fix(@lexical/devtools): Fixed work of the $isElementNode wrapper in w…

…ebsites that rely on "babelHelpers.inheritsLoose"

packages/lexical-devtools/src/lexicalForExtension.ts

@@ -59,17 +59,25 @@ export function $getSelection(): null | lexical.BaseSelection {
 export function $isElementNode(
   node: lexical.LexicalNode | null | undefined,
 ): node is lexical.ElementNode {
+  if (node == null) {
+    return false;
+  }
+
   const editor = getActiveEditor();
-  const ElementNode = Object.getPrototypeOf(
-    editor._nodes.get('paragraph')!.klass,
-  );
+  const ParagraphNode = editor._nodes.get('paragraph')!.klass;
+  const ElementNode = Object.getPrototypeOf(ParagraphNode.prototype);
 
-  return node instanceof ElementNode;
+  // eslint-disable-next-line no-prototype-builtins
+  return ElementNode.isPrototypeOf(node);
 }
 
 export function $isTextNode(
   node: lexical.LexicalNode | null | undefined,
 ): node is lexical.TextNode {
+  if (node == null) {
+    return false;
+  }
+
   const editor = getActiveEditor();
   const TextNode = editor._nodes.get('text')!.klass;