Gordon Cassie

[Performance] Always render a consistent number of elements

2

TLDR: this modification improves performance when an ember-collection is scrolled for the first time after being rendered. Forgive my loose terminology below - let me know if I am not...

Adds `replaceRangeAssumeCapacity` method. This feels like it's missing based on the other methods that are available in ArrayList. Also refactor `orderedRemove` to just call out to `replaceRange`. Happy to revert...