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Discussion on: You don't need null

 
vladivo profile image
vladivo

I might be wrong, of course, but I am still not as convinced as you are. They are simply different and we would probably have quite heated debates regarding some special cases if we were working in same team. And I would also install a swear jar for such words like "nullish" or "falsy". My code is strict and explicit af 😄

Although, to be completely honest, I also have to admit that we really did forbid null in our previous project and mapped all null values as undefined in all our API responses. Didn't regret this decision, in our case (with good models) undefined worked as "empty value" really good, felt natural and the only places where null was really inavoidable were API and Angular forms.

Btw, I have a good example where you really need any. It's JSON:API standard which defines one of the fields as object, so the best you can do on the most abstract level (before any extensions with type narrowing) is something like Record<string, any>.

 
loucyx profile image
Lou Cyx

But you could also do Record<string, unknown>, which is like saying: I know this is an object, I just don't know the type of the properties inside of it ... way better than having any and accidentally calling a method or passing it to a function without first checking what that is. I see unknown as strict any, you can't use it unless you first figure out what it is. And I love it.

I also code pretty strictly and I still see not benefit using null at all (unless, as we said already, I'm interacting with something that needs null). And I share that experience you had, of migrating codebases to only using undefined, or having that no-null ESLint rule, and the best thing about that experience is that not only me, but nobody in those teams missed null (that's also why I shared that talk given by Douglas Crockford, because he had the same experience, years ago).

 
vladivo profile image
vladivo

You're right. And I am stupid. Of course, unknown can be narrowed same as any. Simply forgot that.

 
loucyx profile image
Lou Cyx

You're not stupid! I used to use any quite a lot before unknown was introduced, so it's ok if you're still checking before using it. The main difference is that unknown forces you to do that check, but if you still do it is ok!

 
vladivo profile image
vladivo

The thing is that today I really never use any (except for Angular and such). Absolutely forbidden! But I also wrote the implementation for jsonapi before I learnd unknown. So... 🤷😄

 
loucyx profile image
Lou Cyx • Edited

That's what happen to folks like us that were in this TypeScript game for a long time x'D

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