Webpack：在移动Webpack / React文件位置后，运行npm start时出现“找不到模块：错误：无法解析...”

Question

我的项目一开始运行正常，可以在Chrome上通过localhost:8080查看我的网页。我想学习一些内容，所以把所有的文件都放在一个名叫“dir copy”的文件夹中，而不是原来的“dir”文件夹。当所有的东西都准备好后，我把所有的文件移回到了“dir”文件夹，并关闭了浏览器。当我再次尝试运行npm start时，我收到了以下错误输出：

---

从npm start获取输出

Jacob:Name_html Jacob$ npm start

> Name@ start Dir/Name/Name_html
> node ./node_modules/webpack-dev-server/bin/webpack-dev-server.js

ℹ ｢wds｣: Project is running at http://localhost:8080/
ℹ ｢wds｣: webpack output is served from /
ℹ ｢wds｣: Content not from webpack is served from Dir/Name/Name_html
✖ ｢wdm｣: Hash: a0d05c0fdc6ff660f346
Version: webpack 4.35.0
Time: 1985ms
Built at: 06/28/2019 3:29:15 AM
      Asset     Size  Chunks             Chunk Names
./bundle.js  908 KiB    main  [emitted]  main
Entrypoint main = ./bundle.js
[1] multi (webpack)-dev-server/client?http://localhost ./src/index.jsx 40 bytes {main} [built]
[./es6/Banner.js] 1010 bytes {main} [built]
[./es6/Footer.js] 320 bytes {main} [built]
[./es6/Header.js] 387 bytes {main} [built]
[./es6/HomePageServices.js] 3.4 KiB {main} [built]
[./es6/NavBar.js] 689 bytes {main} [built]
[./node_modules/react-dom/cjs/react-dom.development.js] 768 KiB {main} [built]
[./node_modules/react-dom/index.js] 1.33 KiB {main} [built]
[./node_modules/react/cjs/react.development.js] 62.3 KiB {main} [built]
[./node_modules/react/index.js] 190 bytes {main} [built]
[./node_modules/scheduler/cjs/scheduler.development.js] 23.3 KiB {main} [built]
[./node_modules/scheduler/index.js] 198 bytes {main} [built]
[./node_modules/webpack-dev-server/client/index.js?http://localhost] (webpack)-dev-server/client?http://localhost 4.29 KiB {main} [built]
[./node_modules/webpack/hot sync ^\.\/log$] (webpack)/hot sync nonrecursive ^\.\/log$ 160 bytes {main} [built]
[./src/index.jsx] 561 bytes {main} [built]
    + 2 hidden modules

ERROR in (webpack)-dev-server/client?http://localhost
Module not found: Error: Can't resolve './overlay' in 'Dir/Name/Name_html/node_modules/webpack-dev-server/client'
 @ (webpack)-dev-server/client?http://localhost 10:14-34
 @ multi (webpack)-dev-server/client?http://localhost ./src/index.jsx

ERROR in (webpack)-dev-server/client?http://localhost
Module not found: Error: Can't resolve './socket' in 'Dir/Name/Name_html/node_modules/webpack-dev-server/client'
 @ (webpack)-dev-server/client?http://localhost 8:13-32
 @ multi (webpack)-dev-server/client?http://localhost ./src/index.jsx

ERROR in (webpack)-dev-server/client?http://localhost
Module not found: Error: Can't resolve './utils/createSocketUrl' in 'Dir/Name/Name_html/node_modules/webpack-dev-server/client'
 @ (webpack)-dev-server/client?http://localhost 20:22-56
 @ multi (webpack)-dev-server/client?http://localhost ./src/index.jsx

ERROR in (webpack)-dev-server/client?http://localhost
Module not found: Error: Can't resolve './utils/log' in 'Dir/Name/Name_html/node_modules/webpack-dev-server/client'
 @ (webpack)-dev-server/client?http://localhost 12:15-37
 @ multi (webpack)-dev-server/client?http://localhost ./src/index.jsx

ERROR in (webpack)-dev-server/client?http://localhost
Module not found: Error: Can't resolve './utils/reloadApp' in 'Dir/Name/Name_html/node_modules/webpack-dev-server/client'
 @ (webpack)-dev-server/client?http://localhost 18:16-44
 @ multi (webpack)-dev-server/client?http://localhost ./src/index.jsx

