lerobot/tests/datasets/test_dataset_utils.py

#!/usr/bin/env python

# Copyright 2024 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.

import pytest
import torch

pytest.importorskip("datasets", reason="datasets is required (install lerobot[dataset])")

from datasets import Dataset  # noqa: E402
from huggingface_hub import DatasetCard

from lerobot.datasets.io_utils import hf_transform_to_torch
from lerobot.datasets.utils import create_lerobot_dataset_card
from lerobot.utils.constants import ACTION, OBS_IMAGES
from lerobot.utils.feature_utils import combine_feature_dicts


def calculate_episode_data_index(hf_dataset: Dataset) -> dict[str, torch.Tensor]:
    """Calculate episode data index for testing. Returns {"from": Tensor, "to": Tensor}."""
    episode_data_index: dict[str, list[int]] = {"from": [], "to": []}
    current_episode = None
    if len(hf_dataset) == 0:
        return {"from": torch.tensor([]), "to": torch.tensor([])}
    for idx, episode_idx in enumerate(hf_dataset["episode_index"]):
        if episode_idx != current_episode:
            episode_data_index["from"].append(idx)
            if current_episode is not None:
                episode_data_index["to"].append(idx)
            current_episode = episode_idx
    episode_data_index["to"].append(idx + 1)
    return {k: torch.tensor(v) for k, v in episode_data_index.items()}


def test_default_parameters():
    card = create_lerobot_dataset_card()
    assert isinstance(card, DatasetCard)
    assert card.data.tags == ["LeRobot"]
    assert card.data.task_categories == ["robotics"]
    assert card.data.configs == [
        {
            "config_name": "default",
            "data_files": "data/*/*.parquet",
        }
    ]


def test_with_tags():
    tags = ["tag1", "tag2"]
    card = create_lerobot_dataset_card(tags=tags)
    assert card.data.tags == ["LeRobot", "tag1", "tag2"]


def test_calculate_episode_data_index():
    dataset = Dataset.from_dict(
        {
            "timestamp": [0.1, 0.2, 0.3, 0.4, 0.5, 0.6],
            "index": [0, 1, 2, 3, 4, 5],
            "episode_index": [0, 0, 1, 2, 2, 2],
        },
    )
    dataset.set_transform(hf_transform_to_torch)
    episode_data_index = calculate_episode_data_index(dataset)
    assert torch.equal(episode_data_index["from"], torch.tensor([0, 2, 3]))
    assert torch.equal(episode_data_index["to"], torch.tensor([2, 3, 6]))


def test_merge_simple_vectors():
    g1 = {
        ACTION: {
            "dtype": "float32",
            "shape": (2,),
            "names": ["ee.x", "ee.y"],
        }
    }
    g2 = {
        ACTION: {
            "dtype": "float32",
            "shape": (2,),
            "names": ["ee.y", "ee.z"],
        }
    }

    out = combine_feature_dicts(g1, g2)

    assert ACTION in out
    assert out[ACTION]["dtype"] == "float32"
    # Names merged with preserved order and de-dupuplication
    assert out[ACTION]["names"] == ["ee.x", "ee.y", "ee.z"]
    # Shape correctly recomputed from names length
    assert out[ACTION]["shape"] == (3,)


def test_merge_multiple_groups_order_and_dedup():
    g1 = {ACTION: {"dtype": "float32", "shape": (2,), "names": ["a", "b"]}}
    g2 = {ACTION: {"dtype": "float32", "shape": (2,), "names": ["b", "c"]}}
    g3 = {ACTION: {"dtype": "float32", "shape": (3,), "names": ["a", "c", "d"]}}

    out = combine_feature_dicts(g1, g2, g3)

    assert out[ACTION]["names"] == ["a", "b", "c", "d"]
    assert out[ACTION]["shape"] == (4,)


def test_non_vector_last_wins_for_images():
    # Non-vector (images) with same name should be overwritten by the last image specified
    g1 = {
        f"{OBS_IMAGES}.front": {
            "dtype": "image",
            "shape": (3, 480, 640),
            "names": ["channels", "height", "width"],
        }
    }
    g2 = {
        f"{OBS_IMAGES}.front": {
            "dtype": "image",
            "shape": (3, 720, 1280),
            "names": ["channels", "height", "width"],
        }
    }

    out = combine_feature_dicts(g1, g2)
    assert out[f"{OBS_IMAGES}.front"]["shape"] == (3, 720, 1280)
    assert out[f"{OBS_IMAGES}.front"]["dtype"] == "image"


def test_dtype_mismatch_raises():
    g1 = {ACTION: {"dtype": "float32", "shape": (1,), "names": ["a"]}}
    g2 = {ACTION: {"dtype": "float64", "shape": (1,), "names": ["b"]}}

    with pytest.raises(ValueError, match="dtype mismatch for 'action'"):
        _ = combine_feature_dicts(g1, g2)


def test_non_dict_passthrough_last_wins():
    g1 = {"misc": 123}
    g2 = {"misc": 456}

    out = combine_feature_dicts(g1, g2)
    # For non-dict entries the last one wins
    assert out["misc"] == 456