Merge Tag v0.2.22

lib/atoms.ts

@@ -115,9 +115,27 @@ export const pomodoroAtom = atom<PomodoroAtom>({
   minimized: false,
 })
 
+import { prepareDataForHashing, generateCryptoHash } from '@/lib/utils';
+
 export const userSelectAtom = atom<boolean>(false)
 export const aboutOpenAtom = atom<boolean>(false)
 
+/**
+ * Asynchronous atom that calculates a freshness token (hash) based on the current client-side data.
+ * This token can be compared with a server-generated token to detect data discrepancies.
+ */
+export const clientFreshnessTokenAtom = atom(async (get) => {
+  const settings = get(settingsAtom);
+  const habits = get(habitsAtom);
+  const coins = get(coinsAtom);
+  const wishlist = get(wishlistAtom);
+  const users = get(usersAtom);
+
+  const dataString = prepareDataForHashing(settings, habits, coins, wishlist, users);
+  const hash = await generateCryptoHash(dataString);
+  return hash;
+});
+
 // Derived atom for completion cache
 export const completionCacheAtom = atom((get) => {
   const habits = get(habitsAtom).habits;

lib/server-helpers.ts

@@ -37,4 +37,4 @@ export function verifyPassword(password?: string, storedHash?: string): boolean
   const newHash = saltAndHashPassword(password, salt).split(':')[1]
   // Compare the new hash with the stored hash
   return newHash === hash
-}
+}

lib/utils.test.ts

@@ -22,10 +22,13 @@ import {
   serializeRRule,
   convertHumanReadableFrequencyToMachineReadable,
   convertMachineReadableFrequencyToHumanReadable,
-  getUnsupportedRRuleReason
+  getUnsupportedRRuleReason,
+  prepareDataForHashing,
+  generateCryptoHash
 } from './utils'
-import { CoinTransaction, ParsedResultType } from './types'
+import { CoinTransaction, ParsedResultType, Settings, HabitsData, CoinsData, WishlistData, UserData } from './types'
 import { DateTime } from "luxon";
+import { getDefaultSettings, getDefaultHabitsData, getDefaultCoinsData, getDefaultWishlistData, getDefaultUsersData } from './types';
 import { RRule, Weekday } from 'rrule';
 import { Habit } from '@/lib/types';
 import { INITIAL_DUE } from './constants';
@@ -956,3 +959,96 @@ describe('convertMachineReadableFrequencyToHumanReadable', () => {
     expect(humanReadable).toBe('invalid')
   })
 })
+
+describe('freshness utilities', () => {
+  const mockSettings: Settings = getDefaultSettings();
+  const mockHabits: HabitsData = getDefaultHabitsData();
+  const mockCoins: CoinsData = getDefaultCoinsData();
+  const mockWishlist: WishlistData = getDefaultWishlistData();
+  const mockUsers: UserData = getDefaultUsersData();
+
+  // Add a user to mockUsers for more realistic testing
+  mockUsers.users.push({
+    id: 'user-123',
+    username: 'testuser',
+    isAdmin: false,
+  });
+  mockHabits.habits.push({
+    id: 'habit-123',
+    name: 'Test Habit',
+    description: 'A habit for testing',
+    frequency: 'FREQ=DAILY',
+    coinReward: 10,
+    completions: [],
+    userIds: ['user-123']
+  });
+
+
+  describe('prepareDataForHashing', () => {
+    test('should produce a consistent string for the same data', () => {
+      const data1 = { settings: mockSettings, habits: mockHabits, coins: mockCoins, wishlist: mockWishlist, users: mockUsers };
+      const data2 = { settings: mockSettings, habits: mockHabits, coins: mockCoins, wishlist: mockWishlist, users: mockUsers }; // Identical data
+
+      const string1 = prepareDataForHashing(data1.settings, data1.habits, data1.coins, data1.wishlist, data1.users);
+      const string2 = prepareDataForHashing(data2.settings, data2.habits, data2.coins, data2.wishlist, data2.users);
+
+      expect(string1).toBe(string2);
+    });
+
+    test('should produce a different string if settings data changes', () => {
+      const string1 = prepareDataForHashing(mockSettings, mockHabits, mockCoins, mockWishlist, mockUsers);
+      const modifiedSettings = { ...mockSettings, system: { ...mockSettings.system, timezone: 'America/Chicago' } };
+      const string2 = prepareDataForHashing(modifiedSettings, mockHabits, mockCoins, mockWishlist, mockUsers);
+      expect(string1).not.toBe(string2);
+    });
+
+    test('should produce a different string if habits data changes', () => {
+      const string1 = prepareDataForHashing(mockSettings, mockHabits, mockCoins, mockWishlist, mockUsers);
+      const modifiedHabits = { ...mockHabits, habits: [...mockHabits.habits, { id: 'new-habit', name: 'New', description: '', frequency: 'FREQ=DAILY', coinReward: 5, completions: [] }] };
+      const string2 = prepareDataForHashing(mockSettings, modifiedHabits, mockCoins, mockWishlist, mockUsers);
+      expect(string1).not.toBe(string2);
+    });
+
+    test('should handle empty data consistently', () => {
+      const emptySettings = getDefaultSettings();
+      const emptyHabits = getDefaultHabitsData();
+      const emptyCoins = getDefaultCoinsData();
+      const emptyWishlist = getDefaultWishlistData();
+      const emptyUsers = getDefaultUsersData();
+
+      const string1 = prepareDataForHashing(emptySettings, emptyHabits, emptyCoins, emptyWishlist, emptyUsers);
+      const string2 = prepareDataForHashing(emptySettings, emptyHabits, emptyCoins, emptyWishlist, emptyUsers);
+      expect(string1).toBe(string2);
+      expect(string1).toBeDefined();
+    });
+  });
+
+  describe('generateCryptoHash', () => {
+    test('should generate a SHA-256 hex string', async () => {
+      const dataString = 'test string';
+      const hash = await generateCryptoHash(dataString);
+      expect(hash).toMatch(/^[a-f0-9]{64}$/); // SHA-256 hex is 64 chars
+    });
+
+    test('should generate different hashes for different strings', async () => {
+      const hash1 = await generateCryptoHash('test string 1');
+      const hash2 = await generateCryptoHash('test string 2');
+      expect(hash1).not.toBe(hash2);
+    });
+
+    test('should generate the same hash for the same string', async () => {
+      const hash1 = await generateCryptoHash('consistent string');
+      const hash2 = await generateCryptoHash('consistent string');
+      expect(hash1).toBe(hash2);
+    });
+
+    // Test with a known SHA-256 value if possible, or ensure crypto.subtle.digest is available
+    // For "hello world", SHA-256 is "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9"
+    test('should generate correct hash for a known string', async () => {
+      const knownString = "hello world";
+      const expectedHash = "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9";
+      const actualHash = await generateCryptoHash(knownString);
+      expect(actualHash).toBe(expectedHash);
+    });
+  });
+})

