我有一个反应组件
import React, { useEffect, useRef, useState } from 'react'; import './PopularBrands.scss'; import LG from '../../../assets/images/brands/LG.png'; import Google from '../../../assets/images/brands/Google.jpeg'; import Apple from '../../../assets/images/brands/Apple.png'; import Boch from '../../../assets/images/brands/Boch.png'; import Dyson from '../../../assets/images/brands/Dyson.png'; import Philips from '../../../assets/images/brands/Philips.png'; import Samsung from '../../../assets/images/brands/Samsung.png'; import Simens from '../../../assets/images/brands/Simens.png'; import Sony from '../../../assets/images/brands/Sony.png'; import Xiomi from '../../../assets/images/brands/Xiomi.png'; import { FaChevronLeft } from 'react-icons/fa'; import { FaChevronRight } from 'react-icons/fa'; const PopularBrands = () => { const scrollViewRef = useRef<HTMLDivElement | null>(null); const [screenWidth, setScreenWidth] = useState(0); const [width, setWidth] = useState(0); const [widthTotal, setWidthTotal] = useState(0); const [showArrow, setShowArrow] = useState(false); useEffect(() => { function handleWindowResize() { if (scrollViewRef.current) setWidth(scrollViewRef.current.clientWidth); if (scrollViewRef.current) setWidthTotal(scrollViewRef.current.scrollWidth); } handleWindowResize(); window.addEventListener('resize', handleWindowResize); return () => { window.removeEventListener('resize', handleWindowResize); }; }, []); useEffect(() => { scrollViewRef.current?.scrollTo({ left: screenWidth, behavior: 'smooth' }); }, [screenWidth]); const toNextPage = () => { if (scrollViewRef && screenWidth <= widthTotal) { setScreenWidth(screenWidth + width); } }; const toPreviosPage = () => { if (scrollViewRef && screenWidth >= 0) { setScreenWidth(screenWidth - width); } }; return ( <div className="brandsContainer" onMouseEnter={() => setShowArrow(true)} onMouseLeave={() => setShowArrow(false)}> <div className="brands" ref={scrollViewRef}> <div> <img src={LG} alt="lg" /> </div> <div> <img src={Google} alt="Google" /> </div> <div> <img src={Apple} alt="Apple" /> </div> <div> <img src={Boch} alt="Boch" /> </div> <div> <img src={Dyson} alt="Dyson" /> </div> <div> <img src={Philips} alt="Philips" /> </div> <div> <img src={Samsung} alt="Samsung" /> </div> <div> <img src={Simens} alt="Simens" /> </div> <div> <img src={Sony} alt="Sony" /> </div> <div> <img src={Xiomi} alt="Xiomi" /> </div> </div> {screenWidth > 0 && showArrow && ( <div className="scrollIcon scrollBack" onClick={toPreviosPage}> <FaChevronLeft fontSize={30} /> </div> )} {screenWidth + width < widthTotal && showArrow && ( <div className="scrollIcon scrollNext" onClick={toNextPage}> <FaChevronRight fontSize={30} /> </div> )} </div> ); }; export default PopularBrands;
它在用户界面中工作正常。但是当我编写以下单元测试时:
import React from 'react'; import { render, screen } from '@testing-library/react'; import PopularBrands from './PopularBrands'; describe('PopularBrands', () => { test.only('renders the component', () => { render(<PopularBrands />); expect(screen.getByAltText('lg')).toBeInTheDocument(); expect(screen.getByAltText('Google')).toBeInTheDocument(); expect(screen.getByAltText('Apple')).toBeInTheDocument(); expect(screen.getByAltText('Boch')).toBeInTheDocument(); expect(screen.getByAltText('Dyson')).toBeInTheDocument(); expect(screen.getByAltText('Philips')).toBeInTheDocument(); expect(screen.getByAltText('Samsung')).toBeInTheDocument(); expect(screen.getByAltText('Simens')).toBeInTheDocument(); expect(screen.getByAltText('Sony')).toBeInTheDocument(); expect(screen.getByAltText('Xiomi')).toBeInTheDocument(); }); });
测试未通过,我收到错误日志:
● PopularBrands › renders the component TypeError: _scrollViewRef$curren.scrollTo is not a function 37 | 38 | useEffect(() => { > 39 | scrollViewRef.current?.scrollTo({ left: screenWidth, behavior: 'smooth' }); | ^ 40 | }, [screenWidth]); 41 | 42 | const toNextPage = () => { at src/components/Directory/PopularBrands/PopularBrands.tsx:39:28
我正在尝试寻求帮助来修复我的单元测试。在 useEffect 函数上有一个依赖 screenWidth,当该变化时,我们滚动到图标列表的开头。
我也遇到了类似的问题。我能够通过添加以下内容来使测试通过并消除错误:
通过将其添加到您的 setupTests 文件 setupTests 文件中,它应该可以消除错误,但由于它现在是一个模拟,您将无法测试以太功能。
此外,我喜欢测试库没有准备好或没有装备来测试滚动事件,如果你想测试它们,你需要一个基于浏览器的测试环境,而不是一个像玩笑和测试这样的节点 -图书馆。
希望这有帮助。
编辑1:
但是您可以测试该函数是否已被调用,例如: