Returning semanticsTokenProvider in server capabilities causes vscode to warn about using proposed apis

[kjeremy]

If I use a language server that adverstises semantic token support vscode 1.42 and insiders complain that I am trying to use proposed apis. Simply advertising that the server supports this feature should not trigger this.

[rcjsuen]

@kjeremy I did not encounter this issue though the extension is still using vscode-languageclient 5.x in my case. Did you upgrade to 6.x?

[rcjsuen]

@kjeremy Can you share your code or a link to your branch?

[kjeremy]

vscode-languageclient 6.1.0

It's a branch of https://github.com/rust-analyzer/rust-analyzer ... I will try to come up with something.

[rcjsuen]

@kjeremy Thanks. And which branch should I be looking at?

[kjeremy]

I can publish it in a bit. Actually it looks like we are calling LanguageClient.registerProposedFeatures() in the client. Maybe that's bad?

[kjeremy]

Though enabling call hierarchy on the server side works fine and that's supposed to be proposed...

[rcjsuen]

I can publish it in a bit. Actually it looks like we are calling LanguageClient.registerProposedFeatures() in the client. Maybe that's bad?

@kjeremy Yes, that part will trigger the error.

Though enabling call hierarchy on the server side works fine and that's supposed to be proposed...

They are not the same. I believe the call hierarchy API is live for VS Code but for the LSP it is still considered to be in a proposed state. Proposed VS Code API and proposed LSP API are not 1-to-1.

[rcjsuen]

@kjeremy If you search in the VS Code API, you will see they have the call hierarchy stuff there. Searching for semantic tokens will get you nothing though.

[rcjsuen]

@kjeremy Use this instead of client.registerProposedFeatures() perhaps?

client.registerFeatures(new CallHierarchyFeature(client));

[kjeremy]

@rcjsuen Thanks that at least allowed me to avoid the crash on stable while still getting call hierarchy. Though I think that I will probably have to use lient.registerProposedFeatures() while working on semantic token support.

[rcjsuen]

@kjeremy Yeah, that's what I've been doing as well.

[dbaeumer]

There is a difference between LSP proposed features and VS Code proposed feature. A feature can be final in VS Code but still proposed in LSP. An example is the call hierarchy. A feature can also be proposed in VS Code and LSP. VS Code has very strict rules when an extension can use proposed features. It needs to opt in, the are only available in dev mode and an extension will not work in the market place. There is nothing LSP can do about this so if you want to use proposed feature A but not B you need to register them by hand as outlined by @rcjsuen (btw thanks for posting this).