Support union types and maybe other corner cases about djangorestframework-dataclasses

[oxan]

There's a lot to unpack here.

The following two patches made it work. I think the first one is a bug as it detects wrongly int | str | None as an Optional[int].

That's indeed not correct, though I don't think your patch is a good solution. int | str | None actually is an optional type (optional really just means nullable), but it should be Optional[int | str], not Optional[int].

The second patch allows mapping UnionType aliases to Field serializers but does not support overriding other kinds of aliases.

This part looks correct to me.

In this case, the library calls lookup_type_in_mapping using JsonPrimitive rather than JsonKV. To be honest, I don't know which is the best approach to solve this or even if this should be supported. It makes sense for our dynamic serializers though.

I agree it's not a bad idea to support this, though I'm also not immediately sure of the best way to support this.

[oxan]

The following two patches made it work. I think the first one is a bug as it detects wrongly int | str | None as an Optional[int].

That's indeed not correct, though I don't think your patch is a good solution. int | str | None actually is an optional type (optional really just means nullable), but it should be Optional[int | str], not Optional[int].

This has been fixed in e26c57a (and follow-up bc8d79a).

The second patch allows mapping UnionType aliases to Field serializers but does not support overriding other kinds of aliases.

This part looks correct to me.

This has been fixed in be6359b (I forgot to credit you, sorry about that).

I'll leave this issue open for your last point, though I'm not sure right now if and how that can be fixed.

[emarbo]

Hi @oxan,

Thank you for taking the time to respond and fix that bugs!!! I very much appreciate it. And, my apologies for putting so much stuff in a single issue; these were unrelated things.

Regarding the last point, we can leave this as it is. If we reencounter this problem, we'll try to solve it ourselves and then post some proposal here. And no worries about the credit; not needed at all, we are happy just helping a bit.