[eyelidlessness]

I had similar thoughts (I do JS/TS dev daily but I’m very interested in a lot of what this language appears to offer). But I’d caution trying this with JS for anything more than exploring the ideas presented by the pattern. The reality is that even adding a type checker like TypeScript, and as many lint rules as you can throw at a project, it’s still too easy to end up putting nullish values into your null-safe arrays.

And I similarly wondered why I don’t use this sort of pattern more often, but that wondering is what led me to add this caution. It’s a really compelling idea, but probably extremely hard to debug when it goes wrong in a language and idiomatic ecosystem designed for it to go wrong at any time.

[galaxyLogic]

I guess one reason is that it takes more code to return an Array when in most cases what the caller needs is always just a single value. Many such functions never return null so it is overhead to make them return an array.

But returning an array also makes your functions more general. Maybe in the future you want to modify it so that it does return arrays of length > 1. Evolving the program to that state is then easy if you didn't lock yourself into assumption that this function will never ever need to return more than a single value.