I believe that part of the legislation of the last shutdown included guaranteed back pay for federal workers.

Before that though, it was a case of federal workers being sent home without pay...or told they were essential and had to still work without pay, and part of the details of whatever legislation ended the shutdown would determine whether these workers would be paid.

So it was entirely possible to be forced to work through a shutdown and at the end of it be told that you weren't going to be paid after all.

Now it's mandatory, I think.

So a shutdown is an even bigger waste of tax dollars for the party that claims to hate government waste, since they're effectively giving a paid vacation to the employees of the largest employer in the US: the federal government.

If there's a shutdown, essential employees will work, with guaranteed back pay, while non-essential employees will be sent home and not be allowed to work, also receiving back pay when the shutdown ends.