Using new refreshSchema function to ensure watches are aware of changes made by updateSchema.

Author: Chriztiaan

demos/local-only-todolist/README.md

@@ -71,4 +71,4 @@ graph TD
 ## Limitations
 
 `updateSchema` cannot be called inside a transaction, and it's recommended to perform the schema update when the database isn't connected.
-Additionally, the current implementation of the PowerSync SDK's `watch` method may not correctly track tables that are altered by `updateSchema`. As a result, you will likely need to refresh your `watch` calls after the schema update is complete. In this demo, the `watch` calls are refreshed by navigating to the login and signup pages after the user successfully logs in and the schema update is finished.
+Additionally, the current implementation of the PowerSync SDK's `watch` method may not correctly track tables that are altered by `updateSchema`. Note that `refreshSchema` can be executed after updating the schema to resolve this (the demo uses it in `switchToSyncedSchema` which can be viewed [here](./lib/models/schema.dart)).

demos/local-only-todolist/lib/models/schema.dart

@@ -73,13 +73,16 @@ Schema makeSchema({synced = bool}) {
       Table(table.name, table.columns,
           indexes: table.indexes, viewName: onlineName(table.name)),
     for (var table in tables)
-      Table.localOnly('inactive_local_${table.name}', table.columns,
+      Table.localOnly('local_${table.name}', table.columns,
           indexes: table.indexes, viewName: localName(table.name))
   ]);
 }
 
 switchToSyncedSchema(PowerSyncDatabase db, String userId) async {
   await db.updateSchema(makeSchema(synced: true));
+
+  // needed to ensure that watches/queries are aware of the updated schema
+  await db.refreshSchema();
   await setSyncEnabled(true);
 
   await db.writeTransaction((tx) async {

demos/local-only-todolist/lib/powersync.dart

@@ -185,9 +185,6 @@ Future<void> connectDatabase() async {
 
   if (!isSyncMode) {
     await switchToSyncedSchema(db, getUserId());
-    // Without closing and reopening the database the list pages breaks if there is no data in the tables when logging in/signing up.
-    await db.close();
-    await _openDatabase();
   }
 
   currentConnector = SupabaseConnector(db);

packages/powersync/lib/src/database/native/native_powersync_database.dart

@@ -264,6 +264,11 @@ class PowerSyncDatabaseImpl
     this.schema = schema;
     return updateSchemaInIsolate(database, schema);
   }
+
+  @override
+  Future<void> refreshSchema() async {
+    await database.refreshSchema();
+  }
 }
 
 class _PowerSyncDatabaseIsolateArgs {

packages/powersync/lib/src/database/powersync_database_impl_stub.dart

@@ -118,4 +118,9 @@ class PowerSyncDatabaseImpl
       Map<String, dynamic>? params}) {
     throw UnimplementedError();
   }
+
+  @override
+  Future<void> refreshSchema() {
+    throw UnimplementedError();
+  }
 }

packages/powersync/lib/src/database/web/web_powersync_database.dart

@@ -210,4 +210,9 @@ class PowerSyncDatabaseImpl
     this.schema = schema;
     return database.writeLock((tx) => schema_logic.updateSchema(tx, schema));
   }
+
+  @override
+  Future<void> refreshSchema() {
+    return database.refreshSchema();
+  }
 }

packages/powersync/test/offline_online_test.dart

@@ -1,6 +1,7 @@
 import 'dart:convert';
 
 import 'package:powersync/powersync.dart';
+import 'package:sqlite_async/src/utils/shared_utils.dart';
 import 'package:test/test.dart';
 
 import 'utils/test_utils_impl.dart';
@@ -140,5 +141,25 @@ void main() {
             }
           ]));
     });
+
+    test('Watch correct table after switching schema', () async {
+      // Start with "offline-only" schema.
+      // This does not record any operations to the crud queue.
+      var db =
+          await testUtils.setupPowerSync(path: path, schema: makeSchema(false));
+
+      final customerWatchTables =
+          await getSourceTables(db, 'SELECT * FROM customers');
+
+      expect(
+          customerWatchTables.contains('ps_data_local__local_customers'), true);
+      await db.updateSchema(makeSchema(true));
+      await db.refreshSchema();
+
+      final onlineCustomerWatchTables =
+          await getSourceTables(db, 'SELECT * FROM customers');
+
+      expect(onlineCustomerWatchTables.contains('ps_data__customers'), true);
+    });
   });
 }