test(cameras): add minimal opencv test

tests/cameras/test_opencv.py

@@ -1,13 +1,163 @@
-# from lerobot.common.cameras.opencv import OpenCVCamera, OpenCVCameraConfig
+#!/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 numpy as np
+import pytest
+
+from lerobot.common.cameras.configs import Cv2Rotation
+from lerobot.common.cameras.opencv import OpenCVCamera, OpenCVCameraConfig
+from lerobot.common.errors import DeviceAlreadyConnectedError, DeviceNotConnectedError
 
 
-# class TestCameras(unittest.TestCase):
-# # NOTE(Steven): Independent test func
-# def test_connect():
-#     config = OpenCVCameraConfig(camera_id=0)
-#     camera = OpenCVCamera(config)
-#     camera.connect()
-#     assert camera.is_connected
+def test_base_class_implementation():
+    config = OpenCVCameraConfig(index_or_path=0)
+
+    _ = OpenCVCamera(config)
 
 
-# # 1. Refactor -> opencv , write some test , think about realsese, iterate
+def test_connect():
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png")
+    camera = OpenCVCamera(config)
+
+    camera.connect()
+
+    assert camera.is_connected
+
+
+def test_connect_already_connected():
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png")
+    camera = OpenCVCamera(config)
+    camera.connect()
+
+    with pytest.raises(DeviceAlreadyConnectedError):
+        camera.connect()
+
+
+def test_connect_invalid_camera_path():
+    config = OpenCVCameraConfig(index_or_path="nonexistent/camera.png")
+    camera = OpenCVCamera(config)
+
+    with pytest.raises(ConnectionError):
+        camera.connect()
+
+
+def test_invalid_width_connect():
+    config = OpenCVCameraConfig(
+        index_or_path="tests/artifacts/cameras/fake_cam.png",
+        width=99999,  # Invalid width to trigger error
+        height=480,
+    )
+    camera = OpenCVCamera(config)
+
+    with pytest.raises(RuntimeError):
+        camera.connect()
+
+
+def test_read():
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png")
+    camera = OpenCVCamera(config)
+    camera.connect()
+
+    img = camera.read()
+
+    assert isinstance(img, np.ndarray)
+
+
+def test_read_before_connect():
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png")
+    camera = OpenCVCamera(config)
+
+    with pytest.raises(DeviceNotConnectedError):
+        _ = camera.read()
+
+
+def test_disconnect():
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png")
+    camera = OpenCVCamera(config)
+    camera.connect()
+
+    camera.disconnect()
+
+    assert not camera.is_connected
+
+
+def test_disconnect_before_connect():
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png")
+    camera = OpenCVCamera(config)
+
+    with pytest.raises(DeviceNotConnectedError):
+        _ = camera.disconnect()
+
+
+def test_async_read():
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png")
+    camera = OpenCVCamera(config)
+    camera.connect()
+
+    img = camera.async_read()
+
+    assert camera.thread is not None
+    assert camera.thread.is_alive()
+    assert isinstance(img, np.ndarray)
+    camera.disconnect()  # To stop/join the thread. Otherwise get warnings when the test ends
+
+
+def test_async_read_timeout():
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png")
+    camera = OpenCVCamera(config)
+    camera.connect()
+
+    with pytest.raises(TimeoutError):
+        _ = camera.async_read(timeout_ms=1)
+
+    camera.disconnect()
+
+
+def test_async_read_before_connect():
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png")
+    camera = OpenCVCamera(config)
+
+    with pytest.raises(DeviceNotConnectedError):
+        _ = camera.async_read()
+
+
+@pytest.mark.parametrize(
+    "rotation",
+    [
+        Cv2Rotation.NO_ROTATION,
+        Cv2Rotation.ROTATE_90,
+        Cv2Rotation.ROTATE_180,
+        Cv2Rotation.ROTATE_270,
+    ],
+)
+def test_all_rotations(rotation):
+    config = OpenCVCameraConfig(index_or_path="tests/artifacts/cameras/fake_cam.png", rotation=rotation)
+    camera = OpenCVCamera(config)
+    camera.connect()
+
+    img = camera.read()
+    assert isinstance(img, np.ndarray)
+
+    if rotation in (Cv2Rotation.ROTATE_90, Cv2Rotation.ROTATE_270):
+        assert camera.width == 480
+        assert camera.height == 640
+        assert img.shape[:2] == (640, 480)
+    else:
+        assert camera.width == 640
+        assert camera.height == 480
+        assert img.shape[:2] == (480, 640)
+
+    camera.disconnect()