随笔分类 - React
摘要:You can get a huge amount of confidence and coverage from integration tests that test an entire page, or even your entire app. Let’s write a test that
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摘要:Sometimes your react component may need to do some cleanup work in the return value from useEffect or useLayoutEffect, or the componentWillUnmount lif
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摘要:That setup function is pretty handy. Seems like a good opportunity for an abstraction. Well, we already have one! It’s called React Hooks Testing Libr
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摘要:It’s very common for our components to use state from the redux store (or to be refactored to use it eventually). Having to change our tests every tim
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摘要:We’ve got a custom useCounter hook here and we want to make sure the increment and decrement functions it returns will update the count state that it
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摘要:Mocking the <Redirect /> component in react-router works, but it’s imperfect because we don’t know for sure that the user will be redirected properly.
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摘要:We have the happy path covered for our post editor component, but what happens if there’s an error in saving the user’s information? We should probabl
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摘要:A really important aspect of TDD is the refactor phase. A critical piece to making your tests easier to maintain is using code structure and values to
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摘要:Just make sure the date is in a range then it is fine import React from 'react' import {render, fireEvent, waitFor} from '@testing-library/react' impo
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摘要:Once the data has been saved on the server, we’ll want to redirect the user to the home screen with react-router’s <Redirect /> component. Let’s go ah
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摘要:We have a bit of repetition in our rerender calls here and it would be nice if we could avoid that. Let’s use the wrapper option for React Testing Lib
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摘要:Our error boundary has some other use cases that it supports and we should try to make sure our tests cover all those use cases, so let’s add a test t
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摘要:When testing an error boundary, your console will be filled with console.error calls from React. Those can be a real distraction from the rest of the
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摘要:Error boundary: import React from 'react' import { reportError } from './components/extra/api' export default class ErrorBoundary extends React.Compon
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摘要:There are some situations where you want to focus your tests on a particular component and not any of its children. There are other situations where y
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摘要:If you have a component that makes HTTP requests, you’ll probably want to mock those out for UI unit and integration tests. Let’s see how to use jest’
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摘要:You can use 'rerender' for a component when its props changed. Then if you wnat to check the alert message has gone when we rerender, you need to use
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摘要:The User Event module is part of the Testing Library family of tools and lets you fire events on DOM nodes that more closely resemble the way your use
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摘要:The fireEvent utility in React Testing Library supports all the events that you regularly use in the web (change, click, etc.). Let’s see how we can t
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摘要:While you’re writing your tests it can be helpful to see what the DOM looks like. You can do this with React Testing Library’s debug function which wi
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