test(rewards): add reward model tests and update existing test imports

tests/rewards/test_classifier_processor.py

@@ -17,12 +17,9 @@
 
 import tempfile
 
-import pytest
 import torch
 
 from lerobot.configs.types import FeatureType, NormalizationMode, PolicyFeature
-from lerobot.policies.sac.reward_model.configuration_classifier import RewardClassifierConfig
-from lerobot.policies.sac.reward_model.processor_classifier import make_classifier_processor
 from lerobot.processor import (
     DataProcessorPipeline,
     DeviceProcessorStep,
@@ -31,6 +28,8 @@ from lerobot.processor import (
     TransitionKey,
 )
 from lerobot.processor.converters import create_transition, transition_to_batch
+from lerobot.rewards.classifier.configuration_classifier import RewardClassifierConfig
+from lerobot.rewards.classifier.processor_classifier import make_classifier_processor
 from lerobot.utils.constants import OBS_IMAGE, OBS_STATE
 
 
@@ -42,12 +41,12 @@ def create_default_config():
         OBS_IMAGE: PolicyFeature(type=FeatureType.VISUAL, shape=(3, 224, 224)),
     }
     config.output_features = {
-        "reward": PolicyFeature(type=FeatureType.ACTION, shape=(1,)),  # Classifier output
+        "reward": PolicyFeature(type=FeatureType.ACTION, shape=(1,)),
     }
     config.normalization_mapping = {
         FeatureType.STATE: NormalizationMode.MEAN_STD,
         FeatureType.VISUAL: NormalizationMode.IDENTITY,
-        FeatureType.ACTION: NormalizationMode.IDENTITY,  # No normalization for classifier output
+        FeatureType.ACTION: NormalizationMode.IDENTITY,
     }
     config.device = "cpu"
     return config
@@ -57,8 +56,8 @@ def create_default_stats():
     """Create default dataset statistics for testing."""
     return {
         OBS_STATE: {"mean": torch.zeros(10), "std": torch.ones(10)},
-        OBS_IMAGE: {},  # No normalization for images
+        OBS_IMAGE: {},
-        "reward": {},  # No normalization for classifier output
+        "reward": {},
     }
 
 
@@ -69,17 +68,14 @@ def test_make_classifier_processor_basic():
 
     preprocessor, postprocessor = make_classifier_processor(config, stats)
 
-    # Check processor names
     assert preprocessor.name == "classifier_preprocessor"
     assert postprocessor.name == "classifier_postprocessor"
 
-    # Check steps in preprocessor
     assert len(preprocessor.steps) == 3
-    assert isinstance(preprocessor.steps[0], NormalizerProcessorStep)  # For input features
+    assert isinstance(preprocessor.steps[0], NormalizerProcessorStep)
-    assert isinstance(preprocessor.steps[1], NormalizerProcessorStep)  # For output features
+    assert isinstance(preprocessor.steps[1], NormalizerProcessorStep)
     assert isinstance(preprocessor.steps[2], DeviceProcessorStep)
 
-    # Check steps in postprocessor
     assert len(postprocessor.steps) == 2
     assert isinstance(postprocessor.steps[0], DeviceProcessorStep)
     assert isinstance(postprocessor.steps[1], IdentityProcessorStep)
@@ -90,128 +86,21 @@ def test_classifier_processor_normalization():
     config = create_default_config()
     stats = create_default_stats()
 
-    preprocessor, postprocessor = make_classifier_processor(
+    preprocessor, postprocessor = make_classifier_processor(config, stats)
-        config,
-        stats,
-    )
 
-    # Create test data
-    observation = {
-        OBS_STATE: torch.randn(10),
-        OBS_IMAGE: torch.randn(3, 224, 224),
-    }
-    action = torch.randn(1)  # Dummy action/reward
-    transition = create_transition(observation, action)
-    batch = transition_to_batch(transition)
-
-    # Process through preprocessor
-    processed = preprocessor(batch)
-
-    # Check that data is processed
-    assert processed[OBS_STATE].shape == (10,)
-    assert processed[OBS_IMAGE].shape == (3, 224, 224)
-    assert processed[TransitionKey.ACTION.value].shape == (1,)
-
-
-@pytest.mark.skipif(not torch.cuda.is_available(), reason="CUDA not available")
-def test_classifier_processor_cuda():
-    """Test Classifier processor with CUDA device."""
-    config = create_default_config()
-    config.device = "cuda"
-    stats = create_default_stats()
-
-    preprocessor, postprocessor = make_classifier_processor(
-        config,
-        stats,
-    )
-
-    # Create CPU data
     observation = {
         OBS_STATE: torch.randn(10),
         OBS_IMAGE: torch.randn(3, 224, 224),
     }
     action = torch.randn(1)
     transition = create_transition(observation, action)
-
     batch = transition_to_batch(transition)
 
