Как реализовать бинарное дерево в Javascript

let nodes = [1,2,4,-1,-1,5,-1,-1,3,-1,6,-1,-1];

var idx = -1;
class Node {
    constructor(data){
        this.data = data;
        this.left = null;
        this.right = null;
    }
}

class BinaryTree{
    
    buildTree(nodes){
        idx++;
       
        if(nodes[idx] == -1){
            return null;
        }
        
        let newNode = new Node(nodes[idx]);
      newNode.left =  this.buildTree(nodes);
      newNode.right = this.buildTree(nodes);
       
       return newNode;
    }
}

const nodesdata = new Node();
const tree = new BinaryTree();
 const root =  tree.buildTree(nodes);

console.log(root.data);