Merge remote-tracking branch 'origin/main' into user/khalil-meftah/2026-02-16-rl-stack-refactor

tests/utils/test_sample_weighting.py

@@ -0,0 +1,401 @@
+#!/usr/bin/env python
+
+# 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 sample weighting infrastructure."""
+
+from unittest.mock import Mock
+
+import pytest
+
+pytest.importorskip("pandas", reason="pandas is required (install lerobot[dataset])")
+
+import torch
+
+from lerobot.utils.sample_weighting import (
+    SampleWeighter,
+    SampleWeightingConfig,
+    UniformWeighter,
+    make_sample_weighter,
+)
+
+# =============================================================================
+# Fixtures
+# =============================================================================
+
+
+@pytest.fixture
+def sample_progress_parquet(tmp_path):
+    """Create a sample progress parquet file for testing."""
+    import pandas as pd
+
+    # Create sample progress data for 2 episodes with 10 frames each
+    data = {
+        "index": list(range(20)),
+        "episode_index": [0] * 10 + [1] * 10,
+        "frame_index": list(range(10)) * 2,
+        "progress_sparse": [i / 10.0 for i in range(10)] * 2,
+    }
+    df = pd.DataFrame(data)
+    parquet_path = tmp_path / "sarm_progress.parquet"
+    df.to_parquet(parquet_path)
+    return parquet_path
+
+
+# =============================================================================
+# SampleWeightingConfig Tests
+# =============================================================================
+
+
+def test_config_default_values():
+    """Test default configuration values."""
+    config = SampleWeightingConfig()
+    assert config.type == "rabc"
+    assert config.progress_path is None
+    assert config.head_mode == "sparse"
+    assert config.kappa == 0.01
+    assert config.epsilon == 1e-6
+    assert config.extra_params == {}
+
+
+def test_config_custom_values():
+    """Test configuration with custom values."""
+    config = SampleWeightingConfig(
+        type="rabc",
+        progress_path="/path/to/progress.parquet",
+        head_mode="dense",
+        kappa=0.05,
+        epsilon=1e-8,
+        extra_params={"fallback_weight": 0.5},
+    )
+    assert config.type == "rabc"
+    assert config.progress_path == "/path/to/progress.parquet"
+    assert config.head_mode == "dense"
+    assert config.kappa == 0.05
+    assert config.epsilon == 1e-8
+    assert config.extra_params == {"fallback_weight": 0.5}
+
+
+def test_config_uniform_type():
+    """Test configuration for uniform weighting."""
+    config = SampleWeightingConfig(type="uniform")
+    assert config.type == "uniform"
+
+
+# =============================================================================
+# UniformWeighter Tests
+# =============================================================================
+
+
+def test_uniform_weighter_inherits_from_sample_weighter():
+    """Test that UniformWeighter is a SampleWeighter."""
+    weighter = UniformWeighter(device=torch.device("cpu"))
+    assert isinstance(weighter, SampleWeighter)
+
+
+def test_uniform_weighter_compute_batch_weights_with_action_key():
+    """Test weight computation with 'action' key in batch."""
+    weighter = UniformWeighter(device=torch.device("cpu"))
+    batch = {"action": torch.randn(8, 10)}
+
+    weights, stats = weighter.compute_batch_weights(batch)
+
+    assert weights.shape == (8,)
+    assert torch.allclose(weights, torch.ones(8))
+    assert stats["mean_weight"] == 1.0
+    assert stats["type"] == "uniform"
+
+
+def test_uniform_weighter_compute_batch_weights_with_index_key():
+    """Test weight computation with 'index' key in batch."""
+    weighter = UniformWeighter(device=torch.device("cpu"))
+    batch = {"index": torch.arange(16)}
+
+    weights, stats = weighter.compute_batch_weights(batch)
+
+    assert weights.shape == (16,)
+    assert torch.allclose(weights, torch.ones(16))
+
+
+def test_uniform_weighter_compute_batch_weights_no_tensor_keys():
+    """Test weight computation with no tensor keys (fallback to size 1)."""
+    weighter = UniformWeighter(device=torch.device("cpu"))
+    batch = {"other_key": "some_value"}
+
+    weights, stats = weighter.compute_batch_weights(batch)
+
+    assert weights.shape == (1,)
+    assert torch.allclose(weights, torch.ones(1))
+
+
+def test_uniform_weighter_compute_batch_weights_empty_batch_raises():
+    """Test that empty batch raises ValueError."""
