Add ES module build (#275)

* Rollup build: explicit external/globals to squelch warnings

* Update all Babel and Rollup related packages

* Add pkg.module entry, add ES6 module build

gulpfile.babel.js

@@ -8,7 +8,7 @@ import webpack from 'webpack';
 import webpackStream from 'webpack-stream';
 
 import _ from 'underscore';
-import rollup from 'rollup';
+import {rollup} from 'rollup';
 import babel from 'rollup-plugin-babel';
 import preset from 'babel-preset-es2015-rollup';
 import fs from 'fs';
@@ -68,9 +68,23 @@ function getBanner() {
   return _.template(banner)(manifest);
 }
 
+function buildESModule(bundle) {
+  return bundle.write({
+    format: 'es',
+    dest: manifest.module,
+    sourceMap: true,
+    banner: getBanner()
+  }).then(function(gen) {
+    return gen;
+  }).catch(function(error) {
+    console.log(error);
+  });
+}
+
 function build(done) {
-  rollup.rollup({
+  rollup({
     entry: path.join('src', config.entryFileName),
+    external: ['underscore', 'backbone'],
     plugins: [
       babel({
         sourceMaps: true,
@@ -79,12 +93,15 @@ function build(done) {
       })
     ]
   }).then(function(bundle) {
-    var banner = getBanner();
-
+    buildESModule(bundle);
     var result = bundle.generate({
-      banner: banner,
+      banner: getBanner(),
       format: 'umd',
       sourceMap: 'inline',
+      globals: {
+        underscore: '_',
+        backbone: 'Backbone'
+      },
       sourceMapSource: config.entryFileName + '.js',
       sourceMapFile: exportFileName + '.js',
       moduleName: config.mainVarName

package.json

@@ -4,6 +4,7 @@
   "homepage": "https://github.com/marionettejs/backbone.radio",
   "version": "2.0.0",
   "main": "build/backbone.radio.js",
+  "module": "build/backbone.radio.esm.js",
   "keywords": [
     "backbone",
     "marionette",
@@ -45,13 +46,13 @@
     "underscore": "^1.8.3"
   },
   "devDependencies": {
-    "babel-core": "6.7.0",
-    "babel-eslint": "6.0.4",
+    "babel-core": "6.24.0",
+    "babel-eslint": "7.0.0",
     "babel-loader": "6.2.0",
-    "babel-polyfill": "6.6.1",
-    "babel-preset-es2015": "6.3.13",
-    "babel-preset-es2015-rollup": "1.1.1",
-    "babel-register": "6.4.3",
+    "babel-polyfill": "6.23.0",
+    "babel-preset-es2015": "6.24.0",
+    "babel-preset-es2015-rollup": "3.0.0",
+    "babel-register": "6.24.0",
     "backbone": ">=1.3.3 <1.4.0",
     "chai": "3.4.1",
     "del": "2.2.0",
@@ -76,8 +77,8 @@
     "json-loader": "0.5.3",
     "mkdirp": "0.5.1",
     "mocha": "2.3.4",
-    "rollup": "0.25.4",
-    "rollup-plugin-babel": "2.4.0",
+    "rollup": "0.36.3",
+    "rollup-plugin-babel": "2.6.1",
     "sinon": "1.17.2",
     "sinon-chai": "2.8.0",
     "underscore": "1.8.3",