Unfortunately, they were given such good and detailed plans by A. Q. Khan and the US (through Operation Merlin), it's likely they wouldn't need to test it. All they need is the material, which they're feverishly trying to obtain.
I fear once they have what they need, their "test" would be on an Israeli city or US forces in the ME. Maybe both.
I would bet that NK has already tested one for them.
.......I am not sure they would ever test a nuke.......
A test is not necessary for one overiding reason. If the bomb goes off, it is god’s will. If it fails it is god’s will.
Testing will not affect the will of god. Nothing an Islamic fanatic believer can do will influence the outcome.