Fix policy defaults (#113)

tests/test_policies.py

@@ -5,6 +5,8 @@ from lerobot.common.datasets.factory import make_dataset
 from lerobot.common.datasets.utils import cycle
 from lerobot.common.envs.factory import make_env
 from lerobot.common.envs.utils import postprocess_action, preprocess_observation
+from lerobot.common.policies.act.modeling_act import ActionChunkingTransformerPolicy
+from lerobot.common.policies.diffusion.modeling_diffusion import DiffusionPolicy
 from lerobot.common.policies.factory import make_policy
 from lerobot.common.policies.normalize import Normalize, Unnormalize
 from lerobot.common.policies.policy_protocol import Policy
@@ -113,6 +115,15 @@ def test_policy(env_name, policy_name, extra_overrides):
         new_policy.load_state_dict(policy.state_dict())
 
 
+@pytest.mark.parametrize("policy_cls", [DiffusionPolicy, ActionChunkingTransformerPolicy])
+def test_policy_defaults(policy_cls):
+    kwargs = {}
+    # TODO(alexander-soare): Remove this kwargs hack when we move the scheduler out of DP.
+    if policy_cls is DiffusionPolicy:
+        kwargs = {"lr_scheduler_num_training_steps": 1}
+    policy_cls(**kwargs)
+
+
 @pytest.mark.parametrize(
     "insert_temporal_dim",
     [