Ensure configured Design overrides Template default

panel/template/base.py

@@ -44,6 +44,7 @@
 from ..theme.base import (
     THEMES, DefaultTheme, Design, Theme,
 )
+from ..theme.native import Native
 from ..util import isurl
 from ..viewable import (
     MimeRenderMixin, Renderable, ServableMixin, Viewable,
@@ -119,6 +120,8 @@ def __init__(
         }
         self._render_items: dict[str, tuple[Renderable, list[str]]]  = {}
         self._render_variables: dict[str, Any] = {}
+        if 'design' not in params and self.param.design.default in (None, Design, Native):
+            params['design'] = config.design
         super().__init__(**{
             p: v for p, v in params.items() if p not in _base_config.param or p == 'name'
         })

panel/tests/template/test_base.py

@@ -4,12 +4,13 @@
 from panel.io.notifications import NotificationArea
 from panel.io.state import set_curdoc, state
 from panel.template import VanillaTemplate
+from panel.theme import Material
 from panel.widgets import Button
 
 
 def test_notification_instantiate_on_config(document):
     with config.set(notifications=True):
         tmpl = VanillaTemplate()
 
     assert isinstance(tmpl.notifications, NotificationArea)
 
@@ -22,7 +23,7 @@
 
 
 def test_notification_explicit(document):
     tmpl = VanillaTemplate(notifications=NotificationArea())
 
     assert isinstance(tmpl.notifications, NotificationArea)
 
@@ -34,6 +35,13 @@
         assert state.notifications is tmpl.notifications
 
 
+def test_template_inherits_configured_design():
+    with config.set(design=Material):
+        tmpl = VanillaTemplate()
+
+    assert tmpl.design is Material
+
+
 def test_template_pass_config_params_constructor(document):
     custom_config = {
         'raw_css': ['html { background-color: purple; }'],
@@ -41,14 +49,14 @@
         'js_files': {'foo': 'foo.js'},
         'js_modules': {'bar': 'bar.js'},
     }
     tmpl = VanillaTemplate(**custom_config)
     config = tmpl.config.param.values()
     del config['name']
     assert config == custom_config
 
 
 def test_template_multi_refs():
     tmpl = VanillaTemplate()
     button = Button(name="Click me", button_type="primary")
     tmpl.sidebar.append(button)
     tmpl.main.append(button)