Send partial checkpoint in sync test

Author: simolus3

packages/powersync_core/lib/src/sync/protocol.dart

@@ -136,12 +136,7 @@ final class Checkpoint extends StreamingSyncLine {
       'write_checkpoint': writeCheckpoint,
       'buckets': checksums
           .where((c) => priority == null || c.priority <= priority)
-          .map((c) => {
-                'bucket': c.bucket,
-                'checksum': c.checksum,
-                'priority': c.priority,
-                'count': c.count,
-              })
+          .map((c) => c.toJson())
           .toList(growable: false)
     };
   }
@@ -172,6 +167,15 @@ class BucketChecksum {
         checksum = json['checksum'] as int,
         count = json['count'] as int?,
         lastOpId = json['last_op_id'] as String?;
+
+  Map<String, Object?> toJson() {
+    return {
+      'bucket': bucket,
+      'checksum': checksum,
+      'priority': priority,
+      'count': count,
+    };
+  }
 }
 
 /// A variant of [Checkpoint] that may be sent when the server has already sent

packages/powersync_core/lib/src/sync/streaming_sync.dart

@@ -367,7 +367,6 @@ class StreamingSyncImplementation implements StreamingSync {
             throw PowerSyncProtocolException(
                 'Checkpoint diff without previous checkpoint');
           }
-          _state.updateStatus((s) => s.downloading = true);
           final diff = line;
           final Map<String, BucketChecksum> newBuckets = {};
           for (var checksum in targetCheckpoint.checksums) {
@@ -385,6 +384,9 @@ class StreamingSyncImplementation implements StreamingSync {
               checksums: [...newBuckets.values],
               writeCheckpoint: diff.writeCheckpoint);
           targetCheckpoint = newCheckpoint;
+          final initialProgress = await adapter.getBucketOperationProgress();
+          _state.updateStatus(
+              (s) => s.applyCheckpointStarted(initialProgress, newCheckpoint));
 
           bucketMap = newBuckets.map((name, checksum) =>
               MapEntry(name, (name: name, priority: checksum.priority)));

packages/powersync_core/lib/src/sync/sync_status.dart

@@ -335,7 +335,7 @@ typedef ProgressWithOperations = ({
   double fraction,
 });
 
-/// Provides realtime progress about how PowerSync is downloading rows.
+/// Provides realtime progress on how PowerSync is downloading rows.
 ///
 /// The reported progress always reflects the status towards the end of a
 /// sync iteration (after which a consistent snapshot of all buckets is

packages/powersync_core/test/in_memory_sync_test.dart

@@ -418,10 +418,11 @@ void main() {
 
         // Emit new data, progress should be 0/2 instead of 10/12
         syncService.addLine({
-          'checkpoint': Checkpoint(
-            lastOpId: '12',
-            checksums: [bucket('a', 12)],
-          )
+          'checkpoint_diff': {
+            'last_op_id': '12',
+            'updated_buckets': [bucket('a', 12)],
+            'removed_buckets': const <Object?>[],
+          },
         });
         await expectProgress(status, total: progress(0, 2));
         addDataLine('a', 2);