Ditto disguised as Teddiursa

Hi guys!
During this Halloween event, Ditto is disguised as Teddiursa.
I caught a shiny Teddiursa yesterday, and as I was catching it, a genuine question came to my mind :
What happens if I get a shiny costume Teddiursa and it turns into a Ditto?
Is it possible? If yes, will the Ditto be shiny?

Thanks!