var pathToSum = (node, target, sum = 0, found = false) => {
  sum += node.value;
  console.log(node.value)
  if (sum === target) {
    found = true;
  }

  if (node.left !== null && found === false) {
    found = pathToSum(node.left, target, sum, found);
  }
  if (node.right !== null && found === false) {
    found = pathToSum(node.right, target, sum, found);
  }

  // need to find way to reverse summming when node unwinds if not found, need to assign the sum to result of recursion
  if (node.left === null && node.right === null && found === false) {
    sum -= node.value;
  }

  return found;
};

// binary tree
var node1 = {
              value: 1,
              left: {
              value: 2,
              left: null,
              right: null
            },
            right: {
              value: 3,
              left: {
                value: 4,
                left: {value: -2, left: null, right: null},
                right: null
              },
              right: {
                value: 5,
                left: null,
                right: null

              }
            }
};

// tests

console.log('find 1', pathToSum(node1, 1)) // true - path= root:1
console.log('find 2', pathToSum(node1, 2)) // false
console.log('find 3', pathToSum(node1, 3)) // true - path= root:1, left:2
console.log('find 4', pathToSum(node1, 4)) // true - path= root:1, right:3
console.log('find 5', pathToSum(node1, 5)) // false - no path, but visits (1,2,3,4,-2,5)
console.log('find 6', pathToSum(node1, 6)) // true - path= root:1, right:3, left:4, left:-2
console.log('find 7', pathToSum(node1, 7)) // false - no path, but visits (1,2,3,4,-2,5)
console.log('find 8', pathToSum(node1, 8)) // false - no path, but visits (1,2,3,4,-2,5)