Merging eloquent collections

The Eloquent collection's merge method uses the id to avoid duplicated models.

But if you are merging collections of different Models, it can get you unexpected results.

Use the base collection method instead.

$videos = Video::all();
$images = Image::all();
 
// If there are videos with the same id as images they will get replaced
// You'll end up with missing videos
$allMedia = $videos->merge($images);
 
// call `toBase()` in your eloquent collection to use the base merge method instead
$allMedia = $videos->toBase()->merge($images);

Tip given by @cosmeescobedo