const webpack = require('webpack'); const merge = require('webpack-merge'); const common = require('./webpack.common.js'); config = merge(common, { mode: 'development', devtool: 'cheap-module-source-map', externals: { 'react/addons': true, 'react/lib/ExecutionEnvironment': true, 'react/lib/ReactContext': true, }, module: { rules: [ { test: /\.tsx?$/, exclude: /node_modules/, use: { loader: 'ts-loader', options: { transpileOnly: true, }, }, }, ], }, plugins: [ new webpack.SourceMapDevToolPlugin({ filename: null, // if no value is provided the sourcemap is inlined test: /\.(ts|js)($|\?)/i, // process .js and .ts files only }), ], }); module.exports = config;