Currently reading Functional Light JS by Kyle Simpson. You can read this for free online https://github.com/getify/Functional-Light-JS or buy the ebook from Leanpub.
This book explores the core principles of functional programming (FP) as they are applied to JavaScript. But what makes this book different is that we approach these principles without drowning in all the heavy terminology. We look at a subset of FP foundational concepts that I call “Functional-Light Programming” (FLP) and apply it to JavaScript.