[bjornsing]

Yup. But I guess that typically happens in steps. So next DRY-programmer that comes along will add a cheezeFilledCrust boolean to that make_pizza function and so on. Every time it will seem more reasonable to add another boolean, because otherwise you have to remove the make_pizza function, and there would be SO MUCH CODE DUPLICATION.

I’ve seen this again and again in the field and I wholeheartedly agree with the sentiment in the OP. IMHO different code paths should only share code if there is good reason to believe that the code will be identical forever.

[411111111111111]

Now the next genius turns up and says that make pizza is at it's core always a n-step domain process.

So now you've dumped it down to an interface with a default implementation which calls the create_dough, add_toppings, bake_pizza interfaces in order, each of which are either passed in callbacks or discovered through reflection.

We can even sprinkle in some custom DSL to "abstract away" common step like putting the product into the oven correctly!

Jr's will never understand when why and what is effectively excecuted at runtime. Honestly, at this point I enjoy working with this kind of code. It's always such a high entertainment value and I get paid by the hour, so whatever

[svieira]

This is discussed in detail in "The Wrong Abstraction" by Sandi Metz

https://sandimetz.com/blog/2016/1/20/the-wrong-abstraction

Quote follows:

----

The strength of the reaction made me realize just how widespread and intractable the "wrong abstraction" problem is. I started asking questions and came to see the following pattern:

1. Programmer A sees duplication.

2. Programmer A extracts duplication and gives it a name. This creates a new abstraction. It could be a new method, or perhaps even a new class.

3. Programmer A replaces the duplication with the new abstraction. Ah, the code is perfect. Programmer A trots happily away.

4. Time passes.

5. A new requirement appears for which the current abstraction is almost perfect.

6. Programmer B gets tasked to implement this requirement. Programmer B feels honor-bound to retain the existing abstraction, but since isn't exactly the same for every case, they alter the code to take a parameter, and then add logic to conditionally do the right thing based on the value of that parameter. What was once a universal abstraction now behaves differently for different cases.

7. Another new requirement arrives. Programmer X. Another additional parameter. Another new conditional. Loop until code becomes incomprehensible.

8. You appear in the story about here, and your life takes a dramatic turn for the worse.

Existing code exerts a powerful influence. Its very presence argues that it is both correct and necessary. We know that code represents effort expended, and we are very motivated to preserve the value of this effort. And, unfortunately, the sad truth is that the more complicated and incomprehensible the code, i.e. the deeper the investment in creating it, the more we feel pressure to retain it (the "sunk cost fallacy"). It's as if our unconscious tell us "Goodness, that's so confusing, it must have taken ages to get right. Surely it's really, really important. It would be a sin to let all that effort go to waste."

[avgcorrection]

Not really a sunk cost fallacy. Existing code needs to be maintained. Some of it should be deleted since it costs more to maintain. Some of it shouldn’t be deleted since it might bite you in the behind when you realize that all of that code was correct (although gnarly) and now you’ve introduced regressions. And which code is which? Hard to say.

Sunk cost (fallacy) is about making decisions based on things that you have already lost. But you haven’t lost or expended the code—the code is right there, and it’s hard to know if it’s more of an asset or a burden.

[grog454]

Some languages handle massive parameter lists better than other (ex with defaults). There are also design patterns for this type of problem (ex a PizzaBuilder).

[gcassie]

100% agree and I just wrote this response and then saw you said it better!