From cb459d937a314390295dcf87adabf45010ad9aca Mon Sep 17 00:00:00 2001
From: doowb <brian.woodward@gmail.com>
Date: Sun, 10 Sep 2017 18:58:12 -0400
Subject: [PATCH] add implementation for null and undefined values

---
 index.js | 16 ++++++++++++++--
 1 file changed, 14 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index 621340f..91e23ca 100644
--- a/index.js
+++ b/index.js
@@ -91,11 +91,23 @@ function compare(prop, a, b) {
 
 /**
  * Default compare function used as a fallback
- * for sorting.
+ * for sorting. Built-in array sorting pushes
+ * null and undefined values to the end of the array.
  */
 
 function defaultCompare(a, b) {
-  return a < b ? -1 : (a > b ? 1 : 0);
+  var typeA = typeOf(a);
+  var typeB = typeOf(b);
+
+  if (typeA === 'null') {
+    return typeB === 'null' ? 0 : (typeB === 'undefined' ? -1 : 1);
+  } else if (typeA === 'undefined') {
+    return typeB === 'null' ? 1 : (typeB === 'undefined' ? 0 : 1);
+  } else if (typeB === 'null' || typeB === 'undefined') {
+    return -1;
+  } else {
+    return a < b ? -1 : (a > b ? 1 : 0);
+  }
 }
 
 /**