Generate UMD build with Rollup

build.js

@@ -0,0 +1,22 @@
+var rollup = require( 'rollup' );
+var babel = require( 'rollup-plugin-babel' );
+var replace = require( 'rollup-plugin-replace' );
+
+var env = process.argv[2] === '--prod' ? 'production' : 'development';
+
+rollup.rollup({
+  entry: 'src/index.js',
+  plugins: [
+    replace({
+      'process.env.NODE_ENV': JSON.stringify(env)
+    }),
+    babel()
+  ]
+}).then(function (bundle) {
+  var code = bundle.generate({
+    format: 'umd',
+    moduleName: 'Redux'
+  }).code;
+
+  process.stdout.write(code);
+});

package.json

@@ -13,10 +13,10 @@
     "test:examples": "babel-node examples/testAll.js",
     "check": "npm run lint && npm run test",
     "build:lib": "babel src --out-dir lib",
-    "build:umd": "webpack src/index.js dist/redux.js --config webpack.config.development.js",
-    "build:umd:min": "webpack src/index.js dist/redux.min.js --config webpack.config.production.js",
+    "build:umd": "node build.js > dist/redux.js",
+    "build:umd:min": "node build.js --prod | uglifyjs -c warnings=false -m --screw-ie8 > dist/redux.min.js",
     "build:examples": "babel-node examples/buildAll.js",
-    "build": "npm run build:lib && npm run build:umd && npm run build:umd:min",
+    "build": "npm run build:lib && rm -rf dist && mkdir -p dist && npm run build:umd && npm run build:umd:min",
     "preversion": "npm run clean && npm run check",
     "version": "npm run build",
     "postversion": "git push && git push --tags && npm run clean && npm run docs:publish",
@@ -66,6 +66,9 @@
     "isparta": "^3.0.3",
     "mocha": "^2.2.5",
     "rimraf": "^2.3.4",
+    "rollup": "^0.20.2",
+    "rollup-plugin-babel": "^1.0.0",
+    "rollup-plugin-replace": "^1.0.1",
     "webpack": "^1.9.6"
   },
   "npmName": "redux",