webpack configs(+postcss) without postcss.configs.js file

webpack.config.js

const path = require('path');

module.exports = async ({ config, mode }) => {

  config.module.rules.push({
    test: /\.scss$/,
    use: ['style-loader', 'css-loader', {
      loader: 'postcss-loader', options: {
        ident: 'postcss',
        plugins: (loader) => [
          require('postcss-import')({ root: loader.resourcePath }),
          require('postcss-preset-env')(),
          require('postcss-nested')(),
          require('rucksack-css')(),
          require('lost')()
      ]
    }}],
    include: path.resolve(__dirname, '../'),
  });

  return config;
};