This package will provide you a function checkBST which will validate whether your Binary tree is a Valid Binary Search Tree or not. Make Your Binary tree and import this package and check whether it is valid Binary search tree or not.

Usage

Make your binary tree

class Node{
    constructor(val,left=null,right=null){
        this.val = val;
        this.left = left;
        this.right = right;
    }
}
let root = new Node(5);
root.left = new Node(1);
root.right = new Node(7);
root.right.left = new Node(6);
root.right.right = new Node(9);

Import the package in your file

const validate = require('validate-bst');

Run the checkBST function and give root node as parameter.

console.log(validate.checkBST(root)); //true