Nicolás Bevacqua, author of JavaScript Application Design: A Build First approach (2015) (amazon.com; goodreads.com) has started on his first book in the “Modular JS” series: Practical ES6 - A Practical Dive into ES6 and Maintainable JavaScript Modules (github; O’Reilly Early Release)
Further planned entries are:
- Mastering Modular JavaScript
- Universal JavaScript Modules Everywhere
- Testing JavaScript Modules
- Deploying modern JavaScript Apps