>That is not true. Assuming that both have same functionality, e.g. both either validate address correctness or both don't, you need exactly same test cases. Th

>That is not true. Assuming that both have same functionality, e.g. both either validate address correctness or both don't, you need exactly same test cases. The only difference is that they will be structured differently - in one case you validate address as part of `AddressObject` test and in another as part of `func email` or `func validate_email_address`. Typically when you make a class. You create additional methods under that class. Those additional methods such as getters, setters, constructors, all need to be unit tested for full coverage. Like I said... Cruft code. >Whether you go by functional or object oriented way, validation should be separated from main. It can be in another object or in another function, but it definitely does not belong to main function that does also sending. There is very little difference between two, the only one is that whether you validate before hitting send function of after. We're in agreement here except I never brought up functional programming. Where in my post did I say it? I'm talking about procedural programming. Like C. >It is not big deal either. It does not make it harder to understand, both variants are dead simple. Both are immediately readable. Frankly, people who have low abstract thinking or were lazy to learn basics of OOP hate it. It is the same as with people who hate any other paradigm - functional programming and what have you. Functional programming is too hard to read unless you have put work into learning it. This is besides the point. I don't care about how hard or how simple or how lazy people are. I'm talking about pointless logic and unneeded abstractions. This is what the article is talking about. Here is a way to make it even more clear. Compare the two below: Class Email(AddressObject, SubjectObject, MessageObject, ConfigObject, ClientObject).send_mail(msg: str, subject: str, address: str) func send_mail(msg: str, subject: str, address: str) Do you see how the send_mail method is IDENTICAL to the send_mail function? The class and the dependencies getting injected into the class are a pointless layer of abstractions when ALL you need to send an email is the send_mail method. This is the core of the argument. Don't get into semantics about people being lazy. And also, again, I never mentioned functional programming. I'm not talking about it. I'm talking about straight up procedural programs of just regular functions that you see often in C code. >There is such a thing as bad OOP, but when you pick dead simple easy to read example and claim it is something complicated, the the issue is not with OOP. I picked something dead simple and easy so readers can understand what I'm talking about. You'd rather me hand you some OO source code so you can parse that insanity?