@sveltejs/kit/src/exports/internal/remote-functions.js

SvelteKit is the fastest way to build Svelte apps

/**
 * @param {Record<string, any>} module
 * @param {string} file
 */
export function validate_remote_functions(module, file) {
	if (module.default) {
		throw new Error(
			`Cannot export \`default\` from a remote module (${file}) — please use named exports instead`
		);
	}

	for (const name in module) {
		const type = module[name]?.__?.type;

		if (type !== 'form' && type !== 'command' && type !== 'query' && type !== 'prerender') {
			throw new Error(
				`\`${name}\` exported from ${file} is invalid — all exports from this file must be remote functions`
			);
		}
	}
}