npm i style-resources-loader -D

 function generateLoaders (loader, loaderOptions) {
 const loaders = options.usePostCSS ? [cssLoader, postcssLoader] : [cssLoader]

 if (loader) {
  loaders.push({
  loader: loader + '-loader',
  options: Object.assign({}, loaderOptions, {
   sourceMap: options.sourceMap
  })
  })
 }

 // Extract CSS when that option is specified
 // (which is the case during production build)
 if (options.extract) {
  return ExtractTextPlugin.extract({
  use: loaders,
  fallback: 'vue-style-loader'
  })
 } else {
  return ['vue-style-loader'].concat(loaders)
 }
 }

 // https://vue-loader.vuejs.org/en/configurations/extract-css.html
 return {
 css: generateLoaders(),
 postcss: generateLoaders(),
 less: generateLoaders('less'),
 sass: generateLoaders('sass', { indentedSyntax: true }),
 scss: generateLoaders('sass'),
 stylus: generateLoaders('stylus'),
 styl: generateLoaders('stylus')
 }
}

 if (loader) {
  ...
 }
 if(loader == 'less'){
  loaders.push({
   loader: 'style-resources-loader',
   options: {
    patterns: path.resolve(__dirname, '../src/assets/config/*.less')
   }
  })
 }