Develop Reference

Remove empty bundle file from the HTML template

I have a simple Webpack configuration to compile a static HTML file with the Bootstrap's CSS asset:
const path = require('path');
const glob = require('glob')
const MiniCssExtractPlugin = require('mini-css-extract-plugin')
const PurgeCssPlugin = require('purgecss-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin');
const mode = process.env.NODE_ENV || 'development';
const isProduction = 'production' === mode;
console.log(`Building mode: ${mode}`);
module.exports = {
mode: mode,
entry: './src/index.js',
output: {
path: path.resolve(__dirname, '..'),
filename: isProduction ? 'bundle.[contenthash].js' : 'bundle.js',
clean: false,
},
module: {
rules: [
{
test: /\.s[ac]ss$/i,
exclude: /node_modules/,
use: [
MiniCssExtractPlugin.loader,
'css-loader',
'sass-loader',
],
},
],
},
plugins: [
new HtmlWebpackPlugin({
inject: 'body',
template: 'index.ejs',
minify: isProduction,
}),
new MiniCssExtractPlugin({
filename: isProduction ? 'style.[contenthash].css' : 'style.css',
}),
new PurgeCssPlugin({
paths: glob.sync(path.join(__dirname, '..') + '/*', {nodir: true}),
}),
],
};
The src/index.js file is as simple as:
import "./scss/main.scss"
This configuration works really well, however since there're no JS files included, the generated bundle.js file is empty though it's still injected to the HTML template:
<script defer src="bundle.js"></script>
How can I remove this file completely from the template if it's empty?

Vue Webpack configuration doesn't minify images

So I am working on a simple card game, where i have like 40 images relate to the cards. I am using Vue Cli that already comes with a simple webpack configuration.
So basicly I am saving all the images on the static folder like this:
When I build the project for production, generating the dist folder, it creates the images like this:
this is my webpack production file:
'use strict'
const path = require('path')
const utils = require('./utils')
const webpack = require('webpack')
const config = require('../config')
const merge = require('webpack-merge')
const baseWebpackConfig = require('./webpack.base.conf')
const CopyWebpackPlugin = require('copy-webpack-plugin')
const HtmlWebpackPlugin = require('html-webpack-plugin')
const ExtractTextPlugin = require('extract-text-webpack-plugin')
const OptimizeCSSPlugin = require('optimize-css-assets-webpack-plugin')
const UglifyJsPlugin = require('uglifyjs-webpack-plugin')
const env = process.env.NODE_ENV === 'testing'
? require('../config/test.env')
: require('../config/prod.env')
const webpackConfig = merge(baseWebpackConfig, {
module: {
rules: utils.styleLoaders({
sourceMap: config.build.productionSourceMap,
extract: true,
usePostCSS: true
})
},
devtool: config.build.productionSourceMap ? config.build.devtool : false,
output: {
path: config.build.assetsRoot,
filename: utils.assetsPath('js/[name].[chunkhash].js'),
chunkFilename: utils.assetsPath('js/[id].[chunkhash].js')
},
plugins: [
// http://vuejs.github.io/vue-loader/en/workflow/production.html
new webpack.DefinePlugin({
'process.env': env
}),
new UglifyJsPlugin({
uglifyOptions: {
compress: {
warnings: false
}
},
sourceMap: config.build.productionSourceMap,
