[React Testing] Children with Shallow Rendering

When testing React components, we often want to make sure the rendered output of the component matches what we expect. With the React Shallow Renderer, we can check the entire rendered output of a component, the children prop, or a subset of the chil…

[React Testing] Intro to Shallow Rendering

In this lesson, we walk through how to use one of React's Test Utilities (from thereact-addons-test-utils package) called "Shallow Rendering". This lets us render our React component one level deep - without a DOM - so that we can write tests fo…

[React Testing] className with Shallow Rendering

The React Shallow Renderer test utility lets us inspect the output of a component one level deep. In this lesson, we will examine the rendered output of props, specifically the className prop. We will then use the ES2015 String.includes() method to c…

[React Testing] JSX error diffs -- expect-jsx library

When writing React component tests, it can be hard to decipher the error diffs of broken tests, since they are just the final objects that React uses under the hood. There are some nice libraries that let you extend your assertion library to show JSX…

如何使用TDD和React Testing Library构建健壮的React应用程序

如何使用TDD和React Testing Library构建健壮的React应用程序当我开始学习React时,我努力的一件事就是以一种既有用又直观的方式来测试我的web应用程序. 每次我想测试它时,我都会用Jest的 Enzyme来渲染一个组件. 当然,我绝对滥用快照测试功能. 那么,至少我写了一个测试吧? 您可能听说过编写单元和集成测试会提高您编写的软件的质量. 另一方面,不好的测试会产生错误的信心. 最近,我通过与Kent C. Dodds的workshop.me参加了一个研讨会,他在那…

React Testing All in One

React Testing All in One React 测试 https://reactjs.org/docs/testing.html jest 26.4 https://jestjs.io/zh-Hans/ https://jestjs.io/docs/zh-Hans/tutorial-react $ yarn add -D react-test-renderer $ yarn add -D jest babel-jest @babel/preset-env @babel/preset…

[React Testing] Element types with Shallow Rendering

When you render a component with the Shallow Renderer, you have access to the underlying object. We can write lots of useful tests to check that our components are working as expected. In this lesson, we will use the type property on the shallow rend…

[React Testing] Conditional className with Shallow Rendering

Often our components have output that shows differently depending on the props it is given; in this lesson, we go over how to compare the className prop element tree output based on conditional input. // LikeCounter.js import React from 'react'; impo…

[React & Testing] Simulate Event testing

Here we want to test a toggle button component, when the button was click, state should change, style should change also. Toggle component: // see this live: https://codesandbox.io/s/GvWpGjKQ import React, {Component} from 'react' import PropTypes fr…

[React & Testing] Snapshot testings

For example we have a React comonent: -- A toggle button, we want to test. When it si toggle on, the color is a little bit darken than it's not. // see this live: https://codesandbox.io/s/GvWpGjKQ import React, {Component} from 'react' import PropTyp…

[React Testing] Setting up dependencies && Running tests

To write tests for our React code, we need to first install some libraries for running tests and writing assertions. In this lesson we walk through setting up Mocha as our test runner and expect as our assertion library. We will also set up some Reac…

[React Testing] The Redux Store - Multiple Actions

When using Redux, we can test that our application state changes are working by testing that dispatching actions to the store creates our expected output. In this lesson we will run a few realistic actions back to back (as if the user is using the ap…

[React Testing] Reusing test boilerplate

Setting up a shallow renderer for each test can be redundant, especially when trying to write similar tests that have slight tweaks. In this lesson, we go over how you can reduce some of the overlapping code so that each test only contains the unique…

[React Testing] Confidently Ship Production React Apps

We want to make sure that when we ship new code, our users can use the application. The best way we've found to do that is to write automated tests that run before we deploy a new version of the app. But if our tests aren't doing exactly what the use…

[React Testing] Redux Reducers

Sometimes we want to test our Redux reducers to make sure they work as expected. In this lesson we will walk through setting up some Redux reducer tests for common situations and edge cases. quoteReducer.js import {ADD_QUOTE_BY_ID, REMOVE_QUOTE_BY_ID…

