[ttoinou]

Me too ! I don't follow DRY that much, I'm aware that copy pasting is good enough for a few weeks / months to see how things evolve in the future, and do refactor when it's really needed. That said, how do you know if they mean different things ? For GUI code for example, they do mean the same thing, but there's a good chance the code will evolve in the future so premature refactor are wasted time

[pocksuppet]

GUI code changes as fast as your GUI does. If you have two buttons, call makeButton twice. If they have totally different sizes, don't calculate the size inside makeButton. If tomorrow you want a button and a checkbox, don't call makeButton twice with isCheckbox=true the second time.

Fun fact: Win32 checkboxes are buttons with a bitflag that says they are actually checkboxes.

[Akronymus]

Mostly by looking at the calling site where the code is already used and the calling site where I want to reuse it. If both of those mean the same (calculate the tax on x products, for the purpose of applying to the shopping cart, vs for applying to generating reports) then I'll reuse it, if it can be achieved without adding stuff like flags, in most cases. In other cases, it just looks the same (sum some field + calculate a percentage of that, for example, for discounts vs taxes on products) where it's obvious that they don't mean the same. (Though, I do heavily rely on a good type system to deal with future evolutions of that copied code)

TL;DR: Vibes

[ttoinou]

Its always about how far ahead in the future you plan ahead. And sometimes this future thinking is wasted time