@efesto-cloud/mongodb-database-context

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

Installation

pnpm add @efesto-cloud/mongodb-database-context @efesto-cloud/database-context mongodb

Quick Start

import { MongoClient } from "mongodb";
import MongoDBContext from "@efesto-cloud/mongodb-database-context/MongoDBContext";

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

const db = new MongoDBContext(client);

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

API

interface IMongoDBContext extends IDatabaseContext {
    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 db.session into their MongoDB calls — forgetting to do so opts that operation out of the transaction.