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Code Smells Catalog (luzkan.github.io)
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[-] DScratch@sh.itjust.works 4 points 15 hours ago

I think to present rules like this as hard rules, with little explanation and no nuance is harmful to less experienced engineers.

A prime example here is the Duplicated Code one. Which takes an absolute approach to code duplication, even when the book that is referenced highlights the Rule of Three:

The Rule of Three
Here’s a guideline Don Roberts gave me: The first time you do something,
you just do it. The second time you do something similar, you wince at the
duplication, but you do the duplicate thing anyway. The third time you do
something similar, you refactor.
Or for those who like baseball: Three strikes, then you refactor.

I've seen more junior devs bend over backwards, make their code worse and take twice as long to adhere to some rules that are really more what you'd call guidelines than actual rules.

Sure, try to avoid code duplication, but sometimes duplicating code is better than the wrangling you'd need to do to remove it.

Making extra changes also leaves extra room for bugs to creep in. So now you need to test the place you were working, and anywhere else you touched because of the refactoring.

[-] pcouy@lemmy.pierre-couy.fr 1 points 10 hours ago

Well it's in the name, they are code smells, not hard rules.

Regarding the specific example you cited, I think that with practice it becomes gradually more natural to write reusable functions and methods on the first iteration, removing the need for later DRY-related refactorings.

PS : I love how your quote for the Rule of Three is getting syntax highlighted xD (You can use markdown quotes by starting quoted lines with > )

[-] DScratch@sh.itjust.works 2 points 4 hours ago

The site doesn’t define what a code smell is, though. It’s just a list of Don’t Do’s.

That’s kind of the nuance I would be hoping for.

Something like:

Code Smells are clues that something is amiss. They are not things that always must be ‘fixed’. You as an engineer will, through experience in your own codebase and reading of others, develop a sense of the harm imparted by and the cost of fixing Code Smells. It is up to you and your team to decide what is best for your codebase and project.

(The rule of 3 formatting was intentional, given the community we’re in)

[-] 1hitsong@lemmy.ml 25 points 2 days ago

I've been rallying against clever code for years!

Sure, it makes you have less lines for your l33t code solutions, but in the real world, it sacrifices the maintainability of code that others will eventually work on.

Between a clever 1 line fix and maintainable 10 line fix, I'll choose the 10 line every time.

[-] MonkderVierte@lemmy.ml 5 points 2 days ago

10 lines is a bit much, that's hardly more readable than one.

Then again, it depends on the language.

[-] curbstickle@lemmy.dbzer0.com 9 points 2 days ago

As an extensive commenter, I completely agree.

I need to know wtf I was doing, making it convoluted to save a few lines is pointless.

[-] pcouy@lemmy.pierre-couy.fr 8 points 2 days ago

It's often a good idea to make the code itself very explicit through verbose function and variable names, rather than writing comments that could lead to inconsistencies between code and comments (by not updating the comments at the same time as the code) (see "Fallacious Comments" from the catalog)

[-] curbstickle@lemmy.dbzer0.com 5 points 2 days ago

"Some people do a bad job commenting and updating comments, so lets not do comments" is not an approach that works for me.

Most of my code is at the prototype level. I'm concepting something out, usually paired with hardware.

If someone can't follow what I'm doing, its going to lead to problems. If a change happens to the hardware being controlled, code will not be good enough on its own.

Rather than being accepting of bad commenting practice, make comments (and updating them properly) part of good practice. In my experience, It saves time in the long run and leads to better code at the end.

[-] pcouy@lemmy.pierre-couy.fr 8 points 1 day ago

That's not what I said. I said that comments can often (but not always) be replaced with good and explicit names.

