Wrapping functions

In this section, let's consider some higher-order functions that provide a wrapper around other function, to enhance it in some way, but without altering its original objective. In terms of design patterns (which we'll be revisiting in Chapter 11, Implementing Design Patterns - The Functional Way), we could also speak of decorators. This pattern is based on the concept of adding some behavior to an object (in our case, a function) without affecting other objects. The term decorator is also popular because of its usage in frameworks such as Angular, or (in an experimental mode) for general programming in JS.

Note

Decorators are being considered for general adoption in JS, but are currently (August 2017) at Stage 2, Draft level, and it may be a while until they get to Stage 3 (Candidate) and finally Stage 4 (Finished, meaning officially adopted). You can read more about decorators for JS at https://tc39.github.io/proposal-decorators/ and about the JS adoption process itself...