This plugin will extract stats from your webpack build, transform and write to file.

$ npm install --save-dev @regru/webpack-stats-plugin
$ yarn add --dev @regru/webpack-stats-plugin

const { StatsWriterPlugin } = require("@regru/webpack-stats-plugin");

module.exports = {
  plugins: [
    // Everything else **first**.

    // Write out stats file to build directory.
    new StatsWriterPlugin({
      filename: "stats.json" // Default
    })
  ]
}

The transform function has a signature of:

/**
 * Transform skeleton.
 *
 * @param {Object} stats          Stats object
 * 
 * @returns {String}              String to emit to file
 */
function transform(stats) {}

which you can use like:

const { StatsWriterPlugin } = require("@regru/webpack-stats-plugin");

module.exports = {
  plugins: [
    new StatsWriterPlugin({
      transform(data, opts) {
        return JSON.stringify({
          main: data.assetsByChunkName.main[0],
          css: data.assetsByChunkName.main[1]
        }, null, 2);
      }
    })
  ]
}

• StatsWriterPlugin(opts)

• opts (Object) options
• opts.filename (String) output file name (Default: "stat.json")
• opts.once (Boolean) skip functionality after first occurrence
• opts.statsOptions (Object) options for webpack Stats object (See Stats)
• opts.transform (Function) transform stats obj (Default: JSON.stringify())

Stats writer module.

Stats can be a string or array (we"ll have array from using source maps):

"assetsByChunkName": {
  "main": [
    "cd6371d4131fbfbefaa7.bundle.js",
    "../js-map/cd6371d4131fbfbefaa7.bundle.js.map"
  ]
},

See:

• http://webpack.github.io/docs/long-term-caching.html#get-filenames-from-stats
• https://github.com/webpack/docs/wiki/node.js-api#stats

filename: The opts.filename option can be a file name or path relative to output.path in webpack configuration. It should not be absolute.

transform: By default, the retrieved stats object is JSON.stringify'ed but by supplying an alternate transform you can target any output format. See test/webpack4/webpack.config.js for various examples including Markdown output.

• Warning: The output of transform should be a String, not an object. On Node v4.x if you return a real object in transform, then webpack will break with a TypeError (See #8). Just adding a simple JSON.stringify() around your object is usually what you need to solve any problems.