Spits out some stats about webpack compilation process to a file.

npm install --save-dev webpack-bundle-tracker

var BundleTracker = require('webpack-bundle-tracker'); module.exports = { context: __dirname, entry: { app: ['./app'] }, output: { path: require("path").resolve('./assets/bundles/'), filename: "[name]-[hash].js", publicPath: 'http://localhost:3000/assets/bundles/', }, plugins: [ new BundleTracker({path: __dirname, filename: './assets/webpack-stats.json'}) ] }

./assets/webpack-stats.json will look like,

{ "status":"done", "chunks":{ "app":[{ "name":"app-0828904584990b611fb8.js", "publicPath":"http://localhost:3000/assets/bundles/app-0828904584990b611fb8.js", "path":"/home/user/project-root/assets/bundles/app-0828904584990b611fb8.js" }] } }

In case webpack is still compiling, it'll look like,

{ "status":"compiling", }

And errors will look like,

{ "status": "error", "file": "/path/to/file/that/caused/the/error", "error": "ErrorName", "message": "ErrorMessage" }

ErrorMessage shows the line and column that caused the error.

And in case logTime option is set to true, the output will look like,

{ "status":"done", "chunks":{ "app":[{ "name":"app-0828904584990b611fb8.js", "publicPath":"http://localhost:3000/assets/bundles/app-0828904584990b611fb8.js", "path":"/home/user/project-root/assets/bundles/app-0828904584990b611fb8.js" }] }, "startTime":1440535322138, "endTime":1440535326804 } 

By default, the output JSON will not be indented. To increase readability, you can use the indent option to make the output legible. By default it is off. The value that is set here will be directly passed to the space parameter in JSON.stringify. More information can be found here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/stringify