Setting up a project with back-end Express.js 2.0: Webpack, TypeScript, Jest, ESLint, Prettier configurations.

Setting up a backend project with Express.js 2.0 along with Webpack, TypeScript, Jest, ESLint, and Prettier is a common practice for modern web development. In this tutorial, we will guide you through the process of configuring these technologies in your project.

Step 1: Setup a Node.js Project
First, you need to set up a Node.js project if you haven’t already. You can do this by creating a new directory for your project and running the following commands in your terminal:

mkdir express-project
cd express-project
npm init -y

This will create a package.json file in your project directory.

Step 2: Install Dependencies
Next, you need to install the necessary dependencies for your project. Run the following command to install Express.js and TypeScript:

npm install express @types/express typescript

This will install Express.js and TypeScript as dependencies for your project.

Step 3: Configure TypeScript
Create a tsconfig.json file in your project directory with the following configuration:

{
  "compilerOptions": {
    "target": "ES6",
    "module": "commonjs",
    "outDir": "./dist",
    "strict": true
  }
}

This configuration instructs TypeScript to compile your code to ES6, use CommonJS modules, and output the compiled code to a dist directory.

Step 4: Create an Express.js Server
Create a new file index.ts in your project directory and add the following code to create an Express.js server:

import express from 'express';

const app = express();
const port = 3000;

app.get('/', (req, res) => {
  res.send('Hello World!');
});

app.listen(port, () => {
  console.log(`Server running on port ${port}`);
});

Step 5: Update Package.json Scripts
Update the scripts section in your package.json file to include the following commands:

"scripts": {
  "start": "node dist/index.js",
  "build": "tsc",
}

The start script will run the compiled code, and the build script will compile your TypeScript code using the TypeScript compiler (tsc).

Step 6: Install Webpack
Next, install Webpack as a dev dependency:

npm install webpack webpack-cli --save-dev

Step 7: Configure Webpack
Create a webpack.config.js file in your project directory with the following configuration:

const path = require('path');

module.exports = {
  mode: 'development',
  entry: './dist/index.js',
  output: {
    path: path.resolve(__dirname, 'build'),
    filename: 'bundle.js',
  }
};

This configuration tells Webpack to build the bundle.js file from the dist/index.js file.

Step 8: Update Package.json Scripts
Update the scripts section in your package.json file to include the following command to run Webpack:

"scripts": {
  "start": "node build/bundle.js",
  "build": "tsc && webpack",
}

The build script will now compile your TypeScript code and bundle it using Webpack.

Step 9: Install Jest, ESLint, and Prettier
Next, install Jest, ESLint, and Prettier as dev dependencies:

npm install jest @types/jest eslint prettier --save-dev

Step 10: Configure Jest
Create a jest.config.js file in your project directory with the following configuration:

module.exports = {
  "roots": [
    "<rootDir>/test"
  ],
  "testMatch": [
    "**/*.test.ts"
  ],
  "transform": {
    "^.+.ts$": "ts-jest"
  }
}

This configuration specifies the root directory for your test files and tells Jest how to transform TypeScript files.

Step 11: Configure ESLint
Create an .eslintrc.json file in your project directory with the following configuration:

{
  "extends": ["eslint:recommended", "plugin:@typescript-eslint/recommended"],
  "parser": "@typescript-eslint/parser",
  "parserOptions": {
    "project": "./tsconfig.json"
  }
}

This configuration enables ESLint and sets it up to work with TypeScript.

Step 12: Configure Prettier
Create a .prettierrc file in your project directory with the following configuration:

{
  "singleQuote": true,
  "semi": false
}

This configuration sets up Prettier to use single quotes and omit semicolons in your code.

Step 13: Run Your Project
You can now run your project by running the following commands:

npm run build
npm start

This will compile your TypeScript code, bundle it using Webpack, and start your Express.js server.

In this tutorial, we have walked you through the process of setting up a backend project with Express.js 2.0 and configuring it with Webpack, TypeScript, Jest, ESLint, and Prettier. By following these steps, you can build and deploy modern web applications with ease.