Recent CodeSOD

Code Snippet Of the Day (CodeSOD) features interesting and usually incorrect code snippets taken from actual production code in a commercial and/or open source software projects.

Jul 2019

What a Happy Date

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As is the case with pretty much any language these days, Python comes with robust date handling functionality. If you want to know something like what the day of the month is? datetime.now().day will tell you. Simple, easy, and of course, just an invitation for someone to invent their own.

Jan was witness to a little date-time related office politics. This particular political battle started during a code review. Klaus had written some date mangling code, relying heavily on strftime to parse dates out to strings and then parse them back in as integers. Richard, quite reasonably, pointed out that Klaus was taking the long way around, and maybe Klaus should possibly think about doing it in a simpler fashion.


Some Kind of Magic

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We all have our little bits of sloppiness and our bad habits. Most of us have more than one. One place I'm likely to get lazy, especially as I'm feeling my way around a problem, is with magic numbers. I always mean to go back and replace them with a constant, but sometimes there's another fire you need to put out and you just don't get back to it till somebody calls it out in a code review.

Then, of course, there are the folks who go too far. I once got a note complaining that I shouldn't have used 2*PI, but instead should have created a new constant, TAU. I disavow the need for tau, but my critic said magic numbers, like two, were disallowed, so I said "ciao" and tau is there now.


Null Thought

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These days, it almost seems like most of the developers writing code for the Java Virtual Machine aren’t doing it in Java. It’s honestly an interesting thing for programming language development, as more and more folks put together languages with fundamentally different principles from Java that still work on the JVM.

Like Kotlin. Kotlin blends functional programming styles with object-oriented principles and syntactic features built around writing more compact, concise code than equivalent Java. And it’s not even limited to Java- it can compile down into JavaScript or even target LLVM.


A Long Conversion

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Let’s talk a little bit about .NET’s TryParse method. Many types, especially the built in numerics, support it, alongside a Parse. The key difference between Parse and TryParse is that TryParse bakes the exception handling logic in it. Instead of using exceptions to tell you if it can parse or not, it returns a boolean value, instead.

If, for example, you wanted to take an input, and either store it as an integer in a database, or store a null, you might do something like this:


Break my Validation

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Linda inherited an inner-platform front-end framework. It was the kind of UI framework with an average file size of 1,000 lines of code, and an average test coverage of 0%.

Like most UI frameworks, it had a system for doing client side validation. Like most inner-platform UI frameworks, the validation system was fragile, confusing, and impossible to understand.


Nothing Direct About directAddCartEntry

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It’s old hat, but every function, every class, every code unit you write, should all have a single, well-defined purpose. “Do one thing, and do it well,” as it were.

Of course, sometimes, it’s easier said that done, and mindlessly following that advice can lead to premature abstraction, and then you’ll have quite a mess on your hands. Still, it’s good advice, and a great design goal, even if you don’t head straight there.


Brütäl Glöbs

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Noam and a few friends decided it was time for them to launch their own product. They were young, optimistic about their career, and had some opinions about the best way to handle some basic network monitoring and scanning tasks. So they iterated on the idea a few times, until one day the program just started hanging. At first, Noam thought it was just a hang, but after walking away from the machine for a few minutes in frustration, he discovered that it was just running really slow.

After a little investigation, he tracked down the problem to the function responsible for checking if an IP matched a filter. That filter could contain globs, which made things a bit tricky, but his partner had some ideas about how best to handle them.


Null Error Handling

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Oliver works for a very large company. Just recently, someone decided that it was time to try out those “newfangled REST services.”

Since this was “new”, at least within the confines of the organization, that meant there were a lot more eyes on the project and a more thorough than average code review process. That’s how Oliver found this.


Structured Searching

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It’s hard to do any non-trivial programming in C without having to use a struct. Structs are great! A single variable holds access to multiple pieces of data, and all the nasty details of how they’re laid out in memory are handled by the compiler.

In more modern OO languages, we take that kind of thing for granted. We’re so abstracted from the details of how memory is laid out it’s easy to forget how tricky and difficult actually managing that kind of memory layout is.


The Bogus Animation

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Animations have become such an omnipresent part of our UI designs anymore that we tend to only notice them when they're bad.

Ben is working on an iOS application which appeared to have a "bad" animation. In this case, it's bad because it's slow. How slow? Well, they have a table view with ten items in it, and the items should quickly tween to their new state- position, text, colors all could change in this process. And it was taking four seconds.


Answer the Questions on this Test

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Jake works in Python. Python is a very flexible language, and Jake has some co-workers who like to exploit it as much as possible.

Specifically, they’re notorious for taking advantage of how any symbol can be redefined, as needed. Is int a built-in function? Yes. But what if you want to have a variable called int? No problem! Just go ahead and do it. Python won’t mind if you do int = int(5).


The Wizard of Speed and Time

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Christopher started a new job as a “full-stack” developer. Unfortunately, most of the developers are still on the “why do you need anything other than jQuery” school of front-end development, despite efforts to transition their UIs to Vue.

This meant that Christopher didn’t do much backend, and ended up being the mid-level front-end dev, in practice if not in job title.