Why should countStock be synchronous rather than asynchronous?

The countStock method should be synchronous if it performs a simple counting operation that does not require access to external resources (such as a database or network). Synchronous operation ensures ease of use and predictability of the result without the need to wait.

If countStock were asynchronous, it would complicate the call logic and result handling, especially if counting is just a calculation based on already loaded data.

Example: if you have a local list of items in memory, counting them is an instant operation that does not require asynchrony. Asynchrony is justified when you need to wait for a response from external services.