From 523094bdc85cfa98729d2cc2d204d3bdedc649fd Mon Sep 17 00:00:00 2001
From: Alexey <peretsmobil@gmail.com>
Date: Thu, 6 Aug 2020 18:00:13 +0300
Subject: [PATCH] add comparator for indexOf

---
 package.json      |  2 +-
 src/merkleTree.js | 10 ++++++++--
 2 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index 94a03cf..cdd8ee0 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "fixed-merkle-tree",
-  "version": "0.3.1",
+  "version": "0.3.2",
   "description": "Fixed depth merkle tree implementation with sequential inserts",
   "main": "src/merkleTree.js",
   "scripts": {
diff --git a/src/merkleTree.js b/src/merkleTree.js
index c8cd4d9..e493ba2 100644
--- a/src/merkleTree.js
+++ b/src/merkleTree.js
@@ -134,10 +134,16 @@ class MerkleTree {
   /**
    * Find an element in the tree
    * @param element An element to find
+   * @param comparator A function that checks leaf value equality
    * @returns {number} Index if element is found, otherwise -1
    */
-  indexOf(element) {
-    return this._layers[0].indexOf(element)
+  indexOf(element, comparator) {
+    if (comparator) {
+      const result = this._layers[0].findIndex((el) => comparator(element, el))
+      return result === undefined ? -1 : result
+    } else {
+      return this._layers[0].indexOf(element)
+    }
   }
 
   /**