Method begin

packages/mongodb/src/MongoConnection.ts:412–431

(
    options: {
      isolationLevel?: IsolationLevel;
      ctx?: ClientSession;
      eventBroadcaster?: TransactionEventBroadcaster;
    } & TransactionOptions = {},
  )

  }

  override async begin(
    options: {
      isolationLevel?: IsolationLevel;
      ctx?: ClientSession;
      eventBroadcaster?: TransactionEventBroadcaster;
    } & TransactionOptions = {},
  ): Promise<ClientSession> {
    await this.ensureConnection();
    const { ctx, isolationLevel, eventBroadcaster, ...txOptions } = options;

    if (!ctx) {
      await eventBroadcaster?.dispatchEvent(EventType.beforeTransactionStart);
    }
    const session = ctx || this.getClient().startSession();
    session.startTransaction(txOptions);
    this.logQuery('db.begin();');
    await eventBroadcaster?.dispatchEvent(EventType.afterTransactionStart, session);

    return session;
  }

  override async commit(ctx: ClientSession, eventBroadcaster?: TransactionEventBroadcaster): Promise<void> {
    await this.ensureConnection();