Drift: Support nested transactions

Author: simolus3

packages/drift_sqlite_async/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 0.2.3
+
+- Support nested transactions.
+
 ## 0.2.2
 
 - Fix write detection when using UPDATE/INSERT/DELETE with RETURNING in raw queries.

packages/drift_sqlite_async/lib/src/executor.dart

@@ -129,13 +129,28 @@ class _SqliteAsyncTransactionDelegate extends SupportedTransactionDelegate {
 
   _SqliteAsyncTransactionDelegate(this._db);
 
+  @override
+  FutureOr<void> Function(QueryDelegate, Future<void> Function(QueryDelegate))?
+      get startNested => _startNested;
+
   @override
   Future<void> startTransaction(Future Function(QueryDelegate p1) run) async {
-    await _db.writeTransaction((context) async {
+    await _startTransaction(_db, run);
+  }
+
+  Future<void> _startTransaction(
+      SqliteWriteContext context, Future Function(QueryDelegate p1) run) async {
+    await context.writeTransaction((context) async {
       final delegate = _SqliteAsyncQueryDelegate(context, null);
       return run(delegate);
     });
   }
+
+  Future<void> _startNested(
+      QueryDelegate outer, Future<void> Function(QueryDelegate) block) async {
+    await _startTransaction(
+        (outer as _SqliteAsyncQueryDelegate)._context, block);
+  }
 }
 
 class _SqliteAsyncVersionDelegate extends DynamicVersionDelegate {

packages/drift_sqlite_async/pubspec.yaml

@@ -1,5 +1,5 @@
 name: drift_sqlite_async
-version: 0.2.2
+version: 0.2.3
 homepage: https://github.com/powersync-ja/sqlite_async.dart
 repository: https://github.com/powersync-ja/sqlite_async.dart
 description: Use Drift with a sqlite_async database, allowing both to be used in the same application.
@@ -14,12 +14,12 @@ topics:
 environment:
   sdk: ">=3.0.0 <4.0.0"
 dependencies:
-  drift: ">=2.19.0 <3.0.0"
+  drift: ">=2.28.0 <3.0.0"
   sqlite_async: ^0.11.0
 
 dev_dependencies:
   build_runner: ^2.4.8
-  drift_dev: ">=2.19.0 <3.0.0"
+  drift_dev: ">=2.28.0 <3.0.0"
   glob: ^2.1.2
   lints: ^5.0.0
   sqlite3: ^2.4.0

packages/drift_sqlite_async/test/db_test.dart

@@ -117,5 +117,35 @@ void main() {
       final deleted = await dbu.delete(dbu.todoItems).go();
       expect(deleted, 10);
     });
+
+    test('nested transactions', () async {
+      await dbu
+          .into(dbu.todoItems)
+          .insert(TodoItemsCompanion.insert(description: 'root'));
+
+      await dbu.transaction(() async {
+        await dbu
+            .into(dbu.todoItems)
+            .insert(TodoItemsCompanion.insert(description: 'tx0'));
+
+        await dbu.transaction(() async {
+          await dbu
+              .into(dbu.todoItems)
+              .insert(TodoItemsCompanion.insert(description: 'tx1'));
+
+          await expectLater(() {
+            return dbu.transaction(() async {
+              await dbu
+                  .into(dbu.todoItems)
+                  .insert(TodoItemsCompanion.insert(description: 'tx2'));
+              throw 'rollback';
+            });
+          }, throwsA(anything));
+        });
+      });
+
+      final items = await dbu.todoItems.all().get();
+      expect(items.map((e) => e.description).toSet(), {'root', 'tx0', 'tx1'});
+    });
   });
 }