不允许预设文件导出对象

Question

我有一个carousel文件,我想在其中获取index.js和构建block.build.js,所以我webpack.config.js的:

var config = {
  entry: './index.js',
  output: {
    path: __dirname,
    filename: 'block.build.js',
  },
  devServer: {
    contentBase: './Carousel'
  },
  module : {
    rules : [
      {
        test: /.js$/,
        loader: 'babel-loader',
        exclude: /node_modules/,
        query: {
          presets: ['react', 'es2015'],
          plugins: ['transform-class-properties']
        }
      }
    ]
  }
};
module.exports = config;

在package.json下面,我用的是:

{
  "name": "carousel",
  "version": "1.0.0",
  "description": "",
  "main": "webpack.config.js",
  "dependencies": {
    "@babel/core": "^7.0.0-beta.40",
    "babel-cli": "^6.26.0",
    "babel-loader": "^8.0.0-beta.0",
    "babel-plugin-lodash": "^3.3.2",
    "babel-plugin-react-transform": "^3.0.0",
    "babel-preset-react": "^6.24.1",
    "cross-env": "^5.1.3",
    "lodash": "^4.17.5",
    "react": "^16.2.0",
    "react-dom": "^16.2.0",
    "react-swipeable": "^4.2.0",
    "styled-components": "^3.2.1"
  },
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "watch": "webpack --watch",
    "start": "webpack-dev-server --open",
    "build": "webpack"
  },
  "devDependencies": {
    "webpack": "^4.1.1",
    "webpack-cli": "^2.0.10",
    "webpack-dev-server": "^3.1.0"
  },
  "author": "brad traversy",
  "license": "ISC"
}

...但我收到此错误消息:

ERROR in ./index.js
Module build failed: Error: Plugin/Preset files are not allowed to export objects, only functions.

有谁知道如何解决这个问题？

Answer 1

您使用的是Babel 6和Babel 7的组合.不保证版本之间的兼容性:

"@babel/core": "^7.0.0-beta.40",
"babel-cli": "^6.26.0",
"babel-loader": "^8.0.0-beta.0",
"babel-plugin-lodash": "^3.3.2",
"babel-plugin-react-transform": "^3.0.0",
"babel-preset-react": "^6.24.1",

应该

"@babel/core": "^7.0.0-beta.40",
"@babel/cli": "^7.0.0-beta.40",
"babel-loader": "^8.0.0-beta.0",
"babel-plugin-lodash": "^3.3.2",
"babel-plugin-react-transform": "^3.0.0",
"@babel/preset-react": "^7.0.0-beta.40",

和

    query: {
      presets: ['react', 'es2015'],
      plugins: ['transform-class-properties']
    }

将会

    query: {
      presets: ['@babel/react', '@babel/es2015'],
      plugins: ['@babel/proposal-class-properties']
    }

我也很困惑,因为你没有提到@babel/proposal-class-properties你package.json,但假设它在那里它也应该更新.

Answer 2

它发生在我身上,对我来说一个简单的解决方案是卸载babel-loader@8^并@babel/core:

npm uninstall --save babel-loader
npm uninstall --save @babel/core

...然后安装版本7 babel-loader:

npm install --save-dev babel-loader@^7

Answer 3

同样从babel-loaderv8版本开始，它们有所变化：

webpack 4.x | babel-loader 8.x | 通天塔7.x

npm install -D babel-loader @babel/core @babel/preset-env webpack

webpack 4.x | babel-loader 7.x | 通天塔6.x

npm install -D babel-loader@7 babel-core babel-preset-env webpack

（对于同样的事情@babel/preset-react，而不是babel-preset-react）。

Answer 4

我的webpack / react项目中遇到了相同的问题- .babelrc文件似乎有问题。

我更新了它，如下图所示，它成功了：

{
    "presets": [
        "@babel/preset-env",
        "@babel/preset-react"
    ],
    "plugins": [
        "transform-class-properties",
        "transform-object-rest-spread"
    ]
}

Answer 5

babel 7 从版本 6 开始有升级，请参阅https://babeljs.io/docs/en/v7-migration。解决当前问题/错误

安装

npm install --save-dev @babel/preset-react

npm install --save-dev @babel/preset-env

那么在 .babelrc 中预设的依赖关系应该如下所示

{

"presets":["@babel/preset-env", "@babel/preset-react"],

   "plugins": [
    "react-hot-loader/babel", "transform-object-rest-spread"]

}

Answer 6

这是由于使用了过时的 babel 包。babel 项目，就像大多数其他活跃的 Javascript 项目一样，已经转向使用范围包。因此，包名以@babel

如果您使用纱线，请按照以下步骤操作：

步骤 1：删除旧包

$ yarn remove babel-core babel-loader babel-preset-env babel-preset-react

第 2 步：添加新包

$ yarn add -D @babel/core babel-loader @babel/preset-env @babel/preset-react

如果您使用的是 npm，请按照以下步骤操作：

步骤 1：删除旧包

$ npm uninstall babel-core babel-loader babel-preset-env babel-preset-react

第 2 步：添加新包

$ npm add -D @babel/core babel-loader @babel/preset-env @babel/preset-react

第 3 步：对 npm 或 yarn 通用

安装较新的软件包后，请记住将.babelrc预设从更新react为@babel/preset-react。这是一个简单的例子

{
"presets": [
"@babel/preset-env",
"@babel/preset-react"
]
}