Merge pull request #41 from joeldenning/external-helpers

Adding support for referencing external, global helpers

packages/rollup-plugin-babel/README.md

@@ -39,7 +39,7 @@ rollup({
 }).then(...)
 ```
 
-All options are as per the [Babel documentation](https://babeljs.io/), except `options.include` and `options.exclude` (each a minimatch pattern, or array of minimatch patterns), which determine which files are transpiled by Babel (by default, all files are transpiled).
+All options are as per the [Babel documentation](https://babeljs.io/), except `options.externalHelpers` (a boolean value indicating whether to bundle in the babel helpers), `options.include` and `options.exclude` (each a minimatch pattern, or array of minimatch patterns), which determine which files are transpiled by Babel (by default, all files are transpiled).
 
 Babel will respect `.babelrc` files – this is generally the best place to put your configuration.
 
@@ -90,6 +90,19 @@ rollup.rollup({
 }).then(...)
 ```
 
+Finally, if you do not wish the babel helpers to be included in your bundle at all (but instead reference the global `babelHelpers` object), you may set the `externalHelpers` option to `true`:
+
+```js
+rollup.rollup({
+  ...,
+  plugins: [
+    babel({
+      plugins: ['external-helpers-2'],
+      externalHelpers: true
+    })
+  ]
+}).then(...)
+```
 
 ## License
 

packages/rollup-plugin-babel/src/index.js

@@ -67,6 +67,10 @@ export default function babel ( options ) {
 	const runtimeHelpers = options.runtimeHelpers;
 	delete options.runtimeHelpers;
 
+	var externalHelpers;
+	if ( options.externalHelpers ) externalHelpers = true;
+	delete options.externalHelpers;
+
 	return {
 		transform ( code, id ) {
 			if ( !filter( id ) ) return null;
@@ -101,6 +105,7 @@ export default function babel ( options ) {
 			};
 		},
 		intro () {
+			if ( externalHelpers ) return '';
 			const helpers = Object.keys( bundledHelpers );
 			if ( !helpers.length ) return '';
 

packages/rollup-plugin-babel/test/test.js

@@ -71,6 +71,19 @@ describe( 'rollup-plugin-babel', function () {
 		});
 	});
 
+	it( 'does not add helpers when externalHelpers option is truthy', function () {
+		return rollup.rollup({
+			entry: 'samples/class/main.js',
+			plugins: [ babelPlugin({externalHelpers: true}) ]
+		}).then( function ( bundle ) {
+			var generated = bundle.generate();
+			var code = generated.code;
+
+			assert.ok( code.indexOf( 'babelHelpers =' ) === -1, generated.code );
+			assert.ok( code.indexOf( 'babelHelpers.classCallCheck =' ) === -1, generated.code );
+		});
+	});
+
 	it( 'does not babelify excluded code', function () {
 		return rollup.rollup({
 			entry: 'samples/exclusions/main.js',