fix(native): Handle null correctly as JsNull, not as JsString (cube-js#9717)

Fixing an unexpected issue with treating null as a null string. I figured out this issue while benchmarking the cache store queue. Previously, it could lead to an issue in the production environment while someone moves between cube store versions or has an error while updating the queue_item's extra field.

Author: ovr

packages/cubejs-backend-native/src/orchestrator.rs

@@ -2,7 +2,8 @@ use crate::node_obj_deserializer::JsValueDeserializer;
 use crate::transport::MapCubeErrExt;
 use cubeorchestrator::query_message_parser::QueryResult;
 use cubeorchestrator::query_result_transform::{
-    DBResponsePrimitive, RequestResultData, RequestResultDataMulti, TransformedData,
+    DBResponsePrimitive, DBResponseValue, RequestResultData, RequestResultDataMulti,
+    TransformedData,
 };
 use cubeorchestrator::transport::{JsRawData, TransformDataRequest};
 use cubesql::compile::engine::df::scan::{FieldValue, ValueObject};
@@ -258,7 +259,12 @@ pub fn get_cubestore_result(mut cx: FunctionContext) -> JsResult<JsValue> {
                 let js_row = JsObject::new(&mut cx);
                 for (key, value) in result.columns.iter().zip(row.iter()) {
                     let js_key = cx.string(key);
-                    let js_value = cx.string(value.to_string());
+                    let js_value: Handle<'_, JsValue> = match value {
+                        DBResponseValue::Primitive(DBResponsePrimitive::Null) => cx.null().upcast(),
+                        // For compatibility, we convert all primitives to strings
+                        other => cx.string(other.to_string()).upcast(),
+                    };
+
                     js_row.set(&mut cx, js_key, js_value)?;
                 }
                 Ok(js_row)