Here's a quick way of telling if the pizza you enjoy has actual toppings in it. Chances are it doesn't and you're too scared to try anything that tastes anything even slightly different to what you normally eat.

You Enjoy Shitty Pizzas.md

class Pizza {
    constructor(ingredients) {
        this.ingredients = ingredients;
    }
    // is this thing in the pizza a topping?
    isTopping(topping){
        let newPizza = new Pizza(this.ingredients);
        let index = newPizza.ingredients.indexOf(topping);
        if (index === -1)
            throw new Error(`${this.constructor.name} does not have ${topping} as an ingredient`);
        newPizza.ingredients.splice(index, 1);
        return newPizza.isPizza()
    }

    isPizza() {
        return this._contains(['dough', 'sauce', 'cheese'])
    }

    _contains(things){
        let found = 0;
        for (let x of things){
            for(let i of this.ingredients){
                if (x === i){
                    found++;
                }
            }
        }
        return found === things.length;
    }
}

let margarita = new Pizza(["dough", "cheese", "sauce"]);
console.log(margarita.isPizza()); // true
console.log(margarita.isTopping('cheese')); // false

let capricciosa = new Pizza(["dough", "cheese", "sauce", "ham", "olives", "mushrooms"]);
console.log(capricciosa.isPizza()); // true
console.log(capricciosa.isTopping("ham")); // true

let grilledCheese = new Pizza(["dough", "cheese"]);
console.log(grilledCheese.isPizza()); // false
console.log(grilledCheese.isTopping('cheese')); // false