Add unit tests for data file rotation utility functions

- Implement tests for writing data files with rotation, ensuring backups are created only on changes.
- Verify that old backups are rotated correctly and the maximum number of backups is maintained.
- Test restoration of backups while preserving the current state as a backup.
- Utilize Vitest for testing framework and manage temporary file storage during tests.

server/utils/auth.js

@@ -4,6 +4,7 @@ import crypto from 'crypto'
 import { promises as fs } from 'fs'
 import path from 'path'
 import { encryptObject, decryptObject } from './encryption.js'
+import { writeDataFileWithRotation } from './data-file-rotation.js'
 
 // Export migrateUserRoles für Verwendung in anderen Modulen
 export function migrateUserRoles(user) {
@@ -196,7 +197,7 @@ export async function writeUsers(users) {
   try {
     const encryptionKey = getEncryptionKey()
     const encryptedData = encryptObject(users, encryptionKey)
-    await fs.writeFile(USERS_FILE, encryptedData, 'utf-8')
+    await writeDataFileWithRotation(USERS_FILE, encryptedData, { encoding: 'utf-8' })
     return true
   } catch (error) {
     console.error('Fehler beim Schreiben der Benutzerdaten:', error)
@@ -262,7 +263,7 @@ export async function writeSessions(sessions) {
   try {
     const encryptionKey = getEncryptionKey()
     const encryptedData = encryptObject(sessions, encryptionKey)
-    await fs.writeFile(SESSIONS_FILE, encryptedData, 'utf-8')
+    await writeDataFileWithRotation(SESSIONS_FILE, encryptedData, { encoding: 'utf-8' })
     return true
   } catch (error) {
     console.error('Fehler beim Schreiben der Sessions:', error)