diff --git a/bin/jscoverage b/bin/jscoverage
index a1ceaf3..71171e1 100755
--- a/bin/jscoverage
+++ b/bin/jscoverage
@@ -30,9 +30,8 @@ if (!dest) {
 }
 
 if (exclude) {
-  exclude = exclude.split(',');
-  exclude.forEach(function (v, i, a) {
-    a[i] = new RegExp(v.replace(/\./, '\\.').replace(/\*/g, '.*'));
+  exclude = exclude.split(',').map(function (v) {
+    return new RegExp(v.replace(/\./, '\\.').replace(/\*/g, '.*'));
   });
 }
 try {
@@ -40,30 +39,7 @@ try {
   if (sourceStat.isFile()) {
     jscoverage.processFile(source, dest);
   } else {
-    var count = 0;
-    fs.walk(source, function (err, file, done) {
-      if (err) {
-        console.log(err);
-        return done;
-      }
-      var flag = false;
-      if (exclude) {
-        exclude.forEach(function (v) {
-          if (v.test(file)) {
-            flag = true;
-          }
-        });
-      }
-      count ++;
-      var destFile = path.join(dest, file.substr(source.length));
-      if (flag) {
-        // copy exclude file
-        fs.save(destFile, fs.readFileSync(file));
-      } else {
-        jscoverage.processFile(file, destFile);
-      }
-      done();
-    }, function (err) {
+    jscoverage.processDir(source, dest, {exclude: exclude}, function(err, count) {
       if (err) {
         return console.log(err);
       }
diff --git a/index.js b/index.js
index 3333cd8..46915fc 100755
--- a/index.js
+++ b/index.js
@@ -165,11 +165,13 @@ exports.process = jscoverage.process;
  * @sync
  * @param  {Path} source  absolute Path
  * @param  {Path} dest    absolute Path
- * @param  {Object} option  [description]
  */
-exports.processFile = function (source, dest, option) {
+exports.processFile = function (source, dest, callback) {
+  callback = callback || function(){}
+
   var content;
   var stats;
+
   // test source is file or dir, or not a file
   try {
     stats = fs.statSync(source);
@@ -203,13 +205,58 @@ exports.processFile = function (source, dest, option) {
       filename: source
     });
   }
-  content = this.process(source, content);
+  content = exports.process(source, content);
   if (sheBang) {
     content = sheBang + content;
   }
   fs.writeFileSync(dest, content);
+
+  callback()
 };
 
+/**
+ * processDir, instrument directory
+ * @sync
+ * @param  {Path} source  absolute Path
+ * @param  {Path} dest    absolute Path
+ * @param  {Object} option  [description]
+ */
+exports.processDir = function (source, dest, option, callback) {
+  if(option instanceof Function) {
+    callback = option
+    option = null
+  }
+
+  var count = 0;
+  var exclude = option && option.exclude;
+
+  fs.walk(source, function (err, file, done) {
+    if (err) {
+      return done(err);
+    }
+
+    var flag = false;
+    if (exclude) {
+      for(var v in exclude)
+        if (v.test(file)) {
+          flag = true;
+          break;
+        }
+    }
+    count++;
+    var destFile = path.join(dest, file.substr(source.length));
+    if (flag) {
+      // copy exclude file
+      fs.save(destFile, fs.readFileSync(file));
+      done();
+    } else {
+      exports.processFile(file, destFile, done);
+    }
+  }, function(err) {
+    callback(err, count)
+  });
+}
+
 function fixData(num) {
   return Math.round(num * 10000) / 10000;
 }
diff --git a/package.json b/package.json
index b989bc2..4ad44fa 100644
--- a/package.json
+++ b/package.json
@@ -7,17 +7,17 @@
     "jscoverage": "./bin/jscoverage"
   },
   "scripts": {
-    "test": "./node_modules/mocha/bin/_mocha -t 60000 -r ./index.js -R spec --covinject true test/"
+    "test": "_mocha -t 60000 -r ./index.js -R spec --covinject true test/"
   },
   "engines": {
     "node" : ">=0.8"
   },
   "dependencies" : {
-    "uglify-js" : "2.4.15",
-    "optimist" : "0.3.1",
+    "uglify-js": "2.7.0",
+    "optimist": "0.6.1",
     "xfs" : "0.1.8",
-    "ejs": "1.0.0",
-    "debug": "1.0.3",
+    "ejs": "2.5.1",
+    "debug": "2.2.0",
     "coffee-script": "*"
   },
   "devDependencies" : {