Functional Domain Modelling When You Only Have Classes

2.1-functional-domain-modelling.js

class PreFlightService {
	goToGate(flight) {
		if (flight instanceof Flight !== true) throw new Error('Must be a flight')
		if (flight.atGate) throw new Error('Flight is already at the gate');
		return new Flight(Object.assign({}, flight, {
			atGate: true
		}));
	}
	refuel(flight) {
		if (flight instanceof Flight !== true) throw new Error('Must be a flight')
		if (flight.refueled) throw new Error('Flight has already been refueld');
		return new Flight(Object.assign({}, flight, {
			refueled: true
		}));
	}
	restockFood(flight, food) {
		if (flight instanceof Flight !== true) throw new Error('Must be a flight')
		let instance = Object.assign({}, flight);
		instance.food.push(food);
		return new Flight(instance);
	}
	boardFlightTeamMember(flight, member) {
		let instance = Object.assign({}, flight)
		instance.team.push(member)
		return new Flight(instance)
	}
	boardPassenger(passenger) {
		let instance = Object.assign({}, flight)
		instance.passengers.push(passenger)
		return new Flight(instance)
	}
}
class Flight {
	constructor(data) {
		data = data || {};
		this.passengers = data.passengers || [];
		this.team = data.team || [];
		this.food = data.food || [];
		this.refueled = data.refueled || false;
		this.atGate = data.atGate || false;
	}
}
let service = new PreFlightService;
let flight = new Flight;
service.goToGate(flight);

3.1-domain-modelling-simple-award.js

// Not designed to work - just theoretical as it mixes languages and libraries from non-js langs

var request = {
	data: {
		attributes: {
			title: 'The Oscars',
			year: '2017'
        }
    },
	relationships: {
		schedule: {
			data: {
				nomination_start_date: '2017-05-01 00:00:00',
				nomination_end_date: '2017-05-30 23:59:59',
				voting_start_date: '2017-08-11 00:00:00',
				voting_end_date: '2017-09-11 20:00:00'
            }
        }
    }
}

var controller = (request) {
	// Pre validation of required elements
	// Pre validate - if request.relationship is set

	let award = Award.create(
		new AwardTitle(request.data.attributes.title),
		new AwardYear(request.data.attributes.year)
	);

	if (request.relationships) {
		let nominations = new NominationDates(
			Carbon.createFromFormat('Y M j h:m:s', request.relationships.schedule.data.nomination_start_date),
			Carbon.createFromFormat('Y M j h:m:s', request.relationships.schedule.data.nomination_end_date)
		);

		let votes = new NominationDates(
			Carbon.createFromFormat('Y M j h:m:s', request.relationships.schedule.data.voting_start_date),
			Carbon.createFromFormat('Y M j h:m:s', request.relationships.schedule.data.voting_end_date)
		);

		award = Award.schedule(
			award,
			nominations,
			votes
		);
    }

	award.save();

	return AwardTransformer::item(award)->toType('json');
}

4.1-marketing-example.js

console.clear();

class Page {
	constructor(name) {
  	this.name = name;
    this.created_at = new Date()
  }
}

class ABTest {
	constructor(data) {
  	if (data.pageA instanceof Page === false || data.pageB instanceof Page === false) {
			throw new Error('pageA and pageB must be an instance of Page');
		}
		if (data.testFor === '' || data.testFor === undefined) {
			throw new Error('There must be a reason for testing');
		}
		this.results = data.results || [];
		this.pageA = data.pageA;
    this.pageB = data.pageB;
		this.testFor = data.testFor;
	}

	getWinner() {
		let pageACount = this.results.filter((page) => {
			return page === this.pageA;
		}).length;
		let pageBCount = this.results.filter((page) => {
    	return page === this.pageB;
    }).length;
		return pageACount === pageBCount ? null :
			pageACount > pageBCount ? this.pageA : this.pageB;
	}
}

class Lab {
	test(abtest, winner) {
		if (winner !== abtest.pageA && winner !== abtest.pageB) {
			throw new Exception('Can not assign a page as winner if it is not within this test');
		}
		let test = Object.assign({}, abtest);
				test.results.push(winner);
		return new ABTest(test);
	}
}


let a = new Page('Red button');
let b = new Page('Green button');
let test = new ABTest({
	pageA: a,
	pageB: b,
	testFor: 'Button colors'
});
let lab = new Lab();


let loop = Math.ceil(Math.random() * 10000);

for (var i = 0; i < loop; i++) {
	let page = Math.ceil(Math.random() * 2) === 2 ? a : b;
	test = lab.test(test, page);	
}

console.log(test)
console.log(test.getWinner())

4.2-marketing-example.js

console.clear();

class Page {
	constructor(name) {
  	this.name = name;
    this.created_at = new Date()
  }
}

class ABTest {
	constructor(data) {
  	if (data.pageA instanceof Page === false || data.pageB instanceof Page === false) {
			throw new Error('pageA and pageB must be an instance of Page');
		}
		if (data.testFor === '' || data.testFor === undefined) {
			throw new Error('There must be a reason for testing');
		}
		this.results = data.results || [];
		this.pageA = data.pageA;
    this.pageB = data.pageB;
		this.testFor = data.testFor;
	}

	getWinner() {
		let pageACount = this.results.filter((page) => {
			return page === this.pageA;
		}).length;
		let pageBCount = this.results.filter((page) => {
    	return page === this.pageB;
    }).length;
		return pageACount === pageBCount ? null :
			pageACount > pageBCount ? this.pageA : this.pageB;
	}
}

class Observation {
	constructor(abTest, subject, result) {
		this.abTest = abTest;
		this.subject = subject;
		this.positiveResult = result;
	}
}

let a = new Page('Red button');
let b = new Page('Green button');
let test = new ABTest({
	pageA: a,
	pageB: b,
	testFor: 'Button colors'
});

let observations = [];


let loop = Math.ceil(Math.random() * 10000);

for (var i = 0; i < loop; i++) {
	let page = Math.ceil(Math.random() * 2) === 2 ? a : b;
	let result = Math.ceil(Math.random() * 2) === 2;
	observations.push(new Observation(test, page, result))
}

console.log(observations)
let obs = observations.filter((observation) => {
	return observation.subject === a;
})
console.log(obs.filter((ob) => {
	return ob.positiveResult
}).length / obs.length * 100 + '%');