node_modules/@ types/react/index"'没有默认导出

Leo*_*ban 9 javascript typescript reactjs

试图将React应用程序转换为Typescript并遇到奇怪的错误.

node_modules/@ types/react/index"'没有默认导出.

node_modules/@ types/react-dom/index"'没有默认导出.

我有针对打字稿的tsconfig和webpack设置.将这个组件的扩展名更改.js.tsx我之后,React会出现错误吗?

在此输入图像描述

思考?

tsconfig.json

{
  "compilerOptions": {
    "outDir": "./moonholdings/",
    "sourceMap": true,
    "noImplicitAny": true,
    "module": "commonjs",
    "target": "es5",
    "jsx": "react"
  },
  "include": [
    "./app/**/*"
  ]
}
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的WebPack

/* eslint-disable no-console */
import webpack from 'webpack';
import HtmlWebpackPlugin from 'html-webpack-plugin';
import ExtractTextPlugin from 'extract-text-webpack-plugin';
import CopyWebpackPlugin from 'copy-webpack-plugin';
import path from 'path';
import chalk from 'chalk';

const moonholdings = path.resolve(__dirname, 'moonholdings');
const app = path.resolve(__dirname, 'app');
const nodeModules = path.resolve(__dirname, 'node_modules');

const HtmlWebpackPluginConfig = new HtmlWebpackPlugin({
  template: path.join(__dirname, '/app/index.html'),
  inject: 'body'
});

const ExtractTextPluginConfig = new ExtractTextPlugin({
  filename: 'moonholdings.css',
  disable: false,
  allChunks: true
});

const CopyWebpackPluginConfigOptions = [{
  from: 'app/static',
  to: 'static/'
}];

const CopyWebpackPluginConfig = new CopyWebpackPlugin(CopyWebpackPluginConfigOptions);

const PATHS = {
  app,
  build: moonholdings
};

const LAUNCH_COMMAND = process.env.npm_lifecycle_event;

const isProduction = LAUNCH_COMMAND === 'production';
process.env.BABEL_ENV = LAUNCH_COMMAND;

const productionPlugin = new webpack.DefinePlugin({
  'process.env': {
    NODE_ENV: JSON.stringify('production')
  }
});

const base = {
  // entry: ['babel-polyfill', PATHS.app],
  entry: './app/index.tsx',
  output: {
    path: PATHS.build,
    publicPath: '/',
    filename: 'index_bundle.js'
  },
  resolve: {
    modules: [app, nodeModules],
    extensions: ['.ts', '.tsx', '.js', '.json']
  },
  module: {
    rules: [
      // All files with a '.ts' or '.tsx' extension will be handled by 'awesome-typescript-loader'.
      { test: /\.tsx?$/, loader: 'awesome-typescript-loader' },
      {
        test: /\.js$/,
        loader: 'babel-loader',
        exclude: /node_modules/
      },
      {
        test: /\.s?css/,
        use: [
          'style-loader',
          'css-loader',
          'sass-loader'
        ]
      },
      {
        test: /\.(png|jpg|jpeg|gif|svg|woff|woff2|ttf|eot)/,
        loader: 'file-loader?name=[path][name].[ext]'
      },
      // All output '.js' files will have any sourcemaps re-processed by 'source-map-loader'.
      { enforce: 'pre', test: /\.js$/, loader: 'source-map-loader' }
    ]
  }
};

const developmentConfig = {
  devtool: 'cheap-module-inline-source-map',
  devServer: {
    contentBase: moonholdings
  },
  plugins: [
    CopyWebpackPluginConfig,
    ExtractTextPluginConfig,
    HtmlWebpackPluginConfig
  ]
};

const productionConfig = {
  devtool: 'cheap-module-source-map',
  plugins: [
    CopyWebpackPluginConfig,
    ExtractTextPluginConfig,
    HtmlWebpackPluginConfig,
    productionPlugin
  ]
};

console.log(`${chalk.magenta('?')} ${chalk.green('yarn run:')} ${chalk.red(LAUNCH_COMMAND)}`);

export default Object.assign(
  {}, base,
  isProduction === true ? productionConfig : developmentConfig
);
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QoP*_*QoP 21

你必须使用import * as React from "react";而不是import React from 'react'.

之所以发生这种情况,是因为babel(之前使用过的那个)假定modules.export是默认导出,而typescript(你现在使用的那个)则没有.


Rus*_*ust 9

您只需添加"allowSyntheticDefaultImports": true到您的tsconfig.json

  • 根据这个答案(/sf/answers/3827216501/),从 TypeScript 2.7 开始,您需要添加的选项是 `"esModuleInterop": true`。 (3认同)
  • 这应该是最重要的答案。当您想要导入类型和默认值时,这可以解决问题 - 您无法使用“* as React”方法来做到这一点。 (2认同)