Node.js MongoDB API

This project is a simple Node.js Express API that connects to a MongoDB database to retrieve user data. It features a GET endpoint at /users/:id that allows clients to fetch user details by their ID, ensuring that only users older than 21 are returned. The API gracefully handles invalid ObjectId errors and returns a 404 response if the user is not found.

Project Structure

• src/app.js: Entry point of the application, initializes the Express app and sets up middleware and routes.
• src/controllers/userController.js: Contains the logic for handling user-related requests.
• src/models/user.js: Defines the schema for user documents in MongoDB.
• src/routes/userRoutes.js: Sets up the routes for user-related endpoints.
• src/routes/index.js: Combines all resource routers (e.g., user, post) for modular routing.
• src/db/index.js: Manages the connection to the MongoDB database.
• package.json: Lists project dependencies and scripts.

Getting Started

1. Clone the repository.
2. Run npm install to install the required dependencies.
3. Create a .env file in the project root with your MongoDB connection string:

   MONGODB_URI=mongodb://localhost:27017/your_database_name
   PORT=3000
   

4. Start the server with node src/app.js or npm start.

Usage

To retrieve a user by ID, send a GET request to /users/:id, replacing :id with the actual user ID.
The response will include the user's details if they exist and are over 21 years old, or a 404 error if not found.

Approach

• Used Express for routing and middleware.
• Used Mongoose for MongoDB object modeling.
• Modularized the code for scalability, allowing easy addition of new resource routers.
• Implemented error handling for invalid ObjectId and not found cases.
• Used environment variables for configuration (e.g., MongoDB URI, port).