fix: Flush pending inserts in streamingbatchwriter on delete records

writers/streamingbatchwriter/streamingbatchwriter.go

@@ -154,6 +154,31 @@
 	return nil // not checked below
 }
 
+func (w *StreamingBatchWriter) flushInsertWorkers(ctx context.Context) error {
+	w.workersLock.RLock()
+	workers := make([]*streamingWorkerManager[*message.WriteInsert], 0, len(w.insertWorkers))
+	for _, worker := range w.insertWorkers {
+		workers = append(workers, worker)
+	}
+	w.workersLock.RUnlock()
+
+	for _, worker := range workers {
+		done := make(chan bool)
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case worker.flush <- done:
+		}
+		select {
+		case <-ctx.Done():
+			return ctx.Err()
+		case <-done:
+		}
+	}
+	return nil
+}
+
+
 func (w *StreamingBatchWriter) Close(context.Context) error {
 	w.workersLock.Lock()
 	defer w.workersLock.Unlock()
@@ -323,6 +348,10 @@
 
 		return nil
 	case *message.WriteDeleteRecord:
+		// flush pending inserts and table buffers before deletions
+		if err := w.flushInsertWorkers(ctx); err != nil {
+			return err
+		}
 		w.workersLock.Lock()
 		defer w.workersLock.Unlock()
 
@@ -331,7 +360,6 @@
 			return nil
 		}
 
-		// TODO: flush all workers for nested tables as well (See https://github.com/cloudquery/plugin-sdk/issues/1296)
 		w.deleteRecordWorker = &streamingWorkerManager[*message.WriteDeleteRecord]{
 			ch:        make(chan *message.WriteDeleteRecord),
 			writeFunc: w.client.DeleteRecords,
@@ -516,3 +544,6 @@
 		}
 	}
 }
+
+
+

writers/streamingbatchwriter/streamingbatchwriter_test.go

@@ -624,3 +624,61 @@
 	}
 	return -1
 }
+
+func TestDeleteRecordFlushesPendingInserts(t *testing.T) {
+	t.Parallel()
+
+	ctx := context.Background()
+	errCh := make(chan error, 10)
+
+	testClient := newClient()
+	wr, err := New(testClient, WithBatchSizeRows(1000000)) // large batch to avoid auto-flush
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Create a table for insert
+	insertTable := &schema.Table{
+		Name: "child_table",
+		Columns: []schema.Column{
+			{
+				Name: "id",
+				Type: arrow.PrimitiveTypes.Int64,
+			},
+		},
+	}
+
+	// Build insert record
+	bldr := array.NewRecordBuilder(memory.DefaultAllocator, insertTable.ToArrowSchema())
+	bldr.Field(0).(*array.Int64Builder).Append(1)
+	record := bldr.NewRecord()
+
+	md := arrow.NewMetadata(
+		[]string{schema.MetadataTableName},
+		[]string{insertTable.Name},
+	)
+	newSchema := arrow.NewSchema(
+		record.Schema().Fields(),
+		&md,
+	)
+
+	record = array.NewRecord(newSchema, record.Columns(), record.NumRows())
+
+	// Send insert 
+	if err := wr.startWorker(ctx, errCh, &message.WriteInsert{Record: record}); err != nil {
+		t.Fatal(err)
+	}
+
+	// send delete record to trigger flush
+	del := &message.WriteDeleteRecord{
+		DeleteRecord: message.DeleteRecord{
+			TableName: insertTable.Name,
+		},
+	}
+
+	if err := wr.startWorker(ctx, errCh, del); err != nil {
+		t.Fatal(err)
+	}
+	waitForLength(t, testClient.MessageLen, messageTypeInsert, 1)
+	_ = wr.Close(ctx)
+}