Someones salty about her #1 huh?? You might be right but the matter of the fact is that she did sing the song and obviously sang it well because it's sitting pretty on top of the Hot 100. Chill.
Edit: Also, the song is Halsey's. Thats how features work. It's a #1 for Halsey and The Chainsmokers.
If she is credited, the song wouldn't EXIST in this form if someone else released it, so byE
Also, The Chainsmokers have had 5 flops out of 8 released tracks in the Roses to Closer single run, so this "it's all thanks to the chainsmokers!!11" garbage excuse has got to go. Let's not pretend this is a janelle monae (We Are Young) situation