在 React 應用程式中，Error Boundary 是一種用來捕捉錯誤的元件，今天我們來學習如何測試 Error Boundary。先看一下元件的程式碼：

error-boundary.js

import React from 'react'
import {reportError} from './api'

class ErrorBoundary extends React.Component {
  state = {hasError: false}
  componentDidCatch(error, info) {
    this.setState({hasError: true})
    reportError(error, info)
  }
  tryAgain = () => this.setState({hasError: false})
  render() {
    return this.state.hasError ? (
      <div>
        <div role="alert">There was a problem.</div>{' '}
        <button onClick={this.tryAgain}>Try again?</button>
      </div>
    ) : (
      this.props.children
    )
  }
}

export {ErrorBoundary}

(未完...