Continuous operation when switching from G0 to G1 in laser mode?

[scanheads]

Hi,

this may be a stupid question but I need to verify if my device is working as expected.

I use a (the vendor says) GRBL-based laser cutter. Now when I send a command like e.g.

G0 X10Y0
G1 X20Y0
G0 X30Y0

what should happen exactly?

a) axis moves to position 10,0, stops there, turns on the laser, accelerates again, stops at position 20,0, turns off the laser and moves to position 30,0?

or

b) axis moves continuously and with fixed speed to position 30,0 turns on the laser in position 10,0 and turns it off at position 20,0 without stopping the axis prior to position 30,0?

What is the behaviour to be expected when a proper and up-to-date GRBL is used?

Thanks!