Return if a tree is balanced, difference is not greater than 1 in javascript

TreeIsBalanced.js

// Return Node info
function getNodeHeightBalanced(tree) {
	if (tree === null) return { isBalanced: true, height: -1}
	
	const leftTreeInfo = getNodeHeightBalanced(tree.left)
	const rightTreeInfo = getNodeHeightBalanced(tree.right)

	const isBalanced = (
		// Both left and right sub-tree should be balanced
		(leftTreeInfo.isBalanced && rightTreeInfo.isBalanced) &&
		// Difference should not be longer than 1
		Math.abs(leftTreeInfo.height - rightTreeInfo.height) < 2
	)
	const currentHeight = Math.max(leftTreeInfo.height, rightTreeInfo.height) + 1
  return ({ isBalanced, height: currentHeight })
}

function heightBalancedBinaryTree(tree) {
  // Write your code here.
  return getNodeHeightBalanced(tree).isBalanced;
}