Symbol-Based Private State Encapsulation with WeakMap Storage in Angular Services

import { Injectable } from '@angular/core';
 
const SECRET_KEY = Symbol('InternalVaultKey');
const vaultStorage = new WeakMap<object, Map<symbol, unknown>>();
 
@Injectable({ providedIn: 'root' })
export class SecureVaultService {
  constructor() {
    vaultStorage.set(this, new Map());
  }
 
  setPrivateSecret(secret: string): void {
    const internalStore = vaultStorage.get(this);
    if (internalStore) {
      internalStore.set(SECRET_KEY, Object.freeze({ token: secret, timestamp: Date.now() }));
    }
  }
 
  getPrivateSecret(): { token: string; timestamp: number } | null {
    const internalStore = vaultStorage.get(this);
    const data = internalStore?.get(SECRET_KEY);
    return data ? (data as { token: string; timestamp: number }) : null;
  }
}