-    # Process through preprocessor
-
     processed = preprocessor(batch)
 
-    # Check that data is on CUDA
+    assert processed[OBS_STATE].shape == (10,)
-    assert processed[OBS_STATE].device.type == "cuda"
+    assert processed[OBS_IMAGE].shape == (3, 224, 224)
-    assert processed[OBS_IMAGE].device.type == "cuda"
+    assert processed[TransitionKey.ACTION.value].shape == (1,)
-    assert processed[TransitionKey.ACTION.value].device.type == "cuda"
-
-    # Process through postprocessor
-    postprocessed = postprocessor(processed[TransitionKey.ACTION.value])
-
-    # Check that output is back on CPU
-    assert postprocessed.device.type == "cpu"
-
-
-@pytest.mark.skipif(not torch.cuda.is_available(), reason="CUDA not available")
-def test_classifier_processor_accelerate_scenario():
-    """Test Classifier processor in simulated Accelerate scenario."""
-    config = create_default_config()
-    config.device = "cuda:0"
-    stats = create_default_stats()
-
-    preprocessor, postprocessor = make_classifier_processor(
-        config,
-        stats,
-    )
-
-    # Simulate Accelerate: data already on GPU
-    device = torch.device("cuda:0")
-    observation = {
-        OBS_STATE: torch.randn(10).to(device),
-        OBS_IMAGE: torch.randn(3, 224, 224).to(device),
-    }
-    action = torch.randn(1).to(device)
-    transition = create_transition(observation, action)
-
-    batch = transition_to_batch(transition)
-
-    # Process through preprocessor
-
-    processed = preprocessor(batch)
-
-    # Check that data stays on same GPU
-    assert processed[OBS_STATE].device == device
-    assert processed[OBS_IMAGE].device == device
-    assert processed[TransitionKey.ACTION.value].device == device
-
-
-@pytest.mark.skipif(torch.cuda.device_count() < 2, reason="Requires at least 2 GPUs")
-def test_classifier_processor_multi_gpu():
-    """Test Classifier processor with multi-GPU setup."""
-    config = create_default_config()
-    config.device = "cuda:0"
-    stats = create_default_stats()
-
-    preprocessor, postprocessor = make_classifier_processor(config, stats)
-
-    # Simulate data on different GPU
-    device = torch.device("cuda:1")
-    observation = {
-        OBS_STATE: torch.randn(10).to(device),
-        OBS_IMAGE: torch.randn(3, 224, 224).to(device),
-    }
-    action = torch.randn(1).to(device)
-    transition = create_transition(observation, action)
-
-    batch = transition_to_batch(transition)
-
-    # Process through preprocessor
-
-    processed = preprocessor(batch)
-
-    # Check that data stays on cuda:1
-    assert processed[OBS_STATE].device == device
-    assert processed[OBS_IMAGE].device == device
-    assert processed[TransitionKey.ACTION.value].device == device
 
 
 def test_classifier_processor_without_stats():
@@ -220,18 +109,15 @@ def test_classifier_processor_without_stats():
 
     preprocessor, postprocessor = make_classifier_processor(config, dataset_stats=None)
 
-    # Should still create processors
     assert preprocessor is not None
     assert postprocessor is not None
 
-    # Process should still work
     observation = {
         OBS_STATE: torch.randn(10),
         OBS_IMAGE: torch.randn(3, 224, 224),
     }
     action = torch.randn(1)
     transition = create_transition(observation, action)
-
     batch = transition_to_batch(transition)
 
     processed = preprocessor(batch)
@@ -246,15 +132,12 @@ def test_classifier_processor_save_and_load():
     preprocessor, postprocessor = make_classifier_processor(config, stats)
 
     with tempfile.TemporaryDirectory() as tmpdir:
-        # Save preprocessor
         preprocessor.save_pretrained(tmpdir)
 
-        # Load preprocessor
         loaded_preprocessor = DataProcessorPipeline.from_pretrained(
             tmpdir, config_filename="classifier_preprocessor.json"
         )
 
-        # Test that loaded processor works
         observation = {
             OBS_STATE: torch.randn(10),
             OBS_IMAGE: torch.randn(3, 224, 224),
@@ -269,55 +152,13 @@ def test_classifier_processor_save_and_load():
         assert processed[TransitionKey.ACTION.value].shape == (1,)
 
