fix(cubejs-schema-compiler): Stay unchanged __user / __cubejoinfield names in aliasing (#8303)

* dont change __user / __cubejoinfield names in aliasing

* cast name to lower for `__cubeJoinField` case

* reapply fix

---------

Co-authored-by: Konstantin Burkalev <[email protected]>

Author: Nikita-str

packages/cubejs-schema-compiler/src/adapter/BaseQuery.js

@@ -3693,6 +3693,10 @@ export class BaseQuery {
     }
     // TODO: https://github.com/cube-js/cube.js/issues/4019
     // use single underscore for pre-aggregations to avoid fail of pre-aggregation name replace
+    const lowercaseName = name.toLowerCase();
+    if (lowercaseName === '__user' || lowercaseName === '__cubejoinfield') {
+      return name;
+    }
     return inflection.underscore(name).replace(/\./g, isPreAggregationName ? '_' : '__');
   }
 

rust/cubesql/cubesql/src/compile/engine/df/wrapper.rs

@@ -416,10 +416,7 @@ impl Remapper {
             LazyLock::new(|| Regex::new(r"[^a-zA-Z0-9_]").unwrap());
 
         let alias = start_from;
-        let mut truncated_alias = NON_ID_REGEX
-            .replace_all(&alias, "_")
-            .trim_start_matches("_")
-            .to_lowercase();
+        let mut truncated_alias = NON_ID_REGEX.replace_all(&alias, "_").to_lowercase();
         truncated_alias.truncate(16);
         let mut alias = truncated_alias.clone();
         for i in 1..10000 {

rust/cubesql/cubesql/src/compile/test/test_wrapper.rs

@@ -925,9 +925,9 @@ async fn test_case_wrapper_with_system_fields() {
             .wrapped_sql
             .sql
             .contains(
-                "\\\"cubeName\\\":\\\"KibanaSampleDataEcommerce\\\",\\\"alias\\\":\\\"user\\\""
+                "\\\"cubeName\\\":\\\"KibanaSampleDataEcommerce\\\",\\\"alias\\\":\\\"__user\\\""
             ),
-        r#"SQL contains `\"cubeName\":\"KibanaSampleDataEcommerce\",\"alias\":\"user\"` {}"#,
+        r#"SQL contains `\"cubeName\":\"KibanaSampleDataEcommerce\",\"alias\":\"__user\"` {}"#,
         logical_plan.find_cube_scan_wrapped_sql().wrapped_sql.sql
     );