This can be pushed to some extreme by making functions that only get called at a single place in the code, just for the sake of being able to give a name to the code that's inside (instead of inlining it and adding a comment that conveys the same informations as the function's signature)

It's definetly not for everyone, but for beginners/juniors it gives something objective they can aim for when trying to build good coding habits

[-] curbstickle@lemmy.dbzer0.com 5 points 1 day ago* (last edited 1 day ago)

I am going to disagree, comments should be an explanation.

The code is what's being done, a comment should be why its being done.

[-] pcouy@lemmy.pierre-couy.fr 6 points 1 day ago* (last edited 1 day ago)

I'm not sure how we disagree. At least, I don't disagree with you. My whole comment was talking about "what" comments. "Why" comments are a very good thing to have where they're needed

[-] curbstickle@lemmy.dbzer0.com 0 points 1 day ago

Not updating comments with code is what I'm talking about - that's not a comment problem, thats a programmer problem.

If they aren't updating the "why", that programmer is the problem, not comments.

[-] pcouy@lemmy.pierre-couy.fr 4 points 23 hours ago

When refactoring, it's often the "what" that changes, not the "why"

[-] curbstickle@lemmy.dbzer0.com 0 points 22 hours ago* (last edited 21 hours ago)

That really depends.

Especially for a function that may see use in a variety of scenarios.

I'm going to be firmly against anyone suggesting against proper comments - which, I'm sorry, but you are by your own statement.

Code will change for many, many, many reasons beyond just refactoring.

Edit: and why it was refactored is important as well.

There are just so many reasons, and yes, I will continue to be against this newer trend of "dont comment, make codes your comments".

All that is, is a great way to make your code harder to manage later. It doesnt take much effort to explain why you're doing something.

[-] pcouy@lemmy.pierre-couy.fr 1 points 10 hours ago

Let's rephrase my opinion, so that we can (hopefully) agree on something : What I'm arguing against is the "ChatGPT-style" (or "tutorial-style") comments that I've seen all over juniors' code, even before LLMs got widespread

[-] curbstickle@lemmy.dbzer0.com 1 points 1 hour ago

"Adds a and b"?

Sure, not useful. Thats a what, not a why.

"Combined value needed for these outputs"

The "why". Useful. Shows the purpose, and explains the context it may be used in.

Assuming the "why" is known is the mistake - and one I see from junior and mid level, I dont care what language it is, its the same. Using refactoring code as an example, without context - the why - can cause problems. What may be more efficient for one resulting value being presented can cause issues for others (let's say precision as an example of why it could be a problem). Failing to include why something is being done is usually what introduces these problems, someone misses a different context than what they are looking at, and that belongs in a comment.

A comment on "why" isn't just important - for any block of code - it is, IMO, a requirement. I have and will continue to respond with "add comments as to why and resubmit".

[-] Boomkop3@reddthat.com 19 points 2 days ago* (last edited 2 days ago)

Some of these mostly just someone's opinion, and I don't quite agree with all of them

[-] FizzyOrange@programming.dev 3 points 1 day ago

Any specific ones? I've seen this before and I thought I would feel the same way as you before I read them, but actually the vast majority are pretty basic things that are not really arguable.

It's definitely nice to have a list like this to point inexperienced colleagues to in code reviews. It's a bit more authoritative than "trust me bro, I've written a lot of code".

[-] Boomkop3@reddthat.com 3 points 21 hours ago

To preface, I think it's best to focus on what the right approaches are. Not on what to avoid. And when you see a student making a mistake, showing them how a different approach is handier (if possible) is what I suggest you do.

Having something to point at doesn't help much

vertical separation

This one argues against organizing your code in a way that shares variables are in one place. There are arguments to be made either way, but normally you'd scope your variables in a way that the ones specific to a particular bit of code are not accessible from elsewhere.

null check

Suggest writing a custom class to do what most languages can solve with inheritance or even better: the ? syntax.

inconsistent names / styles

Yes, it can be annoying. No, clarity is more important than insisting on removing that extra underscore.

complicated Boolean expression

They're advocating the use of a function to replace an expression. Sometimes this works, but the task of a boolean expression is not always easily expressed in a couple words. And so you can end up with misleading function names. Instead, just put a comment in the code.

callback hell

Not even a code smell. It's an issue from back when languages like JavaScript didn't support promises yet, but callbacks were popular. Cose got hard to read with a little complexities.

