fix async closing

Author: stevensJourney

.changeset/loud-mangos-kick.md

@@ -0,0 +1,6 @@
+---
+'@powersync/common': patch
+'@powersync/web': patch
+---
+
+Fixed race condition in async closing of databases

packages/common/src/client/AbstractPowerSyncDatabase.ts

@@ -515,7 +515,7 @@ export abstract class AbstractPowerSyncDatabase extends BaseObserver<PowerSyncDB
     }
 
     await this.syncStreamImplementation?.dispose();
-    this.database.close();
+    await this.database.close();
     this.closed = true;
   }
 

packages/common/src/db/DBAdapter.ts

@@ -93,7 +93,7 @@ export interface DBLockOptions {
 }
 
 export interface DBAdapter extends BaseObserverInterface<DBAdapterListener>, DBGetUtils {
-  close: () => void;
+  close: () => void | Promise<void>;
   execute: (query: string, params?: any[]) => Promise<QueryResult>;
   executeBatch: (query: string, params?: any[][]) => Promise<QueryResult>;
   name: string;

packages/web/src/db/adapters/LockedAsyncDatabaseAdapter.ts

@@ -147,9 +147,9 @@ export class LockedAsyncDatabaseAdapter
    * Shared workers might not actually close the connection if other
    * tabs are still using it.
    */
-  close() {
+  async close() {
     this._disposeTableChangeListener?.();
-    this.baseDB?.close?.();
+    await this.baseDB?.close?.();
   }
 
   async getAll<T>(sql: string, parameters?: any[] | undefined): Promise<T[]> {