parallel: true
}),
// extract css into its own file
new ExtractTextPlugin({
filename: utils.assetsPath('css/[name].[contenthash].css'),
// Setting the following option to `false` will not extract CSS from codesplit chunks.
// Their CSS will instead be inserted dynamically with style-loader when the codesplit chunk has been loaded by webpack.
// It's currently set to `true` because we are seeing that sourcemaps are included in the codesplit bundle as well when it's `false`,
// increasing file size: https://github.com/vuejs-templates/webpack/issues/1110
allChunks: true,
}),
// Compress extracted CSS. We are using this plugin so that possible
// duplicated CSS from different components can be deduped.
new OptimizeCSSPlugin({
cssProcessorOptions: config.build.productionSourceMap
? { safe: true, map: { inline: false } }
: { safe: true }
}),
// generate dist index.html with correct asset hash for caching.
// you can customize output by editing /index.html
// see https://github.com/ampedandwired/html-webpack-plugin
new HtmlWebpackPlugin({
filename: process.env.NODE_ENV === 'testing'
? 'index.html'
: config.build.index,
template: 'index.html',
inject: true,
minify: {
removeComments: true,
collapseWhitespace: true,
removeAttributeQuotes: true
// more options:
// https://github.com/kangax/html-minifier#options-quick-reference
},
// necessary to consistently work with multiple chunks via CommonsChunkPlugin
chunksSortMode: 'dependency'
}),
// keep module.id stable when vendor modules does not change
new webpack.HashedModuleIdsPlugin(),
// enable scope hoisting
new webpack.optimize.ModuleConcatenationPlugin(),
// split vendor js into its own file
new webpack.optimize.CommonsChunkPlugin({
name: 'vendor',
minChunks (module) {
// any required modules inside node_modules are extracted to vendor
return (
module.resource &&
/\.js$/.test(module.resource) &&
module.resource.indexOf(
path.join(__dirname, '../node_modules')
) === 0
)
}
}),
// extract webpack runtime and module manifest to its own file in order to
// prevent vendor hash from being updated whenever app bundle is updated
new webpack.optimize.CommonsChunkPlugin({
name: 'manifest',
minChunks: Infinity
}),
// This instance extracts shared chunks from code splitted chunks and bundles them
// in a separate chunk, similar to the vendor chunk
// see: https://webpack.js.org/plugins/commons-chunk-plugin/#extra-async-commons-chunk
new webpack.optimize.CommonsChunkPlugin({
name: 'app',
async: 'vendor-async',
children: true,
minChunks: 3
}),
// copy custom static assets
new CopyWebpackPlugin([
{
from: path.resolve(__dirname, '../static'),
to: config.build.assetsSubDirectory,
ignore: ['.*']
}
])
]
})
if (config.build.productionGzip) {
const CompressionWebpackPlugin = require('compression-webpack-plugin')
webpackConfig.plugins.push(
new CompressionWebpackPlugin({
asset: '[path].gz[query]',
algorithm: 'gzip',
test: new RegExp(
'\\.(' +
config.build.productionGzipExtensions.join('|') +
')$'
),
threshold: 10240,
minRatio: 0.8
})
)
}
if (config.build.bundleAnalyzerReport) {
const BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
webpackConfig.plugins.push(new BundleAnalyzerPlugin())
}
module.exports = webpackConfig
Any help would be appreciate, thanks