React server rendering —— 网易美学主站同构实录

此文已由作者张硕授权网易云社区发布. 欢迎访问网易云社区,了解更多网易技术产品运营经验. 网易美学主站在最初开发时,因为各种历史原因,引入了例如JQuery,Bootstrop,Angular, React等框架,代码结构比较混乱,给后续的开发和维护带来了很大的不便.所以对它进行了重构.下面,我会从以下三个方面对主站的重构方案进行介绍: 我们为什么进行重构? 如何使用React进行同构同构过程中遇到的问题以及解决方案我们为什么要进行重构? Before 对于同一个组件,需要分别使用模板和Re…

对React children 的深入理解

React的核心为组件.你可以像嵌套HTML标签一样嵌套使用这些组件,这使得编写JSX更加容易因为它类似于标记语言. 当我刚开始学习React时,当时我认为“使用 props.children 就这么回事,我知道它的一切”.我错了.. 因为我们使用的事JavaScript,我们会改变children.我们能够给它们发送特殊的属性,以此来决定它们是否进行渲染.让我们来探究一下React中children的作用. 子组件我们有一个组件 <Grid /> 包含了几个组件 <Row />…

React: 通过React.Children访问特定子组件

一.简介 React中提供了很多常用的API,其中有一个React.Children可以用来访问特定组件的子元素.它允许用来统计个数.map映射.循环遍历.转换数组以及显示指定子元素,如下所示: var React = { // Modern Children: { map: ReactChildren.map, //映射 forEach: ReactChildren.forEach,//遍历 count: ReactChildren.count, //个数 toArray: ReactChil…

React (Native) Rendering Lifecycle

How Does React Native Work? The idea of writing mobile applications in JavaScript feels a little odd. How is it possible to use React in a mobile environment? In order to understand the technical underpinnings of React Native, first we’ll need to rec…

React躬行记（14）——测试框架

测试不仅可以发现和预防问题,还能降低风险.减少企业损失.在React中,涌现了多种测试框架,本节会对其中的Jest和Enzyme做详细的讲解. 一.Jest Jest是由Facebook开源的一个测试框架,可无缝兼容React项目,专注简单,推崇零配置,开箱即用的宗旨,用于逻辑和组件的单元测试.它的语法和断言与Jasmine类似,并且还集成了快照测试.Mock.覆盖率报告等功能,支持多进程并行运行测试,在内部使用JSDOM操作DOM,JSDOM是一种模拟的DOM环境,其行为类似于常规浏览器,可用…

【前端单元测试入门02】react的单元测试之Enzyme

React项目的单元测试 React的组件结构和JSX语法,对上一章的内容来讲进行测试显得很勉强. React官方已经提供了一个测试工具库:react-dom/test-utils 只是用起来不够方便,于是有了一些第三方的封装库,比如Airbnb公司的Enzyme 测试项目的配置本次测试项目是根据上一章的测试项目衍生而来,包含上一章讲到的Mocha和chai,这里只介绍新加的一些模块. 项目结构图如下: 因为是React项目,所以自然需要安装React的一些东西: npm install --…

[03] react 测试

测试是开发周期中的一个重要组成部分.没有测试的代码被称为:遗留代码.对于我而言,第一次学习 React 和 JavaScript 的时候,感到很有压力.如果你也是刚开始学习 JS/React,并加入他们的社区,那么也可能会有相同的感觉.想到的会是: 我应该用哪一个构建工具? 哪一个测试框架比较好? 我应该学习哪种流模式? 我需要用到流吗? 为了解决这些烦恼,我决定写这篇文章.经过几个小时的博客文章阅读,查阅 JS 开发者的源码,还有参加 Florida 的 JSConf,终于让我找到了自己的测试…

使用create react app教程

This project was bootstrapped with Create React App. Below you will find some information on how to perform common tasks. You can find the most recent version of this guide here. Updating to New Releases Create React App is divided into two packages:…