Friendly-errors-webpack-plugin

Friendly-errors-webpack-plugin recognizes certain classes of webpack errors and cleans, aggregates and prioritizes them to provide a better Developer Experience.

It is easy to add types of errors so if you would like to see more errors get handled, please open a PR!

Getting started

Installation

npm install friendly-errors-webpack-plugin --save-dev

Basic usage

Simply add FriendlyErrorsWebpackPlugin to the plugin section in your Webpack config.

var FriendlyErrorsWebpackPlugin = require('friendly-errors-webpack-plugin');

var webpackConfig = {
  // ...
  plugins: [
    new FriendlyErrorsWebpackPlugin(),
  ],
  // ...
}

Turn off errors

You need to turn off all error logging by setting your webpack config quiet option to true.

app.use(require('webpack-dev-middleware')(compiler, {
  // ...
  logLevel: 'silent',
  // ...
}));

If you use the webpack-dev-server, there is a setting in webpack's devServer options:

// webpack config root
{
  // ...
  devServer: {
    // ...
    quiet: true,
    // ...
  },
  // ...
}

If you use webpack-hot-middleware, that is done by setting the log option to false. You can do something sort of like this, depending upon your setup:

app.use(require('webpack-hot-middleware')(compiler, {
  log: false
}));

Thanks to webpack-dashboard for this piece of info.

Demo

Build success

eslint-loader errors

babel-loader syntax errors

Module not found

Options

You can pass options to the plugin:

new FriendlyErrorsPlugin({
  compilationSuccessInfo: {
    messages: ['You application is running here http://localhost:3000'],
    notes: ['Some additional notes to be displayed upon successful compilation']
  },
  onErrors: function (severity, errors) {
    // You can listen to errors transformed and prioritized by the plugin
    // severity can be 'error' or 'warning'
  },
  // should the console be cleared between each compilation?
  // default is true
  clearConsole: true,

  // add formatters and transformers (see below)
  additionalFormatters: [],
  additionalTransformers: []
})

Adding desktop notifications

The plugin has no native support for desktop notifications but it is easy to add them thanks to node-notifier for instance.

var FriendlyErrorsPlugin = require('friendly-errors-webpack-plugin');
var notifier = require('node-notifier');
var ICON = path.join(__dirname, 'icon.png');

new FriendlyErrorsPlugin({
    onErrors: (severity, errors) => {
      if (severity !== 'error') {
        return;
      }
      const error = errors[0];
      notifier.notify({
        title: "Webpack error",
        message: severity + ': ' + error.name,
        subtitle: error.file || '',
        icon: ICON
      });
    }
  })

API

Transformers and formatters

Webpack's errors processing, is done in four phases:

1. Extract relevant info from webpack errors. This is done by the plugin here
2. Apply transformers to all errors to identify and annotate well know errors and give them a priority
3. Get only top priority error or top priority warnings if no errors are thrown
4. Apply formatters to all annotated errors

You can add transformers and formatters. Please see transformErrors, and formatErrors in the source code and take a look a the default transformers and the default formatters.

TODO

• Make it compatible with node 4