Step-by-Step Guide: Setting Up a Production-Ready Node.js and Express App

Are you ready to take your Node.js and Express development skills to the next level? This guide walks you through building a modern Express app from scratch, integrating essential tools like TypeScript, Jest, ESLint, and Nodemon for a smooth development experience. Whether you’re new to Express or a seasoned developer, this step-by-step tutorial is packed with tips to streamline your workflow.

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Step 1: Initialize Your Node.js Project

Start in an empty folder by running:

npm init -y

Install TypeScript and related packages:

npm install typescript ts-node @types/node tsconfig-node20-base --save-dev

Generate a tsconfig.json file and extend it with node20-base for modern configurations tailored for Node.js 20.

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Step 2: Set Up Jest for Testing

Install testing dependencies:

npm install jest ts-jest @types/jest --save-dev

Create a jest.config.mjs file to configure Jest with TypeScript support. Add utility functions and test them in the src/tests directory to ensure everything works.

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Step 3: Configure ESLint and Prettier

Maintain clean and error-free code by installing ESLint and Prettier:

npm install eslint prettier eslint-plugin-prettier eslint-config-prettier --save-dev

Run npm init @eslint/config to generate an ESLint configuration. Integrate Prettier for automatic code formatting and enforce rules using the new flat configuration format.

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Step 4: Install and Configure Express

Add Express and middleware:

npm install express cors morgan  
npm install @types/express @types/cors @types/morgan --save-dev

Create a basic server in src/server.ts, with middleware for logging, request parsing, and handling CORS. Add a health check route (GET /health) to verify the server is running.

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Step 5: Automate Development with Nodemon

Install Nodemon for automatic server restarts:

npm install nodemon --save-dev

Create a nodemon.json file to watch for changes in .ts and .json files. Add a script to your package.json:

"scripts": {
  "dev": "nodemon"
}

Run the server with npm run dev and see your changes reflected instantly.

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Bonus: Test Your API

Install the REST Client extension in VS Code to test your API endpoints directly in the editor. Create an api-test.http file and send requests to verify your app’s functionality.

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Conclusion

In this guide, we built a modern Node.js Express app with TypeScript, Jest, ESLint, Prettier, and Nodemon. Each tool plays a vital role in enhancing development efficiency, code quality, and maintainability.