You are right, I only know what was explained to me and how it was done at my home. But I happen to still have the pipe, which I just checked and it has a 30 psi gauge and an air nipple. As I remember now it was pressurized with air and the reading was at mid-point (15 psi). I wouldn't call
15 psi a pressure test, and since any pipe should easily withstand 60 psi, I probably wouldn't call that a pressure test either. Since you are testing for leaks not pressure capability, so it should be a leak test.