Complete Webpack Configuration File

webpack.config.js

module.exports = {
  entry: "./dev/app.js",
  output: {
    path: __dirname + "/public/js",
    filename: "build.js"
  },
  module: {
    preLoaders: [
      { test: /\.js$/, exclude: /node_modules/, loader: "eslint-loader" }
    ],
    loaders: [
      { test: /\.js$/, exclude: /node_modules/, loader: "babel-loader" }
    ]
  },
  eslint: {
    emitError: true,
    emitWarning: true,
    failOnError: true,
    failOnWarning: true
  }
};