Allow jbang --debug to connect to a debugger

[danberindei]

Is your feature request related to a problem? Please describe.

I'd like to run JBang so it connects to a debugger that is listening for incoming connections.
The main advantage over JBang listening for a connection from a debugger is that in IntelliJ I can check "Auto restart" in the remote debug configuration, and a new debug session will start automatically every time I re-run the jbang script.

Describe the solution you'd like

When I run jbang --debug=server=n,address=localhost:5005, JBang should connect to my IDE listening on port 5005 instead of trying to listen on port 5005 itself.

It would also be nice to get a description of the --debug arguments in jbang --help.

Describe alternatives you've considered

I can keep using server=y and start the debugger manually every time I run the script.

Or there may be an enviromnent variable that gives me finer control over the debug arguments.

[maxandersen]

Waaat? Where in your ide do You enable Listening?

[maxandersen]

Cool. Got it working. Never noticed that feature but for sure makes sense. It's a shame it blocks the port and can't run multiple debug sessions this way.

But yeah @quintesse suggested we allow doing:

-debug=server=n,address=localhost:5005

But also

-debug=server=n

Or any other combo of CSV values and thus let you tweak the common default avoiding repeating the common values repeatedly.

[danberindei]

Sorry, I missed your question! Happy you got it working anyway.

It is indeed a shame that the debugger doesn't accept a second connection and it doesn't close the server port either, but with the auto-restart option it's still a win when doing lots of iterations on a script (or as I used to use it, running a test suite repeatedly and using conditional breakpoints to debug flaky tests).

[maxandersen]

Yes. It's now available in jbang latest release.