Javascript based dominoes

dominoes-before-bros.js

var Node = function(a, b) {
  this.data = {a: a, b: b };
  this.parent = undefined;
  this.children = [];

  return this;
};

Node.prototype.isSpinner = function() {
  return this.data.a === this.data.b;
};

Node.prototype.score = function() {
  if (this.isSpinner() && this.children.length < 2) {
    return (this.data.a + this.data.b);
  }

  if (this.children.length === 0) {
    return (this.parent.data.b == this.data.b) ? this.data.a : this.data.b;
  }

  return 0;
};

Node.prototype.add = function(a, b) {
  var child = new Node(a, b);
  this.children.push(child);
  child.parent = this;

  return child;
};

Node.prototype.traverse = function(done) {
  (function recurse(curr) {
     for (var i = 0, length = curr.children.length; i < length; i++) {
       recurse(curr.children[i]);
     }

     done(curr);
  }(this));
};

var spinner = new Node(6, 6);
var node    = spinner.add(6, 3);
//    node    = node.add(3, 5);
//    node    = spinner.add(6, 0);
//    node    = node.add(0, 3);
//    node    = spinner.add(6, 5);
//    node    = spinner.add(6, 2);

var scores = [];

spinner.traverse(function(n) {
  scores.push(n.score());
});

var sum = function(vals) {
  result =  vals.reduce(function(acc, val) {
    return acc + val;
  });

  return (result % 5 === 0) ? result : 0;
};

console.log(sum(scores));