fix: replace bare assert with runtime checks in engine, index, and export

dm_control/mjcf/export_with_assets.py

@@ -51,7 +51,9 @@ def export_with_assets(mjcf_model, out_dir, out_file_name=None,
                      '\'.xml\': got {}'.format(out_file_name))
   assets = mjcf_model.get_assets()
   # This should never happen because `mjcf` does not support `.xml` assets.
-  assert out_file_name not in assets
+  if out_file_name in assets:
+    raise RuntimeError(
+        f"Output filename '{out_file_name}' conflicts with an existing asset")
   assets[out_file_name] = mjcf_model.to_xml_string(
       precision=precision, zero_threshold=zero_threshold)
   if not os.path.exists(out_dir):

dm_control/mujoco/engine.py

@@ -972,19 +972,23 @@ def select(self, cursor_position):
 
     # Validate IDs
     if body_id != -1:
-      assert 0 <= body_id < self._physics.model.nbody
+      if not (0 <= body_id < self._physics.model.nbody):
+        raise ValueError(f"body_id {body_id} out of range [0, {self._physics.model.nbody})")
     else:
       body_id = None
     if geom_id != -1:
-      assert 0 <= geom_id < self._physics.model.ngeom
+      if not (0 <= geom_id < self._physics.model.ngeom):
+        raise ValueError(f"geom_id {geom_id} out of range [0, {self._physics.model.ngeom})")
     else:
       geom_id = None
     if flex_id != -1:
-      assert 0 <= flex_id < self._physics.model.nflex
+      if not (0 <= flex_id < self._physics.model.nflex):
+        raise ValueError(f"flex_id {flex_id} out of range [0, {self._physics.model.nflex})")
     else:
       flex_id = None
     if skin_id != -1:
-      assert 0 <= skin_id < self._physics.model.nskin
+      if not (0 <= skin_id < self._physics.model.nskin):
+        raise ValueError(f"skin_id {skin_id} out of range [0, {self._physics.model.nskin})")
     else:
       skin_id = None
 

dm_control/mujoco/index.py

@@ -230,7 +230,10 @@ def _get_size_name_to_element_names(model):
     body_mocapid = model.body_mocapid[body_id]
     if body_mocapid != -1:
       mocap_body_names[body_mocapid] = body_name
-  assert None not in mocap_body_names
+  if None in mocap_body_names:
+    raise RuntimeError(
+        "Failed to resolve all mocap body names; some body_mocapid mappings "
+        "are missing")
   size_name_to_element_names['nmocap'] = mocap_body_names
 
   return size_name_to_element_names