How To Debug js code in the board?

Yes, I'm hoping that you won't really have to change code manually at all. But for now the idea is:

• Run code normally
  
• Ctrl-C breaks out of the currently running code, into the debug> prompt. Ctrl-C again would exit that and properly break out of the running code.
  
• From there you use next/n, step/s, continue/c to go through your code, and print/p to evaluate an expression. So like text-mode GDB or node's debugger.
  
  

If you wanted to add a breakpoint, you'd add a debugger keyword in the IDE - however there's nothing to say the IDE couldn't do that automatically at some later stage. It could of course also have buttons for next/step/etc which mapped to sending the relevant commands over serial - I'm hoping someone else would do that bit ;)