const util = require('../../lib/util'); describe('utils', () => { it('getFreePort', async () => { const count = 100; const tasks = []; for (let i = 1; i <= count; i++) { tasks.push(util.getFreePort()); } await Promise.all(tasks) .then((results) => { // ensure ports are unique const portMap = {}; results.map((portNumber) => { portMap[portNumber] = true; }); expect(Object.keys(portMap).length).toEqual(count); }); }); });