idb-bridge: avoid unhandled rejection when closing DB

packages/idb-bridge/src/MemoryBackend.ts

@@ -562,10 +562,12 @@ export class MemoryBackend implements Backend {
       throw Error("connection not found - already closed?");
     }
     const myDb = this.databases[myConn.dbName];
+    if (myDb) {
       // FIXME: what if we're still in a transaction?
       myDb.connectionCookies = myDb.connectionCookies.filter(
         (x) => x != conn.connectionCookie,
       );
+    }
     delete this.connections[conn.connectionCookie];
     this.disconnectCond.trigger();
   }

packages/idb-bridge/src/bridge-idb.ts

@@ -2655,13 +2655,13 @@ export class BridgeIDBTransaction
         }
       }
 
-      await waitMacroQueue();
-
       if (!request._source) {
         // Special requests like indexes that just need to run some code,
         // with error handling already built into operation
         await operation();
       } else {
+        await waitMacroQueue();
+
         let event;
         try {
           BridgeIDBFactory.enableTracing &&