here’s a link to the gist <https://gist.github.com...

# codereview

[smilecs]

here’s a link to the gist https://gist.github.com/smilecs/c4e5f880fb8feb30eefebf5a45714c8f

[kingsley]

So many nullability going on in there. I believe you can slim fit a couple of them

For example, if carts were indeed loaded, then onKartLoaded shouldn’t take a nullable parameter.
If you are sure an item will be in a map, you can consider map.getValue(key), which returns a non-null result, instead of using map[key]

Indeed, I would move most of this logic to the presenter, and only callback the view with an already processed List<X>
You could consider the no-arg plugin to avoid unnecessary defaults in class declaration
I suppose you could replace amount = amount.plus(someValue) with amount += someValue
onKartLoaded definitely should be broken into smaller independent functions if possible
And finally, you just might be able to take more advantage of functional operations on those collections to make everything look much cleaner

[dave08]

You could try taking a look at this: https://medium.com/google-developers/viewmodels-and-livedata-patterns-antipatterns-21efaef74a54 @smilecs

[smilecs]

alright, will do so now