Author: Mark Daggett
Reviewer: Ian Elliot
Chapter 3 deals with closures despite the fact that they have been used since the start of the book without a single mention. Again we have a look at the scope problem and the way ECMAScript 6 provides block context, but this time the main target is the this keyword. If the idea of an execution context had been explained earlier, or even at all, then this would not seems so mysterious.
Finally the chapter ends with what you might use closures for. It mentions binding proxies and context for DOM manipulation. It doesn’t mention the most common use for a closure – to create private variables – and it doesn’t mention the standard pattern of using closures to provide event handlers and callbacks with additional data without changing their parameter signature.
From here we return to more conventional topics. Chapter 7 is about style with a list of dos and don’ts. Chapter 8 covers workflow, build tools and unit testing. Chapter 9 is about code quality – metrics and so on. The final chapter is on testability and how to improve it.
jQuery Promises, Deferred WebWorkers