YSK just saying "there is a big surprize / shocking ending" regardless of telling the details or not is already a SPOILER. If you suggest someone a film/tv show/game/book etc. please DON'T DO THAT!
from /r/YouShouldKnow
YSK只说 "有一个大惊喜/震撼的结局"，不管是否告诉细节，都已经是SPOILER了。如果你向别人推荐一部电影/电视剧/游戏/书籍等，请不要这样做!