I'm assuming you used vuejs-templates/webpack, which does not include image optimization out of the box. You can easily add this (with imagemin-webpack-plugin) in your Webpack config:
Install ImageminWebpackPlugin with: npm i -D imagemin-webpack-plugin
In build/webpack.prod.conf.js, import the plugin, and configure it in plugins[] (after CopyWebpackPlugin):
const ImageminPlugin = require('imagemin-webpack-plugin').default;
const webpackConfig = merge(baseWebpackConfig, {
plugins: [
// ...
new ImageminPlugin({
test: /\.(jpe?g|png|gif|svg)$/i,
/* other ImageMin configs */
})
]
}
Running ImageminWebpackPlugin after CopyWebpackPlugin ensures the copied images from static are run through ImageMin optimization.
GitHub repo demo

In the current version of Vue you can use a vue.config.js that looks like this:
const ImageminPlugin = require('imagemin-webpack-plugin').default;
module.exports = {
configureWebpack: {
plugins: [
new ImageminPlugin({
disable: process.env.NODE_ENV !== 'production',
})
]
}
}
This will enable Imagemin on production builds but skip on development builds.

You can have a try. It will help you minify images automaticlly without complicated algorithm configurations. It can also help you to encode(and inline) images (behave more flexible than url-loader).
https://github.com/GaoYYYang/image-optimize-loader
module.exports = {
module: {
rules: [
{
test: /\.(png|jpe?g|webp|git|svg|)$/i,
use: [
{
loader: 'img-optimize-loader'
},
],
},
],
},
};

Require is not defined on reflect-metadata - __webpack_require__ issue

I'm trying to launch my angular app on visual studio but when it starts, it stucks on "Loading..." section.
If i read Chrome's error console i get the following error:
Uncaught ReferenceError: require is not defined at Object. < anonymous > __ webpack_require __
The reflect-metadata contains the following: module.exports = require("reflect-metadata"); , which "require" causes the error.
Here's some of my code...
webpack.config.js
const path = require('path');
const webpack = require('webpack');
const merge = require('webpack-merge');
const AotPlugin = require('#ngtools/webpack').AotPlugin;
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;
var nodeExternals = require('webpack-node-externals');
module.exports = (env) => {
// Configuration in common to both client-side and server-side bundles
const isDevBuild = !(env && env.prod);
const sharedConfig = {
externals: [nodeExternals()], // in order to ignore all modules in node_modules folder
stats: { modules: false },
context: __dirname,
resolve: { extensions: [ '.js', '.ts' ] },
output: {
filename: '[name].js',
publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
},
module: {
rules: [
{ test: /\.ts$/, use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader', 'angular2-router-loader'] : '#ngtools/webpack' },
{ test: /\.html$/, use: 'html-loader?minimize=false' },
{ test: /\.css$/, use: [ 'to-string-loader', 'style-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize' ] },
{ test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' }
]
},
plugins: [new CheckerPlugin()]
};
// Configuration for client-side bundle suitable for running in browsers
const clientBundleOutputDir = './wwwroot/dist';
const clientBundleConfig = merge(sharedConfig, {
entry: { 'main-client': './ClientApp/boot.browser.ts' },
output: { path: path.join(__dirname, clientBundleOutputDir) },
plugins: [
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./wwwroot/dist/vendor-manifest.json')
})
].concat(isDevBuild ? [
// Plugins that apply in development builds only
new webpack.SourceMapDevToolPlugin({
filename: '[file].map', // Remove this line if you prefer inline source maps
moduleFilenameTemplate: path.relative(clientBundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
})
] : [
// Plugins that apply in production builds only
new webpack.optimize.UglifyJsPlugin(),
new AotPlugin({
tsConfigPath: './tsconfig.json',
entryModule: path.join(__dirname, 'ClientApp/app/app.browser.module#AppModule'),
exclude: ['./**/*.server.ts']
})
])
});
// Configuration for server-side (prerendering) bundle suitable for running in Node
const serverBundleConfig = merge(sharedConfig, {
resolve: { mainFields: ['main'] },
entry: { 'main-server': './ClientApp/boot.server.ts' },
plugins: [
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./ClientApp/dist/vendor-manifest.json'),
sourceType: 'commonjs2',
name: './vendor'
})
].concat(isDevBuild ? [] : [
// Plugins that apply in production builds only
new AotPlugin({
tsConfigPath: './tsconfig.json',
entryModule: path.join(__dirname, 'ClientApp/app/app.server.module#AppModule'),
exclude: ['./**/*.browser.ts']
})
]),
output: {
libraryTarget: 'commonjs',
path: path.join(__dirname, './ClientApp/dist')
},
target: 'node',
devtool: 'inline-source-map'
});
return [clientBundleConfig, serverBundleConfig];
};
Searching on the internet, all of the troubleshooting suggests doing something on the systemjs.config file but mine is not an angular-cli app so I can't do it.
UPDATES SECTION
UPDATE #1
Looks like the problem is caused by webpack-node-externals executed in browser mode.
Got to find another way for that.
Got any troubleshooting or potential solution suggestion?
Thanks in advance!
UPDATE #2
I've made it, see my answer below

