preact.config.js

/**
 * 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 (config, env, helpers) => {
	// Use Preact CLI's helpers object to get the babel-loader
	const babel = helpers.getLoadersByName(config, 'babel-loader')[0].rule;
	// Update the loader config to include preact-i18nline
	babel.loader = [
		{ // create an entry for the old loader
			loader: babel.loader,
			options: babel.options,
		},
		{ // add the preact-i18nline webpack loader
			loader: 'preact-i18nline/webpack-loader',
		},
	];
	// remove the old loader options
	delete babel.options;
	config.resolve.alias.styles = './src/styles';
	return config;
};