webpack.development.js

const merge = require('webpack-merge');
const common = require('./webpack.common.js');
const webpack = require('webpack');

module.exports = merge(common, {
    devtool: 'inline-source-map',
    mode: 'development',
    optimization: {
        splitChunks: {
            cacheGroups: {
                vendors: {
                    test: /[\\/]node_modules[\\/]/,
                    chunks: 'all',
                    priority: 1
                }
            }
        }
    },
    plugins: [
        new webpack.DefinePlugin({
            'process.env': {
                'NODE_ENV': JSON.stringify('development')
            }
        })
    ]
});