GOT IT!
The issue was caused by webpack-node-externals used on my common configuration.
See my question and my answer to my own question at the following: Webpack - Excluding node_modules with also keep a separated browser and server management for more details.
So, in a nutshell, the steps that I followed are these:
Installing requireJS ==> http://requirejs.org/docs/node.html
Removing externals: [nodeExternals()], // in order to ignore all modules in node_modules folder from my common webpack configuration and adding it under my server configuration (done before my question, but it's a really important step) [see webpack.config.js content in the question linked right above in this answer or in the snippet below]
Adding target: 'node', before my externals point above, under my server side section (done before my question, but it's a really important step) [see webpack.config.js content in the question linked right above in this answer or in the snippet below]
This makes sure that browser side keeps target:'web' (default target), and target becomes node just for the server.
launched webpack config vendor command manually from powershell webpack --config webpack.config.vendor.js
launched webpack config command manually from powershell webpack --config webpack.config.js
That worked for me! Hope It will works also for anyone else reading this question and encountering this issue!
webpack.config.js content:
const path = require('path');
const webpack = require('webpack');
const merge = require('webpack-merge');
const AotPlugin = require('#ngtools/webpack').AotPlugin;
const CheckerPlugin = require('awesome-typescript-loader').CheckerPlugin;
var nodeExternals = require('webpack-node-externals');
module.exports = (env) => {
// Configuration in common to both client-side and server-side bundles
const isDevBuild = !(env && env.prod);
const sharedConfig = {
//removed from here, moved below.
//externals: [nodeExternals()], // in order to ignore all modules in node_modules folder
stats: { modules: false },
context: __dirname,
resolve: { extensions: [ '.js', '.ts' ] },
output: {
filename: '[name].js',
publicPath: 'dist/' // Webpack dev middleware, if enabled, handles requests for this URL prefix
},
module: {
rules: [
{ test: /\.ts$/, use: isDevBuild ? ['awesome-typescript-loader?silent=true', 'angular2-template-loader', 'angular2-router-loader'] : '#ngtools/webpack' },
{ test: /\.html$/, use: 'html-loader?minimize=false' },
{ test: /\.css$/, use: [ 'to-string-loader', 'style-loader', isDevBuild ? 'css-loader' : 'css-loader?minimize' ] },
{ test: /\.(png|jpg|jpeg|gif|svg)$/, use: 'url-loader?limit=25000' }
]
},
plugins: [new CheckerPlugin()]
};
// Configuration for client-side bundle suitable for running in browsers
const clientBundleOutputDir = './wwwroot/dist';
const clientBundleConfig = merge(sharedConfig, {
entry: { 'main-client': './ClientApp/boot.browser.ts' },
output: { path: path.join(__dirname, clientBundleOutputDir) },
plugins: [
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./wwwroot/dist/vendor-manifest.json')
})
].concat(isDevBuild ? [
// Plugins that apply in development builds only
new webpack.SourceMapDevToolPlugin({
filename: '[file].map', // Remove this line if you prefer inline source maps
moduleFilenameTemplate: path.relative(clientBundleOutputDir, '[resourcePath]') // Point sourcemap entries to the original file locations on disk
})
] : [
// Plugins that apply in production builds only
new webpack.optimize.UglifyJsPlugin(),
new AotPlugin({
tsConfigPath: './tsconfig.json',
entryModule: path.join(__dirname, 'ClientApp/app/app.browser.module#AppModule'),
exclude: ['./**/*.server.ts']
})
])
});
// Configuration for server-side (prerendering) bundle suitable for running in Node
const serverBundleConfig = merge(sharedConfig, {
resolve: { mainFields: ['main'] },
entry: { 'main-server': './ClientApp/boot.server.ts' },
plugins: [
new webpack.DllReferencePlugin({
context: __dirname,
manifest: require('./ClientApp/dist/vendor-manifest.json'),
sourceType: 'commonjs2',
name: './vendor'
})
].concat(isDevBuild ? [] : [
// Plugins that apply in production builds only
new AotPlugin({
tsConfigPath: './tsconfig.json',
entryModule: path.join(__dirname, 'ClientApp/app/app.server.module#AppModule'),
exclude: ['./**/*.browser.ts']
})
]),
output: {
libraryTarget: 'commonjs',
path: path.join(__dirname, './ClientApp/dist')
},
//added target and externals HERE, in order to prevent webpack to read node_modules
//this also prevents fake-positives parsing errors
target: 'node',
externals: [nodeExternals()], // in order to ignore all modules in node_modules folder,
devtool: 'inline-source-map'
});
return [clientBundleConfig, serverBundleConfig];
};

