@dev-nat/mongoose

A simple Mongoose utility for initializing database connections.

Features

• Cached Mongoose connections (global singleton)
• Retry mechanism with configurable delay
• Supports multiple MongoDB connections
• Works well in serverless environments

Install

Install using the following commands:

npm install @dev-nat/mongoose
yarn add @dev-nat/mongoose
pnpm add @dev-nat/mongoose
bun add @dev-nat/mongoose

Basic Usage

Initialize a Mongoose connection:

// your-db-connection-file.ts
import { createMongooseConnection } from '@dev-nat/mongoose';

export const db = await createMongooseConnection({ uri: 'mongodb://localhost:27017/your-db' });

Initialize Mongoose models:

// your-db-models-file.ts
import { Types, Schema, type Model } from 'mongoose';
import { db } from '@your-db-connection-file';

export interface IPerson {
  _id: Types.Object.Id;
  name: string;
  birthDate: Date;
  createdAt: Date;
  updatedAt: Date;
}

const personSchema = new Schema<IPerson>(
  {
    name: { type: String, required: true },
    birthDate: { type: Date, required: true },
  },
  {
    timestamps: true,
    collection: 'person',
  },
);

// export the model, db.models checks if the model is already initialized
// db.model initializes the model if not yet
export const Person: Model<IPerson> = db.models.person || db.model('person', personSchema);

Initialize multiple connections for multiple MongoDB databases:

// your-db-connection-file.ts
import { createMongooseConnection } from '@dev-nat/mongoose';

export const db1 = await createMongooseConnection({ uri: 'mongodb://localhost:27017/your-db-1' });
export const db2 = await createMongooseConnection({ uri: 'mongodb://localhost:27017/your-db-2' });

Start a session and transaction:

// your-database-service-logic.ts
import { db } from '@your-db-connection-file';
import { Person } from '@your-db-models-file';

export async function updateName(personId: string, newName: string) {
  // no need to call mongoose.connect()

  const session = await db.startSession();

  try {
    // do not forget to start a transaction
    // requires replicaSet to be enabled in MongoDB configuration
    session.startTransaction();

    // perform the operation
    await Person.findByIdAndUpdate(personId, { $set: { name: newName } });

    // save changes
    await session.commitTransaction();
    await session.endSession();
  } catch (err) {
    console.error(err);
    // do not save changes when there is error
    await session.abortTransaction();
    await session.endSession();
  }
}

Better Auth integration

To integrate with better-auth, get the MongoClient like the following:

import { betterAuth } from 'better-auth';
import { mongodbAdapter } from 'better-auth/adapters/mongodb';

// you can rename the import to avoid confusion
import { db as connection } from '@your-db-connection-file';

// get the MongoClient
const client = connection.getClient();
const db = client.db();

export const auth = betterAuth({
  database: mongodbAdapter(db, { client }),
  // the rest of your bettter-auth config
});