Support for rust_decimal::Decimal

[corvusrabus]

Goal

Adds support for the currently most popular decimals crate rust_decimal (23m downloads on crates.io).

I think the crates rust_decimal and bigdecimal don't need serde themselves enabled as the users of this library will enable it by themselves if they need it.

Checklist

• I have followed the steps listed in the Contributing guide.
• If necessary, I have added documentation related to the changes made.
• I have added or updated the tests related to the changes made.

[corvusrabus]

@gustavo-shigueo sorry you were so fast with merging my last one that I had to open a new one for this :)

[corvusrabus]

@gustavo-shigueo any chance this could be release 9.1 ?

[gustavo-shigueo]

Don't worry about smol_str, I've updated the feature name on main

[NyxCode]

How does this interact with the serde features of rust_decimal?

There's

• serde-float
• serde-str
• serde-arbitrary-precision
• serde-with-float
• serde-with-str
• serde-with-arbitrary-precision

We had some discussion about this a while back in #273. As far as I can tell, we cannot support this library here properly, and support within rust_decimal itself is needed.
Since there's no clear format to which a Decimal is serialized, I am not sure it's a good idea to generate string bindings for it. I think it might just be better to let users use #[ts(type = "..")] or #[ts(as = "..")] here.

[corvusrabus]

How does this interact with the serde features of rust_decimal?

You're completely right about this suspicion. I didn't remember that rust_decimal has the weird architecture of being allowed to change the serde serialization via feature flag.

I don't see how to get arund this right now. We might in a hacky way serialize a Decimal via serde_json::to_value and see which type we get but I am not sure how to do that at compile time to deduce the types needed to implement TS.

Closing this for now and might reopen if I come up with a new idea.

Any chance you could release version 9.1 that includes the smolstr feature @NyxCode ?