Migrates to Webpack 4

.babelrc

@@ -1,4 +1,3 @@
 {
-  "presets": ["es2015"],
-  "plugins": ["transform-es2015-modules-umd"]
+  "presets": ["env"]
 }

.gitignore

@@ -2,3 +2,5 @@ lib
 npm-debug.log
 bower_components
 node_modules
+yarn-error.log
+yarn.lock

package.json

@@ -17,11 +17,10 @@
     "tiny-emitter": "^2.0.0"
   },
   "devDependencies": {
-    "babel-cli": "^6.5.1",
-    "babel-core": "^6.5.2",
-    "babel-loader": "^6.2.10",
-    "babel-plugin-transform-es2015-modules-umd": "^6.5.0",
-    "babel-preset-es2015": "^6.5.0",
+    "babel-cli": "^6.26.0",
+    "babel-core": "^6.26.0",
+    "babel-loader": "^7.1.4",
+    "babel-preset-env": "^1.6.1",
     "chai": "^3.4.1",
     "cross-env": "^3.1.4",
     "karma": "^1.3.0",
@@ -33,14 +32,22 @@
     "mocha": "^3.1.2",
     "phantomjs-prebuilt": "^2.1.4",
     "sinon": "^1.17.2",
-    "webpack": "^2.2.1"
+    "uglifyjs-webpack-plugin": "^1.2.4",
+    "webpack": "^4.5.0",
+    "webpack-bundle-analyzer": "^2.11.1",
+    "webpack-cli": "^2.0.14"
   },
   "scripts": {
     "build": "npm run build-debug && npm run build-min",
-    "build-debug": "webpack",
-    "build-min": "cross-env NODE_ENV=production webpack --optimize-minimize",
+    "build-debug": "webpack --mode=development",
+    "build-analyze": "cross-env ANALYZE_BUILD=true npm run prepublish",
+    "build-min": "cross-env NODE_ENV=production webpack --mode=production",
     "build-watch": "webpack --watch",
     "test": "karma start --single-run",
     "prepublish": "npm run build"
-  }
+  },
+  "browserslist": [
+    "> 1%",
+    "last 2 versions"
+  ]
 }

webpack.config.js

@@ -1,6 +1,8 @@
 const pkg = require('./package.json');
 const path = require('path');
 const webpack = require('webpack');
+const UglifyJSPlugin = require('uglifyjs-webpack-plugin');
+const { BundleAnalyzerPlugin } = require('webpack-bundle-analyzer');
 
 const production = process.env.NODE_ENV === 'production' || false;
 
@@ -22,20 +24,27 @@ module.exports = {
             {test: /\.js$/, exclude: /node_modules/, loader: 'babel-loader'}
         ]
     },
+    optimization: {
+        minimizer: [
+            new UglifyJSPlugin({
+                parallel: require('os').cpus().length,
+                uglifyOptions: {
+                    ie8: false,
+                    keep_fnames: false,
+                    output: {
+                        beautify: false,
+                        comments: false
+                    }
+                }
+            })
+        ]
+    },
     plugins: production ? [
-            new webpack.optimize.UglifyJsPlugin({
-                beautify: false,
-                mangle: {
-                    screw_ie8: true,
-                    keep_fnames: true
-                },
-                compress: {
-                    screw_ie8: true
-                },
-                comments: false
-            }),
-            new webpack.BannerPlugin({banner})
+            new webpack.BannerPlugin({ banner }),
+            new BundleAnalyzerPlugin({
+                analyzerMode: process.env.ANALYZE_BUILD ? 'server' : 'disabled'
+            })
         ] : [
-            new webpack.BannerPlugin({banner})
+            new webpack.BannerPlugin({ banner })
         ]
 };