Merge pull request #134 from adroitwhiz/module

Build an ES6 module as well

Author: avoidwork

package.json

@@ -18,6 +18,7 @@
   "license": "BSD-3-Clause",
   "browser": "lib/filesize.min.js",
   "main": "lib/filesize.js",
+  "module": "lib/filesize.esm.js",
   "types": "filesize.d.ts",
   "engines": {
     "node": ">= 0.4.0"

rollup.config.js

@@ -16,6 +16,7 @@ const bannerShort = `/*!
 */`;
 
 const umdOutBase = { format: 'umd', name: 'filesize' };
+const esmOutBase = { format: 'esm', name: 'filesize' };
 
 export default [
   {
@@ -25,6 +26,13 @@ export default [
       { ...umdOutBase, file: 'lib/filesize.es6.min.js', banner: bannerShort, plugins: [ terser() ], sourcemap: true },
     ]
   },
+  {
+    input: 'src/filesize.js',
+    output: [
+      { ...esmOutBase, file: 'lib/filesize.esm.js', banner: bannerLong },
+      { ...esmOutBase, file: 'lib/filesize.esm.min.js', banner: bannerShort, plugins: [ terser() ], sourcemap: true },
+    ]
+  },
   {
     input: 'src/filesize.js',
     output: [