Merge pull request GoogleChromeLabs#55 from rontav/feature/firefox-fix

Fix: expected node to have parent

Author: devknoll

src/engine.ts

@@ -187,6 +187,13 @@ export function initializePolyfill() {
         instance?.disconnect();
       }
 
+      if (
+        entry.target.nodeType !== Node.DOCUMENT_NODE &&
+        entry.target.nodeType !== Node.DOCUMENT_FRAGMENT_NODE &&
+        entry.target.parentNode === null
+      ) {
+        continue;
+      }
       if (
         entry.type === 'attributes' &&
         entry.attributeName &&