copy should return length

diff --git a/index.js b/index.js
index 98c8b871d81ae454d5932ea7b354bf147de5773e..5321a25e6a0e2570541282682cbf23d655b7bb09 100644 (file)
--- a/index.js
+++ b/index.js
@@ -868,6 +868,8 @@ Buffer.prototype.copy = function(target, target_start, start, end) {
   } else {
     target._set(this.subarray(start, start + len), target_start)
   }
+
+  return len
 }
 
 // fill(value, start=0, end=buffer.length)