Should a business rule violation throw an exception?

Question

Should a business rule violation throw an exception?

Answer 1

Usualy I put the condition in a Specification object that implements

bool IsVerfiedBy(T entity);

So you can check the condition without exception.

If there is a place in your code where the specification should be verified beforehand, you can throw an exception because this is a prerequisit of you function.

For instance if your entity must be in a specific state before persistance, throw an exception when the specification is not verified, but use the specification before persisting so that the exception does not happen.