And yet, outdated comments are far, far more common than outdated function names.
Also, if you're changing a comment which explains the "what", you should likely change the method name, as well.
It's important for the client to know what the method does by looking at the name, so why would you duplicate your effort?
You're nitpicking.
As it happens, it's just an example to illustrate specifically the "extract to method" issues the author had.
Of course, in a real world scenario we want to limit mutating state, so it's likely this method would return a
Commission
list, which would then be used by a Use Case class which persists it.I'm fairly sure the advice about limiting mutating state is also in the book, though.
At the same time, you're likely going to have a void somewhere, because some use cases are only about mutatimg something (e.g. changing something in the database).