Fix: detect if iframes are already loaded. (#25)

.changeset/breezy-ads-enjoy.md

@@ -0,0 +1,5 @@
+---
+"rpc-anywhere": minor
+---
+
+Fix: detect if iframes are already loaded.

src/transports/iframe.ts

@@ -7,7 +7,11 @@ const IFRAME_MSG_KEY = "[iframe-transport]";
 const IFRAME_READY_MSG = "[iframe-transport-ready]";
 
 async function waitForLoad(element: HTMLElement) {
-  return new Promise((resolve) => element.addEventListener("load", resolve));
+  const readyState = (element as HTMLIFrameElement).contentDocument?.readyState;
+  const location = (element as HTMLIFrameElement).contentWindow?.location.href;
+  return location !== "about:blank" && readyState === "complete"
+    ? Promise.resolve()
+    : new Promise((resolve) => element.addEventListener("load", resolve));
 }
 
 async function portReadyPromise(port: MessagePort) {