Add Interval unit tests

seaborn/_marks/lines.py

@@ -203,7 +203,7 @@ class Lines(Paths):
 @dataclass
 class Interval(Paths):
     """
-    An oriented line mark drawn between min/max values on the other axis.
+    An oriented line mark drawn between min/max values.
     """
     def _setup_lines(self, split_gen, scales, orient):
 

tests/_marks/test_lines.py

@@ -6,7 +6,7 @@
 from numpy.testing import assert_array_equal
 
 from seaborn._core.plot import Plot
-from seaborn._marks.lines import Line, Path, Lines, Paths
+from seaborn._marks.lines import Line, Path, Lines, Paths, Interval
 
 
 class TestPath:
@@ -243,3 +243,50 @@ def test_xy_data(self):
         verts = lines.get_paths()[1].vertices.T
         assert_array_equal(verts[0], [2, 5])
         assert_array_equal(verts[1], [3, 4])
+
+
+class TestInterval:
+
+    def test_xy_data(self):
+
+        x = [1, 2]
+        ymin = [1, 4]
+        ymax = [2, 3]
+
+        p = Plot(x=x, ymin=ymin, ymax=ymax).add(Interval()).plot()
+        lines, = p._figure.axes[0].collections
+
+        for i, path in enumerate(lines.get_paths()):
+            verts = path.vertices.T
+            assert_array_equal(verts[0], [x[i], x[i]])
+            assert_array_equal(verts[1], [ymin[i], ymax[i]])
+
+    def test_mapped_color(self):
+
+        x = [1, 2, 1, 2]
+        ymin = [1, 4, 3, 2]
+        ymax = [2, 3, 1, 4]
+        group = ["a", "a", "b", "b"]
+
+        p = Plot(x=x, ymin=ymin, ymax=ymax, color=group).add(Interval()).plot()
+        lines, = p._figure.axes[0].collections
+
+        for i, path in enumerate(lines.get_paths()):
+            verts = path.vertices.T
+            assert_array_equal(verts[0], [x[i], x[i]])
+            assert_array_equal(verts[1], [ymin[i], ymax[i]])
+            assert same_color(lines.get_colors()[i], f"C{i // 2}")
+
+    def test_direct_properties(self):
+
+        x = [1, 2]
+        ymin = [1, 4]
+        ymax = [2, 3]
+
+        m = Interval(color="r", linewidth=4)
+        p = Plot(x=x, ymin=ymin, ymax=ymax).add(m).plot()
+        lines, = p._figure.axes[0].collections
+
+        for i, path in enumerate(lines.get_paths()):
+            assert same_color(lines.get_colors()[i], m.color)
+            assert lines.get_linewidths()[i] == m.linewidth