Allow clearing diagnostics from addons

[Earlopain]

I have checked that this feature is not already implemented

• This feature does not exist

Use case

Formatter addons should be able to clear diagnostics

Description

Trying to get the rubocop addon up to the same level as the original addon. One thing I'm stuck with is that when .rubocop.yml changes, diagnostics are cleared:

ruby-lsp/lib/ruby_lsp/server.rb

Lines 1098 to 1104 in 83e7cb0

	# Clear all document caches for pull diagnostics
	@store.each { |_uri, document| document.clear_cache("textDocument/diagnostic") }
	# Request a pull diagnostic refresh from the editor
	if @global_state.client_capabilities.supports_diagnostic_refresh
	send_message(Request.new(id: @current_request_id, method: "workspace/diagnostic/refresh", params: nil))
	end

But I don't think I have access to the store in an addon. How could I make that functionality accessible in an addon?

Implementation

No response

[Earlopain]

One easy solution is to always clear the diagnostics when .rubocop.yml changes, even if Requests::Support::RuboCopFormatter is not defined. But that leaves some rubocop specific logic in the server and other formatter addons theoretically also need to do this

[vinistock]

This is a good point indeed. I think it would be valid to expose a way for add-ons to request that pull diagnostics get recomputed. It needs to be through pull diagnostics (like the code you linked to), so that one add-on cannot fully erase diagnostics from another add-on.

We to limit the exposure of documents internal state to add-ons, so maybe we can expose a single API that does everything? Clears the document caches and sends the request to the client for pulling fresh diagnostics.

[Earlopain]

so maybe we can expose a single API that does everything

Yeah, that seems best. But where to put it? I see that there are a few custom messages the server handles under rubyLsp/*, would that be the correct place? And then maybe something on the request class to easily construct it with the right parameters.