update error wording

- Parse JSON once and rely on outer catch
- If content is not an array, log and rewrite with []
- Skip migration only when the new file has a non-empty array
- Prevent silent skips and normalize corrupt task history files

src/core/controller/index.ts

@@ -70,6 +70,10 @@ export class Controller {
 					"[Controller] CRITICAL: Failed to initialize StateManager - extension may not function properly:",
 					error,
 				)
+				HostProvider.window.showMessage({
+					type: ShowMessageType.ERROR,
+					message: "Failed to initialize Cline's application state. Please restart the extension.",
+				})
 			})
 
 		// Set up persistence error recovery

src/core/storage/disk.ts

@@ -202,10 +202,12 @@ export async function readTaskHistoryFromState(context: vscode.ExtensionContext)
 		const filePath = await getTaskHistoryStateFilePath(context)
 		if (await fileExistsAtPath(filePath)) {
 			const contents = await fs.readFile(filePath, "utf8")
-			if (contents.trim() === "") {
-				return []
+			try {
+				return JSON.parse(contents)
+			} catch (error) {
+				console.error("[Disk] Failed to parse task history, it is malformed:", error)
+				throw error
 			}
-			return JSON.parse(contents)
 		}
 		return []
 	} catch (error) {

src/core/storage/state-migrations.ts

@@ -2,7 +2,13 @@ import fs from "fs/promises"
 import path from "path"
 import * as vscode from "vscode"
 import { HistoryItem } from "@/shared/HistoryItem"
-import { ensureRulesDirectoryExists, readTaskHistoryFromState, writeTaskHistoryToState } from "./disk"
+import { fileExistsAtPath } from "@/utils/fs"
+import {
+	ensureRulesDirectoryExists,
+	getTaskHistoryStateFilePath,
+	readTaskHistoryFromState,
+	writeTaskHistoryToState,
+} from "./disk"
 import { StateManager } from "./StateManager"
 
 export async function migrateWorkspaceToGlobalStorage(context: vscode.ExtensionContext) {
@@ -69,37 +75,60 @@ export async function migrateWorkspaceToGlobalStorage(context: vscode.ExtensionC
 
 export async function migrateTaskHistoryToFile(context: vscode.ExtensionContext) {
 	try {
-		// Get data from old location
-		const vscodeGlobalStateTaskHistory = context.globalState.get<HistoryItem[] | undefined>("taskHistory")
+		// Check if the taskHistory is already in the new location.
+		// If it exists and is a valid, non-empty array, we skip the migration.
+		const taskHistoryFilePath = await getTaskHistoryStateFilePath(context)
 
-		// Normalize old location data to array (empty array if undefined/null/not-array)
-		const oldLocationData = Array.isArray(vscodeGlobalStateTaskHistory) ? vscodeGlobalStateTaskHistory : []
+		if (await fileExistsAtPath(taskHistoryFilePath)) {
+			try {
+				const contents = await fs.readFile(taskHistoryFilePath, "utf8")
+				const newTaskHistory = JSON.parse(contents)
+				if (!Array.isArray(newTaskHistory)) {
+					console.error(
+						"[Storage Migration] Task history in the new location is not an array, rewriting with an empty array.",
+					)
+					await writeTaskHistoryToState(context, [])
+				}
+				if (newTaskHistory.length > 0) {
+					console.log("[Storage Migration] Task history already in new location, skipping migration")
+					return
+				}
+			} catch (error) {
+				console.error("[Disk] Failed to read task history:", error)
+				return
+			}
+		}
 
-		// Early return if no migration needed
-		if (oldLocationData.length === 0) {
-			console.log("[Storage Migration] No task history to migrate")
+		// If we have reached this point, then the taskHistory.json file does not exist or it is an empty array.
+		// We will get the taskHistory from the old location in the vs code global state and write it to the new location.
+
+		const oldLocationTaskHistory = context.globalState.get<HistoryItem[] | undefined>("taskHistory") || []
+
+		// We make sure that the old location taskHistory is an array. If it's not, then it's malformed, so we just write an empty array to the new taskHistory storage location.
+		if (!Array.isArray(oldLocationTaskHistory)) {
+			console.error("[Storage Migration] Task history in the vs code global state is not an array, skipping migration")
 			return
 		}
 
-		let finalData: HistoryItem[]
-		let migrationAction: string
+		// We write the taskHistory from the vs code global state to the new storage location in the json file.
+		await writeTaskHistoryToState(context, oldLocationTaskHistory)
 
-		const newLocationData = await readTaskHistoryFromState(context)
-		if (newLocationData.length === 0) {
-			// Move old data to new location
-			finalData = oldLocationData
-			migrationAction = "Migrated task history from old location to new location"
-		} else {
-			// Merge old data (more recent) with new data
-			finalData = [...newLocationData, ...oldLocationData]
-			migrationAction = "Merged task history from old and new locations"
+		// confirm that the data has been successfully written to the file by reading it back
+		const successfullyWrittenData = await readTaskHistoryFromState(context)
+
+		if (!Array.isArray(successfullyWrittenData)) {
+			console.error("[Storage Migration] Task history in the new location is not an array, aborting migration.")
+			return
 		}
 
-		// Perform migration operations sequentially - only clear old data if write succeeds
-		await writeTaskHistoryToState(context, finalData)
-		void context.globalState.update("taskHistory", undefined)
+		if (successfullyWrittenData.length !== oldLocationTaskHistory.length) {
+			console.error("[Storage Migration] Task history has not been successfully written to the file")
+			return
+		}
 
-		console.log(`[Storage Migration] ${migrationAction}`)
+		console.log(
+			`[Storage Migration] Migrated task history from old location to new location. ${successfullyWrittenData.length} items written.`,
+		)
 	} catch (error) {
 		console.error("[Storage Migration] Failed to migrate task history to file:", error)
 	}