I am using Angular 6 and need to convert all scss files to rtl-css files

Question

I have used angular builders and created custom webpack.config.js I am trying to use webpack-rtl-plugin. Following are my custom-webpack.config.js

 module.export = {
   entry: {
     app: path.join(__dirname, './src/main.ts')
   },
   output: {
     path: path.join(__dirname, 'dist'),
     filename: 'bundle.js'
   },
   module: {
     rules: [
       {
         test: /\.js$/,
         loader: 'babel-loader',
         include: path.join(__dirname, 'src')
       },

       {
         test: /\.scss$/,
         // for dev we simply use the style-loader combined with
         // the rtl-css loader
         loaders: ['style-loader', 'rtl-css-loader']
       }
     ]
   }
 };

But I am getting Following error

Invalid CSS after "": expected 1 selector or at-rule, was "var content = requi"

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What is the cause of this? Any alternate solutions?