Merge pull request #39 from powersync-ja/fix-reverting-deletes

Fix reverting failed deletes

Author: rkistner

packages/powersync/lib/src/schema_logic.dart

@@ -53,6 +53,15 @@ FOR EACH ROW
 BEGIN
   DELETE FROM $internalNameE WHERE id = OLD.id;
   INSERT INTO ps_crud(tx_id, data) SELECT current_tx, json_object('op', 'DELETE', 'type', ${quoteString(type)}, 'id', OLD.id) FROM ps_tx WHERE id = 1;
+  INSERT INTO ps_oplog(bucket, op_id, op, row_type, row_id, hash, superseded)
+    SELECT '\$local',
+           1,
+           'REMOVE',
+           ${quoteString(type)},
+           OLD.id,
+           0,
+           0;
+  INSERT OR REPLACE INTO ps_buckets(name, pending_delete, last_op, target_op) VALUES('\$local', 1, 0, $maxOpId);
 END""",
     """
 CREATE TRIGGER ${quoteIdentifier('ps_view_insert_$viewName')}

packages/powersync/test/bucket_storage_test.dart

@@ -674,5 +674,118 @@ void main() {
             {'description': 'server updated'}
           ]));
     });
+
+    test('should revert a failing update', () async {
+      await bucketStorage.saveSyncData(SyncDataBatch([
+        SyncBucketData(
+          bucket: 'bucket1',
+          data: [putAsset1_1, putAsset2_2, putAsset1_3],
+        ),
+      ]));
+
+      await syncLocalChecked(Checkpoint(
+          lastOpId: '3',
+          writeCheckpoint: '3',
+          checksums: [BucketChecksum(bucket: 'bucket1', checksum: 6)]));
+
+      // Local save
+      db.execute('INSERT INTO assets(id, description) VALUES(?, ?)',
+          ['O3', 'inserted']);
+      final batch = bucketStorage.getCrudBatch();
+      await batch!.complete();
+      await bucketStorage.updateLocalTarget(() async {
+        return '4';
+      });
+
+      expect(
+          db.select('SELECT description FROM assets WHERE id = \'O3\''),
+          equals([
+            {'description': 'inserted'}
+          ]));
+
+      await syncLocalChecked(Checkpoint(
+          lastOpId: '3',
+          writeCheckpoint: '4',
+          checksums: [BucketChecksum(bucket: 'bucket1', checksum: 6)]));
+
+      expect(db.select('SELECT description FROM assets WHERE id = \'O3\''),
+          equals([]));
+    });
+
+    test('should revert a failing delete', () async {
+      await bucketStorage.saveSyncData(SyncDataBatch([
+        SyncBucketData(
+          bucket: 'bucket1',
+          data: [putAsset1_1, putAsset2_2, putAsset1_3],
+        ),
+      ]));
+
+      await syncLocalChecked(Checkpoint(
+          lastOpId: '3',
+          writeCheckpoint: '3',
+          checksums: [BucketChecksum(bucket: 'bucket1', checksum: 6)]));
+
+      // Local save
+      db.execute('DELETE FROM assets WHERE id = ?', ['O2']);
+
+      expect(db.select('SELECT description FROM assets WHERE id = \'O2\''),
+          equals([]));
+      // Simulate a permissions error when uploading - data should be preserved.
+      final batch = bucketStorage.getCrudBatch();
+      await batch!.complete();
+
+      await bucketStorage.updateLocalTarget(() async {
+        return '4';
+      });
+
+      await syncLocalChecked(Checkpoint(
+          lastOpId: '3',
+          writeCheckpoint: '4',
+          checksums: [BucketChecksum(bucket: 'bucket1', checksum: 6)]));
+
+      expect(
+          db.select('SELECT description FROM assets WHERE id = \'O2\''),
+          equals([
+            {'description': 'bar'}
+          ]));
+    });
+
+    test('should revert a failing insert', () async {
+      await bucketStorage.saveSyncData(SyncDataBatch([
+        SyncBucketData(
+          bucket: 'bucket1',
+          data: [putAsset1_1, putAsset2_2, putAsset1_3],
+        ),
+      ]));
+
+      await syncLocalChecked(Checkpoint(
+          lastOpId: '3',
+          writeCheckpoint: '3',
+          checksums: [BucketChecksum(bucket: 'bucket1', checksum: 6)]));
+
+      // Local save
+      db.execute('DELETE FROM assets WHERE id = ?', ['O2']);
+
+      expect(db.select('SELECT description FROM assets WHERE id = \'O2\''),
+          equals([]));
+      // Simulate a permissions error when uploading - data should be preserved.
+      final batch = bucketStorage.getCrudBatch();
+      await batch!.complete();
+
+      await bucketStorage.updateLocalTarget(() async {
+        return '4';
+      });
+
+      await syncLocalChecked(Checkpoint(
+          lastOpId: '3',
+          writeCheckpoint: '4',
+          checksums: [BucketChecksum(bucket: 'bucket1', checksum: 6)]));
+
+      expect(
+          db.select('SELECT description FROM assets WHERE id = \'O2\''),
+          equals([
+            {'description': 'bar'}
+          ]));
+    });
   });
 }