MongoDB Repository Pattern

A flexible and type-safe MongoDB repository pattern implementation for TypeScript applications. This package provides a robust abstraction layer for MongoDB operations with a powerful criteria builder for querying.

Features

• 🎯 Type-safe MongoDB operations
• 🔍 Powerful criteria builder for complex queries
• 📦 Connection management for multiple databases
• 🛠️ Repository pattern implementation
• ⚡ Optimized for performance
• 🧪 Well tested with unit and integration tests
• 🔄 Support for transaction-like operations
• 🎨 Clean and maintainable code structure

Installation

npm install mongo-patterns

Quick Start

import { MongoDBRepository, Criteria, MongoDBConnectionManager } from 'mongodb-repository-pattern';

// Define your entity type
interface User {
  id: string;
  name: string;
  email: string;
  age: number;
}

// Create your repository
class UserRepository extends MongoDBRepository<User> {
  constructor(db: Db) {
    super(db, 'users');
  }
}

// Connect to MongoDB
const db = await MongoDBConnectionManager.connect({
  uri: 'mongodb://localhost:27017',
  dbName: 'myapp'
});

// Initialize repository
const userRepo = new UserRepository(db);

// Create a user
const user = await userRepo.create({
  id:"1",
  name: 'John Doe',
  email: '[email protected]',
  age: 30
});

// Find users using criteria
const users = await userRepo.findMany(
  Criteria.create<User>()
    .where('age', 'GREATER_THAN', 25)
    .andWhere('name', 'LIKE', 'John')
    .orderBy('name', 'ASC')
    .take(10)
    .skip(0)
);

Criteria Builder

The Criteria Builder provides a fluent interface for building complex queries:

const criteria = Criteria.create<User>()
  .where('age', 'GREATER_THAN', 18)
  .andWhere('status', 'IN', ['active', 'pending'])
  .orderBy('createdAt', 'DESC')
  .take(10)
  .skip(0);

Available operators:

• EQUAL
• GREATER_THAN
• LESS_THAN
• GREATER_THAN_OR_EQUAL
• LESS_THAN_OR_EQUAL
• NOT_EQUAL
• IN
• NOT_IN
• LIKE
• BETWEEN

Connection Management

The package includes a robust connection management system:

// Connect to multiple databases
const db1 = await MongoDBConnectionManager.connect({
  uri: 'mongodb://localhost:27017',
  dbName: 'db1'
}, 'client1');

const db2 = await MongoDBConnectionManager.connect({
  uri: 'mongodb://localhost:27017',
  dbName: 'db2'
}, 'client2');

// Get database instances
const db1Instance = MongoDBConnectionManager.getDb('client1');
const db2Instance = MongoDBConnectionManager.getDb('client2');

// Disconnect
await MongoDBConnectionManager.disconnect('client1');
await MongoDBConnectionManager.disconnectAll();

Repository Operations

The repository pattern provides standard CRUD operations:

// Create
const created = await repo.create(document);
const manyCreated = await repo.createMany([doc1, doc2]);

// Read
const one = await repo.findOne(criteria);
const many = await repo.findMany(criteria);
const byId = await repo.findById(id);

// Update
const updated = await repo.updateOne(criteria, update);
const updatedById = await repo.updateById(id, update);

// Delete
const deleted = await repo.deleteOne(criteria);
const deletedById = await repo.deleteById(id);

Project Structure

.
├── src/
│   ├── core/                 # Core functionality
│   ├── domain/              # Domain interfaces
│   ├── infrastructure/      # Implementation
│   │   └── mongodb/        
│   └── types/               # Type definitions
├── tests/
│   ├── integration/         # Integration tests
│   └── unit/               # Unit tests

Running Tests

# Install dependencies
npm install

# Run all tests
npm test

# Run tests with coverage
npm run test:coverage

# Run tests in watch mode
npm run test:watch

Configuration

The package supports various MongoDB connection options:

interface MongoDBConfig {
  uri: string;
  dbName: string;
  options?: {
    maxPoolSize?: number;
    minPoolSize?: number;
    retryWrites?: boolean;
    connectTimeoutMS?: number;
    socketTimeoutMS?: number;
    ssl?: boolean;
    replicaSet?: string;
    authSource?: string;
  };
}

Development

# Build the project
npm run build

# Run tests
npm test