Error messages

I mistakenly used xs.combine as if it was Rx’s combineLatest. So, I gave it a combining function.

It took me a while to debug. Not too long. A good error message would be very nice.

I’m sure that’s only one example. Thus the general title.

[staltz]

I don’t want people to think I’m angry at this suggestion or not trying to help, but this suggestion won’t happen, I’m not going to build it and it’s not going to help people.

Building these type of “API misuse errors” is essentially building a weak type checking system. Please recognize that if we would try to write as perfect errors as possible, we would basically be building a crappy version of TypeScript. Worse, it’d run in runtime, not in compile time. Worse, you wouldn’t have that feedback in real time in an IDE.

I’m looking for the ideal developer experience, and the best possible error feedback of API misuse is something like a compile-time type checker or linter. And you can get awesome DX today with TypeScript.

Most users don’t use TypeScript

They should if they want these helpful API misuse warning/errors. Please notice that by using JavaScript, you are acknowledging that you are taking these risks. And this happens ubiquitously with all sorts of libraries and native APIs. If you want helpful API misuse errors, the ideal solution is not to bake in those errors in runtime, the ideal solution is a typed language.

Just give it a try, TypeScript is so easy to adopt. This issue won’t happen, and it’s not because I’m ignorant to people’s problems, it’s because it would never be good enough, and the effort would be large.

[mightyiam]

I see the point, of course. How much penalty do you guys think that something like https://www.npmjs.com/package/runtime-type-checks incur?