Phased Middleware

A middleware system based around installable/uninstallable plugins running through a series of phases

With many middlware systems (such as the express module's built in one), it's up to the developer to assemble the various pieces of middleware in order. Phased Middleware is a generally useful alternative for assembling code pipelines that features:

• Named, in orer 'phases' of the pipeline, as for example seen in Maven's build pipeline.
• Middleware that can install/uninstall itself into the pipeline in known places.
• Can manage multiple simultaenous pipelines that plugins install into.
• Can return a step by step iterator, or a run-everything-now executor.

Usage

import PhasedMiddleware from "phased-middleware"
const pipeline = new PhasedMiddleware({
	pipelines: {
		day: ["rise", "shine"],
		night: ["retire", "rest"]
	}
})
class Meals{
	get phases(){
		return {
			day: {
				rise: this.breakfast,
				shine: this.lunch
			},
			night: {
				retire: this.dinner
			}
		}
	}
	breakfast({ value}){
		console.log("breakfast")
		value.energy += 3
	}
	lunch({ value} ){
		console.log("lunch")
		value.energy += 3
	}
	dinner({ value}){
		console.log("dinner")
		value.energy += 4
	}
}
class Activity{
	constructor( intensity){
		this.intensity= intensity|| 20
	}
	swim({ input, middleware}){
		console.log("swim")
		input.energy -= middleware.intensity
	}
	sleep({ input, setValue}){
		console.log("sleep")
		input.energy += 10
		setValue( input)
	}
}
Activity.prototype.sleep.phase = {pipeline: "night", phase: "retire"}
Activity.prototype.swim.phase = [{pipeline: "day", phase: "rise"}]

// install our middleware
phasedMiddleware.install(new Meals())
phasedMiddleware.install(new Activity())

// run our pipelines
const person= { energy: 10}
phasedMiddleware.pipeline.day( person) //=> "breakfast" "swim" "lunch"
console.log( person.energy) //=> -4
phasedMiddleware.pipeline.night( person) //=> "dinner" "sleep"
console.log(person.energy) //=> 10