WorkDoneProgressCancelNotification is not using the given cancellation strategy

[heejaechang]

according to this - https://github.com/microsoft/vscode-languageserver-node/blob/main/server/src/common/progress.ts#L160 - workDoneProgressCancelNotification is using regular message for the cancellation notification.

this should use the same cancellation strategy provided like the regular cancellation messages - https://github.com/microsoft/vscode-languageserver-node/blob/main/jsonrpc/src/common/connection.ts#L1402, otherwise, anyone who uses custom cancellation strategy won't be able to use workdoneProgress's cancellation feature including ones who use sharedArrayCancellation for browser.

[dbaeumer]

The reason for this is that the work done progress cancellation is not bound to requests. Using a cancellation strategy here is very hard because the strategy works on request ids.

That being said I think if a work done is canceled from a client then usually the request is canceled as well which will honor the strategy. Or do you have a use case were you want to cancel the progress but leave the request running?

[heejaechang]

Or do you have a use case were you want to cancel the progress but leave the request running?

No.

In my case, I am trying to cancel currently running command. and executeCommand doesn't put cancellation token when they send ExecuteCommand request. so that might be the root issue. (https://github.com/microsoft/vscode-languageserver-node/blob/main/client/src/common/executeCommand.ts#L67)

basically, there is no way to cancel long running command.

I think if a work done is canceled from a client then usually the request is canceled as well which will honor the strategy.

this is not actually true if the work done progress bar is requested from server side. and that is what we do to make long running command cancellable. (ex, a refactoring command updating many files)

Using a cancellation strategy here is very hard because the strategy works on request ids.

the id given to cancellationStrategy could be a string and generation of that id is owned by LSP packages, so, as long as one verifies client and server's json rpc is using supported version, it could use the existing cancellationStrategy for workdone progress I think? by creating different shape of Id for WorkDoneProgressCancel?

[heejaechang]

@dbaeumer do you need other info as well?

[rchiodo]

Working on the synchronous stuff, this is also challenging as the synchronous server can't even get the WorkDoneProgressCancelNotification message while it's busy handling the request for the work it's doing. It needs to use a SharedArrayBufferCancellationStrategy when the WorkDoneProgressServerReporterImpl is created.

[rchiodo]

Oh actually I figured out a way to do this in the sync server. It can just send a sync message to the dispatcher. The dispatcher can then just have a normal CancellationTokenSource per progress reporter.