method_missing.js

// This will only work in environments that support ES6 Proxies.
// As of right now, that's pretty much only Firefox.

function Refrigerator(foods) {

  this.foods = foods;

  return new Proxy(this, {
    get: function (receiver, name) {
      if (name in receiver) {
        return receiver[name];
      } else if (name.match(/^findBy(.+)$/)) {
        return receiver.find.bind(receiver, name.match(/^findBy(.+)$/)[1].toLowerCase()); 
      }
    }
  });
}

Refrigerator.prototype.find = function (attribute, query) {
  return this.foods.filter(function (food) {
    return food[attribute] === query;
  });
};

var cucumber = { name: "cucumber", type: "veggie", tastiness: 5 };
var bacon = { name: "bacon", type: "meat", tastiness: 10 };
var celery = { name: "celery", type: "veggie", tastiness: 3 };

var fridge = new Refrigerator([cucumber, bacon, celery]);

console.assert(fridge.foods.length === 3, 'FAILED: Properties should pass through');
console.assert(!fridge.garbage, 'FAILED: Garbage properties should return undefined');
console.assert(fridge.find('name', 'cucumber')[0].name === 'cucumber', 'FAILED: Regular finder');
console.assert(fridge.findByName('cucumber')[0].name === 'cucumber', 'FAILED: Proxy finder');