Port HIL SERL (#644)

Co-authored-by: Michel Aractingi <michel.aractingi@huggingface.co>
Co-authored-by: Eugene Mironov <helper2424@gmail.com>
Co-authored-by: s1lent4gnt <kmeftah.khalil@gmail.com>
Co-authored-by: Ke Wang <superwk1017@gmail.com>
Co-authored-by: Yoel Chornton <yoel.chornton@gmail.com>
Co-authored-by: imstevenpmwork <steven.palma@huggingface.co>
Co-authored-by: Simon Alibert <simon.alibert@huggingface.co>

tests/utils/test_queue.py

@@ -0,0 +1,150 @@
+#!/usr/bin/env python
+
+# Copyright 2025 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 threading
+import time
+from queue import Queue
+
+from lerobot.common.utils.queue import get_last_item_from_queue
+
+
+def test_get_last_item_single_item():
+    """Test getting the last item when queue has only one item."""
+    queue = Queue()
+    queue.put("single_item")
+
+    result = get_last_item_from_queue(queue)
+
+    assert result == "single_item"
+    assert queue.empty()
+
+
+def test_get_last_item_multiple_items():
+    """Test getting the last item when queue has multiple items."""
+    queue = Queue()
+    items = ["first", "second", "third", "fourth", "last"]
+
+    for item in items:
+        queue.put(item)
+
+    result = get_last_item_from_queue(queue)
+
+    assert result == "last"
+    assert queue.empty()
+
+
+def test_get_last_item_different_types():
+    """Test with different data types in the queue."""
+    queue = Queue()
+    items = [1, 2.5, "string", {"key": "value"}, [1, 2, 3], ("tuple", "data")]
+
+    for item in items:
+        queue.put(item)
+
+    result = get_last_item_from_queue(queue)
+
+    assert result == ("tuple", "data")
+    assert queue.empty()
+
+
+def test_get_last_item_maxsize_queue():
+    """Test with a queue that has a maximum size."""
+    queue = Queue(maxsize=5)
+
+    # Fill the queue
+    for i in range(5):
+        queue.put(i)
+
+    # Give the queue time to fill
+    time.sleep(0.1)
+
+    result = get_last_item_from_queue(queue)
+
+    assert result == 4
+    assert queue.empty()
+
+
+def test_get_last_item_with_none_values():
+    """Test with None values in the queue."""
+    queue = Queue()
+    items = [1, None, 2, None, 3]
+
+    for item in items:
+        queue.put(item)
+
+    # Give the queue time to fill
+    time.sleep(0.1)
+
+    result = get_last_item_from_queue(queue)
+
+    assert result == 3
+    assert queue.empty()
+
+
+def test_get_last_item_blocking_timeout():
+    """Test get_last_item_from_queue returns None on timeout."""
+    queue = Queue()
+    result = get_last_item_from_queue(queue, block=True, timeout=0.1)
+    assert result is None
+
+
+def test_get_last_item_non_blocking_empty():
+    """Test get_last_item_from_queue with block=False on an empty queue returns None."""
+    queue = Queue()
+    result = get_last_item_from_queue(queue, block=False)
+    assert result is None
+
+
+def test_get_last_item_non_blocking_success():
+    """Test get_last_item_from_queue with block=False on a non-empty queue."""
+    queue = Queue()
+    items = ["first", "second", "last"]
+    for item in items:
+        queue.put(item)
+
+    # Give the queue time to fill
+    time.sleep(0.1)
+
+    result = get_last_item_from_queue(queue, block=False)
+    assert result == "last"
+    assert queue.empty()
+
+
+def test_get_last_item_blocking_waits_for_item():
+    """Test that get_last_item_from_queue waits for an item if block=True."""
+    queue = Queue()
+    result = []
+
+    def producer():
+        queue.put("item1")
+        queue.put("item2")
+
+    def consumer():
+        # This will block until the producer puts the first item
+        item = get_last_item_from_queue(queue, block=True, timeout=0.2)
+        result.append(item)
+
+    producer_thread = threading.Thread(target=producer)
+    consumer_thread = threading.Thread(target=consumer)
+
+    producer_thread.start()
+    consumer_thread.start()
+
+    producer_thread.join()
+    consumer_thread.join()
+
+    assert result == ["item2"]
+    assert queue.empty()