There's a "tested edge case" where you can check isOdd('1') and it will work - to me the code is already wrong, isOdd(STRING) should throw. The correct solution is to use Typescript and assert the input is a number.

The Number.isSafeInteger check is an interesting one. Yes, it's not "safe" to work with a number outside this but no doubt something in the function would be broken before an is-odd check if it was relied upon.

Often the edge case someone else catered to is something counter to my expectation. I would rather write two lines of code myself and be aware of the behaviour.

The author of both packages has since moved the github repos to an organisation named "i-voted-for-trump" and labelled the packages with the "troll-bait" tag.

But the author also claims those packages where created when they were learning to program, and they seem to have stuck with the idea of small libraries (just not quite that small). The changes seem to be due to grief the programming community has given him about those packages, as some of the worst examples of the pattern.

I suspect the author was being slightly satirical by choosing to do the simplest possible NPM library. But at the same time they probably believed it was a useful package, allowing new programmers (like himself) to calculate the evenness/oddness of numbers without needing to know or google the mod-2 trick. And if you are going to learn how to create npm packages, might as well start small.

If they were aiming to be slightly satirical, they were not expecting that level of outrage.

It's worth pointing out that the libraries do slightly more than just mod-2. It checks the argument passed in was actually an integer, and throws descriptive error messages if the argument is not a number or not an integer.

https://qz.com/646467/how-one-programmer-broke-the-internet-...