Fix the migration error with checkers (#1006)

* fix the migration error with checking user is not new user with proper data

* fix edge case of no timetables key on data

Author: jason4193

client/src/constants/defaults.ts

@@ -1,8 +1,7 @@
 import { createDefaultTimetable } from '../utils/timetableHelpers';
-import { lightTheme, themes } from './theme';
+import { themes } from './theme';
 
 const defaults: Record<string, any> = {
-  themeObject: lightTheme(Object.keys(themes)[0]),
   currentTheme: Object.keys(themes)[0],
   is12HourMode: true,
   isDarkMode: window.matchMedia('(prefers-color-scheme: dark)').matches,
@@ -13,7 +12,7 @@ const defaults: Record<string, any> = {
   isHideExamClasses: false,
   isConvertToLocalTimezone: false,
   courseData: { map: [] },
-  timetables: { T0: createDefaultTimetable('') },
+  timetables: [...createDefaultTimetable('')],
   version: 1,
 };
 

client/src/utils/storage.ts

@@ -80,8 +80,10 @@ const storage = {
 
     if (localStorage[STORAGE_KEY]) {
       data = JSON.parse(localStorage[STORAGE_KEY]);
-      // migrate old data format to new format
-      data = storage.migrate(data);
+      // migrate old data format to new format when the app is already visited
+      if (localStorage['visited']) {
+        data = storage.migrate(data);
+      }
     } else {
       storage.save(data);
     }
@@ -94,9 +96,10 @@ const storage = {
   },
 
   migrate: (data: Record<string, any>) => {
-    // User has never seen Notangles
-    if (!data || typeof data !== 'object') {
-      data = defaults;
+    // Check if data is empty or not an object or it is {}
+    if (!data || typeof data !== 'object' || Object.keys(data).length === 0 || data.timetables === undefined) {
+      storage.save(defaults);
+      return defaults;
     }
 
     // only do this if version does not exist