One skill that s essential for any professional JavaScript developer is the ability to write testable code. This book shows you what writing and maintaining testable JavaScript for the client- or server-side actually entails, whether you re creating a new application or rewriting legacy code.

From methods to reduce code complexity to unit testing, code coverage, debugging, and automation, you ll learn a holistic approach for writing JavaScript code that you and your colleagues can easily fix and maintain going forward. Testing JavaScript code is complicated. This book helps...