Unable to send forms to babashka.nrepl[.browser-server]

[chr15m]

tl;dr: vim-fireplace should not rely on the :classpath op, or System/getProperty. If these return nil it should fail gracefully.

The nREPL server may not implement :classpath op (there's no mention of it on nrepl.org) and and it may not be running on Java. If I force :classpath to return an empty vector [] on a non-Java nREPL then vim-fireplace is happy (in the sense that it doesn't throw an error and will allow me to push eval forms after that), so a fix would be for vim-fireplace to be more robust to nil responses from either of those calls.

This may be related to #401 and may fix it.

I discovered the above in the course of implementing my own nREPL server. I was able to get vim-fireplace working with bb's babashka.nrepl.browser-server and other less rigorously implemented nREPLs by returning an empty vec [] to the :classpath request.

See also #420.