Don't give me serebii or Showdown as a source, test it out ingame.
The easiest way to do things would be to do a battle against another person. I'll list good steps to take:
One player has Noivern with Dragon Pulse. The other player has a Florges with Misty Terrain and any other Pokemon (that isn't Flying or Levitating or Fiary).
The player with Florges leads with the other Pokemon they have. Noivern leads and hits with Dragon Pulse.
Take note of how much damage was done then start a new battle.
In this new battle, lead with Florges. Noivern must not KO it. Florges uses Misty Terrain. Florges then switches out to the Pokemon you used in the previous battle, and Noivern hits it on the switch with Dragon Pulse. Take note of how much damage was done.