/** * @jest-environment jsdom */ import { render } from '@testing-library/react'; import { Interval, EVERY_SECOND, EVERY_MINUTE } from '../index'; jest.useFakeTimers(); describe( 'Interval', () => { test( 'Does not run onTick() on mount', () => { const spy = jest.fn(); render( ); expect( spy ).not.toHaveBeenCalled(); } ); test( 'Runs onTick() on the intervals', () => { const spy = jest.fn(); render( ); jest.advanceTimersByTime( 1000 ); expect( spy ).toHaveBeenCalledTimes( 1 ); } ); test( 'Respects the period passed', () => { const spy = jest.fn(); render( ); jest.advanceTimersByTime( 1000 * 60 ); expect( spy ).toHaveBeenCalledTimes( 1 ); } ); test( 'Stops running the interval on unmount', () => { const spy = jest.fn(); const { unmount } = render( ); jest.advanceTimersByTime( 1000 ); expect( spy ).toHaveBeenCalledTimes( 1 ); unmount(); jest.advanceTimersByTime( 2000 ); expect( spy ).toHaveBeenCalledTimes( 1 ); } ); test( 'Changes the interval when the period changes', () => { const spy = jest.fn(); const { rerender } = render( ); jest.advanceTimersByTime( 1000 ); expect( spy ).toHaveBeenCalledTimes( 1 ); rerender( ); jest.advanceTimersByTime( 1000 ); expect( spy ).toHaveBeenCalledTimes( 1 ); jest.advanceTimersByTime( 60 * 1000 ); expect( spy ).toHaveBeenCalledTimes( 2 ); } ); test( 'Picks up a new ticker even if the period does not change', () => { const spy = jest.fn(); const otherSpy = jest.fn(); const { rerender } = render( ); jest.advanceTimersByTime( 1000 ); expect( spy ).toHaveBeenCalledTimes( 1 ); rerender( ); expect( spy ).toHaveBeenCalledTimes( 1 ); expect( otherSpy ).not.toHaveBeenCalled(); jest.advanceTimersByTime( 1000 ); expect( spy ).toHaveBeenCalledTimes( 1 ); expect( otherSpy ).toHaveBeenCalledTimes( 1 ); } ); } );