class ErrorBoundary extends React.Component {
  constructor(props) {
    super(props);
    this.state = { hasError: false };
  }
  static getDerivedStateFromError(error) {
    // 更新 state 使下一次渲染能夠顯示降級(jí)后的 UI
    return { hasError: true };
  }
  componentDidCatch(error, errorInfo) {
    // 你同樣可以將錯(cuò)誤日志上報(bào)給服務(wù)器
    logErrorToMyService(error, errorInfo);
  }
  render() {
    if (this.state.hasError) {
      // 你可以自定義降級(jí)后的 UI 并渲染
      return <h1>Something went wrong.</h1>;
    }
    return this.props.children;
  }
}

<ErrorBoundary>
  <MyWidget />
</ErrorBoundary>

class ErrorBoundary extends React.Component {
  state = { error: false };
  static getDerivedStateFromError(error) {
    return { error };
  }
  componentDidCatch(error, errorInfo) {
    if (this.props.onError) {
      //上報(bào)日志通過父組件注入的函數(shù)進(jìn)行執(zhí)行
      this.props.onError(error, errorInfo.componentStack);
    }
  }
  render() {
    const { fallback, FallbackComponent } = this.props;
    const { error } = this.state;
    if (error) {
      const fallbackProps = { error };
      //判斷是否為React Element
      if (React.isValidElement(fallback)) {
        return fallback;
      }
      //組件方式傳入
      if (FallbackComponent) {
        return <FallbackComponent {...fallbackProps} />;
      }
      throw new Error("ErrorBoundary 組件需要傳入兜底UI");
    }
    return this.props.children;
  }
}

resetErrorBoundary = () => {
  if (this.props.onReset) this.props.onReset();
  this.setState({ error: false });
};

 render() {
    const { fallback, FallbackComponent, fallbackRender } = this.props;
    const { error } = this.state;
    if (error) {
      const fallbackProps = {
        error,
        resetErrorBoundary: this.resetErrorBoundary,
      };
      ...
      if (typeof fallbackRender === "function")return fallbackRender(fallbackProps);
      ...
    }
    return this.props.children;
  }

import React from "react";
import DefaultErrorBoundary from "./core";
const catchreacterror = (Boundary = DefaultErrorBoundary) => InnerComponent => {
  return props => (
    <Boundary {...props}>
      <InnerComponent {...props} />
    </Boundary>
  );
};

//Function組件
const fnCount1 = ({ count }) => {
  if (count == 3) throw new Error("count is three");
  return <span>{count}</span>;
};
//Class組件
class fnCount2 extends React.Component {
  render() {
    const { count } = this.props;
    if (count == 2) throw new Error("count is two");
    return <span>{count}</span>;
  }
}

const errorbackfn = ({ error: { message }, resetErrorBoundary }) => (
  <div>
    <p>出錯(cuò)啦</p>
    <pre>{message}</pre>
    <button onClick={resetErrorBoundary}>Try again</button>
  </div>
);

const errorbackcom = () => <h1>出錯(cuò)啦,不可撤銷</h1>;

//對(duì)發(fā)起異常的組件進(jìn)行包裹處理，返回一個(gè)可以處理錯(cuò)誤編輯的高階組件
const SafeCount1 = catchreacterror()(fnCount1);
const SafeCount2 = catchreacterror()(fnCount2);
//測(cè)試主組件
const App = () => {
  const [count, setCount] = useState(0);
  const ListenError = (arg, info) => console.log("出錯(cuò)了:" + arg.message, info); //錯(cuò)誤時(shí)進(jìn)行的回調(diào)
  const onReset = () => setCount(0); //點(diǎn)擊重置時(shí)進(jìn)行的回調(diào)
  return (
    <div className="App">
      <section>
        <button onClick={() => setCount(count => count + 1)}>+</button>
        <button onClick={() => setCount(count => count - 1)}>-</button>
      </section>
      <hr />
      <div>
        Class componnet:
        <SafeCount2
          count={count}
          fallbackRender={errorbackfn}
          onReset={onReset}
          onError={ListenError}
        />
      </div>
      <div>
        Function componnet:
        <SafeCount1
          count={count}
          FallbackComponent={errorbackcom}
          onError={ListenError}
        />
      </div>
    </div>
  );
};