refactor(useNodesInit): check for handleBounds, false for no nodes

packages/core/src/hooks/useNodesInitialized.ts

@@ -1,7 +1,14 @@
 import { ReactFlowState } from '../types';
+import { internalsSymbol } from '../utils';
 import { useStore } from './useStore';
 
-const selector = (s: ReactFlowState) => Array.from(s.nodeInternals.values()).every((n) => n.width && n.height);
+const selector = (s: ReactFlowState) => {
+  if (s.nodeInternals.size === 0) {
+    return false;
+  }
+
+  return Array.from(s.nodeInternals.values()).every((n) => n[internalsSymbol]?.handleBounds !== undefined);
+};
 
 function useNodesInitialized(): boolean {
   const initialized = useStore(selector);