Sourcemaps are detected in chrome but original source is not loaded, using webpack-2

Question

When running an application that is built using webpack 2, sourcemaps are detected in chrome but original source is not loaded. I'm using webpack beta21.

These files used to be detected automatically, ie when a breakpoint was put in the the output from webpack js file, the source view would jump to the original source input to webpack. But now I am stuck with this screen:

config:

var path = require("path");
var webpack = require("webpack");
var WebpackBuildNotifierPlugin = require('webpack-build-notifier');


const PATHS = {
  app: path.join(__dirname, '../client'),
  build: path.join(__dirname, '../public')
};

module.exports = {


  entry: {
    app: PATHS.app + '/app.js'
  },
  output: {
    path: PATHS.build,
    filename: '[name].js'
  },


  devtool: "source-map",
  module: {
    loaders: [
      {
        test: /\.js?$/,
        loader: 'babel-loader',
        include: [
          path.resolve(__dirname, 'client'),
        ],
        exclude: /node_modules/

      },

      {
        test: /\.css/,
        loader: "style!css"
      }
    ]
  },
  resolve: {
    // you can now require('file') instead of require('file.js')
    extensions: ['', '.js', '.json']
  } ,
  plugins: [
    new WebpackBuildNotifierPlugin()
  ]

};

Gorham

For me this only works with inline-source-map. – Emogeneemollient

Any solution for this issue since then? I am hitting this with Electron (Chrome 86), Webpack 4 and inline-source-maps – Theophrastus

I stopped using web pack two years ago – Gorham

Answer 1

Generated files with source maps won't automatically redirect to their original files, because there's potentially a 1-to-many relationship.

If you see the message Source Map Detected, the original file should already appear on the side file tree or the file explorer via Crl + P. If you don't know the original file name, you can open the source map file itself.

1. The source map path can be identified by a //# sourceMappingURL= comment or the X-SourceMap header:

2. Open up the source map via url and look for the sources property for the original file name:

3. The original file should be visible in the sources panel:

If you don't see the message Source Map Detected

You can manually add an external source map by right clicking and selecting Add Source Map:

Additional Resources

• If that still doesn't work, you can try a Source Map Validator
• For webpack specifically, you can configure the devtool property

Bartholomeo

I have tried to add the source map, but it does nothing. The source map validator is not working as well. I have tried with the mozilla library and is parsing the source map correctly. – Villose

For people using NW.js, note that your source map path need to be a file:/// path if using the 'Add source map...' option. – G

Answer 2

If you're mapping to a workspace, that means you already have the source code. Including the source code in your source map is creating an unnecessary redundancy.

Use nosources-source-map instead.

Zippora

Answer 3

The issue with external source maps was fixed in Chrome 52 but it looks like you've got your devtool set differently from mine, I use:

devtool: '#source-maps'

How are you building your source? If you're running with -d it will switch to inline source maps

Meri

What's the difference when you add the #? – Tribunal

The '#' controls the directive that does into the JS file. You can use '@' instead for older browsers:The original source map spec used '@', but this conflicted with 'conditional compilation' (which is activated with @cc_on) in IE<11, which runs code in comments, and would result in errors of the type: – Meri

Not cryptic at all – Cedar

@ThomasGrainger Where is that documented? There is no mention of hashes or at-signs in the official docs: webpack.js.org/configuration/devtool – Sabotage