'use strict'; 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 && slashIndex !== moduleName.length - 1) { moduleName = moduleName.slice(0, slashIndex); } return moduleSet.has(moduleName); };