access mode in webpack config

webpack.config.js

@@ -4,6 +4,12 @@ const MiniCssExtractPlugin = require('mini-css-extract-plugin');
 const TerserJSPlugin = require('terser-webpack-plugin');
 const OptimizeCSSAssetsPlugin = require('optimize-css-assets-webpack-plugin');
 
+const env = process.env.NODE_ENV
+
+const config = {
+   mode: env || 'development'
+}
+
 module.exports = {
     entry: {
       main: './src/index.js',