Movie audiences love happy endings, which kind of sucks for screenwriters who love writing stories with gritty, realistic endings that aren’t always uplifting or neatly tied up in a bow. Because of that, many movies with the standard Hollywood Happy Ending ™ don’t actually start off that way. What normally happens is the film is test-screened first. If the audience hates the ending, it gets chucked and replaced with a different, happier one. It happens a lot more than you think, too. Below, a few of the biggest examples. Warning, there be spoilers ahead!
1
‘Pretty Woman’
2
‘Toy Story 3’
3
‘Get Out’
4
‘Frozen’
5
Little Shop of Horrors
6
28 Days Later
7
Rampage
8
Dodgeball
9
Star Wars: Return of the Jedi
Source : https://www.distractify.com/entertainment/2018/11/16/ZirOT0/dark-original-endings-to-happy-movies