webpack configuration using html-webpack-plugin

I am using HTML-Webpack-plugin with build setting:
build: {
env: require('./prod.env'),
index: path.resolve(__dirname, '../app/templates/dist/index.html'),
assetsRoot: path.resolve(__dirname, '../app/static'),
assetsSubDirectory: 'dist'
app structure:
app-
static-
dist-
css- minified css files
js- minified js files
templates-
dist-
index.html
When the output is built using npm run build the output index.html file looks like:
<!DOCTYPE html><html><head><meta charset=utf-8><title>app</title><link href=/dist/css/app.22f236.css
However, I want the href path to include /static prior to /dist for all paths in index.html ie
/static/dist/css...
my webpack.prod.conf.js:
var path = require('path')
var utils = require('./utils')
var webpack = require('webpack')
var config = require('../config')
var merge = require('webpack-merge')
var baseWebpackConfig = require('./webpack.base.conf')
var CopyWebpackPlugin = require('copy-webpack-plugin')
var HtmlWebpackPlugin = require('html-webpack-plugin')
var ExtractTextPlugin = require('extract-text-webpack-plugin')
var OptimizeCSSPlugin = require('optimize-css-assets-webpack-plugin')
var env = process.env.NODE_ENV === 'testing'
? require('../config/test.env')
: config.build.env
var webpackConfig = merge(baseWebpackConfig, {
module: {
rules: utils.styleLoaders({
sourceMap: config.build.productionSourceMap,
extract: true
})
},
devtool: config.build.productionSourceMap ? '#source-map' : false,
output: {
path: config.build.assetsRoot,
filename: utils.assetsPath('js/[name].[chunkhash].js'),
chunkFilename: utils.assetsPath('js/[id].[chunkhash].js')
},
plugins: [
// http://vuejs.github.io/vue-loader/en/workflow/production.html
new webpack.DefinePlugin({
'process.env': env
}),
new webpack.optimize.UglifyJsPlugin({
compress: {
warnings: false
},
sourceMap: true
}),
// extract css into its own file
new ExtractTextPlugin({
filename: utils.assetsPath('css/[name].[contenthash].css')
}),
// Compress extracted CSS. We are using this plugin so that possible
// duplicated CSS from different components can be deduped.
new OptimizeCSSPlugin({
cssProcessorOptions: {
safe: true
}
}),
// generate dist index.html with correct asset hash for caching.
// you can customize output by editing /index.html
// see https://github.com/ampedandwired/html-webpack-plugin
new HtmlWebpackPlugin({
filename: process.env.NODE_ENV === 'testing'
? 'index.html'
: config.build.index,
template: 'index.html',
inject: true,
minify: {
removeComments: true,
collapseWhitespace: true,
removeAttributeQuotes: true
// more options:
// https://github.com/kangax/html-minifier#options-quick-reference
},
// necessary to consistently work with multiple chunks via CommonsChunkPlugin
chunksSortMode: 'dependency'
}),
// keep module.id stable when vender modules does not change
new webpack.HashedModuleIdsPlugin(),
// split vendor js into its own file
new webpack.optimize.CommonsChunkPlugin({
name: 'vendor',
minChunks: function (module, count) {
// any required modules inside node_modules are extracted to vendor
return (
module.resource &&
/\.js$/.test(module.resource) &&
module.resource.indexOf(
path.join(__dirname, '../node_modules')
) === 0
)
}
}),
// extract webpack runtime and module manifest to its own file in order to
// prevent vendor hash from being updated whenever app bundle is updated
new webpack.optimize.CommonsChunkPlugin({
name: 'manifest',
chunks: ['vendor']
}),
// copy custom static assets
new CopyWebpackPlugin([
{
from: path.resolve(__dirname, '../static'),
to: config.build.assetsSubDirectory,
ignore: ['.*']
}
])
]
})
if (config.build.productionGzip) {
var CompressionWebpackPlugin = require('compression-webpack-plugin')
webpackConfig.plugins.push(
new CompressionWebpackPlugin({
asset: '[path].gz[query]',
algorithm: 'gzip',
test: new RegExp(
'\\.(' +
config.build.productionGzipExtensions.join('|') +
')$'
),
threshold: 10240,
minRatio: 0.8
})
)
}
if (config.build.bundleAnalyzerReport) {
var BundleAnalyzerPlugin = require('webpack-bundle-analyzer').BundleAnalyzerPlugin
webpackConfig.plugins.push(new BundleAnalyzerPlugin())
}
module.exports = webpackConfig
I there any way to change the injected path in index.html to include a parent folder in front of each path? (other than writing a bash script to do this).

