Invoice App Backend

This is the backend for the Invoice App, a full-stack application that allows users to create, update, delete, and manage invoices securely. Built with Node.js, Express, and MongoDB, this RESTful API serves as the server-side solution to store and process data.

The corresponding front-end repository is:

• Invoice App Frontend (built with Angular and Tailwind CSS)

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Features

User Authentication

• Secure user registration and login with password hashing using bcrypt.
• JWT-based authentication for secure access to API endpoints.

Invoice Management

• CRUD operations: Create, Read, Update, and Delete invoices.
• Filter invoices by status (draft, pending, paid).
• Validate invoice details before saving.

Data Validation

• Robust validation using Express Validator to ensure data integrity.

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Tech Stack

• Node.js: JavaScript runtime environment
• Express: Web framework for creating the REST API
• MongoDB: NoSQL database for storing user and invoice data
• Mongoose: ODM for MongoDB
• Passport.js: Middleware for authentication (local strategy and JWT)
• Bcrypt: Password hashing
• Express Validator: Request validation middleware
• Dotenv: Manage environment variables

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Installation and Setup

Prerequisites

Ensure you have the following installed on your system:

• Node.js
• MongoDB

Steps

1. Clone the repository

   git clone https://github.com/yourusername/invoice-app-backend.git
   cd invoice-app-backend

2. Install dependencies

   npm install

3. Set up environment variables Create a .env file in the project root and add the following:

 MONGO_URI=your_mongodb_connection_string
JWT_SECRET=your_jwt_secret
PORT=5000

4. Run the server For development:

   npm run dev

For production:

   npm start

The server will start at http://localhost:5000 (default port).

API Endpoints

Method	Endpoint	Description	Authentication
POST	/login	Log in a user	No
POST	/users	Register a new user	No
PUT	/users/:username	Update user data	Yes
DELETE	/users/:username	Delete a user	Yes
GET	/invoices	Get all invoices	Yes
GET	/invoices/:id	Get a specific invoice by ID	Yes
POST	/invoices	Create a new invoice	Yes
PUT	/invoices/:id	Update an invoice	Yes
PATCH	/invoices/:id/mark-as-paid	Mark an invoice as "paid"	Yes
DELETE	/invoices/:id	Delete an invoice	Yes

Future Enhancements

Improved error handling and logging Input sanitization for additional security Allow filtering invoices by date and client name

License

This project is licensed under the MIT License.