apollo_config: update config map by pointers skip optional values

Author: itamar-starkware

crates/apollo_config/src/dumping.rs

@@ -86,6 +86,37 @@ pub fn generate_struct_pointer<T: SerializeConfig>(
     res
 }
 
+/// Generates pointers for an optional struct:
+/// - All fields under `target_prefix` (using `default_instance.dump()`), pointed to by each prefix
+///   in `pointer_prefixes`.
+/// - The optional flag `<target_prefix>.#is_none`, pointed to by `<prefix>.#is_none` for each
+///   prefix in `pointer_prefixes`.
+pub fn generate_optional_struct_pointer<T: SerializeConfig>(
+    target_prefix: ParamPath,
+    default_instance: &T,
+    pointer_prefixes: HashSet<ParamPath>,
+    is_none_default: bool,
+    is_none_description: &str,
+) -> ConfigPointers {
+    let mut res =
+        generate_struct_pointer(target_prefix.clone(), default_instance, pointer_prefixes.clone());
+
+    // Add a pointer target and pointing params for the optional flag.
+    let target_is_none_param = format!("{target_prefix}{FIELD_SEPARATOR}{IS_NONE_MARK}");
+    let pointer_target = ser_pointer_target_param(
+        target_is_none_param.as_str(),
+        &is_none_default,
+        is_none_description,
+    );
+    let pointing_params: Pointers = pointer_prefixes
+        .into_iter()
+        .map(|prefix| format!("{prefix}{FIELD_SEPARATOR}{IS_NONE_MARK}"))
+        .collect();
+    res.push((pointer_target, pointing_params));
+
+    res
+}
+
 // Converts a serialized param to a pointer target.
 fn serialized_param_to_pointer_target(
     target_prefix: ParamPath,

crates/apollo_config/src/loading.rs

@@ -204,6 +204,26 @@ pub(crate) fn update_config_map_by_pointers(
     pointers_map: &BTreeMap<ParamPath, ParamPath>,
 ) -> Result<(), ConfigError> {
     for (param_path, target_param_path) in pointers_map {
+        // 1) Resolve flags first: these populate "<prefix>.#is_none" into the config_map.
+        if param_path.ends_with(&format!("{FIELD_SEPARATOR}{IS_NONE_MARK}")) {
+            let Some(target_value) = config_map.get(target_param_path) else {
+                return Err(ConfigError::PointerTargetNotFound {
+                    target_param: target_param_path.to_owned(),
+                });
+            };
+            config_map.insert(param_path.to_owned(), target_value.clone());
+            continue;
+        }
+
+        // 2) If the optional prefix is already marked as disabled, skip resolving nested pointers.
+        if let Some((prefix, _)) = param_path.rsplit_once('.') {
+            if config_map.get(&format!("{prefix}{FIELD_SEPARATOR}{IS_NONE_MARK}"))
+                == Some(&json!(true))
+            {
+                continue;
+            }
+        }
+
         let Some(target_value) = config_map.get(target_param_path) else {
             return Err(ConfigError::PointerTargetNotFound {
                 target_param: target_param_path.to_owned(),