[-] FizzyOrange@programming.dev 1 points 5 hours ago

There are arguments to be made either way, but normally you’d scope your variables in a way that the ones specific to a particular bit of code are not accessible from elsewhere.

Sounds like you agree with that one to me? I'm not sure I follow their arguments about regions there (I've never used regions), but the example of declaring a variable in a block way before it is every used is spot on. I've seen code written like that and 99% of the time it's a bad idea. I think a lot of it comes from people who learnt C where you have to do that (or maybe Javascript which has weird rules for var).

Suggest writing a custom class to do what most languages can solve with inheritance or even better: the ? syntax.

Yeah I'll give you that one. They even suggest using Optional as a solution, which is what their "smelly" code did in the first place!

Yes, it can be annoying. No, clarity is more important than insisting on removing that extra underscore.

Not sure what your point is here. Of course inconsistent naming is a code smell. Do you want inconsistent names?

They’re advocating the use of a function to replace an expression. Sometimes this works, but the task of a boolean expression is not always easily expressed in a couple words. And so you can end up with misleading function names. Instead, just put a comment in the code.

Erm, yeah that's why this is a code smell. They aren't saying never have complex boolean expressions - just that if you do you'd better have a good reason because probably you'd be better off splitting it up into named parts.

callback hell - Not even a code smell. It’s an issue from back when languages like JavaScript didn’t support promises yet, but callbacks were popular.

Indeed, so now it is a code smell.

[-] Boomkop3@reddthat.com 1 points 4 hours ago

Indeed, so now it is a code smell.

Fair enough, code from a different era smells different

[-] Boomkop3@reddthat.com 1 points 4 hours ago

They aren't saying never have complex boolean expressions...

That's not what I'm saying either. But I think this is to be judged on a case by case basis. And it can depend on your understanding of the context. I think there's simply too much nuance here to just say "this smells"

[-] Boomkop3@reddthat.com 1 points 4 hours ago

Not sure what your point is here. Of course inconsistent naming is a code smell. Do you want inconsistent names?

Of course not. But in some (uncommon in my experience) cases method names can be unclear or just plain impractically long. In such cases, I would rather see an exception to the rule than having to rely on a comment to explain the name choice.

I had a great example a couple months back, but I can't remember it right now. But here's a (bad) example of such a situation.

An example of this could be a button that triggers a click. You might call it BtnClick. Then the click event for it could be BtnClickClick. In this case, I'd rather see BtnClick_click. Ugly? Yes. Bad example? yes. But the idea is that it's more clear that the _Click action is seperate from the name.

[-] Boomkop3@reddthat.com 1 points 4 hours ago

There are arguments to be made either way, but normally you’d scope your variables in a way that the ones specific to a particular bit of code are not accessible from elsewhere.

They're arguing to do this:

int field = 1;
void may() {
   do(field);
}

int field = 3;
void you() {
   do(field);
}

int field = 3;
void be() {
   do(field);
}

int field = 7;
void happy() {
   do(field);
}

rather than

int field = 1;
int field = 3;
int field = 3;
int field = 7;

void may() {
   do(field);
}
void you() {
   do(field);
}
void be() {
   do(field);
}
void happy() {
   do(field);
}

A bad example of encapsulation would be:

class AClass {
    private class HelloThere {
         int a = 1;
         int b = 3;
         int c = 3;
         int d = 7;
         void DoStuff(AClass self) {
              Do(a, b);
         }
    }
    private HelloThere field = new();
    void World() {
        field.DoStuff(this);
    }
}

Of course, there is nuance here. Is this class encapsulating enough that it's got a right to exist? That'll depend on the situation.

