Add PowerSyncDatabase.getClientId().

Author: rkistner

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

@@ -287,6 +287,13 @@ mixin PowerSyncDatabaseMixin implements SqliteConnection {
     return database.isolateConnectionFactory();
   }
 
+  /// Get an unique id for this client.
+  /// This id is only reset when the database is deleted.
+  Future<String> getClientId() async {
+    final row = await get('SELECT powersync_client_id() as client_id');
+    return row['client_id'] as String;
+  }
+
   /// Get upload queue size estimate and count.
   Future<UploadQueueStats> getUploadQueueStats(
       {bool includeSize = false}) async {

packages/powersync/test/powersync_shared_test.dart

@@ -1,5 +1,7 @@
 import 'package:sqlite_async/mutex.dart';
 import 'package:test/test.dart';
+import 'package:uuid/parsing.dart';
+import 'package:uuid/v4.dart';
 import 'utils/test_utils_impl.dart';
 
 final testUtils = TestUtils();
@@ -79,5 +81,13 @@ void main() {
       await db.execute('PRAGMA wal_checkpoint(TRUNCATE)');
       await db.execute('VACUUM');
     });
+
+    test('should have a client id', () async {
+      final db = await testUtils.setupPowerSync(path: path);
+
+      final id = await db.getClientId();
+      // Check that it is a valid uuid
+      final _uuid = UuidParsing.parseAsByteList(id);
+    });
   });
 }