Adding an "only" option

README.md

@@ -53,6 +53,11 @@ export default {
       // Lock the module search in this path (like a chroot). Module defined
       // outside this path will be marked as external
       jail: '/my/jail/path', // Default: '/'
+
+      // Set to an array of strings and/or regexps to lock the module search
+      // to modules that match at least one entry. Modules not matching any
+      // entry will be marked as external
+      only: [ 'some_module', /^@some_scope\/.*$/ ], // Default: null
 
       // If true, inspect resolved files to check that they are
       // ES2015 modules

src/index.js

@@ -44,6 +44,7 @@ export default function nodeResolve ( options = {} ) {
 	const preferBuiltins = isPreferBuiltinsSet ? options.preferBuiltins : true;
 	const customResolveOptions = options.customResolveOptions || {};
 	const jail = options.jail;
+	const only = options.only;
 	const browserMapCache = {};
 
 	const onwarn = options.onwarn || CONSOLE_WARN;
@@ -99,6 +100,8 @@ export default function nodeResolve ( options = {} ) {
 				id = resolve( importer, '..', importee );
 			}
 
+			if (only && !only.some(pattern => id.match(pattern))) return null;
+
 			return new Promise( ( fulfil, reject ) => {
 				let disregardResult = false;
 				let packageBrowserField = false;

test/samples/only/main.js

@@ -0,0 +1,7 @@
+import foo from '@scoped/foo';
+import bar from '@scoped/bar';
+import test from 'test';
+
+console.log( foo );
+console.log( bar );
+console.log( test );

test/test.js

@@ -552,6 +552,32 @@ describe( 'rollup-plugin-node-resolve', function () {
 		});
 	});
 
+	it( '"only" option allows to specify the only packages to resolve', () => {
+		return rollup.rollup({
+			input: 'samples/only/main.js',
+			plugins: [
+				nodeResolve({
+					only: [ 'test' ]
+				})
+			]
+		}).then(bundle => {
+			assert.deepEqual( bundle.imports.sort(), [ '@scoped/bar', '@scoped/foo' ] );
+		});
+	});
+
+	it( '"only" option works with a regex', () => {
+		return rollup.rollup({
+			input: 'samples/only/main.js',
+			plugins: [
+				nodeResolve({
+					only: [ /^@scoped\/.*$/ ]
+				})
+			]
+		}).then(bundle => {
+			assert.deepEqual( bundle.imports.sort(), [ 'test' ] );
+		});
+	});
+
 	it( 'allows custom options', () => {
 		return rollup.rollup({
 			input: 'samples/custom-resolve-options/main.js',