fix(provider): Add Send bound to return type of JsonRpcClient::request

[wigy-opensource-developer]

Motivation

#[async_trait] implementations require return types to be Send. So except for trivial cases the JsonRpcClient::request demanded implementors to be impossibly generic.

Solution

Add Send bound to the method and follow-up on its callers inside the monorepo.

PR Checklist

• Added Tests
• Added Documentation
• Updated the changelog
• Breaking changes

[gakonst]

#[async_trait] implementations require return types to be Send. So except for trivial cases the JsonRpcClient::request demanded implementors to be impossibly generic.

Got it - could you please add a test to avoid regressions? cc @mattsse is this too restrictive?

[wigy-opensource-developer]

Do you mean a test that breaks the build if someone removes this Send bound? I will, but they would probably remove the test as well then 😃

[gakonst]

Do you mean a test that breaks the build if someone removes this Send bound? I will, but they would probably remove the test as well then 😃

A test that would only compile if the Send bound is satisfied, i.e. a test that would fail on main but pass on this branch

[mattsse]

I think this is reasonable since we don't expect that the response type is not Send because it's also DeserializeOwned

[gakonst]

Hm I guess that makes sense? DeserializeOwned is owned, so it's probably going to be Send? Surprised they haven't done that themselves on the trait level? Are there any cases when that's not the case? Probably w/ unsafe?

[mattsse]

unsure, there's the rc feature which allows deserializing directly into an Rc which would no longer work after this PR, but imo this is perfectly fine.
I don't think there are any response types that are deserialized into a type !Send fields like Cell,Rc,etc.. so this should be okay imo.

RawValue is Send

https://docs.rs/serde_json/latest/serde_json/value/struct.RawValue.html

[gakonst]

SGTM - let's send it and keep an eye open.