Method fork

packages/core/src/EntityManager.ts:2523–2577

* Returns new EntityManager instance with its own identity map

(options: ForkOptions = {})

   * Returns new EntityManager instance with its own identity map
   */
  fork(options: ForkOptions = {}): this {
    const em = options.disableContextResolution ? this : this.getContext(false);
    options.clear ??= true;
    options.useContext ??= false;
    options.freshEventManager ??= false;
    options.cloneEventManager ??= false;

    const eventManager = options.freshEventManager
      ? new EventManager(em.config.get('subscribers'))
      : options.cloneEventManager
        ? em.eventManager.clone()
        : em.eventManager;

    // we need to allow global context here as forking from global EM is fine
    const allowGlobalContext = em.config.get('allowGlobalContext');
    em.config.set('allowGlobalContext', true);
    const fork = new (em.constructor as typeof EntityManager)(
      em.config,
      em.driver,
      em.metadata,
      options.useContext,
      eventManager,
    );
    fork.setFlushMode(options.flushMode ?? em.#flushMode);
    fork.#disableTransactions =
      options.disableTransactions ?? this.#disableTransactions ?? this.config.get('disableTransactions');
    em.config.set('allowGlobalContext', allowGlobalContext);

    if (options.keepTransactionContext) {
      fork.#transactionContext = em.#transactionContext;
    }

    fork.#filters = { ...em.#filters };
    fork.#filterParams = Utils.copy(em.#filterParams);
    fork.loggerContext = Utils.merge({}, em.loggerContext, options.loggerContext);
    fork.#schema = options.schema ?? em.#schema;
    fork.signal = options.signal ?? em.signal;
    fork.inflightQueryAbortStrategy = options.inflightQueryAbortStrategy ?? em.inflightQueryAbortStrategy;

    if (!options.clear) {
      for (const entity of em.#unitOfWork.getIdentityMap()) {
        fork.#unitOfWork.register(entity);
      }

      for (const entity of em.#unitOfWork.getPersistStack()) {
        fork.#unitOfWork.persist(entity);
      }

      for (const entity of em.#unitOfWork.getOrphanRemoveStack()) {
        fork.#unitOfWork.getOrphanRemoveStack().add(entity);
      }
    }

    return fork as this;
  }

  /**
   * Gets the UnitOfWork used by the EntityManager to coordinate operations.