import * as React from 'react' import {render, configure} from '../' describe('rerender API', () => { let originalConfig beforeEach(() => { // Grab the existing configuration so we can restore // it at the end of the test configure(existingConfig => { originalConfig = existingConfig // Don't change the existing config return {} }) }) afterEach(() => { configure(originalConfig) }) test('rerender will re-render the element', () => { const Greeting = props =>
{props.message}
const {container, rerender} = render() expect(container.firstChild).toHaveTextContent('hi') rerender() expect(container.firstChild).toHaveTextContent('hey') }) test('hydrate will not update props until next render', () => { const initialInputElement = document.createElement('input') const container = document.createElement('div') container.appendChild(initialInputElement) document.body.appendChild(container) const firstValue = 'hello' initialInputElement.value = firstValue const {rerender} = render( null} />, { container, hydrate: true, }) expect(initialInputElement).toHaveValue(firstValue) const secondValue = 'goodbye' rerender( null} />) expect(initialInputElement).toHaveValue(secondValue) }) test('re-renders options.wrapper around node when reactStrictMode is true', () => { configure({reactStrictMode: true}) const WrapperComponent = ({children}) => (
{children}
) const Greeting = props =>
{props.message}
const {container, rerender} = render(, { wrapper: WrapperComponent, }) expect(container.firstChild).toMatchInlineSnapshot(`
hi
`) rerender() expect(container.firstChild).toMatchInlineSnapshot(`
hey
`) }) test('re-renders twice when reactStrictMode is true', () => { configure({reactStrictMode: true}) const spy = jest.fn() function Component() { spy() return null } const {rerender} = render() expect(spy).toHaveBeenCalledTimes(2) spy.mockClear() rerender() expect(spy).toHaveBeenCalledTimes(2) }) })