Should have better IDE support

[ralfbiedert]

Motivation

I have the same problem as @panstromek in this PR. With the changes that landed there code completion in IntelliJ broke; and in turn yew + web-sys became unusable for me.

One could argue this is an IDE issue and having them fix the problem would be nice, but for example the underlying IntelliJ ticket has been around for 3 years, so it's unlikely to happen soon.

For most other libs I'd just switch to something with autocomplete support, but web-sys has a quasi monopoly on client-web interop, so one could also argue there is some shared responsibility.

Possible Solution?

Microsoft's win-rt uses build.rs + proc macros to create a winrt.rs, as described here, which can be included via include!(concat!(env!("OUT_DIR"), "/winrt.rs"));. This works really well for me. I am wondering if something similar is possible here?

[alexcrichton]

Thanks for the report! I'm happy to review PRs and/or discuss possible ways to solve this, but unfortunately I don't have time to work on this myself. That PR is beneficial enough that I do not think it's worth reverting, additionally.

[vlad20012]

Do I understand correctly that previously all wasm-bindgen work was done in during build.rs step yielding complete IDE-supported code, but now most of the wasm-bindgen work is done by procedural macros?

[panstromek]

@vlad20012 no, this was true only for web-sys crate. All wasm-bindgen stuff is done through proc-macros, just the web-sys crate used to be
an exception generated with a build script (I guess for historical reasons). That mentioned PR just unified it with js-sys and all other user code that uses wasm-bindgen.

[panstromek]

@vlad20012 now, when you're here, I thought about this some more and I think it shouldn't be that complicated to support it in the plugin, if you're willing to special case it, because wasm-bindgen uses pretty predictable structure and the support is already "almost there". Plugin can already resolve the functions and types but namespaces them incorrectly.

Basically this is the failing structure:

#[wasm_bindgen]
extern "C" {
  type SomeJsType;
  #[wasm_bindgen]
  fn method(this: &SomeJsType);
}

Plugin sees this as a function and unrelated type but it should interpret it as:

struct SomeJsType;
impl SomeJsType {
  fn method(&self){}
}

This would make the resolution correct.

[vlad20012]

Oh, let's just support proc macros

[panstromek]

Well.. if you think that's simpler solution 😄 😄

[ralfbiedert]

Closing since the latest IntelliJ update fixed the situation for me. Feel free to reopen if someone has stronger opinions about IDE support.