netris-nestri/packages/core/src/utils/memo.ts

export function memo<T>(fn: () => T, cleanup?: (input: T) => Promise<void>) {
	let value: T | undefined;
	let loaded = false;

	const result = (): T => {
		if (loaded) return value as T;
		loaded = true;
		value = fn();
		return value as T;
	};
	result.reset = async () => {
		if (cleanup && value) await cleanup(value);
		loaded = false;
		value = undefined;
	};

	return result;
}