ndelangen / webpack-split-by-path

Split a Webpack entry bundle by path into any number of arbitrarily defined smaller bundles

Split By Path Webpack Plugin

This plugin will split a Webpack entry bundle into any number of arbitrarily defined smaller bundles.

Based on Split by Name Webpack Plugin.

Unlike original component, it uses absolute path to identify bundle.

Why?

• Browsers will open [between 6 and 10][browserscope] parallel connections to a single host. By splitting up one large file (your main bundle) into a number of smaller ones, you can leverage these connections to download the files [faster][stevesouders].
• It's likely that you will have some third party scripts which you change infrequently. By putting these into their own bundle, then if they haven't changed between builds, your users may still be able to use the cached version from before.

How?

Configuration of the plugin is simple. You instantiate the plugin with an array of objects, each containing the keys name and path. Any modules which are in your entry chunk which match the bucket's path (first matching bucket is used), are then moved to a new chunk with the given name.

path should be an absolute path string value. It can be also an array of such values.

Creating a 'catch-all' bucket is not necessary: anything which doesn't match one of the defined buckets will be left in the original chunk.

Now, by separating the manifest info into a standalone chunk, vendor chunks(something like that) will stay the same with or without hashing unless you change their version.

API

new SplitByPathPlugin(chunks, options);

• chunks - array of objects { name: string, path: string | string[] }
• options - object, optional { ignore: string | string[], ignoreChunks: string | string[], manifest: string }

new SplitByPathPlugin([
  { name: 'c1', path: 'src/c1' },
  { name: 'vendor', path: path.join(__dirname, 'node_modules/')},
  ...chunkN
], {
  ignore: [
    'path/to/ingore/file/or/dir1',
    'path/to/ingore/file/or/dir2'
  ]
});

Example

var SplitByPathPlugin = require('webpack-split-by-path');
module.exports = {
  entry: {
    app: 'app.js'
  },
  output: {
    path: __dirname + '/public',
    filename: "[name]-[chunkhash].js",
    chunkFilename: "[name]-[chunkhash].js"
  },
  plugins: [
    new SplitByPathPlugin([
      {
        name: 'vendor',
        path: path.join(__dirname, 'node_modules')
      }
    ], {
      manifest: 'app-entry'
    })
  ]
};

So every module that is being requested from node_modules will be placed in public/vendor.js and everything else will be placed in public/app.js.