Fixes hydra to discover presets in deeply nested dictionary

source/isaaclab_tasks/config/extension.toml

@@ -1,7 +1,7 @@
 [package]
 
 # Note: Semantic Versioning is used: https://semver.org/
-version = "1.5.11"
+version = "1.5.12"
 
 # Description
 title = "Isaac Lab Environments"

source/isaaclab_tasks/docs/CHANGELOG.rst

@@ -1,6 +1,21 @@
 Changelog
 ---------
 
+1.5.12 (2026-03-15)
+~~~~~~~~~~~~~~~~~~~
+
+Fixed
+^^^^^
+
+* Fixed :func:`~isaaclab_tasks.utils.hydra.collect_presets` not discovering
+  presets inside nested dicts (e.g. ``EventTerm.params.terms.*.params``).
+
+Added
+^^^^^
+
+* Added unit tests for the Hydra preset system.
+
+
 1.5.11 (2026-03-13)
 ~~~~~~~~~~~~~~~~~~~
 

source/isaaclab_tasks/isaaclab_tasks/utils/hydra.py

@@ -147,13 +147,21 @@ def collect_presets(cfg, path: str = "") -> dict:
             else:
                 result.update(collect_presets(value, child_path))
         elif isinstance(value, dict):
-            for dict_key, dict_val in value.items():
-                if hasattr(dict_val, "__dataclass_fields__"):
-                    result.update(collect_presets(dict_val, f"{child_path}.{dict_key}"))
+            _collect_from_dict(value, child_path, result)
 
     return result
 
 
+def _collect_from_dict(d: dict, path: str, result: dict) -> None:
+    """Recursively collect presets from dict values, including nested dicts."""
+    for dict_key, dict_val in d.items():
+        child_path = f"{path}.{dict_key}"
+        if hasattr(dict_val, "__dataclass_fields__"):
+            result.update(collect_presets(dict_val, child_path))
+        elif isinstance(dict_val, dict):
+            _collect_from_dict(dict_val, child_path, result)
+
+
 def resolve_task_config(task_name: str, agent_cfg_entry_point: str):
     """Resolve env and agent configs with Hydra overrides, presets, and scalars fully applied.
 
@@ -274,12 +282,25 @@ def resolve_preset_defaults(cfg):
         elif hasattr(value, "__dataclass_fields__"):
             resolve_preset_defaults(value)
         elif isinstance(value, dict):
-            for dict_val in value.values():
-                if hasattr(dict_val, "__dataclass_fields__"):
-                    resolve_preset_defaults(dict_val)
+            _resolve_from_dict(value)
     return cfg
 
 
+def _resolve_from_dict(d: dict) -> None:
+    """Recursively resolve preset defaults in dict values, including nested dicts."""
+    for dict_key, dict_val in d.items():
+        if isinstance(dict_val, PresetCfg) and hasattr(dict_val, "__dataclass_fields__"):
+            default = getattr(dict_val, "default", None)
+            if default is not None:
+                d[dict_key] = default
+                if hasattr(default, "__dataclass_fields__"):
+                    resolve_preset_defaults(default)
+        elif hasattr(dict_val, "__dataclass_fields__"):
+            resolve_preset_defaults(dict_val)
+        elif isinstance(dict_val, dict):
+            _resolve_from_dict(dict_val)
+
+
 def register_task(task_name: str, agent_entry: str) -> tuple:
     """Load configs, collect presets recursively, register base config to Hydra.