Source Maps not working with Webpack

Question

I\'m pretty new to webpack and having some trouble configuring it to produce the necessary source maps. In the devtools it says

Source Map detected

Answer 1

The issue I was facing was in my nginx configuration. My nginx configuration was throwing 404 for the source map files, because it couldn't identify the .map files where to look for. So added .map also in addition to .js|.css and it was fixed.

location ~* \.(?:css|js|map)$ {
  expires 1y;
  access_log off;
  add_header Cache-Control "public";
}

Answer 2

In bundle.js you will see original transpiled webpack bundle - this is normal behaviour.

Open webpack:// and you will see your project files.

Answer 3

Please add in you webpack.config.js file the following`

devtool: "#inline-source-map",

You can find clear information about it from the site of webpack` https://webpack.github.io/docs/configuration.html

Also please find attached screenshot of sourcemap part, from webpack site.

Answer 4

Make sure you have --mode development in your npm build script,

{
 "name": "test",
 "version": "1.0.1",
 "description": "",
 "scripts": {
 "build": "webpack",
  "start": "webpack-dev-server --mode development --open"
   "test": "echo \"Error: no test specified\" && exit 1",
 },
  "author": "",
  "license": "",
  "devDependencies": {
  "babel-core": "^6.26.3",
  "babel-loader": "^7.1.5",
  "babel-preset-env": "^1.7.0",
  "webpack": "^4.19.1",
  "webpack-cli": "^3.1.0",
  "webpack-dev-server": "^3.1.8"
  },
  "dependencies": {}
 }

webpack.config.js

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

module.exports = {
    entry: './src/web.js',
    devtool: 'inline-source-map',
    output: {
        filename: 'main.js',
        path: path.resolve(__dirname, 'dist')
    },
    mode: 'development',
    module: {
        rules: [{
            test: /\.js$/,
            exclude: /(node_modules)/,
            use: {
                loader: "babel-loader",
                options: {
                    presets: ["babel-preset-env"]
                }
            }
        }]
    },
    devServer: {
        inline: true,
        contentBase: path.join(__dirname, 'dist'),
        compress: true,
        port: 9000,
        watchOptions: {
            index: 'index.html',
            open: true,
            poll: true,
            watchContentBase: true
        }
    },
    watch: true,
    watchOptions: {
        aggregateTimeout: 500,
        ignored: /node_modules/,
        poll: 3000
    }
}