From e7aa74715ae8db9d47431add47f1c9729b2cb115 Mon Sep 17 00:00:00 2001
From: Jeremy Tice <jetpacmonkey@gmail.com>
Date: Mon, 30 Oct 2017 20:24:55 -0400
Subject: [PATCH] fix: improve global object and DOM detection

Fixes #91
---
 index.js | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/index.js b/index.js
index 1c5406e..406dca2 100644
--- a/index.js
+++ b/index.js
@@ -6,8 +6,20 @@
  * MIT Licensed
  */
 var promiseExists = typeof Promise === 'function';
-var globalObject = typeof window !== 'undefined' ? window : typeof global !== 'undefined' ? global : self; // eslint-disable-line
-var isDom = 'location' in globalObject && 'document' in globalObject;
+
+/* eslint-disable no-undef */
+var globalObject = typeof self === 'object' ? self : global; // eslint-disable-line id-blacklist
+
+/*
+ * All of these attributes must be available on the global object for the current environment
+ * to be considered a DOM environment (browser)
+ */
+var isDom = typeof window === 'object' &&
+  'document' in window &&
+  'navigator' in window &&
+  'HTMLElement' in window;
+/* eslint-enable */
+
 var symbolExists = typeof Symbol !== 'undefined';
 var mapExists = typeof Map !== 'undefined';
 var setExists = typeof Set !== 'undefined';
@@ -160,7 +172,7 @@ module.exports = function typeDetect(obj) {
      * Test: `Object.prototype.toString.call(document.createElement('blockquote'))``
      *  - IE <=10 === "[object HTMLBlockElement]"
      */
-    if (obj instanceof HTMLElement && obj.tagName === 'BLOCKQUOTE') {
+    if (obj instanceof globalObject.HTMLElement && obj.tagName === 'BLOCKQUOTE') {
       return 'HTMLQuoteElement';
     }
 
@@ -176,7 +188,7 @@ module.exports = function typeDetect(obj) {
      *  - Firefox === "[object HTMLTableCellElement]"
      *  - Safari === "[object HTMLTableCellElement]"
      */
-    if (obj instanceof HTMLElement && obj.tagName === 'TD') {
+    if (obj instanceof globalObject.HTMLElement && obj.tagName === 'TD') {
       return 'HTMLTableDataCellElement';
     }
 
@@ -192,7 +204,7 @@ module.exports = function typeDetect(obj) {
      *  - Firefox === "[object HTMLTableCellElement]"
      *  - Safari === "[object HTMLTableCellElement]"
      */
-    if (obj instanceof HTMLElement && obj.tagName === 'TH') {
+    if (obj instanceof globalObject.HTMLElement && obj.tagName === 'TH') {
       return 'HTMLTableHeaderCellElement';
     }
   }