Like I said, we will know only if they talk about it. Both China and Russia constantly perform such tests. They just don't talk about it and neither does the West.
Here's an example:
Russia has successfully test-launched a new missile defense system at its Sary Shagan firing range in neighboring Kazakhstan, the country’s Defense Ministry announced Friday. “The anti-missile defense system is in service with the Aerospace Forces and is designed to protect against air and...
www.themoscowtimes.com
Doesn't talk about the system they tested, nor the target.