ES6 classes without a class keyword but with class variable

README.md

noclass

Here is an example of ES6 classes without a class keyword but with class variables. Looks the same as classes and has the same structure internally.

Example

// class
var Foo = {
  classVariable: true,

  // constructor
  [$constructor](who){
    this.me = who;
    this.species = 'fufel';
  },

  // methods
  identify(){
    return 'I am ' + this.me;
  }
}

// class extends Foo
var Bar = $extends(Foo, {

  // constructor
  [$constructor](who){
    $super(Foo, this, who);
    this.subtype = 'barashek';
  },

  // methods
  speak(){
    console.log('Hello, ' + this.identify());
  },
  bark(num){
    console.log('Woof');
  }
});

Multiple "inheritance"

// class
var Foo = {
  classVariable: true,

  // constructor
  [$constructor](who){
    this.me = who;
    this.species = 'fufel';
  },

  // methods
  identify(){
    return 'I am ' + this.me;
  }
}

var Logger = {
  logEnabled: true,
  log(){
    if(logEnabled){
      console.log('Log saved.');
    } else {
      throw Error('Log disabled');
    }
  },
  startLogging(num){
    this.logEnabled = true;
  },
  stopLogging(num){
    this.logEnabled = false;
  },
}

var Tester = {
  test(){
    if(this.speak){
      console.log('Can speak.');
    }
  }
}

// class extends Foo
var Bar = $extends([Foo, Tester, Logger], {

  // constructor
  [$constructor](who){
    $super(this, who);
    this.subtype = 'barashek';
  },

  // methods
  speak(){
    console.log('Hello, ' + this.identify());
  },
  bark(num){
    console.log('Woof');
  }
});

example.js

// Helper
const $constructor = Symbol();
const $extends = (parents, child) => {
  if(Array.isArray(parents) && parents.length){
    parents.reduce((proto, parent) => {
      Object.setPrototypeOf(proto, parent);
      return parent;
    });
    parents = parents[0];
  }
  return Object.assign(Object.create(parents), child);
}
const $new = (object, ...args) => {
  let instance = Object.create(object);
  instance[$constructor].call(instance, ...args);
  return instance;
}
const $super = (context, ...args) => {
  Object.getPrototypeOf(
    Object.getPrototypeOf(context)
  )[$constructor].call(context, ...args);
}

// class
var Foo = {
  classVariable: true,

  // constructor
  [$constructor](who){
    this.me = who;
    this.species = 'fufel';
  },

  // methods
  identify(){
    return 'I am ' + this.me;
  }
}

var Logger = {
  logEnabled: true,
  log(){
    if(logEnabled){
      console.log('Log saved.');
    } else {
      throw Error('Log disabled');
    }
  },
  startLogging(num){
    this.logEnabled = true;
  },
  stopLogging(num){
    this.logEnabled = false;
  },
}

var Tester = {
  test(){
    if(this.speak){
      console.log('Can speak.');
    }
  }
}

// class extends Foo
var Bar = $extends([Foo, Tester, Logger], {

  // constructor
  [$constructor](who){
    $super(this, who);
    this.subtype = 'barashek';
  },

  // methods
  speak(){
    console.log('Hello, ' + this.identify());
  },
  bark(num){
    console.log('Woof');
  }
});

var a1 = $new(Foo, 'a1');
var b1 = $new(Bar, 'b1');
console.log(a1, b1);
console.log('b1.classVariable', b1.classVariable);

noclass.js

const $constructor = Symbol();

function $extends(parents, child){
  if(Array.isArray(parents) && parents.length){
    parents.reduce((proto, parent) => {
      Object.setPrototypeOf(proto, parent);
      return parent;
    });
    parents = parents[0];
  }
  return Object.assign(Object.create(parents), child);
}

function $new(object, ...args){
  let instance = Object.create(object);
  instance[$constructor].call(instance, ...args);
  return instance;
}

function $super(context, ...args){
  Object.getPrototypeOf(
    Object.getPrototypeOf(context))
      [$constructor].call(context, ...args);
}

export {$new, $extends, $constructor, $super};