refactor(storage): add legacy task normalization for migration to IndexedDB

Author: tyler-dane

packages/web/src/common/utils/storage/task-migration.util.test.ts

@@ -195,6 +195,29 @@ describe("task-migration.util", () => {
       expect(allTasks).toHaveLength(1);
       expect(allTasks[0].title).toBe("Valid Task");
     });
+
+    it("should migrate legacy tasks with id mapped to _id", async () => {
+      const task = createMockTask({
+        _id: "legacy-task-id",
+        title: "Legacy Task",
+      });
+      const { _id, ...rest } = task;
+      const legacyTask = { ...rest, id: _id };
+
+      localStorage.setItem(
+        `${TASK_STORAGE_KEY_PREFIX}2024-01-15`,
+        JSON.stringify([legacyTask]),
+      );
+
+      const migratedCount = await migrateTasksFromLocalStorageToIndexedDB();
+
+      expect(migratedCount).toBe(1);
+
+      const allTasks = await loadAllTasksFromIndexedDB();
+      expect(allTasks).toHaveLength(1);
+      expect(allTasks[0]._id).toBe("legacy-task-id");
+      expect(allTasks[0].title).toBe("Legacy Task");
+    });
   });
 
   describe("resetTaskMigrationFlag", () => {

packages/web/src/common/utils/storage/task-migration.util.ts

@@ -5,6 +5,29 @@ import { saveTaskToIndexedDB } from "./task.storage.util";
 const MIGRATION_FLAG_KEY = "compass.tasks.migrated-to-indexeddb";
 const TASK_STORAGE_KEY_PREFIX = "compass.today.tasks.";
 
+function normalizeLegacyTask(item: unknown): Task | null {
+  if (isTask(item)) {
+    return item;
+  }
+
+  if (!item || typeof item !== "object") {
+    return null;
+  }
+
+  const legacyTask = item as Record<string, unknown> & { id?: unknown };
+  if (typeof legacyTask.id !== "string") {
+    return null;
+  }
+
+  const { id, ...rest } = legacyTask;
+  const mappedTask = {
+    ...rest,
+    _id: id,
+  };
+
+  return isTask(mappedTask) ? mappedTask : null;
+}
+
 /**
  * Checks if task migration from localStorage to IndexedDB has been completed.
  */
@@ -69,13 +92,15 @@ export async function migrateTasksFromLocalStorageToIndexedDB(): Promise<number>
         // in localStorage so successful migrations are not duplicated on retry.
         const remainingTasks: Task[] = [];
         for (const item of parsed) {
-          if (isTask(item)) {
+          const normalizedTask = normalizeLegacyTask(item);
+
+          if (normalizedTask) {
             try {
-              await saveTaskToIndexedDB(item, dateKey);
+              await saveTaskToIndexedDB(normalizedTask, dateKey);
               migratedCount++;
             } catch (saveError) {
               hasSaveFailures = true;
-              remainingTasks.push(item);
+              remainingTasks.push(normalizedTask);
               console.error(
                 `Failed to save task to IndexedDB for dateKey: ${dateKey}`,
                 saveError,