modulesOnly option

README.md

@@ -36,12 +36,6 @@ export default {
       // – see https://github.com/rollup/rollup-plugin-commonjs
       main: true,  // Default: true
 
-      // if there's something your bundle requires that you DON'T
-      // want to include, add it to 'skip'. Local and relative imports
-      // can be skipped by giving the full filepath. E.g.,
-      // `path.resolve('src/relative-dependency.js')`
-      skip: [ 'some-big-dependency' ],  // Default: []
-
       // some package.json files have a `browser` field which
       // specifies alternative files to load for people bundling
       // for the browser. If that's you, use this option, otherwise

package.json

@@ -17,7 +17,8 @@
   "module": "dist/rollup-plugin-node-resolve.es.js",
   "jsnext:main": "dist/rollup-plugin-node-resolve.es.js",
   "scripts": {
-    "pretest": "rollup -c",
+    "build": "rollup -c",
+    "pretest": "npm run build",
     "test": "mocha",
     "posttest": "eslint src test/*.js",
     "prepublish": "npm test",
@@ -30,6 +31,7 @@
   "dependencies": {
     "browser-resolve": "^1.11.0",
     "builtin-modules": "^1.1.0",
+    "is-module": "^1.0.0",
     "resolve": "^1.1.6"
   },
   "repository": "rollup/rollup-plugin-node-resolve",

rollup.config.js

@@ -3,7 +3,7 @@ import buble from 'rollup-plugin-buble';
 export default {
 	entry: 'src/index.js',
 	plugins: [ buble() ],
-	external: [ 'path', 'fs', 'builtin-modules', 'resolve', 'browser-resolve' ],
+	external: [ 'path', 'fs', 'builtin-modules', 'resolve', 'browser-resolve', 'is-module' ],
 	targets: [
 		{ dest: 'dist/rollup-plugin-node-resolve.cjs.js', format: 'cjs' },
 		{ dest: 'dist/rollup-plugin-node-resolve.es.js', format: 'es' }

src/index.js

@@ -2,6 +2,7 @@ import { dirname, resolve, normalize, sep } from 'path';
 import builtins from 'builtin-modules';
 import _nodeResolve from 'resolve';
 import browserResolve from 'browser-resolve';
+import isModule from 'is-module';
 import fs from 'fs';
 
 const COMMONJS_BROWSER_EMPTY = _nodeResolve.sync( 'browser-resolve/empty.js', __dirname );
@@ -48,7 +49,7 @@ export default function nodeResolve ( options = {} ) {
 				id = resolve( importer, '..', importee );
 			}
 
-			return new Promise( fulfil => {
+			return new Promise( ( fulfil, reject ) => {
 				let disregardResult = false;
 
 				resolveId(
@@ -91,7 +92,18 @@ export default function nodeResolve ( options = {} ) {
 							}
 						}
 
-						fulfil( resolved );
+						if ( resolved && options.modulesOnly ) {
+							fs.readFile( resolved, 'utf-8', ( err, code ) => {
+								if ( err ) {
+									reject( err );
+								} else {
+									const valid = isModule( code );
+									fulfil( valid ? resolved : null );
+								}
+							});
+						} else {
+							fulfil( resolved );
+						}
 					}
 				);
 			});

test/samples/deep-import-non-module/main.js

@@ -0,0 +1,3 @@
+import deep from 'foo/deep';
+
+console.log( deep );

test/test.js

@@ -372,4 +372,15 @@ describe( 'rollup-plugin-node-resolve', function () {
 			);
 		});
 	});
+
+	it( 'ignores deep-import non-modules', () => {
+		return rollup.rollup({
+			entry: 'samples/deep-import-non-module/main.js',
+			plugins: [ nodeResolve({
+				modulesOnly: true
+			}) ]
+		}).then( bundle => {
+			assert.deepEqual( bundle.imports, [ 'foo/deep' ] );
+		});
+	});
 });