Function flushSync

packages/svelte/src/internal/client/reactivity/batch.js:1006–1033

(fn)

 * @returns {T}
 */
export function flushSync(fn) {
	var was_flushing_sync = is_flushing_sync;
	is_flushing_sync = true;

	try {
		var result;

		if (fn) {
			if (current_batch !== null && !current_batch.is_fork) {
				current_batch.flush();
			}

			result = fn();
		}

		while (true) {
			flush_tasks();

			if (current_batch === null) {
				return /** @type {T} */ (result);
			}

			current_batch.flush();
		}
	} finally {
		is_flushing_sync = was_flushing_sync;
	}
}

function infinite_loop_guard() {
	if (DEV) {