From a23f07269d68f603f4f71d33a493b2ab7ab4d78f Mon Sep 17 00:00:00 2001
From: ddukstas <dominykas.dukstas@gmail.com>
Date: Fri, 6 Mar 2015 14:25:11 +0200
Subject: [PATCH] added new param to specify folders which will be excluded
 from calculation of checksum of root directory

---
 lib/dirsum.js | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/lib/dirsum.js b/lib/dirsum.js
index 33e98dd..2ed1f07 100644
--- a/lib/dirsum.js
+++ b/lib/dirsum.js
@@ -24,16 +24,24 @@ function _summarize(method, hashes) {
   return obj;
 }
 
-function digest(root, method, callback) {
+function digest(root, method, exclude, callback) {
   if (!root || typeof(root) !== 'string') {
     throw new TypeError('root is required (string)');
   }
+
   if (method) {
     if (typeof(method) === 'string') {
       // NO-OP
+      if(typeof(exclude) === 'function') {
+        callback = exclude;
+        exclude = [];
+      }else if(typeof(exclude) !== 'object'){
+        throw new TypeError('exclude must be an object');
+      }
     } else if (typeof(method) === 'function') {
       callback = method;
       method = 'md5';
+      exclude = [];
     } else {
       throw new TypeError('hash must be a string');
     }
@@ -49,12 +57,20 @@ function digest(root, method, callback) {
   fs.readdir(root, function(err, files) {
     if (err) return callback(err);
 
+    exclude.forEach(function(folder){
+        var index = files.indexOf(folder);
+        if(index != -1){
+            files.splice(index, 1);
+        }
+    });
+    
     if (files.length === 0) {
       return callback(undefined, {hash: '', files: {}});
     }
-
+    
     var hashed = 0;
     files.forEach(function(f) {
+
       var path = root + '/' + f;
       fs.stat(path, function(err, stats) {
         if (err) return callback(err);