Bugfix sort order query string in elastic search api.

The sort order was parsed using the generated from_str_name method.
The spec of this method probably changed at one point, and we ended up
requiring sort order to be uppercase.

This PR changes the behavior to follow what we do when we parse a json
string, and adds unit tests.

Closes #5491

quickwit/quickwit-serve/src/elasticsearch_api/model/search_query_params.rs

@@ -21,7 +21,6 @@ use std::fmt;
 use std::str::FromStr;
 use std::time::Duration;
 
-use quickwit_proto::search::SortOrder;
 use quickwit_query::BooleanOperand;
 use quickwit_search::SearchError;
 use serde::{Deserialize, Serialize};
@@ -232,10 +231,16 @@ pub struct DeleteQueryParams {
     pub timeout: Option<String>,
 }
 
+/// Parses a string as if it was a json value string.
+fn parse_str_like_json<T: serde::de::DeserializeOwned>(s: &str) -> Option<T> {
+    let json_value = serde_json::Value::String(s.to_string());
+    serde_json::from_value::<T>(json_value).ok()
+}
+
 // Parse a single sort field parameter from ES sort query string parameter.
 fn parse_sort_field_str(sort_field_str: &str) -> Result<SortField, SearchError> {
     if let Some((field, order_str)) = sort_field_str.split_once(':') {
-        let order = SortOrder::from_str_name(order_str).ok_or_else(|| {
+        let order = parse_str_like_json(order_str).ok_or_else(|| {
             SearchError::InvalidArgument(format!(
                 "invalid sort order `{}`. expected `asc` or `desc`",
                 field
@@ -375,3 +380,58 @@ impl fmt::Display for SuggestMode {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+
+    use quickwit_proto::search::SortOrder;
+
+    use super::*;
+
+    #[derive(Deserialize, PartialEq, Eq, Debug)]
+    #[serde(rename_all = "snake_case")]
+    enum TestEnum {
+        FirstItem,
+        SecondItem,
+    }
+
+    #[test]
+    fn test_parse_str_like_json() {
+        assert_eq!(
+            parse_str_like_json::<TestEnum>("first_item").unwrap(),
+            TestEnum::FirstItem
+        );
+        assert!(parse_str_like_json::<TestEnum>("FirstItem").is_none());
+    }
+
+    #[test]
+    fn test_sort_order_qs() {
+        let sort_order_qs = parse_sort_field_str("timestamp:DESC").unwrap();
+        assert_eq!(
+            sort_order_qs,
+            SortField {
+                field: "timestamp".to_string(),
+                order: SortOrder::Desc,
+                date_format: None
+            }
+        );
+        let sort_order_qs = parse_sort_field_str("timestamp:desc").unwrap();
+        assert_eq!(
+            sort_order_qs,
+            SortField {
+                field: "timestamp".to_string(),
+                order: SortOrder::Desc,
+                date_format: None
+            }
+        );
+        let sort_order_qs = parse_sort_field_str("timestamp:asc").unwrap();
+        assert_eq!(
+            sort_order_qs,
+            SortField {
+                field: "timestamp".to_string(),
+                order: SortOrder::Asc,
+                date_format: None
+            }
+        );
+    }
+}

quickwit/rest-api-tests/scenarii/es_compatibility/0008-sort_by.yaml

@@ -15,6 +15,21 @@ expected:
           actor:
             id: 10791502
 ---
+# Checking that passing the sort params as a query string works.
+params:
+    sort: "actor.id:desc"
+    q: "*"
+    size: 1
+expected:
+    hits:
+        total:
+            value: 100
+            relation: eq
+        hits:
+            - _source:
+                actor:
+                    id: 10791502
+---
 json:
   size: 1
   query:
@@ -113,4 +128,3 @@ expected:
       - _source:
           actor:
             id: 1762355
-