webpack.common.js

const path = require('path');
const merge = require('webpack-merge');

const devConfig = require('./webpack.dev.config');
const prodConfig = require('./webpack.prod.config');

var config;

const common = {
  entry: {
    app: './app'
  },
  output: {
    path: './build',
    filename: '[name].js'
  }
};

switch(process.env.NODE_ENV) {
  case 'development':
    config = merge(common, devConfig);
    break;
  default:
    config = merge(common, prodConfig);
}

module.exports = config;