node.js – 找不到模块’@ babel / core’

https://www.youtube.com/watch?v=deyxI-6C2u4

我完全跟着它,直到他运行npm的部分开始.不同的是,他的应用程序运行,我的错误：

找不到模块’@ babel / core’

完整的错误：

ERROR in ./src/index.js
Module build Failed (from ./node_modules/babel-loader/lib/index.js):
Error: CAnnot find module '@babel/core'
    at Function.Module._resolveFilename (module.js:547:15)
    at Function.Module._load (module.js:474:25)
    at Module.require (module.js:596:17)
    at require (internal/module.js:11:18)
    at Object.<anonymous> (C:\Users\joeyf\Desktop\Code\Github\webpack4-sample\node_modules\babel-loader\lib\index.js:5:15)
    at Module._compile (module.js:652:30)
    at Object.Module._extensions..js (module.js:663:10)
    at Module.load (module.js:565:32)
    at trymoduleLoad (module.js:505:12)
    at Function.Module._load (module.js:497:3)
 @ multi (webpack)-dev-server/client?http://localhost:8080 (webpack)/hot/dev-server.js ./src/index.js main[2]

我曾尝试重新安装babel-core,但仍未找到.这是我的package.json：

{
  "name": "webpack4-sample","version": "1.0.0","description": "A sample setup of Webpack4 with React and Babel","main": "index.js","scripts": {
    "start": "webpack-dev-server --mode development --open --hot","build": "webpack --mode production"
  },"author": "Joey Fenny","license": "ISC","dependencies": {
    "babel": "^6.23.0","babel-cli": "^6.26.0","react": "^16.4.2","react-dom": "^16.4.2"
  },"devDependencies": {
    "babel-core": "^7.0.0-rc.4","babel-loader": "^8.0.0","babel-preset-env": "^1.7.0","babel-preset-react": "^6.24.1","html-webpack-plugin": "^3.2.0","webpack": "^4.17.1","webpack-cli": "^3.1.0","webpack-dev-server": "^3.1.6"
  }
}

我的webpack.config.js：

const path = require('path');
const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
    entry: './src/index.js',output: {
        path: path.join(__dirname,'/dist'),filename: 'index_bundle.js'
    },module: {
        rules: [{
            test: /\.js$/,exclude: path.join(__dirname,'/node_modules'),use: {
                loader: 'babel-loader'
            }
        }]
    },plugins: [
        new HtmlWebpackPlugin({
            template: './src/index.html'
        })
    ]
}

这是一个git repo的链接：

https://gitlab.com/jfny/webpack4-sample

有谁知道发生了什么？谢谢.