Features layer change test

src/napari_matplotlib/tests/conftest.py

@@ -26,6 +26,20 @@ def brain_data():
     return data.brain(), {"rgb": False}
 
 
+@pytest.fixture
+def points_with_features_data():
+    n_points = 100
+    np.random.seed(10)
+    points_data = 100 * np.random.random((100, 2))
+    points_features = {
+        "feature_0": np.random.random((n_points,)),
+        "feature_1": np.random.random((n_points,)),
+        "feature_2": np.random.random((n_points,)),
+    }
+
+    return points_data, {"features": points_features}
+
+
 @pytest.fixture(autouse=True, scope="session")
 def set_strict_qt():
     env_var = "NAPARI_STRICT_QT"

src/napari_matplotlib/tests/scatter/test_scatter_features.py

@@ -9,29 +9,22 @@
 
 
 @pytest.mark.mpl_image_compare
-def test_features_scatter_widget_2D(make_napari_viewer):
+def test_features_scatter_widget_2D(
+    make_napari_viewer, points_with_features_data
+):
     viewer = make_napari_viewer()
     viewer.theme = "light"
     widget = FeaturesScatterWidget(viewer)
 
-    # make the points data
-    n_points = 100
-    np.random.seed(10)
-    points_data = 100 * np.random.random((100, 2))
-    points_features = {
-        "feature_0": np.random.random((n_points,)),
-        "feature_1": np.random.random((n_points,)),
-        "feature_2": np.random.random((n_points,)),
-    }
-
-    viewer.add_points(points_data, features=points_features)
+    viewer.add_points(
+        points_with_features_data[0], **points_with_features_data[1]
+    )
+    assert len(viewer.layers) == 1
     # De-select existing selection
     viewer.layers.selection.clear()
 
     # Select points data and chosen features
-    viewer.layers.selection.add(
-        viewer.layers["points_data"]
-    )  # images need to be selected
+    viewer.layers.selection.add(viewer.layers[0])  # images need to be selected
     widget.x_axis_key = "feature_0"
     widget.y_axis_key = "feature_1"
 

src/napari_matplotlib/tests/test_layer_changes.py

@@ -6,7 +6,11 @@
 import pytest
 from napari.viewer import Viewer
 
-from napari_matplotlib import HistogramWidget, SliceWidget
+from napari_matplotlib import (
+    FeaturesScatterWidget,
+    HistogramWidget,
+    SliceWidget,
+)
 from napari_matplotlib.base import NapariMPLWidget
 from napari_matplotlib.tests.helpers import (
     assert_figures_equal,
@@ -39,10 +43,48 @@ def assert_one_layer_plot_changes(
     by `widget_cls` also changes.
     """
     widget = widget_cls(viewer)
-
     viewer.add_image(data1[0], **data1[1])
     viewer.add_image(data2[0], **data2[1])
+    assert_plot_changes(viewer, widget)
+
 
+@pytest.mark.parametrize("widget_cls", [FeaturesScatterWidget])
+def test_change_features_layer(
+    make_napari_viewer, points_with_features_data, widget_cls
+):
+    """
+    Test all widgets that take one layer with features as input to make sure the
+    plot changes when the napari layer selection changes.
+    """
+    viewer = make_napari_viewer()
+    assert_features_plot_changes(viewer, widget_cls, points_with_features_data)
+
+
+def assert_features_plot_changes(
+    viewer: Viewer,
+    widget_cls: Type[NapariMPLWidget],
+    data: Tuple[npt.NDArray[np.generic], Dict[str, Any]],
+) -> None:
+    """
+    When the selected layer is changed, make sure the plot generated
+    by `widget_cls` also changes.
+    """
+    widget = widget_cls(viewer)
+    viewer.add_points(data[0], **data[1])
+    # Change the features data for the second layer
+    data[1]["features"] = {
+        name: data + 1 for name, data in data[1]["features"].items()
+    }
+    viewer.add_points(data[0], **data[1])
+    assert_plot_changes(viewer, widget)
+
+
+def assert_plot_changes(viewer: Viewer, widget: NapariMPLWidget) -> None:
+    """
+    Assert that a widget plot changes when the layer selection
+    is changed. The passed viewer must already have two layers
+    loaded.
+    """
     # Select first layer
     viewer.layers.selection.clear()
     viewer.layers.selection.add(viewer.layers[0])