Handle builtins appropriately for resolve 1.11.0. Fixes #394.

package.json

@@ -47,7 +47,7 @@
     "rollup": "^1.12.0",
     "rollup-plugin-babel": "^4.3.2",
     "rollup-plugin-json": "^4.0.0",
-    "rollup-plugin-node-resolve": "^5.0.0",
+    "rollup-plugin-node-resolve": "^5.1.0",
     "shx": "^0.3.2",
     "source-map": "^0.6.1",
     "source-map-support": "^0.5.12",

src/index.js

@@ -1,5 +1,5 @@
 import { extname, resolve } from 'path';
-import { sync as nodeResolveSync } from 'resolve';
+import { sync as nodeResolveSync, isCore } from 'resolve';
 import { createFilter } from 'rollup-pluginutils';
 import { peerDependencies } from '../package.json';
 import { EXTERNAL_SUFFIX, getIdFromExternalProxyId, getIdFromProxyId, HELPERS, HELPERS_ID, PROXY_SUFFIX } from './helpers';
@@ -16,10 +16,19 @@ export default function commonjs(options = {}) {
 	const customNamedExports = {};
 	if (options.namedExports) {
 		Object.keys(options.namedExports).forEach(id => {
+			let resolveId = id;
 			let resolvedId;
 
+			if (isCore(id)) {
+				// resolve will not find npm modules with the same name as
+				// core modules without a trailing slash. Since core modules
+				// must be external, we can assume any core modules defined
+				// here are npm modules by that name.
+				resolveId += '/';
+			}
+
 			try {
-				resolvedId = nodeResolveSync(id, { basedir: process.cwd() });
+				resolvedId = nodeResolveSync(resolveId, { basedir: process.cwd() });
 			} catch (err) {
 				resolvedId = resolve(id);
 			}

test/samples/custom-named-exports-browser-shims/main.js

@@ -0,0 +1,4 @@
+import { message, foo } from 'events';
+
+assert.equal( message, 'this is not builtin' );
+assert.equal( foo, 'this is a hidden export' );

test/samples/custom-named-exports-warn-builtins/main.js

@@ -1,3 +1,3 @@
-import events from 'events';
+import { message } from 'events';
 
-assert.equal( events, 'x' );
+assert.equal( message, 'this is not builtin' );

test/test.js

@@ -342,6 +342,24 @@ describe('rollup-plugin-commonjs', () => {
 			});
 		});
 
+		it('handles named exports for built-in shims', async () => {
+			const bundle = await rollup({
+				input: 'samples/custom-named-exports-browser-shims/main.js',
+				plugins: [
+					resolve({
+						preferBuiltins: false
+					}),
+					commonjs({
+						namedExports: {
+							events: ['foo']
+						}
+					})
+				]
+			});
+
+			await executeBundle(bundle);
+		});
+
 		it('ignores false positives with namedExports (#36)', async () => {
 			const bundle = await rollup({
 				input: 'samples/custom-named-exports-false-positive/main.js',