Recognize alias modules and node: protocol (#6)

Author: fisker

index.js

@@ -2,11 +2,21 @@
 const builtinModules = require('builtin-modules');
 
 const moduleSet = new Set(builtinModules);
+const NODE_PROTOCOL = 'node:';
 
 module.exports = moduleName => {
 	if (typeof moduleName !== 'string') {
 		throw new TypeError('Expected a string');
 	}
 
+	if (moduleName.startsWith(NODE_PROTOCOL)) {
+		moduleName = moduleName.slice(NODE_PROTOCOL.length);
+	}
+
+	const slashIndex = moduleName.indexOf('/');
+	if (slashIndex !== -1) {
+		moduleName = moduleName.slice(0, slashIndex);
+	}
+
 	return moduleSet.has(moduleName);
 };

readme.md

@@ -18,6 +18,12 @@ const isBuiltinModule = require('is-builtin-module');
 isBuiltinModule('fs');
 //=> true
 
+isBuiltinModule('fs/promises');
+//=> true
+
+isBuiltinModule('node:fs/promises');
+//=> true
+
 isBuiltinModule('unicorn');
 //=> false
 ```

test.js

@@ -4,5 +4,28 @@ import isBuiltinModule from '.';
 test('main', t => {
 	t.true(isBuiltinModule('fs'));
 	t.true(isBuiltinModule('console'));
+
+	t.true(isBuiltinModule('fs/promises'));
+	t.true(isBuiltinModule('assert/strict'));
+
+	// These are actually not, but should not exist
+	t.true(isBuiltinModule('fs/'));
+	t.true(isBuiltinModule('fs/unknown'));
+	t.true(isBuiltinModule('fs/promises/unknown'));
+	t.true(isBuiltinModule('fs/promises?query=1'));
+
+	t.true(isBuiltinModule('node:fs'));
+	t.true(isBuiltinModule('node:fs/promises'));
+
 	t.false(isBuiltinModule('unicorn'));
+	t.false(isBuiltinModule('unknown'));
+	t.false(isBuiltinModule('FS'));
+	t.false(isBuiltinModule('nodE:fs'));
+	t.false(isBuiltinModule('node:fS'));
+	t.false(isBuiltinModule('fsnode:'));
+	t.false(isBuiltinModule('node:unknown'));
+	t.false(isBuiltinModule('node:node:fs'));
+	t.false(isBuiltinModule('node:/fs'));
+	t.false(isBuiltinModule('file:fs/promises'));
+	t.false(isBuiltinModule('data:text/javascript;utf-8,export {default} from "fs";'));
 });