multi-entry support in core rollup lib

src/rollup.js

@@ -3,6 +3,7 @@ import { writeFile } from './utils/fs.js';
 import { assign, keys } from './utils/object.js';
 import { mapSequence } from './utils/promise.js';
 import validateKeys from './utils/validateKeys.js';
+import ensureArray from './utils/ensureArray.js';
 import SOURCEMAPPING_URL from './utils/sourceMappingURL.js';
 import Bundle from './Bundle.js';
 
@@ -52,7 +53,10 @@ export function rollup ( options ) {
 		return Promise.reject( error );
 	}
 
-	const bundle = new Bundle( options );
+	const entries = ensureArray(options.entry);
+
+	return Promise.all( entries.map( entry => {
+		const bundle = new Bundle( assign( { }, options, { entry } ) );
 
 		return bundle.build().then( () => {
 			function generate ( options ) {
@@ -74,7 +78,9 @@ export function rollup ( options ) {
 				exports: keys( bundle.entryModule.exports ),
 				modules: bundle.orderedModules.map( module => module.toJSON() ),
 
+				entry,
 				generate,
+
 				write: options => {
 					if ( !options || !options.dest ) {
 						throw new Error( 'You must supply options.dest to bundle.write' );
@@ -112,4 +118,6 @@ export function rollup ( options ) {
 
 			return result;
 		});
+	}))
+	.then( results => results.length === 1 ? results[0] : results );
 }