extend test coverage

Author: DanielYang59

cmasher/tests/test_utils.py

@@ -97,6 +97,17 @@ def test_combine_cmaps(self, cmaps, nodes):
 
         assert combined_cmap.N == 256
 
+    # Test combine cmaps with default nodes
+    def test_default_nodes(self):
+        combined_cmap = combine_cmaps("Blues", "Oranges", nodes=None, n_rgb_levels=256)
+
+        blues_cmap = mpl.colormaps["Blues"]
+        oranges_cmap = mpl.colormaps["Oranges"]
+
+        assert np.allclose(combined_cmap(0.0), blues_cmap(0))
+        assert np.allclose(combined_cmap(0.5), oranges_cmap(0))
+        assert np.allclose(combined_cmap(1.0), oranges_cmap(255))
+
     # Test if combining less than 2 colormaps triggers an error
     @pytest.mark.parametrize(
         "cmaps",