Concurrency and errors

Members of the Node community develop new packages and projects every day. Because of Node's evented nature, callbacks permeate these codebases. We've considered several of the key ways in which events might be queued, dispatched, and handled through the use of callbacks. Let's spend a little time outlining the best practices, in particular, about conventions for designing callbacks and handling errors, and discuss some useful patterns when designing complex chains of events and callbacks. In particular, let's look at the newPromise, Generator, and async/await patterns that you will see in this book, and other examples of modern Node code.

Managing concurrency

Simplifying control flows has been a concern of the Node community since the very beginning of the project. Indeed, this potential criticism was one of the very first anticipated by Ryan Dahl, who discussed it at length during the talk in which he introduced Node to the JavaScript developer community.

Because deferred...