Also, c has local static variables. Depending on your use case, it might just be easier in c than in C# and similar.

// a method with a state, horrid in some contexts, great in others
void PrintCounter() {
    static int count = 0;
    Print(count);
    count += 1;
}

And just in case you're still reading and curious:

#region PingPong
    // hi! I am in a region, collapse me using your ide!
#endregion
[-] SwordInStone@lemmy.world 1 points 21 hours ago

inheritance rarely solves anything

[-] Boomkop3@reddthat.com 1 points 21 hours ago

You gotta know how to use it properly

[-] StrikeForceZero@programming.dev 2 points 15 hours ago

At that point I would argue composition/traits are the way to go.

"This extends Draggable". That's great but now we can't extend "Button" to override the click handler.

Traits: You wanna have Health, and do Damage, but don't want to implement InventoryItem? No problem. You wanna be an Enemy and InventoryItem? Go for it. What's this function take? Anything that implements InventoryItem + Consumable

[-] Boomkop3@reddthat.com 1 points 15 hours ago
[-] StrikeForceZero@programming.dev 1 points 13 hours ago* (last edited 13 hours ago)

Yeah Interfaces would be the next best thing.

The only reason why traits are considered better is because in languages like rust it can enable static dispatch. Whereas interfaces in C#, Java, Typescript, (and C++ via abstract classes, not templates) are always dynamic dispatch.

[-] Boomkop3@reddthat.com 1 points 11 hours ago* (last edited 11 hours ago)

Looking at the Rust docs, it looks like it's not much more than a difference in implementation under the hood.

It would be clunky, but in C# you could duct tape this: make a static abstract method in an interface that takes an object named 'self', then an extension method that extends the class and just casts then runs the function with Unsafe.As<TFrom, TTo>(ref obj), or an explicitly aligned struct with overlapping values.

I don't expect any such implementation anytime soon though :/

ps: Typescript can go take a hike, it's a superset for a language that was never designed for this

[-] Michal@programming.dev 3 points 1 day ago
[-] Boomkop3@reddthat.com 3 points 1 day ago

And focussing on what not to do is not the best way to get things right

[-] onlinepersona@programming.dev 0 points 2 days ago

Agreed. Every time somebody links this to "prove" or underline their argument, I roll my eyes. There are a lot of subjective things there and many that are actually valid code.

Anti Commercial-AI license

[-] DrDeadCrash@programming.dev 10 points 2 days ago

I feel like if one tried to follow all of these "rules" at all times nothing would get done, at all.

[-] BradleyUffner@lemmy.world 11 points 2 days ago

A code smell isn't supposed to be automatically bad. A smell is an indication that something might be wrong. Sometimes using a smelly pattern is legitimately the only way to do something.

[-] pcouy@lemmy.pierre-couy.fr 6 points 2 days ago* (last edited 2 days ago)

Apart from the fact that, as another commenter said, "smells" are not "rules", I think most of these points come down to developing good habits, and ultimately save a lot of time in the long run by initially spending some time thinking about maintainability and preventing/limiting technical debt accumulation.

[-] morrowind@lemmy.ml 6 points 2 days ago

half of these will make your code better lmao

[-] SwordInStone@lemmy.world 9 points 2 days ago
[-] DScratch@sh.itjust.works 1 points 16 hours ago

Like all things programming; It Depends.

[-] bhamlin@lemmy.world 12 points 2 days ago

I'll never tell

[-] shnizmuffin@lemmy.inbutts.lol 5 points 2 days ago

My code is exclusively Complicated Regular Expressions and it's screaming fast.

[-] morrowind@lemmy.ml 4 points 2 days ago

I'm not going through every one, but null checks, vertical separation, status variables and binary operator in name, are all things that often make your code better and more readable

this post was submitted on 05 Jan 2025
60 points (90.5% liked)

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