component-example.js

// Basic entity-component closure
function Component(api) {
  return function(entity) {
    for(var key in api) {
      if (api.hasOwnProperty(key)) {
        entity[key] = api[key];
      }
    }
  }
}

var MeleeComponent = Component({
  attack: function() {
    console.log('melee'); 
  }
});

var FireComponent = Component({
  fire: function() {
    console.log('fireball');
  }
})

var entity = {};
MeleeComponent(entity); // entity now has entity.attack()
FireComponent(entity); // entity now has entity.fire()

// test
entity.attack();
entity.fire();