class-utils
Utils for working with JavaScript classes and prototype methods.
static-extend
Adds a static `extend` method to a class, to simplify inheritance. Extends the static properties, prototype properties, and descriptors from a `Parent` constructor onto `Child` constructors.
hoopy
Like an array, but rounder.
jest-sorted
Inspired by chai sorted and jest-extended. This packages extends jest.expect with 2 custom matchers, `toBeSorted` and `toBeSortedBy`