Add invalid LogNorm limits test

dstansby · dstansby · commit c56c551476cb · 2019-04-18T11:21:54.000+01:00
diff --git a/lib/matplotlib/tests/test_colors.py b/lib/matplotlib/tests/test_colors.py
@@ -145,6 +145,16 @@ def test_BoundaryNorm():
     assert np.all(bn(vals).mask)
 
 
+@pytest.mark.parametrize("vmin,vmax", [[-1, 2], [3, 1]])
+def test_lognorm_invalid(vmin, vmax):
+    # Check that invalid limits in LogNorm error
+    norm = mcolors.LogNorm(vmin=vmin, vmax=vmax)
+    with pytest.raises(ValueError):
+        norm(1)
+    with pytest.raises(ValueError):
+        norm.inverse(1)
+
+
 def test_LogNorm():
     """
     LogNorm ignored clip, now it has the same
