핫 모듈 교체 핫 모듈 교체

{
  "name": "webpack-demo",
  "version": "1.0.0",
  "description": "",
  "private": true,
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "watch": "webpack --watch",
    "start": "webpack-dev-server --open",
    "server": "node server.js",
    "build": "webpack"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "clean-webpack-plugin": "^3.0.0",
    "css-loader": "^3.0.0",
    "csv-loader": "^3.0.2",
    "express": "^4.17.1",
    "file-loader": "^4.0.0",
    "html-webpack-plugin": "^3.2.0",
    "style-loader": "^0.23.1",
    "url-loader": "^2.0.1",
    "webpack": "^4.35.0",
    "webpack-cli": "^3.3.5",
    "webpack-dev-middleware": "^3.7.0",
    "webpack-dev-server": "^3.7.2",
    "webpack-manifest-plugin": "^2.0.4",
    "xml-loader": "^1.2.1"
  },
  "dependencies": {
    "lodash": "^4.17.11"
  }
} 

import _ from 'lodash';
import printMe from './print.js';
import './style.css';

function component() {
    const element = document.createElement('div');
    const btn = document.createElement('button');

    element.innerHTML = _.join(['Hello', 'webpack'], ' ');

    btn.innerHTML = 'Click me and check the console!';
    btn.onclick = printMe;  // onclick event is bind to the original printMe function

    element.appendChild(btn);

    return element;
}


let element = component(); // Store the element to re-render on print.js changes
document.body.appendChild(element);

if (module.hot) {
    module.hot.accept('./print.js', function () {
        console.log('########################');
        document.body.removeChild(element);
        element = component(); // Re-render the "component" to update the click handler
        document.body.appendChild(element);
    })
} 

export default function printMe() {
    console.log('3335')
} 

body {
    background: blue;
} 

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin'); //  index.html
const {CleanWebpackPlugin} = require('clean-webpack-plugin'); // dist 
var ManifestPlugin = require('webpack-manifest-plugin'); // a mapping of all source file names to their corresponding output file
const webpack = require('webpack');
module.exports = {
    // entry: './src/index.js',
    mode: 'development',
    entry: {
        app: './src/index.js'
        // print: './src/print.js'
    },
    devtool: 'inline-source-map',
    devServer: {
        contentBase: './dist',
        hot: true
    },
    devtool: 'inline-cheap-module-source-map',
    plugins: [
        new ManifestPlugin(),
        new CleanWebpackPlugin(),
        new HtmlWebpackPlugin({
            title: 'Output Management'
        }),
        new webpack.HotModuleReplacementPlugin()
    ],
    // output: {
    //     filename: 'bundle.js',
    //     path: path.resolve(__dirname, 'dist')
    // }
    output: {
        filename: '[name].bundle.js',
        path: path.resolve(__dirname, 'dist'),
        publicPath: '/'
    },
    module: {
        rules: [
            {
                test: /\.css$/,
                use: ['style-loader', 'css-loader']
            }
        ]
    },
}