import { sleep } from './sleep' ; describe ( 'sleep' , ( ) => { beforeEach ( ( ) => { jest . setTimeout ( 500 ) ; jest . useFakeTimers ( ) ; } ) ; afterEach ( ( ) => { jest . useRealTimers ( ) ; } ) ; it ( 'should sleep the duration of timeoutMs' , async ( ) => { const promise = sleep ( 1000 ) ; jest . advanceTimersByTime ( 1000 ) ; await promise ; } ) ; } ) ;