Jest の beforeEach() / test() と Promise と setTimeout() の関係 - Qiita

describe('async test', () => { let called; function promise() { console.log(called = 'function'); setTimeout(() => { console.log(called = 'setTimeout()'); }, 0); return new Promise(resolve => { console.log(called = 'Promise()'); resolve(); }).then(() => { console.log(called = 'then()'); }); } describe('test() only', () => { test('without await', () => { promise(); expect(called).toBe('Promise()');