module level attribute and add tests

mujoco_playground/_src/dm_control_suite/__init__.py

@@ -101,7 +101,10 @@
 }
 
 
-ALL = list(_envs.keys())
+def __getattr__(name):
+  if name == 'ALL':
+    return list(_envs.keys())
+  raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
 
 
 def register_environment(
@@ -118,8 +121,6 @@ def register_environment(
   """
   _envs[env_name] = env_class
   _cfgs[env_name] = cfg_class
-  if env_name not in ALL:
-    ALL.append(env_name)
 
 
 def get_default_config(env_name: str) -> config_dict.ConfigDict:
@@ -149,6 +150,6 @@ def load(
       An instance of the environment.
   """
   if env_name not in _envs:
-    raise ValueError(f"Env '{env_name}' not found. Available envs: {ALL}")
+    raise ValueError(f"Env '{env_name}' not found. Available envs: {_cfgs.keys()}")
   config = config or get_default_config(env_name)
   return _envs[env_name](config=config, config_overrides=config_overrides)

mujoco_playground/_src/locomotion/__init__.py

@@ -112,7 +112,11 @@
     "Go1Footstand": go1_randomize.domain_randomize,
 }
 
-ALL = list(_envs.keys())
+
+def __getattr__(name):
+  if name == "ALL":
+    return list(_envs.keys())
+  raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
 
 
 def register_environment(
@@ -129,8 +133,6 @@ def register_environment(
   """
   _envs[env_name] = env_class
   _cfgs[env_name] = cfg_class
-  if env_name not in ALL:
-    ALL.append(env_name)
 
 
 def get_default_config(env_name: str) -> config_dict.ConfigDict:
@@ -160,7 +162,7 @@ def load(
       An instance of the environment.
   """
   if env_name not in _envs:
-    raise ValueError(f"Env '{env_name}' not found. Available envs: {ALL}")
+    raise ValueError(f"Env '{env_name}' not found. Available envs: {_cfgs.keys()}")
   config = config or get_default_config(env_name)
   return _envs[env_name](config=config, config_overrides=config_overrides)
 

mujoco_playground/_src/manipulation/__init__.py

@@ -58,7 +58,10 @@
     "LeapCubeReorient": leap_cube_reorient.domain_randomize,
 }
 
-ALL = list(_envs.keys())
+def __getattr__(name):
+  if name == "ALL":
+    return list(_envs.keys())
+  raise AttributeError(f"module '{__name__}' has no attribute '{name}'")
 
 
 def register_environment(
@@ -75,8 +78,6 @@ def register_environment(
   """
   _envs[env_name] = env_class
   _cfgs[env_name] = cfg_class
-  if env_name not in ALL:
-    ALL.append(env_name)
 
 
 def get_default_config(env_name: str) -> config_dict.ConfigDict:
@@ -106,7 +107,7 @@ def load(
       An instance of the environment.
   """
   if env_name not in _envs:
-    raise ValueError(f"Env '{env_name}' not found. Available envs: {ALL}")
+    raise ValueError(f"Env '{env_name}' not found. Available envs: {_cfgs.keys()}")
   config = config or get_default_config(env_name)
   return _envs[env_name](config=config, config_overrides=config_overrides)
 

mujoco_playground/_src/registry.py

@@ -28,8 +28,6 @@
     Callable[[mjx.Model, jax.Array], Tuple[mjx.Model, mjx.Model]]
 ]
 
-ALL_ENVS = locomotion.ALL + manipulation.ALL + dm_control_suite.ALL
-
 
 def get_default_config(env_name: str):
   if env_name in manipulation.ALL:
@@ -54,7 +52,9 @@ def load(
   elif env_name in dm_control_suite.ALL:
     return dm_control_suite.load(env_name, config, config_overrides)
 
-  raise ValueError(f"Env '{env_name}' not found. Available envs: {ALL_ENVS}")
+  all_envs = manipulation.ALL + locomotion.ALL + dm_control_suite.ALL
+
+  raise ValueError(f"Env '{env_name}' not found. Available envs: {all_envs}")
 
 
 def get_domain_randomizer(env_name: str) -> Optional[DomainRandomizer]:

mujoco_playground/_src/registry_test.py

@@ -0,0 +1,58 @@
+# Copyright 2025 DeepMind Technologies Limited
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+# ==============================================================================
+"""Tests for the registry module."""
+
+from absl.testing import absltest
+import jax.numpy as jp
+from ml_collections import config_dict
+
+from mujoco_playground._src import registry
+from mujoco_playground._src.dm_control_suite import register_environment as register_dm_control_suite
+from mujoco_playground._src.locomotion import register_environment as register_locomotion
+from mujoco_playground._src.manipulation import register_environment as register_manipulation
+
+
+class RegistryTest(absltest.TestCase):
+
+  def test_new_env(self):
+    class DemoEnv:
+
+      def __init__(self, config, config_overrides):
+        pass
+
+    def demo_default_config():
+      return config_dict.ConfigDict()
+
+    register_dm_control_suite('DemoEnv', DemoEnv, demo_default_config)
+    env = registry.load('DemoEnv')
+    self.assertIsInstance(env, DemoEnv)
+    config = registry.get_default_config('DemoEnv')
+    self.assertEqual(config, config_dict.ConfigDict())
+
+    register_manipulation('DemoEnv', DemoEnv, demo_default_config)
+    env = registry.load('DemoEnv')
+    self.assertIsInstance(env, DemoEnv)
+    config = registry.get_default_config('DemoEnv')
+    self.assertEqual(config, config_dict.ConfigDict())
+
+    register_locomotion('DemoEnv', DemoEnv, demo_default_config)
+    env = registry.load('DemoEnv')
+    self.assertIsInstance(env, DemoEnv)
+    config = registry.get_default_config('DemoEnv')
+    self.assertEqual(config, config_dict.ConfigDict())
+
+
+if __name__ == '__main__':
+  absltest.main()