R language server got errors.

[vvxin]

Fresh Helix installation on WSL2.

then install R and R/languageserver package.

but got the bottom error and the function description stays there on top. No auto-completion for user variables.

I googled that error message but got no clue. Any help, thanks!

[dgkf]

I can reproduce this.

Exploring the log, it looks like the R LSP is replying to a signatureHelp request with response {"signatures":[],"activeSignature":-1}.

According to the LSP spec

export interface SignatureHelp {
  ...
  activeSignature?: uinteger
  ...
}

Which describes this particular field with

The active signature. If omitted or the value lies outside the range of signatures the value defaults to zero or is ignore if the SignatureHelp as no signatures.

When they say it can lie outside the range of signatures, I don't think they mean that it can be a negative value since its type is defined as a uinteger. This looks like an issue with R's languageserver package which sets a default of -1. Instead, they should not be passing activeSignature as part of the response if there is no active signature to return.

I'm familiar with the languageserver code base and can submit a PR to it to fix.

[archseer]

This was also a problem with some other language server if I remember correctly

[vvxin]

Thanks @dgkf
The GitHub version of REditorSupport/languageserver now works fine with Helix.