ERROR in (webpack)-dev-server/client?http://localhost
Module not found: Error: Can't resolve './utils/sendMessage' in 'Dir/Name/Name_html/node_modules/webpack-dev-server/client'
 @ (webpack)-dev-server/client?http://localhost 16:18-48
 @ multi (webpack)-dev-server/client?http://localhost ./src/index.jsx

ERROR in ./node_modules/react-dom/cjs/react-dom.development.js
Module not found: Error: Can't resolve 'object-assign' in 'Dir/Name/Name_html/node_modules/react-dom/cjs'
 @ ./node_modules/react-dom/cjs/react-dom.development.js 19:14-38
 @ ./node_modules/react-dom/index.js
 @ ./src/index.jsx
 @ multi ./src/index.jsx

ERROR in ./node_modules/react/cjs/react.development.js
Module not found: Error: Can't resolve 'object-assign' in 'Dir/Name/Name_html/node_modules/react/cjs'
 @ ./node_modules/react/cjs/react.development.js 18:14-38
 @ ./node_modules/react/index.js
 @ ./src/index.jsx
 @ multi ./src/index.jsx

ERROR in ./node_modules/react-dom/cjs/react-dom.development.js
Module not found: Error: Can't resolve 'prop-types/checkPropTypes' in 'Dir/Name/Name_html/node_modules/react-dom/cjs'
 @ ./node_modules/react-dom/cjs/react-dom.development.js 20:21-57
 @ ./node_modules/react-dom/index.js
 @ ./src/index.jsx
 @ multi ./src/index.jsx

ERROR in ./node_modules/react/cjs/react.development.js
Module not found: Error: Can't resolve 'prop-types/checkPropTypes' in 'Dir/Name/Name_html/node_modules/react/cjs'
 @ ./node_modules/react/cjs/react.development.js 19:21-57
 @ ./node_modules/react/index.js
 @ ./src/index.jsx
 @ multi ./src/index.jsx

ERROR in ./node_modules/react-dom/cjs/react-dom.development.js
Module not found: Error: Can't resolve 'scheduler/tracing' in 'Dir/Name/Name_html/node_modules/react-dom/cjs'
 @ ./node_modules/react-dom/cjs/react-dom.development.js 22:14-42
 @ ./node_modules/react-dom/index.js
 @ ./src/index.jsx
 @ multi ./src/index.jsx

ERROR in (webpack)-dev-server/client?http://localhost
Module not found: Error: Can't resolve 'strip-ansi' in 'Dir/Name/Name_html/node_modules/webpack-dev-server/client'
 @ (webpack)-dev-server/client?http://localhost 6:16-37
 @ multi (webpack)-dev-server/client?http://localhost ./src/index.jsx
ℹ ｢wdm｣: Failed to compile.

---

以下是一些未成功的方法

在 webpack.config.js 中添加 modules: ["src", "node_modules"]

删除 node_modules 并再次运行 npm install

---

src/index.jsx

import React from 'react';
import ReactDOM from 'react-dom';
import someSelfCreatedComponents from ../es6/SelfCreatedComponents

const Content = () => {
    return (
        <React.Fragment>
            <Header />
            <Banner />
            <MoreThings />
            <Footer />
        </React.Fragment>
    )
}

ReactDOM.render (
    <Content />,
    document.getElementById('Content')
)

webpack.config.js

module.exports = {
 entry: [
  './src/index.jsx' 
 ],
 output: {
  filename: './bundle.js' //File that all react gets compioled into
 },
 module: {
  rules: [
   {
    exclude: /node_modules/,
    use: [
     'babel-loader'
    ]
   }
  ]
 },
 resolve: {
  extensions: ['js', '.jsx']
 }
}

package.json

{
  "name": "Name",
  "version": "",
  "description": "",
  "main": "index.js",
  "scripts": {
    "start": "node ./node_modules/webpack-dev-server/bin/webpack-dev-server.js"
  },
  "dependencies": {
    "@babel/preset-es2015": "^7.0.0-beta.53",
    "babel-core": "^6.26.3",
    "babel-plugin-transform-object-rest-spread": "^6.26.0",
    "babel-preset-env": "^1.7.0",
    "babel-preset-es2015": "^6.24.1",
    "babel-preset-react": "^6.24.1",
    "babel-preset-stage-1": "^6.24.1",
    "react": "^16.8.6",
    "react-dom": "^16.8.6",
    "webpack-cli": "^3.3.5",
    "webpack-dev-server": "^3.7.2"
  },
  "devDependencies": {
    "@babel/core": "^7.4.5",
    "@babel/preset-env": "^7.4.5",
    "@babel/preset-react": "^7.0.0",
    "babel-loader": "^8.0.6",
    "webpack": "^4.35.0"
  }
}

