模块未找到:错误:无法解决“sass-loader”

Question

webpack新来的。试着让sass-加载器很好地发挥我的反应项目，遵循教程。配置似乎是正确的，但结果总是“无法解决‘sass-加载程序’”。

我怀疑这是一个明显的错误，但没有多少搜索或谷歌引导我找到它。任何帮助都很感激。

误差

ERROR in ./ui/index.js
Module not found: Error: Can't resolve 'sass-loader' in '/root/src'
 @ ./ui/index.js 19:0-33
 @ multi webpack-hot-middleware/client?reload=true babel-polyfill ./ui/index.js

我到目前为止所做的事情(关于先前存在的反应项目)：

npm i --save-dev node-sass sass-loader

package.json，在devDependencies下

"node-sass": "^4.7.2",
"sass-loader": "^6.0.6",
"webpack": "~2.2.1",
"webpack-dev-middleware": "~1.12.0",
"webpack-hot-middleware": "~2.20.0",
"webpack-node-externals": "~1.6.0"

index.js

import React from 'react';
import ReactDOM from 'react-dom';
import { HashRouter } from 'react-router-dom';
import App from './src/App';

require('./src/styles/main.scss');

ReactDOM.render(<HashRouter><App /></HashRouter>, 
document.getElementById('root'));

webpack.config.react.js：

const path = require('path');
const webpack = require('webpack');

const ExtractTextPlugin = require('extract-text-webpack-plugin');
const HtmlWebpackPlugin = require('html-webpack-plugin');

const sourcePath = path.join(__dirname, './ui');
const extractStyle = new ExtractTextPlugin('styles.css');

//======break to module rules=======

module: {
  rules: [
    {
      test: /\.jsx?$/,
      include: sourcePath,
      exclude: /node_modules/,
      loader: 'babel-loader',
      query: {
        presets: ['react'],
      },
    },
    {
      test: /\.scss$/,
      include: sourcePath,
      exclude: /node_modules/,
      use: extractStyle.extract('sass-loader?sourceMap'),
    },
    {
      test: /\.css$/,
      exclude: sourcePath,
      loader: extractStyle.extract('css-loader'),
    },
  ],
},

//======= break again for plugins =====

plugins: [
  extractStyle,
  new HtmlWebpackPlugin({
    template: 'ui/index.html',
    title: 'name',
  }),
  new webpack.HotModuleReplacementPlugin(),
  new webpack.NamedModulesPlugin(),
  new webpack.optimize.OccurrenceOrderPlugin(),
  new webpack.NoErrorsPlugin(),
  new webpack.DefinePlugin({
    'process.env.NODE_ENV': JSON.stringify('development'),
  }),
]

可能的混淆器:所有这些都在开发坞容器中运行。不过，它已经重建，npm安装已经再次运行。

Answer 1

如上文所述-虚惊。在Docker映像缓存和npm之间，sass加载程序和节点sass模块被报告为已安装，而实际上尚未安装。通常的rm node_modules和重建没有缓存技巧，修复了它。

Answer 2

转到项目并运行以下两个命令

npm install sass-loader -D

npm install node-sass -D

Answer 3

此问题可能是缓存的结果。没有必要重新启动这个项目。

在终端上运行以下命令

rm -r node_modules

npm install

npm install -D sass-loader@^10 sass