lib/utils.ts

@@ -2,11 +2,12 @@ import { clsx, type ClassValue } from "clsx"
 import { twMerge } from "tailwind-merge"
 import { DateTime, DateTimeFormatOptions } from "luxon"
 import { datetime, RRule } from 'rrule'
-import { Freq, Habit, CoinTransaction, Permission, ParsedFrequencyResult, ParsedResultType, User } from '@/lib/types'
+import { Freq, Habit, CoinTransaction, Permission, ParsedFrequencyResult, ParsedResultType, User, Settings, HabitsData, CoinsData, WishlistData, UserData } from '@/lib/types'
 import { DUE_MAP, INITIAL_DUE, RECURRENCE_RULE_MAP } from "./constants"
 import * as chrono from 'chrono-node'
 import _ from "lodash"
 import { v4 as uuidv4 } from 'uuid'
+import stableStringify from 'json-stable-stringify';
 
 export function cn(...inputs: ClassValue[]) {
   return twMerge(clsx(inputs))
@@ -481,3 +482,50 @@ export function hasPermission(
   // Otherwise, check specific permissions.
   return checkPermission(currentUser.permissions, resource, action);
 }
+
+/**
+ * Prepares a consistent string representation of the data for hashing.
+ * It combines all relevant data pieces into a single object and then stringifies it stably.
+ */
+export function prepareDataForHashing(
+  settings: Settings,
+  habits: HabitsData,
+  coins: CoinsData,
+  wishlist: WishlistData,
+  users: UserData
+): string {
+  // Combine all data into a single object.
+  // The order of keys in this object itself doesn't matter due to stableStringify,
+  // but being explicit helps in understanding what's being hashed.
+  const combinedData = {
+    settings,
+    habits,
+    coins,
+    wishlist,
+    users,
+  };
+  const stringifiedData = stableStringify(combinedData);
+  // Handle cases where stringify might return undefined.
+  if (stringifiedData === undefined) {
+    throw new Error("Failed to stringify data for hashing. stableStringify returned undefined.");
+  }
+  return stringifiedData;
+}
+
+/**
+ * Generates a SHA-256 hash for a given string using the Web Crypto API.
+ * This function is suitable for both client-side and server-side (Node.js 19+) environments.
+ * @param dataString The string to hash.
+ * @returns A promise that resolves to the hex string of the hash.
+ */
+export async function generateCryptoHash(dataString: string): Promise<string> {
+  const encoder = new TextEncoder();
+  const data = encoder.encode(dataString);
+  // globalThis.crypto should be available in modern browsers and Node.js (v19+)
+  // For Node.js v15-v18, you might need: const { subtle } = require('node:crypto').webcrypto;
+  const hashBuffer = await globalThis.crypto.subtle.digest('SHA-256', data);
+  const hashArray = Array.from(new Uint8Array(hashBuffer));
+  // Convert buffer to hex string
+  const hashHex = hashArray.map(b => b.toString(16).padStart(2, '0')).join('');
+  return hashHex;
+}