.babelrc

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

index.html

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>Name</title>
    
    <link rel="stylesheet" type="text/css" href="css/Main.css">

    <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
    <meta name="viewport" content="width=device-width, initial-scale=1.00, maximum-scale=1.10, minimum-scale=0.80">

  </head>
  <body>
    <div id='Content'></div>
    <script src='bundle.js'></script>
  </body>
</html>

文件排列

---

更新

我读了下面答案中Saheed发布的博客文章，并尝试通过删除webpack.config.js文件以及将文件减少到以下内容来修复我的项目:

module.exports = {
 module: {
  rules: [
   {
    exclude: /node_modules/,
    use: [
     'babel-loader'
    ]
   }
  ]
 },
 resolve: {
  extensions: ['js', '.jsx']
 }
 
}

我尝试了两次，但仍然收到相同的错误信息。

- Sam

Answer 1

如果你希望避免核选项，请确保在webpack的解析扩展中包括.js。

这里的问题可能是由于js前缺少.引起的：

module.exports = {
    // ...
    resolve: {
        extensions: ['.js', '.jsx']
    }
}

- Pier-Luc Gendreau

---

谢谢你！你救了我。 - Marty McGee

Answer 2

找到了一个解决方案，但它并没有完全回答我的代码有什么问题，下面有一条评论试图回答问题。

我删除了我的 .babelrc、package-lock.json、webpack.config.js、package.json 和 node modules，然后按照这个教程从头开始设置 react、babel7 和 webpack4，因为它是我能找到的最有帮助的教程。

以下是它的摘要。

---

他们从以下命令开始：

mkdir default && cd default && yarn init -y

然后我安装了以下模块：

npm install @babel/core @babel/cli @babel/preset-env @babel/preset-react babel-loader -D

然后将下面的代码复制并粘贴到文件.babelrc中

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

---

我安装了一些更多的模块

npm install webpack webpack-cli webpack-dev-server html-webpack-plugin html-webpack-template -D

然后我将以下代码复制并粘贴到 webpack.config.js 中（稍作调整，因为我遇到了错误 Uncaught Error: Target container is not a DOM element.）

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

const config = {
  entry: './src/index.js',
  output: {
    path: path.resolve(__dirname, './dist'),
    filename: 'bundle.js',
  },
  module: {
    rules: [
      {
        test: /\.(js|jsx)$/,
        use: 'babel-loader',
        exclude: /node_modules/,
      },
    ],
  },
  resolve: {
    extensions: ['.js', '.jsx'],
  },
};

module.exports = config;

npm install react react-dom

我没有改变我的index.js，但教程中列出的那个是

import React from "react";
import ReactDOM from "react-dom";

function App() {
  return (
    <div>
      <h1>Hello blog readers</h1>
    </div>
  );
}

const rootElement = document.getElementById("app");
ReactDOM.render(<App />, rootElement);

- Sam

---

你原来的webpack.config.js输出属性有一个文件名prop，它的值是一个相对路径+文件名，例如'./bundle.js'。而你修改后的输出只提供了一个文件名，即'bundle.js'。此外，修改后的配置通过提供一个目录路径来添加精度，以查找文件bundle.js，这告诉输出确切地将bundle.js放在哪里，即YOUR_ROOT/dist/bundle.js；而你原来的配置没有给出精度。https://webpack.js.org/configuration/output/#outputfilename和https://webpack.js.org/configuration/output/#outputpath。 - Jason Ashley

Answer 3

在我的情况下，我正在处理 TypeScript 项目。

我使用的是 ts-loader 版本 8.2.0，我升级到了版本 ts-loader@9.2.5，错误就消失了。

- Raushan