 
-@pytest.mark.skipif(not torch.cuda.is_available(), reason="CUDA not available")
-def test_classifier_processor_mixed_precision():
-    """Test Classifier processor with mixed precision."""
-    config = create_default_config()
-    config.device = "cuda"
-    stats = create_default_stats()
-
-    preprocessor, postprocessor = make_classifier_processor(config, stats)
-
-    # Replace DeviceProcessorStep with one that uses float16
-    modified_steps = []
-    for step in preprocessor.steps:
-        if isinstance(step, DeviceProcessorStep):
-            modified_steps.append(DeviceProcessorStep(device=config.device, float_dtype="float16"))
-        else:
-            modified_steps.append(step)
-    preprocessor.steps = modified_steps
-
-    # Create test data
-    observation = {
-        OBS_STATE: torch.randn(10, dtype=torch.float32),
-        OBS_IMAGE: torch.randn(3, 224, 224, dtype=torch.float32),
-    }
-    action = torch.randn(1, dtype=torch.float32)
-    transition = create_transition(observation, action)
-
-    batch = transition_to_batch(transition)
-
-    # Process through preprocessor
-
-    processed = preprocessor(batch)
-
-    # Check that data is converted to float16
-    assert processed[OBS_STATE].dtype == torch.float16
-    assert processed[OBS_IMAGE].dtype == torch.float16
-    assert processed[TransitionKey.ACTION.value].dtype == torch.float16
-
-
 def test_classifier_processor_batch_data():
     """Test Classifier processor with batched data."""
     config = create_default_config()
     stats = create_default_stats()
 
-    preprocessor, postprocessor = make_classifier_processor(
+    preprocessor, postprocessor = make_classifier_processor(config, stats)
-        config,
-        stats,
-    )
 
-    # Test with batched data
     batch_size = 16
     observation = {
         OBS_STATE: torch.randn(batch_size, 10),
@@ -325,14 +166,10 @@ def test_classifier_processor_batch_data():
     }
     action = torch.randn(batch_size, 1)
     transition = create_transition(observation, action)
-
     batch = transition_to_batch(transition)
 
-    # Process through preprocessor
-
     processed = preprocessor(batch)
 
-    # Check that batch dimension is preserved
     assert processed[OBS_STATE].shape == (batch_size, 10)
     assert processed[OBS_IMAGE].shape == (batch_size, 3, 224, 224)
     assert processed[TransitionKey.ACTION.value].shape == (batch_size, 1)
@@ -343,20 +180,13 @@ def test_classifier_processor_postprocessor_identity():
     config = create_default_config()
     stats = create_default_stats()
 
-    preprocessor, postprocessor = make_classifier_processor(
+    preprocessor, postprocessor = make_classifier_processor(config, stats)
-        config,
-        stats,
-    )
 
-    # Create test data for postprocessor
+    reward = torch.tensor([[0.8], [0.3], [0.9]])
-    reward = torch.tensor([[0.8], [0.3], [0.9]])  # Batch of rewards/predictions
     transition = create_transition(action=reward)
-
     _ = transition_to_batch(transition)
 
-    # Process through postprocessor
     processed = postprocessor(reward)
 
-    # IdentityProcessor should leave values unchanged (except device)
     assert torch.allclose(processed.cpu(), reward.cpu())
     assert processed.device.type == "cpu"

tests/rewards/test_modeling_classifier.py

@@ -1,5 +1,3 @@
-# !/usr/bin/env python
-
 # Copyright 2025 The HuggingFace Inc. team. All rights reserved.
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
@@ -18,8 +16,8 @@ import pytest
 import torch
 
 from lerobot.configs.types import FeatureType, NormalizationMode, PolicyFeature
-from lerobot.policies.sac.reward_model.configuration_classifier import RewardClassifierConfig
+from lerobot.rewards.classifier.configuration_classifier import RewardClassifierConfig
-from lerobot.policies.sac.reward_model.modeling_classifier import ClassifierOutput
+from lerobot.rewards.classifier.modeling_classifier import ClassifierOutput
 from lerobot.utils.constants import OBS_IMAGE, REWARD
 from tests.utils import require_package
 
