Ask HN: How often do you really reuse your code?

#1

Post by humble_dev » Fri, Sep 11, 2015, 10:42 AM UTC

As most of developers, I try to create as much reusable code as possible. But in reality, I rarely use my code again. I could easily say that less than 5% of my code will be reused in the future.

I wonder how it looks for other people, is it worth to make your code reusable in the first place?

Re: Ask HN: How often do you really reuse your code?

#2

Post by csmattryder » Fri, Sep 11, 2015, 11:10 AM UTC

Depends if I move across problem domains, but I spend a bit of time writing games with LibGDX, and do have a Java package with some basic stuff such as screen generation and asset loading. It does end up saving me a good hour on getting a new game prototyped.

Though in Rails, very rarely, it's usually faster just rewriting it than trying to 'frankenstein' it from a set of piecemeal snippets.

Re: Ask HN: How often do you really reuse your code?

#3

Post by mr_nobody » Fri, Sep 11, 2015, 11:31 AM UTC

It remindes me of: http://blog.codinghorror.com/the-delusion-of-reuse/

Re: Ask HN: How often do you really reuse your code?

#4

Post by lsiunsuex » Fri, Sep 11, 2015, 12:02 PM UTC

Random Wordpress website - 50-75% reuse - most generic sites are the same - upload a theme I've used in the past, change colors, some layout, images, etc... saves a lot of time to have a vetted baseline

Custom CMS - 100% reuse - always start with a rolling base and constantly improving it though WP sites have cut into this - people think WP is better - get what you pay for.

Random 1-offs - how many times I've had to build a newsletter system... Base system gets copied and installed with specifics changed - where to pull the email list from, mailgun or aws for sending, etc...

Server config could be considered "code reuse" - I'll almost always refer to another server I built or run myself to copy apache / php / whatever config sections as a starting point.

Re: Ask HN: How often do you really reuse your code?

#5

Post by seiji » Fri, Sep 11, 2015, 2:55 PM UTC

Try to structure your problems as: If a pre-existing library existed to solve my problem, what would it look like?

Then, go and create that library. You'll get more reuse (and better test coverage, maintainability, open-source ability) than just making spaghetti code every time.

Re: Ask HN: How often do you really reuse your code?

#6

Post by twunde » Fri, Sep 11, 2015, 5:29 PM UTC

5% reuse is low, although it probably depends on what exactly you're working on. One approach is to make as much of your code into libraries as possible. This works especially well if you're making new applications using the same framework, although it's still valuable if you're maintaining an application. I've also found that separating the ui into partial views can save a lot of time, especially if you can reuse some of them for other projects. A third option is to make some functions that you use by convention. For example if you're using Selenium for testing there are 15+ ways to find something on a webpage. Choose 5 and only use those.

Re: Ask HN: How often do you really reuse your code?

#7

Post by AnimalMuppet » Fri, Sep 11, 2015, 5:44 PM UTC

Depends on how you look at it. Arguably, I reuse my code every time I modify an application to make it do something it couldn't do before. That effort to make the code reusable helps (if done right) when I have to modify the program some time in the future.

But that's probably not the way you were looking at it when you asked the question...

Re: Ask HN: How often do you really reuse your code?

#8

Post by insoluble » Sat, Sep 12, 2015, 3:05 AM UTC

In terms of desktop application development, I easily reuse 30% or more of my code, mostly in a linked fashion. I sometimes have to port between languages, but I still consider that reusing. When it comes to Web Dev, I reuse much less, perhaps only 5 or 10%. I also have less experience with Web Dev than Desktop development, which may be a part of the reason.

Re: Ask HN: How often do you really reuse your code?

#9

Post by iMerNibor » Sat, Sep 12, 2015, 9:40 PM UTC

The huge advantage of making reusable code, even if you never reuse it, is that it's clean and decoupled from the other parts of your application. Thus it'll be easier to understand and to deal with - you won't have to look over what dependencies might cause unwanted effects here or there or what might be able to go wrong in case X. With decoupled code you only need to make sure it does it's "one" (main) function properly.

It also prevents code from turning into spaghetti when adding "special" cases

Re: Ask HN: How often do you really reuse your code?

#10

Post by mattkrea » Sun, Sep 13, 2015, 12:25 AM UTC

iMerNibor wrote: post #9

The huge advantage of making reusable code, even if you never reuse it, is that it's clean and decoupled from the other parts of your application. Thus it'll be easier to understand and to deal with - you won't have to look over what dependencies might cause unwanted effects here or there or what might be able to go wrong in case X. With decoupled code you only need to make sure it does it's "one" (main) function pro…

Do you write test cases? If not I'd recommend it. The decoupling required for effective tests leads you into modularizing things you may not have otherwise. I have seen myself that after this started code re-use in general has jumped due to the modules already sitting around where previously I may have just written somewhat similar functionality from scratch all over again in a new project.