Webpack@4.41 在构建反应脚本时出现 babel-loader@8 错误（模块解析失败：意外令牌）

Question

我正在尝试实现 webpack@4.41 和 babel-loader@8 来处理反应脚本。我在捆绑 jsx 语法时遇到了麻烦（webpack babel-loader 在遇到任何 html 标签时出现错误退出。

我使用命令：npm run build (webpack --mode production)

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! webpack_test@1.0.0 build: `webpack --mode production`
npm ERR! Exit status 2

在尝试执行以下操作时，捆绑也经常失败：render(<App/>, document.getElementById('app')); 从另一个文件导入 App 组件或定义呈现 html 标签的 App 函数后。

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，这似乎有效（命令 npx babel --presets @babel/preset-env,@babel/preset-react ）。我已经尝试解决这个问题太久了，我真的很感激一些指点 :) 感谢您的帮助，

更新 webpack.config.js 有一个尾随空格，因此 webpack 无法识别。

Answer 1

你可以检查我的配置

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：

确保将 "eslint": "^6.8.0" 安装到你的 package.json 的 devDependencies 部分