preact.config.js

import preactCliTypeScript from "preact-cli-plugin-typescript";

/**
 * Function that mutates original webpack config.
 * Supports asynchronous changes when promise is returned.
 *
 * @param {object} config original webpack config.
 * @param {object} env options passed to CLI.
 * @param {WebpackConfigHelpers} helpers object with useful helpers when working with config.
 **/
export default function(config, env, helpers) {
  preactCliTypeScript(config);
}