Add tests to cover new handling and fix related issues

coloraide/average.py

@@ -28,11 +28,10 @@ def average(
     cs = obj.CS_MAP[space]
     if cs.is_polar():
         hue_index = cs.hue_index()  # type: ignore[attr-defined]
-        has_radial = hasattr(cs, 'radial_index')
-        is_hwb = not has_radial and isinstance(cs, HWBish)
+        is_hwb = isinstance(cs, HWBish)
     else:
         hue_index = 1
-        has_radial = is_hwb = False
+        is_hwb = False
     channels = cs.channels
     chan_count = len(channels)
     alpha_index = chan_count - 1
@@ -92,10 +91,10 @@ def average(
     # Create the color and if polar and there is no defined hue, force an achromatic state.
     color = obj.update(space, sums[:-1], sums[-1])
     if cs.is_polar():
-        if has_radial and math.isnan(color[hue_index]):
-            color[cs.radial_index()] = 0  # type: ignore[attr-defined]
-        elif is_hwb and math.isnan(color[hue_index]):
+        if is_hwb and math.isnan(color[hue_index]):
             w, b = cs.indexes()[1:]  # type: ignore[attr-defined]
             if color[w] + color[b] < 1:
                 color[w] = 1 - color[b]
+        elif math.isnan(color[hue_index]):
+            color[cs.radial_index()] = 0  # type: ignore[attr-defined]
     return color

tests/test_average.py

@@ -122,6 +122,29 @@ def test_average_ignore_undefined_alpha_premultiplied(self):
         colors = [Color('darkgreen'), Color('color(srgb 0 0.50196 0 / none)'), Color('color(srgb 0 0 1)')]
         self.assertEqual(Color.average(colors, space='srgb').to_string(color=True), 'color(srgb 0 0.29804 0.33333)')
 
+    def test_evenly_distributed(self):
+        """Test evenly distributed colors."""
+
+        colors = ['red', 'green', 'blue']
+        self.assertEqual(
+            Color.average(colors, space='hsl').to_string(color=True, none=True),
+            'color(--hsl none 0 0.41699)'
+        )
+
+    def test_hwb_handling(self):
+        """Test HWB handling."""
+
+        colors = ['red', 'green', 'blue']
+        self.assertEqual(
+            Color.average(colors, space='hwb').to_string(color=True, none=True),
+            'color(--hwb none 0.83399 0.16601)'
+        )
+
+        self.assertEqual(
+            Color.average(['orange', 'purple', 'darkgreen'], space='hwb').to_string(color=True),
+            'color(--hwb 38.824 0 0.36863)'
+        )
+
     def test_all_undefined_hue(self):
         """Test all hues undefined."""