@efesto-cloud/mongodb-unit-of-work

MongoDB implementation of IUnitOfWork. Wraps a MongoClient and exposes a ClientSession that repositories can use for session-scoped reads/writes inside runWithTransaction.

Installation

pnpm add @efesto-cloud/mongodb-unit-of-work @efesto-cloud/unit-of-work mongodb

Quick Start

import { MongoClient } from "mongodb";
import MongoDBUnitOfWork from "@efesto-cloud/mongodb-unit-of-work/MongoDBUnitOfWork";

const client = new MongoClient(process.env.MONGO_URL!);
await client.connect();

const uow = new MongoDBUnitOfWork(client);

await uow.runWithTransaction(async () => {
    await coll.updateOne(
        { _id: id },
        { $set: { … } },
        { session: uow.session },   // pass the session to every op
    );
});

API

interface IMongoDBUnitOfWork extends IUnitOfWork {
    readonly session: ClientSession | undefined; // active session, if any
    readonly sessionOrNull: ClientSession | null;

    runWithTransaction<T>(fn: () => Promise<T>): Promise<T>;
}

• session / sessionOrNull — the currently active ClientSession. Pass it as { session } to every MongoDB operation so reads/writes participate in the transaction.
• runWithTransaction(fn) — starts a session and wraps fn in session.withTransaction. If a transaction is already running (nested call), it reuses the outer one and just invokes fn.

Notes

• The session is started lazily on the first runWithTransaction call and ended when the outermost call returns.
• Nesting is safe: inner runWithTransaction calls run within the outer transaction without starting a new one.
• Repositories should always thread uow.session into their MongoDB calls — forgetting to do so opts that operation out of the transaction.