Don't modify DOM elements when comparing them in deepEqual

sinonjs · Dec 30, 2010 · 083b66a · 083b66a
1 parent dc56062
commit 083b66a
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Showing 2 changed files with 18 additions and 3 deletions.
diff --git a/lib/sinon.js b/lib/sinon.js
@@ -12,14 +12,20 @@ var sinon = (function () {
     var div = typeof document != "undefined" && document.createElement("div");
 
     function isNode(obj) {
+        var success = false;
+
         try {
-            div.appendChild(obj);
-            div.removeChild(obj);
+            obj.appendChild(div);
+            success = div.parentNode == obj;
         } catch (e) {
             return false;
+        } finally {
+            try {
+                obj.removeChild(div);
+            } catch (e) {}
         }
 
-        return true;
+        return success;
     }
 
     function isElement(obj) {

diff --git a/test/sinon_test.js b/test/sinon_test.js
@@ -175,6 +175,15 @@
             assertFalse(sinon.deepEqual(this.element, el));
         },
 
+        "should not modify DOM elements when comparing them": function () {
+            /*:DOC += <div id="hey"></div> */
+            var el = document.getElementById("hey");
+            sinon.deepEqual(el, {})
+
+            assertSame(document.body, el.parentNode);
+            assertEquals(0, el.childNodes.length);
+        },
+
         "should pass deep objects": function () {
             var func = function () {};