Add UI block tests for skeleton color combo

Adds a new `tests/gui/ui_blocks/test_ui_blocks.py` suite to validate skeleton color dropdown behavior. The tests cover presence of the gradient option, round-tripping both gradient and solid styles, fallback to the default solid color when an unknown color is provided, and icon creation when enabled.

Author: C-Achard

tests/gui/ui_blocks/test_ui_blocks.py

@@ -0,0 +1,99 @@
+from __future__ import annotations
+
+from dlclivegui.display import BBoxColors
+from dlclivegui.gui.misc.color_dropdowns import (
+    get_skeleton_style_from_combo,
+    make_skeleton_color_combo,
+    set_skeleton_combo_from_style,
+)
+
+
+def test_skeleton_combo_contains_gradient_and_all_colors(
+    qtbot,
+) -> None:
+    combo = make_skeleton_color_combo(
+        BBoxColors,
+        include_icons=False,
+    )
+    qtbot.addWidget(combo)
+
+    assert combo.count() == 1 + len(BBoxColors)
+
+    gradient = combo.itemData(0)
+    assert gradient == {
+        "mode": "gradient_keypoints",
+        "color": None,
+    }
+
+
+def test_skeleton_combo_round_trips_gradient_style(
+    qtbot,
+) -> None:
+    combo = make_skeleton_color_combo(
+        BBoxColors,
+        include_icons=False,
+    )
+    qtbot.addWidget(combo)
+
+    set_skeleton_combo_from_style(
+        combo,
+        mode="gradient_keypoints",
+        color=None,
+    )
+
+    assert get_skeleton_style_from_combo(combo) == (
+        "gradient_keypoints",
+        None,
+    )
+
+
+def test_skeleton_combo_round_trips_solid_color(
+    qtbot,
+) -> None:
+    combo = make_skeleton_color_combo(
+        BBoxColors,
+        include_icons=False,
+    )
+    qtbot.addWidget(combo)
+
+    set_skeleton_combo_from_style(
+        combo,
+        mode="solid",
+        color=(0, 255, 0),
+    )
+
+    assert get_skeleton_style_from_combo(combo) == (
+        "solid",
+        (0, 255, 0),
+    )
+
+
+def test_skeleton_combo_falls_back_to_first_solid_color(
+    qtbot,
+) -> None:
+    combo = make_skeleton_color_combo(
+        BBoxColors,
+        include_icons=False,
+    )
+    qtbot.addWidget(combo)
+
+    set_skeleton_combo_from_style(
+        combo,
+        mode="solid",
+        color=(1, 2, 3),
+    )
+
+    mode, color = get_skeleton_style_from_combo(combo)
+
+    assert mode == "solid"
+    assert color == BBoxColors.RED.value
+
+
+def test_skeleton_combo_can_create_icons(qtbot) -> None:
+    combo = make_skeleton_color_combo(
+        BBoxColors,
+        include_icons=True,
+    )
+    qtbot.addWidget(combo)
+
+    assert not combo.itemIcon(0).isNull()