Just to expand a little more on the subject. Once you play Juniper you finish your turn. Then once it's your turn again, you lose because then you have no more cards left in your deck to draw from. The only reason why you don't lose when you play the Juniper is because you do as much of the card as you can. You draw as much of the required 7, that Juniper makes you draw, as you can. Whether you have 1, 5 or 7 cards left in your deck, you do as much of the card effects as possible. The only way to prevent you from decking out would be if you can some how put a card back into your deck. Like if you play a Pokemon Communication and put a Pokemon back in your deck or your opponent uses N and you draw less than the amount of cards you put back.