@@ -42,7 +40,7 @@ def test_classifier_output():
     reason="helper2424/resnet10 needs to be updated to work with the latest version of transformers"
 )
 def test_binary_classifier_with_default_params():
-    from lerobot.policies.sac.reward_model.modeling_classifier import Classifier
+    from lerobot.rewards.classifier.modeling_classifier import Classifier
 
     config = RewardClassifierConfig()
     config.input_features = {
@@ -86,7 +84,7 @@ def test_binary_classifier_with_default_params():
     reason="helper2424/resnet10 needs to be updated to work with the latest version of transformers"
 )
 def test_multiclass_classifier():
-    from lerobot.policies.sac.reward_model.modeling_classifier import Classifier
+    from lerobot.rewards.classifier.modeling_classifier import Classifier
 
     num_classes = 5
     config = RewardClassifierConfig()
@@ -128,11 +126,15 @@ def test_multiclass_classifier():
     reason="helper2424/resnet10 needs to be updated to work with the latest version of transformers"
 )
 def test_default_device():
-    from lerobot.policies.sac.reward_model.modeling_classifier import Classifier
+    from lerobot.rewards.classifier.modeling_classifier import Classifier
 
     config = RewardClassifierConfig()
-    assert config.device == "cpu"
+    assert config.device is None or config.device == "cpu"
 
+    config.input_features = {
+        OBS_IMAGE: PolicyFeature(type=FeatureType.VISUAL, shape=(3, 224, 224)),
+    }
+    config.num_cameras = 1
     classifier = Classifier(config)
     for p in classifier.parameters():
         assert p.device == torch.device("cpu")
@@ -143,11 +145,15 @@ def test_default_device():
     reason="helper2424/resnet10 needs to be updated to work with the latest version of transformers"
 )
 def test_explicit_device_setup():
-    from lerobot.policies.sac.reward_model.modeling_classifier import Classifier
+    from lerobot.rewards.classifier.modeling_classifier import Classifier
 
     config = RewardClassifierConfig(device="cpu")
     assert config.device == "cpu"
 
+    config.input_features = {
+        OBS_IMAGE: PolicyFeature(type=FeatureType.VISUAL, shape=(3, 224, 224)),
+    }
+    config.num_cameras = 1
     classifier = Classifier(config)
     for p in classifier.parameters():
         assert p.device == torch.device("cpu")

tests/rewards/test_reward_model_base.py

@@ -0,0 +1,101 @@
+# Copyright 2026 The HuggingFace Inc. team. All rights reserved.
+#
+# 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 reward model base classes and registry."""
+
+import pytest
+import torch
+
+from lerobot.configs.rewards import RewardModelConfig
+from lerobot.rewards.pretrained import PreTrainedRewardModel
+
+
+def test_reward_model_config_registry():
+    """Verify that classifier and sarm are registered."""
+    known = RewardModelConfig.get_known_choices()
+    assert "reward_classifier" in known
+    assert "sarm" in known
+
+
+def test_reward_model_config_lookup():
+    """Verify that we can look up configs by name."""
+    cls = RewardModelConfig.get_choice_class("reward_classifier")
+    from lerobot.rewards.classifier.configuration_classifier import RewardClassifierConfig
+
+    assert cls is RewardClassifierConfig
+
+
+def test_factory_get_reward_model_class():
+    """Test the get_reward_model_class factory."""
+    from lerobot.rewards.factory import get_reward_model_class
+
+    cls = get_reward_model_class("sarm")
+    from lerobot.rewards.sarm.modeling_sarm import SARMRewardModel
+
+    assert cls is SARMRewardModel
+
+
+def test_factory_unknown_raises():
+    """Unknown name should raise ValueError."""
+    from lerobot.rewards.factory import get_reward_model_class
+
+    with pytest.raises(ValueError, match="not available"):
+        get_reward_model_class("nonexistent_reward_model")
+
+
+def test_pretrained_reward_model_requires_config_class():
+    """Subclass without config_class should fail."""
+    with pytest.raises(TypeError, match="must define 'config_class'"):
+
+        class BadModel(PreTrainedRewardModel):
+            name = "bad"
+
+            def compute_reward(self, batch):
+                pass
+
+
+def test_pretrained_reward_model_requires_name():
+    """Subclass without name should fail."""
+    with pytest.raises(TypeError, match="must define 'name'"):
+
+        class BadModel(PreTrainedRewardModel):
+            config_class = RewardModelConfig
+
+            def compute_reward(self, batch):
+                pass
+
+
+def test_non_trainable_forward_raises():
+    """Non-trainable model should raise on forward()."""
+    from dataclasses import dataclass
+
+    from lerobot.optim.optimizers import AdamWConfig
+
+    @dataclass
+    class DummyConfig(RewardModelConfig):
+        def get_optimizer_preset(self):
+            return AdamWConfig(lr=1e-4)
+
+    class DummyReward(PreTrainedRewardModel):
+        config_class = DummyConfig
+        name = "dummy_test"
+
+        def compute_reward(self, batch):
+            return torch.zeros(1)
+
+    config = DummyConfig()
+    model = DummyReward(config)
+
+    with pytest.raises(NotImplementedError, match="not trainable"):
+        model.forward({"x": torch.zeros(1)})

