fix(builder): fix extractCSS problem

lib/builder/webpack/base.mjs

@@ -4,6 +4,7 @@ import TimeFixPlugin from 'time-fix-plugin'
 import webpack from 'webpack'
 import _ from 'lodash'
 import VueLoader from 'vue-loader'
+import MiniCssExtractPlugin from 'mini-css-extract-plugin'
 
 import { isUrl, urlJoin } from '../../common/utils'
 
@@ -214,6 +215,13 @@ export default class WebpackBaseConfig {
       plugins.push(new StatsPlugin(this.options.build.stats))
     }
 
+    // CSS extraction
+    if (this.options.build.extractCSSS) {
+      plugins.push(new MiniCssExtractPlugin(Object.assign({
+        filename: this.getFileName('css')
+      }, this.options.build.extractCSS)))
+    }
+
     return plugins
   }
 

lib/builder/webpack/client.mjs

@@ -3,7 +3,6 @@ import path from 'path'
 import webpack from 'webpack'
 import HTMLPlugin from 'html-webpack-plugin'
 import BundleAnalyzer from 'webpack-bundle-analyzer'
-import MiniCssExtractPlugin from 'mini-css-extract-plugin'
 import UglifyJsWebpackPlugin from 'uglifyjs-webpack-plugin'
 import FriendlyErrorsWebpackPlugin from '@nuxtjs/friendly-errors-webpack-plugin'
 
@@ -73,14 +72,6 @@ export default class WebpackClientConfig extends WebpackBaseConfig {
       )
     }
 
-    // CSS extraction
-    const extractCSS = this.options.build.extractCSS
-    if (extractCSS) {
-      plugins.push(new MiniCssExtractPlugin(Object.assign({
-        filename: this.getFileName('css')
-      }, typeof extractCSS === 'object' ? extractCSS : {})))
-    }
-
     return plugins
   }