Introduction

In this chapter, we’ll explore some of the most popular structural design patterns and discover how they apply to Node.js. Structural design patterns are focused on providing ways to realize relationships between entities.

In particular, we’ll examine the following patterns:

• Proxy: A pattern that allows us to control access to another object.

• Decorator: A common pattern that allows us to augment the behavior of an existing object dynamically.

• Adapter: A pattern that allows us to access the functionality of an object using a different interface.

We’ll also explore some interesting concepts such as reactive programming (RP), and we’ll also spend some time playing with LevelDB, a database technology that is commonly adopted in the Node.js ecosystem.

By the end of this chapter, we’ll be familiar with several scenarios in which structural design patterns can be useful and we’ll be able to implement them effectively in our Node.js applications.