Object Oriented API (OOP)

[hinell]

fastify/lib/route.js

Lines 55 to 62 in f4a8f36

	function buildRouting (options) {
	const router = FindMyWay(options.config)
	let avvio
	let fourOhFour
	let requestIdLogLabel
	let logger
	let hasLogger

Why fastify doesn't stick to OOP concept by providing basic class for Route? Why don't you extend FindMyWay and export it?

Other libraries like Hapi and ExpressJS provide their basic classes that can be extended and reused.

I wish your API be more extensible. I also would like to override basic classes and provide them to Fastify so I don't use wrappers in controlling handlers:

// app.js

class MyResponse extends fastify.Response { ... }
class MyRouter extends fastify.Router { ... }

fastify.context.Response = MyResponse
fastify.context.Router = MyRouter

...

[jsumners]

Fastify uses factory functions to build new instances by extending the core prototypes with the provided options. This is a common OOP pattern, particularly in prototypal JavaScript. It is central to how Fastify provides the speed benefits it promises.

[hinell]

Well factory assumes that class is given to it to produce instances. This is not the case as you invoke FindMyWay from a module scope, which is not good.

This way it breaks ability to compose & inherit classes.

Assuming I can inherit from FindMyWay, how does one passes new subclass to the buildRouting(...) factory ?

[metcoder95]

Do you have a special use case in which FindMayWay needs to be altered, and it's not covered by fastify?
What @jsumners describes is the chore of Fastify, and the decorators fulfills in most cases the need to extend the core "classes" of the framework without compromising performance.

[hinell]

I don't need it be altered. I want to extend it. This is a huge difference. I would like to extend router at least and provide it to the fastify as a dependency replacing built-in one.

Decorators aren't the good way to go. Too many projects trying to play-around inheritance and break dependency-injection. This is a non-starter really.

[mcollina]

Thanks for letting us know your opinion. I’m glad that there are plenty of other frameworks to choose from. Hapi is great!