[WIP] BREAKING: interop, take 2

.eslintrc

@@ -1,23 +1,24 @@
 {
-	"rules": {
-		"indent": [ 2, "tab", { "SwitchCase": 1 } ],
-		"quotes": [ 2, "single" ],
-		"linebreak-style": [ 2, "unix" ],
-		"semi": [ 2, "always" ],
-		"space-after-keywords": [ 2, "always" ],
-		"space-before-blocks": [ 2, "always" ],
-		"space-before-function-paren": [ 2, "always" ],
-		"no-mixed-spaces-and-tabs": [ 2, "smart-tabs" ],
-		"no-cond-assign": [ 0 ]
-	},
-	"env": {
-		"es6": true,
-		"browser": true,
-		"mocha": true,
-		"node": true
-	},
-	"extends": "eslint:recommended",
-	"ecmaFeatures": {
-		"modules": true
-	}
+  "rules": {
+    "indent": [ 2, "tab", { "SwitchCase": 1 } ],
+    "quotes": [ 2, "single", { "allowTemplateLiterals": true } ],
+    "linebreak-style": [ 2, "unix" ],
+    "semi": [ 2, "always" ],
+    "keyword-spacing": [ 2, { "before": true, "after": true } ],
+    "space-before-blocks": [ 2, "always" ],
+    "space-before-function-paren": [ 2, "always" ],
+    "no-mixed-spaces-and-tabs": [ 2, "smart-tabs" ],
+    "no-cond-assign": [ 0 ]
+  },
+  "env": {
+    "es6": true,
+    "browser": true,
+    "mocha": true,
+    "node": true
+  },
+  "extends": "eslint:recommended",
+  "parserOptions": {
+    "ecmaVersion": 6,
+    "sourceType": "module"
+  }
 }

package.json

@@ -9,7 +9,8 @@
     "rollup": "^0.33.0",
     "rollup-plugin-buble": "^0.12.1",
     "rollup-plugin-node-resolve": "^1.7.1",
-    "source-map": "^0.5.6"
+    "source-map": "^0.5.6",
+    "source-map-support": "^0.4.2"
   },
   "main": "dist/rollup-plugin-commonjs.cjs.js",
   "jsnext:main": "dist/rollup-plugin-commonjs.es.js",

rollup.config.js

@@ -4,6 +4,11 @@ var external = Object.keys( require( './package.json' ).dependencies ).concat([
 
 export default {
 	entry: 'src/index.js',
-	plugins: [ buble() ],
-	external: external
+	plugins: [
+		buble({
+			transforms: { dangerousForOf: true }
+		})
+	],
+	external: external,
+	sourceMap: true
 };

src/defaultResolver.js

@@ -0,0 +1,39 @@
+import * as fs from 'fs';
+import { dirname, resolve } from 'path';
+
+function isFile ( file ) {
+	try {
+		const stats = fs.statSync( file );
+		return stats.isFile();
+	} catch ( err ) {
+		return false;
+	}
+}
+
+function addJsExtensionIfNecessary ( file ) {
+	if ( isFile( file ) ) return file;
+
+	file += '.js';
+	if ( isFile( file ) ) return file;
+
+	return null;
+}
+
+const absolutePath = /^(?:\/|(?:[A-Za-z]:)?[\\|\/])/;
+
+function isAbsolute ( path ) {
+	return absolutePath.test( path );
+}
+
+export default function defaultResolver ( importee, importer ) {
+	// absolute paths are left untouched
+	if ( isAbsolute( importee ) ) return addJsExtensionIfNecessary( resolve( importee ) );
+
+	// if this is the entry point, resolve against cwd
+	if ( importer === undefined ) return addJsExtensionIfNecessary( resolve( process.cwd(), importee ) );
+
+	// external modules are skipped at this stage
+	if ( importee[0] !== '.' ) return null;
+
+	return addJsExtensionIfNecessary( resolve( dirname( importer ), importee ) );
+}

src/helpers.js

@@ -0,0 +1,15 @@
+export const HELPERS_ID = '\0commonjsHelpers';
+
+export const HELPERS = `
+export var commonjsGlobal = typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : typeof self !== 'undefined' ? self : {};
+
+export function unwrapExports (x) {
+	return x && x.__esModule ? x['default'] : x;
+}
+
+export function createCommonjsModule(fn, module) {
+	return module = { exports: {} }, fn(module, module.exports), module.exports;
+}`;
+
+export const PREFIX = '\0commonjs-proxy:';
+export const EXTERNAL = '\0commonjs-external:';