JSON error when running <myTreeViewId>.focus-command

[jrieken]

• have a custom view with id foo
• from the extension host run the foo.focus command
• on the main side a silent error occurs (run with break on all errors)

[jrieken]

cc @alexandrudima for us ignoring all those errors... https://github.com/Microsoft/vscode/blob/b36ee32fe7ca1da5285f1392be22c8bd14355315/src/vs/workbench/services/extensions/node/rpcProtocol.ts#L22-L29

[alexdima]

I have to ignore them... Extensions constantly make RPC calls which involve recursive datastructures... This was always showing up in error telemetry.

This was also one of the root causes for leakages, e.g. a command invocation would never complete if serializing its result would throw.

Long story short, the "contract" is that calling with a non serializable object leads to the UI side getting "null". IMHO this is not so bad. The errors don't go to error telemetry because they then reach me and I have nothing to do with them.

[jrieken]

How about a console.warn-statement when in dev-mode process.env.VSCODE_DEV?