dandi8
Good abstractions are important for the code to be readable. An AbstractEventHandlerManager is probably not a good abstraction.
The original commenter said that their code was “generic with lot of interfaces and polymorphism” - it sounds like they chose abstractions which hindered maintainability and readability.
How do abstractions help with that? Can you tell, from the symptoms, which “level of abstraction” contains the bug? Or do you need to read through all six (or however many) “levels”, across multiple modules and functions, to find the error?
I usually start from the lowest abstraction, where the stack trace points me and don’t need to look at the rest, because my code is written well.
It’s only as incomprehensible as you make it.
If there are 6 subfunctions, that means there’s 6 levels of abstraction (assuming the method extraction was not done blindly), which further suggests that maybe they should actually be part of a different class (or classes). Why would you be interested in 6 levels of abstraction at once?
But we’re arguing hypotheticals here. Of course you can make the method implementations a complete mess, the book cannot guarantee that the person applying the principles used their brain, as well.
I never claimed it’s not important, I’m just saying it’s not relevant here, as there is no context to where this method was put in the code.
As I said, it might be top-level. You have to mutate state somewhere, because that’s what applications ultimately do. You just don’t want state mutations everywhere, because that makes bad code.
Clean code does not prevent writing bad code, it just makes it a bit easier to write good code.
OF COURSE you can follow the principles and still write bad code, because so much more goes into it, including skill.
A giant method with everything laid out, potentially mixing abstractions sounds like a nightmare to me. It leads to cognitive overload.
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).
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?