Result and undefined about hooks HOT 8 CLOSED

You should already be able to set it to null instead.

from hooks.

null is not undefined - they are not strictly equal and typescript won't even allow to assign null there.

from hooks.

The typing should be updated to allow null then since it should be possible. undefined is however not supported as a service return or hook result value.

from hooks.

But hooks are not only about services, aren't they?

Well if the official position is that undefined should not be supported as a possible return value of a function - then this can be closed.

from hooks.

That's fair. One option would be to add an UNDEFINED symbol that you can set the result to in https://github.com/feathersjs/hooks so it would be possible going forward.

from hooks.

Yeah, thought about it (symbol). But it creates problems when you work with arbitrary functions and set their result to result property. So now you'll need to replace their undefined with UNDEFINED and if you access context.result you need to remember about UNDEFINED and so on... (and I'm sure nobody will remember)

from hooks.

It creates problems when undefined can mean both things - actual return value and absence of a value.

In feathers ecosystem you control rules and you can ban undefined as a return value of services, solving the ambiguity.

But when it is about random functions (many of which will be void, so should return only undefined) - i don't think you can make it work without opening door for bugs...

I assume that you don't like the idea because of breaking nature, right? Or is there anything else against it?

from hooks.

You're right, this is a good suggestion and I don't think it would be a breaking change.

I just created a pull request in #70 that should allow to do what you are suggesting by checking if there is a property descriptor for context.result. That way if context.result is ever set to anything at all in the hook chain, the method call will be skipped.

from hooks.