Rhax
Rhax is a Typescript-first library for simple and elegant data transformations.
It was created with the "casual" Typescript functional programmer in mind, and aims to provide the advantages of functional programming, without requiring the programmer to surrender the entire codebase to the paradigm's constraints, restrictive methods, and ocean of jargon.
However, even if you don't use Typescript, or don't know what Functional Programming is, RHax can still be of use for you!
It is lightweight, easy to pick up, and simple to introduce to new as well as existing projects.
Installation
npm install rhax
# or
yarn add rhax
The idea
Functional programming (FP) is a progamming paradigm founded on the ideas of immutability, function purity, and others. It has become increasingly popular over the past few years, and its benefits shine in a variety of applications. Most popular modern languages (JS/TS included) have FP capabilities, and you, like most developers of those languages, are probably already using FP to some degree, perhaps without realizing it. If you're interested in diving into FP, I recommend Professor Frisby's Mostly Adequate Guide to Functional Programming, but there are many other good resources.
However, the world of FP has many deep concepts - some rooted in abstract mathematics, some shrouded in FP terminology - and "true" functional programming requires a good understanding of most of those, as well as a commitment to the paradigm that's difficult to "break out" of when needed. This combination of a steep learning curve and a binding commitment is off-putting for many developers (myself included). Rhax was created with this slice of developers in mind - it aspires to provide a simple way for Javascript developers, new and seasoned, to enjoy the benefits of FP, without having to climb or move mountains.
FP and types
Another point is that FP - and its concepts of declarability and function purity in particular - deal extremely well with type systems. It can make a big difference in developer experience and in quality (elegance, brevity and maintainability). This is mostly true for Typescript developers, but can also assist plain Javascript developers through the intellisense features of modern IDEs.