fix: less recursion

packages/idos-sdk-js/src/lib/enclave-providers/iframe-enclave.ts

@@ -110,15 +110,10 @@ export class IframeEnclave implements EnclaveProvider {
     }) as Promise<idOSCredential[]>;
   }
 
-  async #loadEnclave(): Promise<unknown> {
-    const container = document.querySelector(this.container);
-    const iframeElem = document.getElementById(this.iframe.id);
-
-    if (iframeElem) {
-      console.warn("An Iframe already exists in the container");
-      container?.removeChild(iframeElem);
-      return new Promise((resolve) => this.#loadEnclave().then(resolve));
-    }
+  async #loadEnclave(): Promise<void> {
+    const container =
+      document.querySelector(this.container) ||
+      throwNew(Error, `Can't find container with selector ${this.container}`);
 
     // https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Permissions-Policy#directives
     const permissionsPolicies = ["publickey-credentials-get", "storage-access"];
@@ -152,11 +147,15 @@ export class IframeEnclave implements EnclaveProvider {
       this.iframe.style.setProperty(k, v);
     }
 
-    if (!container) throw new Error(`Can't find container with selector ${this.container}`);
-
-    container.appendChild(this.iframe);
+    // This was the best way we found at the time to check if we had already
+    // added the element to the tree.
+    if (!document.getElementById(this.iframe.id)) {
+      container.appendChild(this.iframe);
+    }
 
-    return new Promise((resolve) => this.iframe.addEventListener("load", () => resolve()));
+    return new Promise((resolve) =>
+      this.iframe.addEventListener("load", () => resolve(), { once: true }),
+    );
   }
 
   #showEnclave() {
@@ -240,3 +239,7 @@ export class IframeEnclave implements EnclaveProvider {
     };
   }
 }
+
+function throwNew(ErrorClass: ErrorConstructor, ...args: Parameters<ErrorConstructor>): never {
+  throw new ErrorClass(...args);
+}