npm start 给出 webpack cli 错误 React.js

Question

我刚开始从这个网站 tutorailspoint and React.js 学习 react.js。

当我运行这个命令 npm start 遵循所有设置信息后，出现以下错误：

C:\Users\USER\Desktop\reactapp>npm start

> reactapp@0.0.1 start C:\Users\USER\Desktop\reactapp
> webpack-dev-server.cmd --content-base app

The CLI moved into a separate package: webpack-cli.
Please install 'webpack-cli' in addition to webpack itself to use the CLI.
-> When using npm: npm install webpack-cli -D
-> When using yarn: yarn add webpack-cli -D
module.js:442
    throw err;
    ^

Error: Cannot find module 'webpack-cli/bin/config-yargs'
    at Function.Module._resolveFilename (module.js:440:15)
    at Function.Module._load (module.js:388:25)
    at Module.require (module.js:468:17)
    at require (internal/module.js:20:19)
    at Object.<anonymous> (C:\Users\USER\Desktop\reactapp\node_modules\webpack-dev-server\bin\webpack-dev-server.js:65:1)

安装后

C:\Users\USER\Desktop\reactapp>npm start

> reactapp@0.0.1 start C:\Users\USER\Desktop\reactapp
> webpack-dev-server --hot

× ｢wds｣: Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
 - configuration.module has an unknown property 'loaders'. These properties are valid:
   object { exprContextCritical?, exprContextRecursive?, exprContextRegExp?, exprContextRequest?, noParse?, rules?, defaultRules?, unknownContextCritical?, unknownContextRecursive?, unknownContextRegExp?, unknownContextRequest?, unsafeCache?, wrappedContextCritical?, wrappedContextRecursive?, wrappedContextRegExp?, strictExportPresence?, strictThisContextOnImports? }
   -> Options affecting the normal modules (`NormalModuleFactory`).

npm ERR! Windows_NT 10.0.17134

安装后我的package.json：

 {
  "name": "reactapp",
  "version": "0.0.1",
  "description": "first test",
  "main": "index.js",
  "scripts": {
    "start": "webpack-dev-server --hot"
  },
  "author": "",
  "license": "ISC",
  "dependencies": {
    "react": "^16.4.2",
    "react-dom": "^16.4.2",
    "webpack": "^4.16.5",
    "webpack-dev-server": "^3.1.5"
  },
  "devDependencies": {
    "webpack-cli": "^3.1.0"
  }
}

Answer 1

我认为你应该安装 webpack-cli： npm i -D webpack-cli

Answer 2

因为你是基于一篇没有指定 webpack 版本的旧文章，看起来你是运行较新版本的 webpack 相对于具有旧版本 webpack 配置的旧代码库。您有 2 个选择：

回滚到正确的 webpack 版本，该版本将与您的 webpack 配置一起使用，而不要求您安装 CLI。
使用最新的 webpack 版本，安装 CLI 和其他任何必要的东西，并将你的 webpack 配置更新到最新的 API。

我还建议您寻找更好的更新 post。

Answer 3

您收到的错误告诉您 "The CLI moved into a separate package: webpack-cli."。看起来您正在关注的教程是从 webpack 软件包也随 CLI 一起提供的时候开始的。您必须使用较新的版本单独安装它。

npm i -D webpack-cli

你的第二个错误来自于 Webpack 曾经在 configuration.module.loaders 中定义了加载程序，但它已经更改为 configuration.module.rules。

webpack.config.js

var config = {
  // ...
  module: {
    rules: [
      {
        test: /\.jsx?$/,
        exclude: /node_modules/,
        loader: "babel-loader",
        query: {
          presets: ["es2015", "react"]
        }
      }
    ]
  }
};

module.exports = config;

npm start 给出 webpack cli 错误 React.js

npm start is giving webpack cli error with React.js

node.js

reactjs

webpack

webpack-dev-server

webpack-4