Add Copilot EA for language server

[genlu]

No description provided.

[CyrusNajmabadi]

This feels very broad in exposing everything

[dibarbet]

not necessarily opposed to this - they'd still be limited to accessing services that are directly made available by external access (since they have to pass the generic type to this call)

[CyrusNajmabadi]

but they have access to the solution. So they can do solution.Services.GetService<T>. So i don't see why we need to broaden the surface area here. We should make EA as minimal as possible. only what is absolutley necessary to expose.

[genlu]

With this we can MEF export services and use them in the language server extension itself, right (like this)? I think it provides more flexibility

[dibarbet]

not necessarily opposed to this - they'd still be limited to accessing services that are directly made available by external access (since they have to pass the generic type to this call)

[dibarbet]

since we have requireslspsolution this should always be not null (would potentially throw here if context.Solution is null)

[genlu]

Suggested change

	public Solution? Solution => context.Solution;
	public Solution Solution => context.Solution ?? throw new InvalidOperationException();

You meant something like this?

[dibarbet]

yup

[dibarbet]

do you need the factory right now? If not I would avoid exposing it as at some point I may want to remove the factory entirely.

[genlu]

No, I can remove it, included it since I saw compiler-dev-sdk uses it. Just to make sure, I could away use ExportCopilotStatelessLspServiceAttribute to export single instance services in the server, right?

[dibarbet]

Yup thats right