltip(path)}
 								</span>
 							</PathTooltip>
 						</>
+					) : (
+						<span className="whitespace-nowrap overflow-hidden text-ellipsis text-left mr-2 text-vscode-descriptionForeground italic">
+							Loading file...
+						</span>
 					)}
 					<div className="flex-grow-1" />
 					{/* Prefer diff stats over generic progress indicator if available */}

webview-ui/src/i18n/locales/ca/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo vol obtenir instruccions detallades per ajudar amb la tasca actual."
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo s'està preparant per editar un fitxer...",
 		"wantsToRead": "Roo vol llegir aquest fitxer",
 		"wantsToReadOutsideWorkspace": "Roo vol llegir aquest fitxer fora de l'espai de treball",
 		"didRead": "Roo ha llegit aquest fitxer",

webview-ui/src/i18n/locales/de/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo möchte detaillierte Anweisungen abrufen, um bei der aktuellen Aufgabe zu helfen"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo bereitet die Bearbeitung einer Datei vor...",
 		"wantsToRead": "Roo möchte diese Datei lesen",
 		"wantsToReadAndXMore": "Roo möchte diese Datei und {{count}} weitere lesen",
 		"wantsToReadOutsideWorkspace": "Roo möchte diese Datei außerhalb des Arbeitsbereichs lesen",

webview-ui/src/i18n/locales/en/chat.json

@@ -203,6 +203,7 @@
 		"wantsToFetch": "Roo wants to fetch detailed instructions to assist with the current task"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo wants to read this file",
 		"wantsToReadMultiple": "Roo wants to read multiple files",
 		"wantsToReadAndXMore": "Roo wants to read this file and {{count}} more",

webview-ui/src/i18n/locales/es/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo quiere obtener instrucciones detalladas para ayudar con la tarea actual"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo quiere leer este archivo",
 		"wantsToReadOutsideWorkspace": "Roo quiere leer este archivo fuera del espacio de trabajo",
 		"didRead": "Roo leyó este archivo",

webview-ui/src/i18n/locales/fr/chat.json

@@ -179,6 +179,7 @@
 		"current": "Actuel"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo veut lire ce fichier",
 		"wantsToReadOutsideWorkspace": "Roo veut lire ce fichier en dehors de l'espace de travail",
 		"didRead": "Roo a lu ce fichier",

webview-ui/src/i18n/locales/hi/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo को वर्तमान कार्य में सहायता के लिए विस्तृत निर्देश प्राप्त करना है"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo इस फ़ाइल को पढ़ना चाहता है",
 		"wantsToReadOutsideWorkspace": "Roo कार्यक्षेत्र के बाहर इस फ़ाइल को पढ़ना चाहता है",
 		"didRead": "Roo ने इस फ़ाइल को पढ़ा",

webview-ui/src/i18n/locales/id/chat.json

@@ -206,6 +206,7 @@
 		"wantsToFetch": "Roo ingin mengambil instruksi detail untuk membantu tugas saat ini"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo ingin membaca file ini",
 		"wantsToReadMultiple": "Roo ingin membaca beberapa file",
 		"wantsToReadAndXMore": "Roo ingin membaca file ini dan {{count}} lainnya",

webview-ui/src/i18n/locales/it/chat.json

@@ -182,6 +182,7 @@
 		"current": "Corrente"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo vuole leggere questo file",
 		"wantsToReadOutsideWorkspace": "Roo vuole leggere questo file al di fuori dell'area di lavoro",
 		"didRead": "Roo ha letto questo file",

webview-ui/src/i18n/locales/ja/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Rooは現在のタスクを支援するための詳細な指示を取得したい"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Rooはこのファイルを読みたい",
 		"wantsToReadOutsideWorkspace": "Rooはワークスペース外のこのファイルを読みたい",
 		"didRead": "Rooはこのファイルを読みました",

webview-ui/src/i18n/locales/ko/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo는 현재 작업을 지원하기 위해 자세한 지침을 가져오려고 합니다"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo가 이 파일을 읽고 싶어합니다",
 		"wantsToReadOutsideWorkspace": "Roo가 워크스페이스 외부의 이 파일을 읽고 싶어합니다",
 		"didRead": "Roo가 이 파일을 읽었습니다",

webview-ui/src/i18n/locales/nl/chat.json

@@ -177,6 +177,7 @@
 		"wantsToFetch": "Roo wil gedetailleerde instructies ophalen om te helpen met de huidige taak"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo wil dit bestand lezen",
 		"wantsToReadOutsideWorkspace": "Roo wil dit bestand buiten de werkruimte lezen",
 		"didRead": "Roo heeft dit bestand gelezen",

webview-ui/src/i18n/locales/pl/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo chce pobrać szczegółowe instrukcje, aby pomóc w bieżącym zadaniu"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo chce przeczytać ten plik",
 		"wantsToReadOutsideWorkspace": "Roo chce przeczytać ten plik poza obszarem roboczym",
 		"didRead": "Roo przeczytał ten plik",

webview-ui/src/i18n/locales/pt-BR/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo quer buscar instruções detalhadas para ajudar com a tarefa atual"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo quer ler este arquivo",
 		"wantsToReadOutsideWorkspace": "Roo quer ler este arquivo fora do espaço de trabalho",
 		"didRead": "Roo leu este arquivo",

webview-ui/src/i18n/locales/ru/chat.json

@@ -177,6 +177,7 @@
 		"wantsToFetch": "Roo хочет получить подробные инструкции для помощи с текущей задачей"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo хочет прочитать этот файл",
 		"wantsToReadOutsideWorkspace": "Roo хочет прочитать этот файл вне рабочей области",
 		"didRead": "Roo прочитал этот файл",

webview-ui/src/i18n/locales/tr/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo mevcut göreve yardımcı olmak için ayrıntılı talimatlar almak istiyor"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo bu dosyayı okumak istiyor",
 		"wantsToReadOutsideWorkspace": "Roo çalışma alanı dışındaki bu dosyayı okumak istiyor",
 		"didRead": "Roo bu dosyayı okudu",

webview-ui/src/i18n/locales/vi/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo muốn lấy hướng dẫn chi tiết để hỗ trợ nhiệm vụ hiện tại"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo muốn đọc tệp này",
 		"wantsToReadOutsideWorkspace": "Roo muốn đọc tệp này bên ngoài không gian làm việc",
 		"didRead": "Roo đã đọc tệp này",

webview-ui/src/i18n/locales/zh-CN/chat.json

@@ -182,6 +182,7 @@
 		"wantsToFetch": "Roo 想要获取详细指示以协助当前任务"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "需要读取文件",
 		"wantsToReadOutsideWorkspace": "请求访问外部文件",
 		"didRead": "已读取文件",

webview-ui/src/i18n/locales/zh-TW/chat.json

@@ -203,6 +203,7 @@
 		"wantsToFetch": "Roo 想要取得詳細指示以協助目前工作"
 	},
 	"fileOperations": {
+		"preparingToEdit": "Roo is preparing to edit a file...",
 		"wantsToRead": "Roo 想要讀取此檔案",
 		"wantsToReadMultiple": "Roo 想要讀取多個檔案",
 		"wantsToReadAndXMore": "Roo 想要讀取此檔案以及另外 {{count}} 個檔案",