fix(query_range): skip data field on errors (#5520)

* fix: skip serializing PrometheusResponse when None

* fix: fix unit test

* chore: clippy

src/servers/src/http/prometheus.rs

@@ -95,7 +95,7 @@ pub struct PromData {
     pub result: PromQueryResult,
 }
 
-#[derive(Debug, Serialize, Deserialize, PartialEq)]
+#[derive(Debug, Default, Serialize, Deserialize, PartialEq)]
 #[serde(untagged)]
 pub enum PrometheusResponse {
     PromData(PromData),
@@ -106,6 +106,8 @@ pub enum PrometheusResponse {
     BuildInfo(OwnedBuildInfo),
     #[serde(skip_deserializing)]
     ParseResult(promql_parser::parser::Expr),
+    #[default]
+    None,
 }
 
 impl PrometheusResponse {
@@ -144,11 +146,9 @@ impl PrometheusResponse {
             }
         }
     }
-}
 
-impl Default for PrometheusResponse {
-    fn default() -> Self {
-        PrometheusResponse::PromData(Default::default())
+    pub fn is_none(&self) -> bool {
+        matches!(self, PrometheusResponse::None)
     }
 }
 

src/servers/src/http/result/prometheus_resp.rs

@@ -42,6 +42,8 @@ use crate::http::prometheus::{
 #[derive(Debug, Default, Serialize, Deserialize, PartialEq)]
 pub struct PrometheusJsonResponse {
     pub status: String,
+    #[serde(skip_serializing_if = "PrometheusResponse::is_none")]
+    #[serde(default)]
     pub data: PrometheusResponse,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub error: Option<String>,
@@ -90,7 +92,7 @@ impl PrometheusJsonResponse {
     {
         PrometheusJsonResponse {
             status: "error".to_string(),
-            data: PrometheusResponse::default(),
+            data: PrometheusResponse::None,
             error: Some(reason.into()),
             error_type: Some(error_type.to_string()),
             warnings: None,

tests-integration/tests/http.rs

@@ -766,7 +766,7 @@ pub async fn test_prom_http_api(store_type: StorageType) {
         .await;
     assert_eq!(res.status(), StatusCode::BAD_REQUEST);
     let data = res.text().await;
-    let expected = "{\"status\":\"error\",\"data\":{\"resultType\":\"\",\"result\":[]},\"error\":\"invalid promql query\",\"errorType\":\"InvalidArguments\"}";
+    let expected = "{\"status\":\"error\",\"error\":\"invalid promql query\",\"errorType\":\"InvalidArguments\"}";
     assert_eq!(expected, data);
 
     // range_query with __name__ not-equal matcher