Reaction测试库如何使用waitFor
我正在跟踪a tutorial的反应测试。本教程有一个如下所示的简单组件,用于展示如何测试异步操作:
import React from 'react'
const TestAsync = () => {
const [counter, setCounter] = React.useState(0)
const delayCount = () => (
setTimeout(() => {
setCounter(counter + 1)
}, 500)
)
return (
<>
<h1 data-testid="counter">{ counter }</h1>
<button data-testid="button-up" onClick={delayCount}> Up</button>
<button data-testid="button-down" onClick={() => setCounter(counter - 1)}>Down</button>
</>
)
}
export default TestAsync
测试文件如下:
import React from 'react';
import { render, cleanup, fireEvent, waitForElement } from '@testing-library/react';
import TestAsync from './TestAsync'
afterEach(cleanup);
it('increments counter after 0.5s', async () => {
const { getByTestId, getByText } = render(<TestAsync />);
fireEvent.click(getByTestId('button-up'))
const counter = await waitForElement(() => getByText('1'))
expect(counter).toHaveTextContent('1')
});
终端显示waitForElement
已弃用,请改用waitFor
。
如何在此测试文件中使用waitFor
?
解决方案
如果您是waiting for appearance,可以这样使用:
it('increments counter after 0.5s', async() => {
const { getByTestId, getByText } = render(<TestAsync />);
fireEvent.click(getByTestId('button-up'));
await waitFor(() => {
expect(getByText('1')).toBeInTheDocument();
});
});
使用getByText('1')
获取该元素时,检查.toHaveTextContent('1')
有点奇怪,因此我将其替换为.toBeInTheDocument()
。
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