Wait for the created room to come down sync before placing a group call

src/matrix-utils.ts

@@ -8,6 +8,7 @@ import { MemoryCryptoStore } from "matrix-js-sdk/src/crypto/store/memory-crypto-
 import { createClient, MatrixClient } from "matrix-js-sdk/src/matrix";
 import { ICreateClientOpts } from "matrix-js-sdk/src/matrix";
 import { ClientEvent } from "matrix-js-sdk/src/client";
+import { Room } from "matrix-js-sdk/src/models/room";
 import { Visibility, Preset } from "matrix-js-sdk/src/@types/partials";
 import {
   GroupCallIntent,
@@ -226,6 +227,23 @@ export async function createRoom(
   name: string,
   isPtt = false
 ): Promise<string> {
+  let setExpectedRoomId: (roomId: string) => void;
+  const expectedRoomId = new Promise<string>(
+    (resolve) => (setExpectedRoomId = resolve)
+  );
+
+  // There's no telling whether the new room will come down sync in the middle
+  // of the createRoom request, or after it, so start watching for it beforehand
+  const roomReceived = new Promise<void>((resolve) => {
+    const onRoom = async (room: Room) => {
+      if (room.roomId === (await expectedRoomId)) {
+        resolve();
+        client.off(ClientEvent.Room, onRoom);
+      }
+    };
+    client.on(ClientEvent.Room, onRoom);
+  });
+
   const createRoomResult = await client.createRoom({
     visibility: Visibility.Private,
     preset: Preset.PublicChat,
@@ -256,6 +274,10 @@ export async function createRoom(
     },
   });
 
+  // Wait for the room to come down sync before doing anything with it
+  setExpectedRoomId(createRoomResult.room_id);
+  await roomReceived;
+
   console.log(`Creating ${isPtt ? "PTT" : "video"} group call room`);
 
   await client.createGroupCall(