True test is to pressurize the cabin and then coat every fitting with soap and water. Where air is bubbling out is indicative of a leak. Close all hatches and windows putting tape over the hatch seals to insure no air can seep from there. Then place a piece of plastic taped over the entire companionway and put a small slit in it. Insert a leaf blower and tape that well. Make sure you have a bucket of real soapy water with a brush. While you are holding the leaf blower, have the other person to brush all fittings and rub rail, etc. and where air is bubbling out, there is where you have a leak. Generally found more than what was expected.