modify webpack sourcemap settings

config/webpack.common.js

@@ -59,7 +59,10 @@ module.exports = function (options) {
           test: /\.scss$/,
           use: ExtractTextPlugin.extract({
             fallback: 'style-loader',
-            use: 'css-loader!sass-loader'
+            use: [
+              { loader: 'css-loader', options: { minimize: isProd, sourceMap: !isProd } },
+              { loader: 'sass-loader', options: { sourceMap: !isProd } }
+            ]
           }),
           include: [helpers.root('resource/styles/scss')]
         },

config/webpack.dev.js

@@ -63,7 +63,7 @@ module.exports = function (options) {
         },
         dllDir: helpers.root('public/dll'),
         webpackConfig: webpackMergeDll(commonConfig({env: ENV}), {
-          devtool: 'cheap-module-source-map',
+          devtool: undefined,
           plugins: [],
         })
       }),

config/webpack.prod.js

@@ -26,7 +26,7 @@ const PORT = process.env.PORT || 3000;
 
 module.exports = function (env) {
   return webpackMerge(commonConfig({ env: ENV }), {
-    devtool: 'source-map',
+    devtool: undefined,
     output: {
       path: helpers.root('public/js'),
       publicPath: '/js/',