Bare PCB testing is mainly to test whether the PCB exist short circuit or open circuit, and the common testing methods are flying probe test (for sample or small quantity) and PCB testing jig test (for mass production).

BTW, there are two PCB testing way after soldering (PCBA Testing):

One is the ICT online test, which mainly tests the function of components, and sees whether there are short circuits or solder joints in the soldering process.

The other is function test, which is to analog the function of circuit board and test while power-on in order to check the function of board.