WIP: Fix IPC URL warning

Author: pimterry

src/index.ts

@@ -599,10 +599,10 @@ if (!amMainInstance) {
 const ipcHandler = <A, R>(fn: (...args: A[]) => R) => (
     event: Electron.IpcMainInvokeEvent,
     ...args: A[]
-): R => {
+): R | Promise<void> => {
     console.log('IPC call from', event.senderFrame?.url);
     if (!event.senderFrame || !hasTrustedOrigin(new URL(event.senderFrame.url))) {
-        throw new Error(`Invalid IPC sender URL: ${event.senderFrame?.url}`);
+        return Promise.reject(new Error(`Invalid IPC sender URL: ${event.senderFrame?.url}`));
     } else {
         return fn(...args);
     }