Webpack + cssnext-loader + stylelint + file-loader

webpack.config.js

// webpack.config.js
var webpack = require("webpack")
var ExtractTextPlugin = require("extract-text-webpack-plugin")
var path = require("path")
var options = require("minimist")(process.argv.slice(2))
var pathDest = (options.docs) ? "./docs" : "./build"
var cssnext = require("cssnext-loader")
var configSuitcss = require("stylelint-config-suitcss")

var ext = function ext() {
  for (var _len = arguments.length, suffix = Array(_len), _key = 0; _key < _len; _key++) {
    suffix[_key] = arguments[_key];
  }

  return new RegExp('\\.(?:' + suffix.join('|') + ')(?:[?#].*)?$');
};

module.exports = {
  // The standard entry point and output config
  entry: {
    index: "./index.js"
  },
  output: {
    filename: "[name].js",
    path: path.join(__dirname, pathDest),
    publicPath: "",
  },
  resolve: {
    extensions: [
      "",
      ".js",
    ],
  },
  cssnext: {
    browsers: ['ff >= 20', 'ie >= 9', 'safari >= 5.1', 'opera >= 12', 'chrome >=20'],
    compress: true,
    messages: {console: true},
    import: {
      plugins:[
        require("stylelint")(configSuitcss),
        require("postcss-reporter")
      ]
    }
  },
  module: {
    loaders: [
    // Extract css files
      {
       test: /\.css$/,
        loader: ExtractTextPlugin.extract(
          "style",
          "css!cssnext"
        )
      },
      { test: ext('svg', 'otf', 'eot', 'ttf', 'woff2?', "png", "gif", ".jp?g"), loader: "file" }

    ]
  },
  // Use the plugin to specify the resulting filename (and add needed behavior to the compiler)
  plugins: [
    new ExtractTextPlugin("[name].css")
  ]
}