webpack.config.js

const webpack = require("webpack")
const path = require("path")
const UglifyJsPlugin = require("uglifyjs-webpack-plugin")
const env = require("yargs").argv.env // use --env with webpack 2
const pkg = require("./package.json")

let libraryName = "validation-controller"

let plugins = [],
  outputFile

if (env === "build") {
  plugins.push(new UglifyJsPlugin())
  outputFile = libraryName + ".min.js"
} else {
  outputFile = libraryName + ".js"
}

module.exports = {
  mode: "development",
  entry: {
    bundle: "./src/validation_controller.js"
  },

  output: {
    path: path.resolve(__dirname, "dist"),
    filename: outputFile,
    library: "StimulusValidation",
    libraryTarget: "umd"
  },

  module: {
    rules: [
      {
        test: /\.js$/,
        include: path.resolve(__dirname, "src"),
        exclude: [/node_modules/],
        use: [{ loader: "babel-loader" }]
      }
    ]
  },

  plugins: plugins
}