Binary search tree implementation in JavaScript

bst.js

var Node = function (value, left, right) {
    this.value = value;
    this.left = left;
    this.right = right;
};

function insert(root, v) {
    if (root == null) {
        root = new Node(v, null, null);
    }
    else if (v < root.value) {
        root.left = insert(root.left, v);
    }
    else {
        root.right = insert(root.right, v);
    }

    return root;
}

function traverse(root) {
    if (root == null) {
        return;
    }

    traverse(root.left);
    traverse(root.right);
}

var root = null;
const SIZE = 2000000;
var a = [];

console.log("Generating random array with " + SIZE + " values...");

console.time("generate");

for (var i = 0; i < SIZE; i++) {
    a[i] = Math.floor(Math.random() * 10000);
}

console.timeEnd("generate");
console.log();
console.log("Filling the tree with " + SIZE + " nodes...");

console.time("fill");

for (var i = 0; i < SIZE; i++) {
    root = insert(root, a[i]);
}

console.timeEnd("fill");
console.log();
console.log("Traversing all " + SIZE + " nodes in tree...");

console.time("traverse");

traverse(root);

console.timeEnd("traverse");