Babel：检测到重复的插件/预设错误

Question

我正在 Front-end Masters 上学习 React 课程，我们需要修改 babel 配置以允许在类组件中使用状态初始化，如：state = {index: 0}。但是，在运行以下命令后：
npm install -D babel-eslint @babel/core @babel/preset-env @babel/plugin-proposal-class-properties @babel/preset-react
并在根目录下创建一个.babelrc 文件并将其修改为如下内容：
{ "presets": ["@babel/preset-react", "@babel/preset-env"], "plugins": ["@babel/plugin-proposal-class-properties"] }.
我遇到了以下错误：

/home/rahat/Documents/react_adopt_me/src/App.js: Duplicate plugin/preset detected.
    If you'd like to use two separate instances of a plugin,
    they need separate names, e.g.
    
      plugins: [
        ['some-plugin', {}],
        ['some-plugin', {}, 'some unique name'],
      ]
    
    Duplicates detected are:
    [
      {
        "alias": "/home/rahat/Documents/react_adopt_me/src/node_modules/@babel/plugin-proposal-class-properties/lib/index.js",
        "dirname": "/home/rahat/Documents/react_adopt_me/src",
        "ownPass": false,
        "file": {
          "request": "@babel/plugin-proposal-class-properties",
          "resolved": "/home/rahat/Documents/react_adopt_me/src/node_modules/@babel/plugin-proposal-class-properties/lib/index.js"
        }
      },
      {
        "alias": "base$2",
        "options": {
          "loose": "#__internal__@babel/preset-env__prefer-false-but-true-is-ok-if-it-prevents-an-error"
        },
        "dirname": "/home/rahat/Documents/react_adopt_me/src",
        "ownPass": false
      }
    ]

- Rahat

Answer 1

我认为这可能是一个节点版本问题。

如果你想快速解决，可以通过以下方式卸载 plugin-proposal-class-properties 插件：

npm uninstall @babel/plugin-proposal-class-properties

然后在 .babelrc 文件中禁用/删除该插件：

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

清除缓存：

运行命令 npm run clear-build-cache

然后再次启动服务器。

- jcoszig