Javascript 此实验性语法需要启用以下解析器插件之一：'；classPrivateProperties、classPrivateMethods'；

我正在尝试使用parcel捆绑我的javascript文件，一切都正常，只是在运行

npm run start

@parcel/transformer-js: This experimental syntax requires enabling one of the following parser plugin(s): 'classPrivateProperties, classPrivateMethods'

在谷歌搜索之后，我发现我需要安装

classPrivateProperties

和

classPrivateMethods

，所以我安装了，但这里出现的问题是我的

package.json

文件

{
  "name": "starter",
  "version": "1.0.0",
  "description": "",
  "main": "index.html",
  "scripts": {
    "start": "parcel index.html",
    "build": "parcel build index.html"
  },
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "@babel/plugin-proposal-private-methods": "^7.13.0",
    "@babel/plugin-proposal-private-property-in-object": "^7.13.0",
    "@parcel/optimizer-cssnano": "^2.0.0-nightly.612",
    "@parcel/optimizer-htmlnano": "^2.0.0-nightly.612",
    "@parcel/packager-css": "^2.0.0-nightly.612",
    "@parcel/packager-html": "^2.0.0-nightly.612",
    "@parcel/transformer-css": "^2.0.0-nightly.612",
    "@parcel/transformer-html": "^2.0.0-nightly.612",
    "@parcel/transformer-postcss": "^2.0.0-nightly.612",
    "@parcel/transformer-posthtml": "^2.0.0-nightly.612",
    "@parcel/transformer-sass": "^2.0.0-nightly.612",
    "node": "^15.10.0",
    "parcel": "^2.0.0-beta.1",
    "postcss": "^8.2.6",
    "sass": "^1.26.10"
  },
  "dependencies": {
    "core-js": "^3.6.5",
    "fractional": "^1.0.0",
    "regenerator-runtime": "^0.13.7"
  },
  "plugins": [
    "@babel/plugin-proposal-private-methods",
    "@babel/plugin-proposal-private-property-in-object"
  ]
}

---

感谢您的帮助

我通过安装插件并将.babelrc配置文件添加到我的项目根目录中，解决了这个问题

{
  "plugins": [
    "@babel/plugin-proposal-class-properties",
    "@babel/plugin-proposal-private-methods"
  ]
}

---

如果您正在谈论Parcel.js，您需要安装和配置一些Babel插件，以启用类私有属性和方法：

使用NPM安装此软件包：

npm i@babel/plugin提案私有方法@babel/plugin提案类属性

使用以下命令在项目的根文件夹中创建

.babelrc

文件：

再跑一次包裹

    {
      "plugins": [
        "@babel/plugin-proposal-class-properties",
        "@babel/plugin-proposal-private-methods"
      ]
    }