Summary

Structural design patterns are definitely some of the most widely adopted design patterns in software engineering and it is important to be confident with them. In this chapter, we explored the Proxy, the Decorator, and the Adapter patterns and we discussed different ways to implement these in the context of Node.js.

We saw how the Proxy pattern can be a very valuable tool to control access to existing objects. In this chapter, we also mentioned how the Proxy pattern can enable different programming paradigms such as reactive programming using the Change Observer pattern.

In the second part of the chapter, we found out that the Decorator pattern is an invaluable tool to be able to add additional functionality to existing objects. We saw that its implementation doesn't differ much from the Proxy pattern and we explored some examples built around the LevelDB ecosystem.

Finally, we discussed the Adapter pattern, which allows us to wrap an existing object...