如何将HMR与SASS和ng2样式加载一起使用？

// 配置HMR
const webpack = require('webpack');
const HtmlWebpackPlugin = require('html-webpack-plugin');

module.exports = {
  // ...
  devServer: {
    hot: true,
  },
  plugins: [
    new webpack.HotModuleReplacementPlugin(),
    new HtmlWebpackPlugin({
      template: './src/index.html',
    }),
  ],
  // ...
  module: {
    rules: [
      // 配置SASS加载器
      {
        test: /\.scss$/,
        use: [
          'style-loader',
          'css-loader',
          'sass-loader',
        ],
      },
      // 配置ng2样式加载器
      {
        test: /\.component\.css$/,
        use: [
          'to-string-loader',
          'css-loader',
        ],
      },
    ],
  },
};

npm install node-sass sass-loader --save-dev

// app.component.scss
$primary-color: #007bff;

.header {
  background-color: $primary-color;
  color: white;
}

// app.component.ts
import { Component } from '@angular/core';

@Component({
  selector: 'app-root',
  templateUrl: './app.component.html',
  styleUrls: ['./app.component.css', './app.component.scss'],
})
export class AppComponent {
  // ...
}