It was discussed before. The Liaoning doesn't have a testing rig for the engines. I don't know if they are planning to fix the engines on board. But if they do they will have to test the engines on the flight deck after it has been installed into the plane.
and while that will not be most efficient, it will be the most practical, chain the J-15 down away from air-ops, personnel, etc with the exhaust venting over board and light her up, in reality, every aircraft gets "run up" prior to the first flight of the day, and at the pilots discretion after that. Bottom line is, if its out of normal operating temps, pressures etc, it is OFF flight status, and back to the hangar. If they confine their scope of ops close to home, you take sixteen birds with four designated as "spares", and work on them when you get home if they require "heavy maintenance"...You usually have four-six tied down on deck as the "alert" aircraft anyway.