We should always be wary of "(.+)-driven development". Things like test-driven development, or domain-driven development are fine, but they're also frequently approached from a perspective of dogma, which creates its own terrible outcomes.

But let's talk about domain-driven development. Without getting too bogged down into the details of the approach, the idea is pretty straightforward: describe you domain model without reference to any lower-level concerns, so you can effectively write your domain logic in an abstract language tuned to your specific needs. In other words, it's just a pretty good practice. DDD offers tools and techniques for doing it, and as stated, can be adopted as a point of dogma instead of technique.

Today's anonymous submitter sends us a React view that presents some admin options. Of course, it should only show us those admin options if the user is authorized to do that. So let's see how they implemented it:

{(isAdmin || canSeeResults) && (
    <div>
        <p>Admin Actions</p>
            {(isAdmin || canSeeResults) && (
                <div>
                    <button> Show Results </button>
                </div>
            )}
    </div>
)}

If there's one thing that seems to be a constant source of issues, it's people constructing SQL queries through string concatenation. Even if you're using parameters in the query, I'm opposed to handling raw SQL as strings in my programs. My solution is always "use a builder"- an API that constructs a syntax tree that it can then render to SQL as needed. (Yes, a builder, not an ORM, that's a whole other discussion, I'm not dogmatically anti-ORM, but it's a leaky abstraction at best.)

Many languages have such a thing, Java included. Lukasz's team was using Java, and they had a rule: "don't do SQL strings, use a builder". Unfortunately for Lukasz's team, their guideline didn't specify what kind of builder.

Frank suspected something odd when he spotted a use of React's useMemo function in some JavaScript code. Now, there's nothing wrong with using that method, in and of itself. It watches some variables and recalculates a callback if they change for any reason. It's a great tool for when you want to avoid recalculating expensive things over and over again.

But in this case, the calculation in question was isAuthorized, which wasn't an expensive calculation; it was just checking if certain values are set. The code looked like this:

Volodya sends us some bad date handling code in PHP. Which, I know, you're just reaching for the close tab and yawning when you hear that. You've seen it before. But bear with me, this one still has some fun bits to it.

$monthes = array(
        1 => 'Января', 2 => 'Февраля', 3 => 'Марта', 4 => 'Апреля',
        5 => 'Мая', 6 => 'Июня', 7 => 'Июля', 8 => 'Августа',
        9 => 'Сентября', 10 => 'Октября', 11 => 'Ноября', 12 => 'Декабря'
);