Add a test for clickable bar ranges

tests/renderables/test_underline_bar.py

@@ -1,3 +1,9 @@
+from unittest.mock import create_autospec
+
+from rich.console import Console
+from rich.console import ConsoleOptions
+from rich.text import Text
+
 from tests.utilities.render import render
 from textual.renderables.underline_bar import UnderlineBar
 
@@ -119,3 +125,19 @@ def test_custom_styles():
         f"{GREEN}╺{STOP}"
         f"{GREEN}━{STOP}"
     )
+
+
+def test_clickable_ranges():
+    bar = UnderlineBar(highlight_range=(0, 1), width=6, clickable_ranges={"foo": (0, 2), "bar": (4, 5)})
+
+    console = create_autospec(Console)
+    options = create_autospec(ConsoleOptions)
+    text: Text = list(bar.__rich_console__(console, options))[0]
+
+    start, end, style = text.spans[-2]
+    assert (start, end) == (0, 2)
+    assert style.meta == {'@click': "range_clicked('foo')"}
+
+    start, end, style = text.spans[-1]
+    assert (start, end) == (4, 5)
+    assert style.meta == {'@click': "range_clicked('bar')"}