Add test

jdaviz/configs/default/plugins/plot_options/plot_options.py

@@ -629,7 +629,7 @@ def apply_RGB_presets(self):
         visible_layers = []
         for layer in image_layers:
             self.layer_selected = layer
-            if self.image_visible:
+            if self.image_visible.value:
                 visible_layers.append(layer)
 
         # Set opacity to something that seems sensible
@@ -638,7 +638,7 @@ def apply_RGB_presets(self):
         if n_visible > 2:
             default_opacity = 1 / math.log2(n_visible)
         # Sample along a colormap if we have too many layers
-        if len(visible_layers) > 5:
+        if n_visible > 5:
             cmap = matplotlib.colormaps['gist_rainbow'].resampled(n_visible)
 
             def _rgb_to_hex(rgb):
@@ -648,7 +648,7 @@ def _rgb_to_hex(rgb):
         for i in range(n_visible):
             self.layer_selected = visible_layers[i]
             self.image_opacity_value = default_opacity
-            if len(visible_layers) < 6:
+            if n_visible < 6:
                 self.image_color_value = preset_colors[i]
             else:
                 self.image_color_value = _rgb_to_hex(cmap(i))

jdaviz/configs/default/plugins/plot_options/tests/test_plot_options.py

@@ -2,6 +2,7 @@
 import pytest
 from astropy import units as u
 from astropy.nddata import NDData
+import matplotlib
 from numpy.testing import assert_allclose
 from photutils.datasets import make_4gaussians_image
 
@@ -250,3 +251,56 @@ def test_update_knots_mismatched_length():
     stretch = SplineStretch()
     with pytest.raises(ValueError):
         stretch.update_knots(x=[0, 0.1, 0.2], y=[0, 0.05])
+
+
+def test_apply_presets(imviz_helper):
+    arr = np.arange(36).reshape(6, 6)
+    po = imviz_helper.plugins['Plot Options']
+
+    preset_colors = [po._obj.swatches_palette[0][0], "#0000FF", "#00FF00",
+                     po._obj.swatches_palette[1][0],]
+
+    # Test applying presets with < 6 layers
+
+    for i in range(4):
+        imviz_helper.load_data(arr, data_label=f"array_{i}")
+
+    po.image_color_mode = "Monochromatic"
+    po.apply_RGB_presets()
+
+    for i in range(4):
+        po.layer = f"array_{i}"
+        assert po.stretch_function.value == "arcsinh"
+        assert po.stretch_preset.value == 99
+        assert po.image_color.value == preset_colors[i]
+
+    # Test applying presets with > 5 layers
+
+    for i in range(4):
+        imviz_helper.load_data(arr, data_label=f"array_{i+4}")
+
+    po.layer = "array_5"
+    po.image_visible = False
+    po.layer = "array_3"
+
+    po.apply_RGB_presets()
+
+    assert po.layer.selected == "array_3"
+
+    colorbar_colors = matplotlib.colormaps['gist_rainbow'].resampled(7)
+    color_ind = 0
+
+    def _rgb_to_hex(rgb):
+        rgb = [int(x * 255) for x in rgb]
+        return f"#{rgb[0]:02x}{rgb[1]:02x}{rgb[2]:02x}{rgb[3]:02x}"
+
+    for i in range(8):
+        po.layer = f"array_{i}"
+        if i == 5:
+            # Make sure this one didn't change
+            assert po.stretch_function.value == "linear"
+        else:
+            assert po.stretch_function.value == "arcsinh"
+            assert po.stretch_preset.value == 99
+            assert po.image_color.value == _rgb_to_hex(colorbar_colors(color_ind))
+            color_ind += 1