Thank you for the bug report

• I am using the latest version of lsp-mode related packages.
• I checked FAQ and Troubleshooting sections
• You may also try reproduce the issue using clean environment using the following command: M-x lsp-start-plain

Bug description

Hi,

It seems that the vue-language-server recently refactored their server implementation. I believe that this has broken lsp-mode's implementation.

Upon initializing lsp-mode, I'm immediately met with a ⛔ Warning (lsp-mode): Unknown notification: tsserver/request.

I can see in the upstream source that tsserver/request was added in version 3.0.0, the changelog indicates the following:

feat(vscode, language-server, typescript-plugin): communicate with tsserver based on request forwarding (#5252, #5395, #5443) 

So, I have to apologize for my lack of understanding on the details of either lsp-mode or the vue language server, but I can gather from the source that tsserver/request is the primary way for the LSP to request specific typescript-related information, and it expects a matching tsserver/response.

This seems not to be expected or supported by current lsp-mode implementation.

Steps to reproduce

Open any vue file with @vue/language-server@3.0.0 or @vue/language-server@3.0.1 and matching @vue/typescript-plugin.

Expected behavior

No error message, functioning communication between emacs and language server.

Which Language Server did you use?

@vue/language-server@3.0.1 with @vue/typescript-plugin@3.0.1

OS

MacOS

Error callstack

Anything else?

No response