tests/rewards/test_sarm_processor.py

@@ -104,8 +104,8 @@ class TestSARMEncodingProcessorStepEndToEnd:
     def mock_clip_model(self):
         """Mock CLIP model to avoid loading real weights."""
         with (
-            patch("lerobot.policies.sarm.processor_sarm.CLIPModel") as mock_model_cls,
+            patch("lerobot.rewards.sarm.processor_sarm.CLIPModel") as mock_model_cls,
-            patch("lerobot.policies.sarm.processor_sarm.CLIPProcessor") as mock_processor_cls,
+            patch("lerobot.rewards.sarm.processor_sarm.CLIPProcessor") as mock_processor_cls,
         ):
             # Mock the CLIP model - return embeddings based on input batch size
             mock_model = MagicMock()
@@ -142,7 +142,7 @@ class TestSARMEncodingProcessorStepEndToEnd:
     @pytest.fixture
     def processor_with_mocks(self, mock_clip_model):
         """Create a processor with mocked CLIP and dataset metadata for dual mode."""
-        from lerobot.policies.sarm.processor_sarm import SARMEncodingProcessorStep
+        from lerobot.rewards.sarm.processor_sarm import SARMEncodingProcessorStep
 
         # Dual mode config with both sparse and dense annotations
         config = MockConfig(
@@ -256,7 +256,7 @@ class TestSARMEncodingProcessorStepEndToEnd:
 
     def test_call_with_batched_input(self, mock_clip_model):
         """Test processor __call__ with a batched input (multiple frames) in dual mode."""
-        from lerobot.policies.sarm.processor_sarm import SARMEncodingProcessorStep
+        from lerobot.rewards.sarm.processor_sarm import SARMEncodingProcessorStep
 
         config = MockConfig(
             n_obs_steps=8,
@@ -332,7 +332,7 @@ class TestSARMEncodingProcessorStepEndToEnd:
 
     def test_targets_increase_with_progress(self, mock_clip_model):
         """Test that both sparse and dense targets increase as frame index progresses."""
-        from lerobot.policies.sarm.processor_sarm import SARMEncodingProcessorStep
+        from lerobot.rewards.sarm.processor_sarm import SARMEncodingProcessorStep
 
         config = MockConfig(
             n_obs_steps=8,
@@ -404,7 +404,7 @@ class TestSARMEncodingProcessorStepEndToEnd:
 
     def test_progress_labels_exact_values(self, mock_clip_model):
         """Test that progress labels (stage.tau) are computed correctly for known positions."""
-        from lerobot.policies.sarm.processor_sarm import SARMEncodingProcessorStep
+        from lerobot.rewards.sarm.processor_sarm import SARMEncodingProcessorStep
 
         # Simple setup: 2 sparse stages, 4 dense stages, 100 frame episode
         config = MockConfig(
@@ -495,7 +495,7 @@ class TestSARMEncodingProcessorStepEndToEnd:
         """Test that rewind augmentation correctly extends sequence and generates targets."""
         import random
 
-        from lerobot.policies.sarm.processor_sarm import SARMEncodingProcessorStep
+        from lerobot.rewards.sarm.processor_sarm import SARMEncodingProcessorStep
 
         config = MockConfig(
             n_obs_steps=8,
@@ -587,8 +587,8 @@ class TestSARMEncodingProcessorStepEndToEnd:
 
     def test_full_sequence_target_consistency(self, mock_clip_model):
         """Test that the full sequence of targets is consistent with frame positions."""
-        from lerobot.policies.sarm.processor_sarm import SARMEncodingProcessorStep
+        from lerobot.rewards.sarm.processor_sarm import SARMEncodingProcessorStep
-        from lerobot.policies.sarm.sarm_utils import find_stage_and_tau
+        from lerobot.rewards.sarm.sarm_utils import find_stage_and_tau
 
         config = MockConfig(
             n_obs_steps=8,

tests/rewards/test_sarm_utils.py

@@ -18,7 +18,7 @@ import numpy as np
 import pytest
 import torch
 
-from lerobot.policies.sarm.sarm_utils import (
+from lerobot.rewards.sarm.sarm_utils import (
     apply_rewind_augmentation,
     compute_absolute_indices,
     compute_tau,