CODEWITHSUNDEEP
reactjsexpresswebpack
Angelzzz
Angelzzz

Reputation: 1446

How to enable watch for webpack MERN?

I'm making MERN (with React in Front-end and Express in Back-end) based application from a scratch. And I want webpack to reload page every time I save files. But it's not working.

My webpack.config.js

const path = require('path');
const entryFile = path.resolve(__dirname, 'src', 'client', 'app.js');
const outputDir = path.resolve(__dirname, 'public');

module.exports = {
  entry: ['babel-polyfill', entryFile],
  output: {
    filename: 'bundle.js',
    path: outputDir
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        loader: 'babel-loader',
        exclude: /node_modules/
      },
      {
        test: /\.(scss|css)$/,
        use: [
          {
            loader: 'style-loader'
          }, 
          { 
            loader: 'css-loader',
          }, 
          { 
            loader: 'sass-loader'
          }
        ]
      }
    ]
  }
};

my package.json

{
  ...
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "babel-node src/server/app.js",
    "prestart": "webpack --mode development"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/2u4u/share-book.git"
  },
  ...
  "dependencies": {
    "express": "^4.16.3",
    "webpack": "^4.17.1",
    "webpack-dev-server": "^3.1.5"
  },
  "devDependencies": {
    "babel-cli": "^6.26.0",
    "babel-core": "^6.26.3",
    "babel-loader": "^7.1.5",
    "babel-polyfill": "^6.26.0",
    "babel-preset-env": "^1.7.0",
    "babel-preset-react": "^6.24.1",
    "babel-preset-stage-0": "^6.24.1",
    "css-loader": "^1.0.0",
    "node-sass": "^4.9.3",
    "react": "^16.4.2",
    "react-dom": "^16.4.2",
    "sass-loader": "^7.1.0",
    "style-loader": "^0.22.1",
    "webpack-cli": "^3.1.0",
    "webpack-command": "^0.4.1"
  }
}

I tried to add watch: true in the end of webpack config, but it's not starting server then. Where is the problem?

UPD: Can problem be in server/app.js?

import express from 'express';
import path from 'path';
const app = express();
const publicPath = path.resolve(__dirname, '..', '..', 'public');
app.use(express.static(publicPath));
app.listen(3000, () => {   
    console.log(`NEW one MERN Boilerplate listening on port 3000 and looking in folder ${publicPath}`);
});

Upvotes: 1

Views: 312

Answers (3)

PlayMa256
PlayMa256

Reputation: 6841

"prestart": "webpack --mode development --watch"

Simple and easy. This has to be ran into one terminal, the server in another one.

Upvotes: 0

Sakhi Mansoor
Sakhi Mansoor

Reputation: 8102

Add -- hot in your dev script it should work if you’re using webpack v4. Otherwise you can add hot module in your webpack config. The following should be your devDependencies

 "dependencies": {
   "webpack": "^4.17.1",
   "webpack-dev-server": "^3.1.5"
 },

and make changes in your "start and "prestart" script:

"prestart": webpack-dev-server --mode development --config webpack.config.js --open --hot
"start": "babel-node nodemon src/server/app.js",

Upvotes: 1

Hemadri Dasari
Hemadri Dasari

Reputation: 33994

You can directly add watch to prestart script in package.json

"prestart": "webpack --mode development" --watch --hot

OR

add devserver in webpack.config.js file something like below

devServer: {
    contentBase: './public',
    hot: true,
    watch: true
}

Upvotes: 1

Related Questions