[Webpack] Basics

Intro

Video: https://www.youtube.com/watch?v=GU-2T7k9NfI

npm install webpack --save-dev

Webpack helps compose the frontend files and dependency imports.

package.json

"scripts":{
    "build": "webpack src/js/app.js dist/bundle.js", // webpack ENTRYPOINT TARGET
    "build prod": "webpack src/js/app.js dist/bundle.js -p" // production mode, with minified code
}

Webpack dev server

npm install --save-dev webpack-dev-server

package.json

"scripts":{
    "build": "webpack-dev-server --entry ./src/js/app.js --output-filename ./dist/bundle.js",
}

npm run build will serve the files from local server.

Webpack core concepts

entry => module loaders => plugins => output

webpack.config.js

const path = require('path');
const webpack = require('webpack');

module.exports = {
    entry: './src/js/app.js', // define the entry point and get all its imports
    output: {
        path: path.resolve(__dirname, 'dist'), // the output path needs to be an absolute path, and the __dirname is the absolute path to the current directory
        filename: 'bundle.js',
        publicPath: '/dist' // where should the webpack server look for the output 
    },
    module: {
        rules: [
            {
                test: /\.css$/, // lets the webpack know how does specific rule apply
                // loader: 'css-loader', // allows the javascript file to import css, but don't make it compiled
                use: [ // use multiple loaders, order is IMPORTANT, the compile order is reversed, the bottom loads FIRST!!
                    'style-loader', // inject css in DOM
                    'css-loader',
                ]
            },
        ]
    },
    plugins: [
        new webpack.optimize.UglifyJsPlugin({ // minify the bundle code
            //...
        })
    ]
}

package.json

"scripts":{
    "build": "webpack-dev-server",
    "biuld:prod": "webpack -p"
}

Loader & Modules

Modules and loaders allow us to transform the files.

npm install css-loader style-loader --save-dev

• Loaders are applied on a file base
• Plugins are applied to the whole bundle

Babel + SCSS example: https://www.youtube.com/watch?v=8vnkM8JgjpU&list=PL55RiY5tL51rcCnrOrZixuOsZhAHHy6os&index=4