New Jersey plumber would never repair it this way but some plumbers use shortcuts, especially hidden ones.
Plumbing sewer and drain subcodes in New Jersey permits the use of certain materials and fittings and the first step of course is to shut off the water.
Main water valve is usually located in the ground or basement floor next to the water meter. Try to find it around water copper or PVC pipes and its always better to know where the main valve is located just in case of an emergency water leak so you don’t need to waste time calling a plumber or the fire department to shut off your water.
We highly recommend that two or three times a year you test the main water valve visually and manually close it and open it. Shut off the main water and reopen it.
Main water valve does not need to be used so often and what happens if you need to turn off the water after 10 years of the handle being in the same position you might break the valve and the water will splash all over or the valve might be stuck so hard that you will not be able to shut off the water.
For further advice and help we are always here to listen, advise and help.
Make it a wonderful day!