Notebook Document support is not implemented correctly

[moucha19]

Hello,

I was trying to connect from the LanguageClient to the pylsp server and when I did this with the current version of pylsp that supports LSP v. 3.17, the Initialize call ends in following Exception related to JSON Deserialization:

Cannot deserialize the current JSON array (e.g. [1,2,3]) into type 'OmniSharp.Extensions.LanguageServer.Protocol.Models.NotebookSelector' because the type requires a JSON object (e.g. {"name":"value"}) to deserialize correctly

I did some digging and the culprit seems to be this part of the pylsp response that specifies server capabilities:

'notebookDocumentSync': {'notebookSelector': [{'cells': [{'language': 'python'}]}]}

As you can see, the top-level object of notebookSelector is array, which is (if I understand the LSP documentation correctly) a valid syntax, but the LanguageClient does not seem to support it.

[manandre]

Sorry I misread the LSP spec, the payload is right.
I have been influenced by the invalid example in the specification :/

{
  notebookDocumentSync: {
    notebookSelector: {
      notebook: { scheme: 'file', notebookType: 'jupyter-notebook' },
      cells: [{ language: 'python' }]
    }
  }
}

[manandre]

The implementation is not aligned on the LSP 3.17 specification.

csharp-language-server-protocol/src/Protocol/Features/Document/NotebookDocumentSyncFeature.cs

Lines 757 to 765 in 86dc4ac

	public partial class NotebookDocumentSyncOptions : INotebookDocumentRegistrationOptions
	{
	///
	/// The notebook to be synced. If a string
	/// value is provided it matches against the
	/// notebook type. '*' matches every notebook.
	///
	public NotebookSelector NotebookSelector { get; set; }

NotebookSelector should be handled as an array/container.

[manandre]

For information, pylsp have recently changed their implementation to comply to the specification.
See python-lsp/python-lsp-server#453
https://github.com/python-lsp/python-lsp-server/releases/tag/v1.8.2

[manandre]

LSP documentation fix: microsoft/language-server-protocol#1831
Implementation fix: #1077