const defaultConfig = require( '@wordpress/scripts/config/webpack.config' ); module.exports = { ...defaultConfig, module: { ...defaultConfig.module, rules: [ ...defaultConfig.module.rules, { test: /\.js$/, exclude: /node_modules\/(?!react-sortablejs)/, // Include react-sortablejs use: { loader: 'babel-loader', options: { presets: [ '@babel/preset-env', '@babel/preset-react' ], plugins: [ '@babel/plugin-proposal-class-properties' ], }, }, }, ], }, };