Move into class

web/apps/cast/src/pages/index.tsx

@@ -6,7 +6,7 @@ import { useRouter } from "next/router";
 import { useEffect, useState } from "react";
 import { advertiseCode, getCastData, register } from "services/pair";
 import { storeCastData } from "services/render";
-import { castReceiverLoadingIfNeeded } from "../utils/cast-receiver";
+import { castReceiverLoadingIfNeeded } from "../services/cast-receiver";
 
 export default function Index() {
     const [publicKeyB64, setPublicKeyB64] = useState<string | undefined>();

web/apps/cast/src/services/cast-receiver.tsx

@@ -2,8 +2,22 @@
 
 export type Cast = typeof cast;
 
-let _cast: Cast | undefined;
-let _loader: Promise<Cast> | undefined;
+/**
+ * A holder for the "cast" global object exposed by the Chromecast SDK,
+ * alongwith auxiliary state we need around it.
+ */
+class CastReceiver {
+    /**
+     * A reference to the `cast` global object that the Chromecast Web Receiver
+     * SDK attaches to the window.
+     *
+     * https://developers.google.com/cast/docs/web_receiver/basic
+     */
+    cast: Cast | undefined;
+    loader: Promise<Cast> | undefined;
+}
+
+const castReceiver = new CastReceiver();
 
 /**
  * Load the Chromecast Web Receiver SDK and return a reference to the `cast`
@@ -15,18 +29,18 @@ let _loader: Promise<Cast> | undefined;
  * https://developers.google.com/cast/docs/web_receiver/basic
  */
 export const castReceiverLoadingIfNeeded = async (): Promise<Cast> => {
-    if (_cast) return _cast;
-    if (_loader) return await _loader;
+    if (castReceiver.cast) return castReceiver.cast;
+    if (castReceiver.loader) return await castReceiver.loader;
 
-    _loader = new Promise((resolve) => {
+    castReceiver.loader = new Promise((resolve) => {
         const script = document.createElement("script");
         script.src =
             "https://www.gstatic.com/cast/sdk/libs/caf_receiver/v3/cast_receiver_framework.js";
 
+        castReceiver.cast = cast;
         script.addEventListener("load", () => resolve(cast));
         document.body.appendChild(script);
     });
-    const c = await _loader;
-    _cast = c;
-    return c;
+
+    return await castReceiver.loader;
 };

web/apps/cast/src/services/pair.ts

@@ -3,7 +3,7 @@ import { boxSealOpen, toB64 } from "@ente/shared/crypto/internal/libsodium";
 import castGateway from "@ente/shared/network/cast";
 import { wait } from "@ente/shared/utils";
 import _sodium from "libsodium-wrappers";
-import { type Cast } from "../utils/cast-receiver";
+import { type Cast } from "./cast-receiver";
 
 export interface Registration {
     /** A pairing code shown on the screen. A client can use this to connect. */