As you know, you should ALWAYS fire up your new circuit and test it before you wire up your switch and box it up. Amazingly many people don't. Now there's no excuse...
This simple circuit emulates your final jack, power and footswitch wiring, so you can easily test your nice new build without much work.
Simply connect your four offboard wires for IN, OUT, +V and GND to this tester and you're ready to plug in and play.
The tester has the option to connect individual wires or plug in a Direct Connect ribbon cable (4 or 6 way), so should cover you for all standard negative-ground builds. For posi-ground effects you'll have to use the wired connections, but no biggy.
As everything is totally board-mounted on the tester there's very little to go wrong when building it.
Invaluable on any builder's bench.