SebastianHGonzalez

function loggerAspect(joinPoint, logger) {
    return (...args) => {
        logger.log("logging");
        return joinPoint(...args);
    }
}

function add(a, b) {
    return a + b;
}

SebastianHGonzalez

function loggerAspect(joinPoint, logger) {
        return function (...args) {
                logger.log("logging");
                return joinPoint.apply(this, args)
        }
}

const psyduck = {
	sound: "PSYDUCK!",
	cuack: function() {return this.sound}

SebastianHGonzalez

function loggerAspect(joinPoint, logger) {
        return function (...args) {
                logger.log("logging");
                return joinPoint.apply(this, args)
        }
}

class Person {
        constructor(name) {
                this.name = name

SebastianHGonzalez

function aspect(joinPoint, { before, around, after }) {
    return function (...args) {
        before && before(this, joinPoint.name, ...args);
        const result = around ? around(this, joinPoint, ...args) : joinPoint.apply(this, args);
        after && after(this, joinPoint.name, result, ...args);
        return result;
    }
}

function loggerAspect(joinPoint, logger) {

SebastianHGonzalez

function timeAspect(joinPoint, logger) {
    const timer = {
        start: function () { this.startTime = Date.now() },
        stop: function () { this.stopTime = Date.now() },
        time: function () { return this.stopTime - this.startTime }
    };

    function before() { timer.start() }
    function after() { timer.stop(), logger.log(timer.time) }
    return aspect(joinPoint, { before, after })

SebastianHGonzalez

function greet() {
    return "Hello " + this.name ;
}

const john = {
    name: "John"
}

const jane = {
    name: "Jane"

SebastianHGonzalez

const personGreetingPC = new PointCut({class: Person, methodName: "greet"});

jhon.greet();
// <- "Hello jhon"

personGreetingPC.addAspect(loggerAspect);

jhon.greet();
// logging
// <- "Hello jhon"

SebastianHGonzalez

class PointCut {
    constructor(definition) {
        this.inject(definition);
    }

    inject(definition) {
        this.injectAspectToObjectMethods(definition.class.prototype);
    }

    injectAspectToObjectMethods(prototype) {

SebastianHGonzalez

function timeAspect(joinPoint, logger) {
    const aspect = {
      logger,
      timer: {
        start: function () { this.startTime = Date.now() },
        stop: function () { this.stopTime = Date.now() },
        time: function () { return this.stopTime - this.startTime }
      },
      before: function () { this.timer.start() },

SebastianHGonzalez

class LoggerAspect {

  constructor(logger) {
    this.logger = logger;
  }
  
  before(context, joinPointName, ...args) {
    this.logger.log("logging");
  }
}