[email protected]，在构建React脚本时出现babel-loader @ 8错误（模块解析失败：意外令牌）

Question

我正在尝试实现[email protected]和babel-loader @ 8来处理反应脚本。我在捆绑jsx语法时遇到了麻烦（遇到任何html标记时，webpack babel-loader退出并出现错误。

我使用命令：npm run build（webpack --mode生产）

index.js

// Import the wrapper component, and the the creator function
import React  from 'react';
import ReactDOM from 'react-dom';


class App extends React.Component {
  render () {
    return <p> Hello React project</p>;
  }
}

render(<App/>, document.getElementById('app'));

通常的错误信息：

[0] ./src/index.js 339 bytes {0} [built] [failed] [1 error]

ERROR in ./src/index.js 9:11
Module parse failed: Unexpected token (9:11)
You may need an appropriate loader to handle this file type, currently no loaders are configured to process this file. See https://webpack.js.org/concepts#loaders
| class App extends React.Component {
|   render () {
>     return <p> Hello React project</p>;
|   }
| }
npm ERR! code ELIFECYCLE
npm ERR! errno 2
npm ERR! [email protected] build: `webpack --mode production`
npm ERR! Exit status 2

[捆绑在尝试执行时也总是失败：render(<App/>, document.getElementById('app'));从另一个文件导入App组件或定义了呈现html标签的App函数之后。

webpack.config.js

var webpack = require('webpack');
var path = require('path');

module.exports = {
  output: {
    filename: 'bundle.js'
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: {
          loader: "babel-loader",
          options: {
            presets: ['@babel/preset-env', '@babel/preset-react']
          }
        }
      }
    ]
  }
};

package.json

  "name": "webpack_test",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "build": "webpack --mode production"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/core": "^7.8.6",
    "@babel/preset-env": "^7.8.6",
    "@babel/preset-react": "^7.8.3",
    "babel-loader": "^8.0.6",
    "webpack": "^4.41.6",
    "webpack-cli": "^3.3.11"
  },
  "dependencies": {
    "react": "^16.13.0",
    "react-dom": "^16.13.0",
    "react-router-dom": "^5.1.2"
  }
}

我尝试将index.js文件与@babel/cli捆绑在一起，这似乎可以正常工作（命令npx babel --presets @babel/preset-env,@babel/preset-react）。我已经尝试解决这个问题太长时间了，非常感谢您提供一些指示信息：)感谢您的帮助，

UPDATEwebpack.config.js的末尾有空格，因此webpack无法识别。

Answer 1

您可以检查我的配置

我的网页包

{
        test: /\.(js|jsx)$/,
        exclude: /node_modules/,
        use: ["babel-loader", "eslint-loader"]
},

。babelrc文件

{
    "presets": ["@babel/preset-env", "@babel/preset-react"],
    "plugins": [
        "@babel/plugin-proposal-class-properties",
        "@babel/plugin-transform-runtime"
    ]
}

package.json

    "@babel/core": "^7.8.4",
    "@babel/plugin-proposal-class-properties": "^7.8.3",
    "@babel/plugin-transform-runtime": "^7.8.3",
    "@babel/preset-env": "^7.8.4",
    "@babel/preset-react": "^7.8.3",

更新：

请确保在devDependencies部分中将"eslint": "^6.8.0"安装到package.json中>