在Typescript中创建React HOC时出现错误

时间:2019-04-14 20:06:01

标签: reactjs typescript

我正在尝试在Typescript中创建和编译React Higer Order组件。

但是我得到一个错误。首先,VSCode对此抱怨

'WrappedComponent' refers to a value, but is being used as a type here.

**我的Typescript编译器抛出此错误。**

lib/auth.ts:44:30 - error TS1005: '>' expected.

44     return <WrappedComponent {...this.props} />;
                                ~

lib/auth.ts:44:47 - error TS1109: Expression expected.

44     return <WrappedComponent {...this.props} />;
                                                 ~

lib/auth.ts:44:48 - error TS1109: Expression expected.

44     return <WrappedComponent {...this.props} />;

**这是我下面的React HOC组件代码**

import * as React from 'react';
import Router from 'next/router';
import { NextContext } from 'next';
import nextCookie from 'next-cookies';
import { MOVED_TEMPORARILY } from 'http-status-codes';

interface ComponentExtra extends React.Component, React.SFC {
  getInitialProps: Function;
}

export const withAuthSync = (WrappedComponent: ComponentExtra) => class extends React.Component {
  static async getInitialProps(ctx: NextContext) {
    const token = auth(ctx);
    const componentProps = WrappedComponent.getInitialProps && (await WrappedComponent.getInitialProps(ctx));
    return { ...componentProps, token };
  }

  render() {
    return <WrappedComponent {...this.props} />;
  }
};

export const auth = (ctx: NextContext) => {
  const { req, res } = ctx;
  const { token } = nextCookie(ctx);

  if (req && res && !token) {
    res.writeHead(MOVED_TEMPORARILY, { Location: '/signin' }).end();
    return;
  }

  return token;
};

**更新错误是由于文件扩展名不是.tsx而是.ts **

2 个答案:

答案 0 :(得分:1)

该错误意味着未将JSX语法解析为这样:

  

lib / auth.ts:44:30-出现错误TS1005:“>”。

44     return <WrappedComponent {...this.props} />;

为此,应将auth.ts重命名为auth.tsx。如果为JSX正确配置了TypeScript,则这是唯一需要的修复程序。

答案 1 :(得分:0)

我有相同的错误,但是原因不同。我在上一行中注释了一个JSX元素,例如:

file1.tsx
  export const WrappedComponent = HocFunction(Component);


file2.tsx
  import { WrappedComponent }  from './file1.tsx';
  ...
  // <SomeJSXTag />
  <WrappedComponent /> --- Error: 'WrappedComponent' refers to a value, but is being used as a type here.

我终于通过将注释更改为以下内容来修复它:

  {/*
  <SomeJSXTag />
  */}
  <WrappedComponent /> --- Error Disappeared

错误消失了。

目前,这可能只是JSX行为:https://wesbos.com/react-jsx-comments/