Как правильно записать настройки Laravel mix + webpack?

Question

[SM_ST]

еcть файл webpack.mix.js

const mix = require('laravel-mix');
mix
  .js('resources/js/app.js', 'assets/js')
  .sass('resources/sass/app.scss', 'assets/css')
  .sass('resources/sass/media.scss', 'assets/css')
  .webpackConfig({
    postcss: {
      plugins: {
        cssnano: {
          preset: ['advanced', {
            autoprefixer: false,
            cssDeclarationSorter: false,
            zindex: false,
            discardComments: {
              removeAll: true
            }
          }]
        }
      },
      preset: {
        browsers: 'cover 99.5%',
        autoprefixer: true
      },

      order: 'cssnanoLast'
    },
  })
  .browserSync('site.test:8000');

как правильно записать настройки для webpackConfig, чтобы не выдавал вот такую ошибку

Invalid configuration object. Webpack has been initialised using a configuration object that does not match the API schema.
 - configuration has an unknown property 'postcss'. These properties are valid:
   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, externals?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, serve?, stats?, target?, watch?, watchOptions? }
   For typos: please correct them.
   For loader options: webpack >= v2.0.0 no longer allows custom properties in configuration.
     Loaders should be updated to allow passing options via loader options in module.rules.
     Until loaders are updated one can use the LoaderOptionsPlugin to pass these options to the loader:
     plugins: [
       new webpack.LoaderOptionsPlugin({
         // test: /\.xxx$/, // may apply this only for some modules
         options: {
           postcss: …
         }
       })
     ]

Comments

[Сергей delphinpro]

в тексте ошибки вроде все написано

[SM_ST]

Сергей delphinpro, да, но я не понимаю как правильно прописать это

[Сергей delphinpro]

SM_ST, я не пробовал. Но вроде как даже пример настройки вам показывают.
пробовали через LoaderOptionsPlugin подключить?