+    weighter = UniformWeighter(device=torch.device("cpu"))
+    batch = {}
+
+    with pytest.raises(ValueError, match="empty batch"):
+        weighter.compute_batch_weights(batch)
+
+
+def test_uniform_weighter_compute_batch_weights_scans_all_keys():
+    """Test that batch size is determined by scanning all tensor values."""
+    weighter = UniformWeighter(device=torch.device("cpu"))
+    # Batch with non-standard key containing a tensor
+    batch = {"custom_tensor": torch.randn(7, 3)}
+
+    weights, stats = weighter.compute_batch_weights(batch)
+
+    assert weights.shape == (7,)
+    assert torch.allclose(weights, torch.ones(7))
+
+
+def test_uniform_weighter_compute_batch_weights_on_cuda():
+    """Test that weights are placed on the correct device."""
+    if not torch.cuda.is_available():
+        pytest.skip("CUDA not available")
+
+    weighter = UniformWeighter(device=torch.device("cuda"))
+    batch = {"action": torch.randn(4, 10)}
+
+    weights, _ = weighter.compute_batch_weights(batch)
+
+    assert weights.device.type == "cuda"
+
+
+def test_uniform_weighter_get_stats():
+    """Test get_stats returns expected structure."""
+    weighter = UniformWeighter(device=torch.device("cpu"))
+    stats = weighter.get_stats()
+
+    assert stats == {"type": "uniform"}
+
+
+# =============================================================================
+# make_sample_weighter Factory Tests
+# =============================================================================
+
+
+def test_factory_returns_none_for_none_config():
+    """Test that None config returns None weighter."""
+    policy = Mock()
+    device = torch.device("cpu")
+
+    result = make_sample_weighter(None, policy, device)
+
+    assert result is None
+
+
+def test_factory_creates_uniform_weighter():
+    """Test creation of UniformWeighter."""
+    config = SampleWeightingConfig(type="uniform")
+    policy = Mock()
+    device = torch.device("cpu")
+
+    weighter = make_sample_weighter(config, policy, device)
+
+    assert isinstance(weighter, UniformWeighter)
+    assert isinstance(weighter, SampleWeighter)
+
+
+def test_factory_raises_for_unknown_type():
+    """Test that unknown type raises ValueError."""
+    config = SampleWeightingConfig(type="unknown_type")
+    policy = Mock()
+    device = torch.device("cpu")
+
+    with pytest.raises(ValueError, match="Unknown sample weighting type"):
+        make_sample_weighter(config, policy, device)
+
+
+def test_factory_rabc_requires_chunk_size():
+    """Test that RABC weighter requires chunk_size in policy config."""
+    config = SampleWeightingConfig(
+        type="rabc",
+        progress_path="/path/to/progress.parquet",
+    )
+    policy = Mock()
+    policy.config = Mock()
+    policy.config.chunk_size = None  # No chunk_size
+    device = torch.device("cpu")
+
+    with pytest.raises(ValueError, match="chunk_size"):
+        make_sample_weighter(config, policy, device)
+
+
+def test_factory_rabc_requires_progress_path_or_dataset_info():
+    """Test that RABC weighter requires progress_path or dataset info for auto-detection."""
+    config = SampleWeightingConfig(
+        type="rabc",
+        progress_path=None,  # No progress path
+    )
+    policy = Mock()
+    policy.config = Mock()
+    policy.config.chunk_size = 50
+    device = torch.device("cpu")
+
+    # Should fail when no progress_path AND no dataset info
+    with pytest.raises(ValueError, match="progress_path"):
+        make_sample_weighter(config, policy, device)
+
+
+def test_factory_rabc_auto_detects_from_dataset_root(sample_progress_parquet):
+    """Test that RABC weighter auto-detects progress_path from dataset_root."""
+    config = SampleWeightingConfig(
+        type="rabc",
+        progress_path=None,  # Not provided, should auto-detect
+    )
+    policy = Mock()
+    policy.config = Mock()
+    policy.config.chunk_size = 5
+    device = torch.device("cpu")
+
+    # The parquet file is at sample_progress_parquet, get its parent directory
+    dataset_root = sample_progress_parquet.parent
+    weighter = make_sample_weighter(
+        config,
+        policy,
+        device,
+        dataset_root=str(dataset_root),
+    )
+
+    assert weighter is not None
+    from lerobot.rewards.sarm.rabc import RABCWeights
+
+    assert isinstance(weighter, RABCWeights)
+
+
+def test_factory_rabc_auto_detects_from_repo_id():
+    """Test that RABC weighter constructs HF path from repo_id."""
