Support compiling Subxt to WASM

[amiyatulu]

subxt is not supported in yew. It gives error on trunk serve

error[E0583]: file not found for module `sys`
   --> /home/amiya/.cargo/registry/src/github.jparrowsec.cn-1ecc6299db9ec823/socket2-0.4.7/src/lib.rs:124:1
    |
124 | mod sys;
    | ^^^^^^^^
    |
    = help: to create the module `sys`, create file "/home/amiya/.cargo/registry/src/github.jparrowsec.cn-1ecc6299db9ec823/socket2-0.4.7/src/sys.rs" or "/home/amiya/.cargo/registry/src/github.jparrowsec.cn-1ecc6299db9ec823/socket2-0.4.7/src/sys/mod.rs"

error: Socket2 doesn't support the compile target
   --> /home/amiya/.cargo/registry/src/github.jparrowsec.cn-1ecc6299db9ec823/socket2-0.4.7/src/lib.rs:127:1
    |
127 | compile_error!("Socket2 doesn't support the compile target");

[niklasad1]

Yeah, it doesn't work at the moment.

You would have to disable to jsonrpsee feature and provide your own JSON-RPC transport for now to compile down to WASM.
It might be other things along the way too, I should look into that

[niklasad1]

Blocked on paritytech/scale-decode#4 for now

[jsdw]

And now blocked on getting the right features etc enabled to make the substrate based crates play nicely.

So, the goal here should be to dig into the crate features and figure out how to get the library part of Subxt (including the codegen crate ideally; may be good to remove bitvec from here to support this) compiling. This may lead to tweaks in Substrate crates to expose the relevant features. We'll probably need a feature flag like "js" in Subxt which we can use to toggle various Substrate crate features on/off as needed.

So, we know what to do, but it may prove to be quite tricky getting this over the line.

[Xanewok]

FYI I started working on it, hopefully this will not be blocked by any version releases upstream.

[niklasad1]

@Xanewok I forgot to mention that I already have a branch working for WASM that https://github.com/paritytech/subxt/compare/na-wasm-support?expand=1 but I never committed that but did right now just in case it helps you.

Perhaps your stuff is better but feel free to use anything from there :P

[niklasad1]

My stuff is using a special jsonrpsee branch to have async-wasm-feature but it should work on the latest release with a bunch of replace jsonrpsee with jsonrpsee-wasm-client instead of that feature I used.

EDIT: fixed again

[Xanewok]

Oh, that's great, thanks!