The output paths for compilation assets do not depend on settings you can provide with html-webpack-plugin (aside for the HTML file itself). You will have to configure the compiler output path and module rules to ensure that the assets get emitted at a desired public path.

How to version CSS file in Webpack and update manifest?

I have a webpack config that has multiple JS entry points. In one of those entry points, I am requiring my styles: require('../sass/app.scss'); and then using a loader to extract the styles into another file app.css.
test: /\.scss$/,
loader: ExtractTextPlugin.extract({
fallback: 'style-loader',
use: 'css-loader!postcss-loader!sass-loader',
})
And that is working great. Of course, we are having issues with old styles being served when we deploy because they are not being versioned like our JS. I have been searching around for a few hours on how to do this and I cannot find a source on how to not only version the CSS, but also get a manifest file for the CSS. I tried creating a new instance of the versioning plugin that I am using, but it only created a manifest for the JS files. I am assuming that since I only have an output for JS that is the reason for this. Anyhow, here is my webpack.config.js:
const webpack = require('webpack');
const autoprefixer = require('autoprefixer');
const BrowserSyncPlugin = require('browser-sync-webpack-plugin');
const CommonsPlugin = require('webpack/lib/optimize/CommonsChunkPlugin');
const ExtractTextPlugin = require('extract-text-webpack-plugin');
const path = require('path');
const VersioningPlugin = require('versioning-webpack-plugin');
const WebpackMd5Hash = require('webpack-md5-hash');
const routes = require('./resources/assets/js/routes');
module.exports = {
entry: routes,
devtool: 'eval-source-map',
output: {
path: path.join(__dirname, 'public/js'),
filename: '[name].[chunkhash:6].js'
},
module: {
loaders: [
{
test: /\.js$/,
loader: 'babel-loader?presets[]=env',
exclude: path.resolve(__dirname, 'node_modules/')
},
{
test: /\.scss$/,
loader: ExtractTextPlugin.extract({
fallback: 'style-loader',
use: 'css-loader!postcss-loader!sass-loader',
})
}
],
},
plugins: [
new CommonsPlugin({
minChunks: 3,
name: 'common'
}),
new BrowserSyncPlugin({
host: 'localhost',
port: 3000,
proxy: 'napaautocarepro.dev',
files: [
'public/css/app.css',
{
match: ['public/js/*.js', 'app/**/**/*.php', 'resources/views/**/**/*.php'],
fn: function(event, file) {
this.reload();
}
}
]
}, {
injectChanges: true,
reload: false
}),
new ExtractTextPlugin('../css/app.css'),
new VersioningPlugin({
cleanup: true,
basePath: 'js/',
manifestPath: path.join(__dirname, 'public/manifest.json')
}),
new WebpackMd5Hash()
]
};
And here is my weback.prod.config.js:
const config = require('./webpack.config');
const path = require('path');
const webpack = require('webpack');
const CleanWebpackPlugin = require('clean-webpack-plugin');
const OptimizeCssAssetsPlugin = require('optimize-css-assets-webpack-plugin');
config.plugins.unshift(
new CleanWebpackPlugin(['js', 'css'], {
root: path.join(__dirname, 'public'),
verbose: true,
dry: false,
}),
new webpack.optimize.UglifyJsPlugin({
compress: {
warnings: false
},
comments: false,
sourceMap: true
}),
new OptimizeCssAssetsPlugin({
assetNameRegExp: /\.css$/g,
cssProcessor: require('cssnano'),
canPrint: true,
cssProcessorOptions: { discardComments: { removeAll: true } }
})
);
module.exports = config;
How in the world can I version my CSS file and get it into a manifest so I can autoload the correct version?

Add [chunkhash] to the name of the file, something like:
plugins: [
//...
new ExtractTextPlugin('../css/app.[chunkhash].css'),
//...
]
(from https://github.com/webpack-contrib/extract-text-webpack-plugin#options )