+    config = SampleWeightingConfig(
+        type="rabc",
+        progress_path=None,  # Not provided, should auto-detect
+    )
+    policy = Mock()
+    policy.config = Mock()
+    policy.config.chunk_size = 50
+    device = torch.device("cpu")
+
+    # This will construct the path but fail when trying to load (file doesn't exist)
+    # We just verify it doesn't raise the "progress_path required" error
+    with pytest.raises(Exception) as exc_info:
+        make_sample_weighter(
+            config,
+            policy,
+            device,
+            dataset_repo_id="test-user/test-dataset",
+        )
+    # Should NOT be the "progress_path required" error - it should try to load the file
+    assert (
+        "progress_path" not in str(exc_info.value).lower() or "auto-detection" in str(exc_info.value).lower()
+    )
+
+
+# =============================================================================
+# Integration Tests with RABCWeights
+# =============================================================================
+
+
+def test_rabc_weights_is_sample_weighter(sample_progress_parquet):
+    """Test that RABCWeights inherits from SampleWeighter."""
+    from lerobot.rewards.sarm.rabc import RABCWeights
+
+    weighter = RABCWeights(
+        progress_path=sample_progress_parquet,
+        chunk_size=5,
+        head_mode="sparse",
+    )
+    assert isinstance(weighter, SampleWeighter)
+
+
+def test_rabc_compute_batch_weights(sample_progress_parquet):
+    """Test RABCWeights.compute_batch_weights returns correct structure."""
+    from lerobot.rewards.sarm.rabc import RABCWeights
+
+    weighter = RABCWeights(
+        progress_path=sample_progress_parquet,
+        chunk_size=5,
+        head_mode="sparse",
+        device=torch.device("cpu"),
+    )
+
+    batch = {"index": torch.tensor([0, 1, 2, 3])}
+    weights, stats = weighter.compute_batch_weights(batch)
+
+    assert isinstance(weights, torch.Tensor)
+    assert weights.shape == (4,)
+    assert isinstance(stats, dict)
+    assert "mean_weight" in stats
+
+
+def test_rabc_get_stats(sample_progress_parquet):
+    """Test RABCWeights.get_stats returns expected structure."""
+    from lerobot.rewards.sarm.rabc import RABCWeights
+
+    weighter = RABCWeights(
+        progress_path=sample_progress_parquet,
+        chunk_size=5,
+        head_mode="sparse",
+    )
+
+    stats = weighter.get_stats()
+
+    assert stats["type"] == "rabc"
+    assert "num_frames" in stats
+    assert "chunk_size" in stats
+    assert stats["chunk_size"] == 5
+    assert "head_mode" in stats
+    assert stats["head_mode"] == "sparse"
+    assert "delta_mean" in stats
+    assert "delta_std" in stats
+
+
+def test_factory_creates_rabc_weighter(sample_progress_parquet):
+    """Test factory creates RABCWeights with valid config."""
+    from lerobot.rewards.sarm.rabc import RABCWeights
+
+    config = SampleWeightingConfig(
+        type="rabc",
+        progress_path=str(sample_progress_parquet),
+        head_mode="sparse",
+        kappa=0.01,
+    )
+    policy = Mock()
+    policy.config = Mock()
+    policy.config.chunk_size = 5
+    device = torch.device("cpu")
+
+    weighter = make_sample_weighter(config, policy, device)
+
+    assert isinstance(weighter, RABCWeights)
+    assert isinstance(weighter, SampleWeighter)
+
+
+def test_rabc_weights_normalization(sample_progress_parquet):
+    """Test that RABCWeights normalizes weights to sum to batch_size."""
+    from lerobot.rewards.sarm.rabc import RABCWeights
+
+    weighter = RABCWeights(
+        progress_path=sample_progress_parquet,
+        chunk_size=5,
+        head_mode="sparse",
+        device=torch.device("cpu"),
+    )
+
+    batch = {"index": torch.tensor([0, 1, 2, 3])}
+    weights, _ = weighter.compute_batch_weights(batch)
+
+    # Weights should be normalized to sum approximately to batch_size
+    batch_size = 4
+    assert abs(weights.sum().item() - batch_size) < 0.1