refactor: rename the node from opencv-plot to dora-plot

The repository is dora-plot, but the package, the entrypoint, the manifest
name and the window title were all opencv-plot. Consumers wire the node by
`path:`, so the split name was visible in every dataflow.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018WLVZCFFcCH1EpTXGfS9aD

tests/test_dora_plot.py

@@ -0,0 +1,135 @@
+"""Tests that need neither a dataflow nor a display."""
+
+import io
+
+import cv2
+import numpy as np
+import pytest
+from PIL import Image
+
+from dora_plot import bbox, decode
+from dora_plot.plot import Bboxes, Plot
+
+WIDTH, HEIGHT = 12, 8
+
+
+class FakeStorage:
+    """Stands in for the Arrow array dora hands to the node."""
+
+    def __init__(self, data: np.ndarray) -> None:
+        self._data = data
+
+    def to_numpy(self) -> np.ndarray:
+        return self._data
+
+
+@pytest.fixture
+def frame() -> np.ndarray:
+    rng = np.random.default_rng(seed=0)
+    return rng.integers(0, 255, (HEIGHT, WIDTH, 3), dtype=np.uint8)
+
+
+def test_bgr8_round_trips_unchanged(frame):
+    decoded = decode.to_bgr(FakeStorage(frame.ravel()), "bgr8", WIDTH, HEIGHT)
+
+    np.testing.assert_array_equal(decoded, frame)
+
+
+def test_rgb8_round_trips_unchanged(frame):
+    rgb = cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)
+
+    decoded = decode.to_bgr(FakeStorage(rgb.ravel()), "rgb8", WIDTH, HEIGHT)
+
+    np.testing.assert_array_equal(decoded, frame)
+
+
+@pytest.mark.parametrize(("suffix", "encoding"), [
+    (".png", "png"),
+    (".jpg", "jpeg"),
+    (".bmp", "bmp"),
+    (".webp", "webp"),
+])
+def test_self_describing_encodings_need_no_dimensions(frame, suffix, encoding):
+    ok, buffer = cv2.imencode(suffix, frame)
+    assert ok
+
+    decoded = decode.to_bgr(FakeStorage(buffer.ravel()), encoding, None, None)
+
+    assert decoded.shape == (HEIGHT, WIDTH, 3)
+
+
+def test_yuv420_is_decoded(frame):
+    planes = cv2.cvtColor(frame, cv2.COLOR_BGR2YUV_I420)
+
+    decoded = decode.to_bgr(FakeStorage(planes.ravel()), "yuv420", WIDTH, HEIGHT)
+
+    assert decoded.shape == (HEIGHT, WIDTH, 3)
+
+
+def test_avif_is_decoded(frame):
+    buffer = io.BytesIO()
+    Image.fromarray(cv2.cvtColor(frame, cv2.COLOR_BGR2RGB)).save(buffer, format="AVIF")
+    payload = np.frombuffer(buffer.getvalue(), dtype=np.uint8)
+
+    decoded = decode.to_bgr(FakeStorage(payload), "avif", None, None)
+
+    assert decoded.shape == (HEIGHT, WIDTH, 3)
+
+
+def test_decoded_frame_is_writable():
+    storage = FakeStorage(np.arange(2 * 3 * 3, dtype=np.uint8))
+
+    decoded = decode.to_bgr(storage, "bgr8", width=3, height=2)
+
+    # The frame is annotated in place, so it must not be a read-only view.
+    decoded[0, 0] = 0
+
+
+def test_raw_encodings_need_dimensions():
+    storage = FakeStorage(np.zeros(18, dtype=np.uint8))
+    with pytest.raises(RuntimeError, match="width"):
+        decode.to_bgr(storage, "bgr8", width=None, height=None)
+
+
+def test_short_payload_is_rejected():
+    storage = FakeStorage(np.zeros(4, dtype=np.uint8))
+    with pytest.raises(RuntimeError, match="expected at least"):
+        decode.to_bgr(storage, "bgr8", width=3, height=2)
+
+
+def test_unsupported_encoding_is_rejected():
+    storage = FakeStorage(np.zeros(4, dtype=np.uint8))
+    with pytest.raises(RuntimeError, match="unsupported image encoding"):
+        decode.to_bgr(storage, "tiff", width=None, height=None)
+
+
+def test_xywh_is_converted_to_corners():
+    import pyarrow as pa
+
+    value = pa.array(
+        [
+            {
+                "bbox": np.array([10.0, 20.0, 4.0, 6.0]),
+                "conf": np.array([0.5]),
+                "labels": np.array(["cat"]),
+            },
+        ],
+    )
+
+    boxes = bbox.parse(value, "xywh")
+
+    np.testing.assert_allclose(boxes.corners, [[8.0, 17.0, 12.0, 23.0]])
+    assert list(boxes.labels) == ["cat"]
+
+
+def test_headless_show_draws_without_a_window():
+    plot = Plot(headless=True, text="hello")
+    plot.bboxes = Bboxes(
+        corners=np.array([[1.0, 1.0, 5.0, 5.0]]),
+        conf=np.array([0.9]),
+        labels=np.array(["cat"]),
+    )
+    frame = np.zeros((32, 32, 3), dtype=np.uint8)
+
+    assert plot.show(frame) is False
+    assert frame.any(), "the overlays should have marked the frame"