test: fix flaky test

Author: darrachequesne

test/util.ts

@@ -33,6 +33,9 @@ function createServerAndClient(pool: Pool) {
     }),
   });
 
+  // calling init() sends an INITIAL_HEARTBEAT message to the other nodes, so each node knows about the others
+  io.of("/").adapter.init();
+
   return new Promise<{
     io: Server;
     socket: ServerSocket;
@@ -55,6 +58,7 @@ function createServerAndClient(pool: Pool) {
 
 function isInitComplete(servers: Server[]) {
   return servers.every((server) => {
+    // @ts-expect-error nodesMap is private
     return server.of("/").adapter.nodesMap.size === servers.length - 1;
   });
 }
@@ -86,8 +90,6 @@ export async function setup() {
   const serverSockets = results.map(({ socket }) => socket);
   const clientSockets = results.map(({ clientSocket }) => clientSocket);
 
-  servers.forEach((server) => server.of("/").adapter.init());
-
   while (!isInitComplete(servers)) {
     await sleep(20);
   }