fix: autorouting should pick up modules that only define routes

Instead of having a Page component, we should also just allow a user
to define a set of routes.
This is what we need for the /apps/scrolling example.

solara/autorouting.py

@@ -218,17 +218,25 @@ def get_args(f):
         title = route_current.label or "No title"
         title_element = solara.Title(title)
         module = None
-        if route_current.module is not None:
+        Page = route_current.component
+        # translate the default RenderPage as no value given (None)
+        if Page is RenderPage:
+            Page = None
+        if route_current.module is not None and (Page is None):
+            # if not a custom component is given, we try to find a Page component
+            # in the module
             assert route_current.module is not None
             module = route_current.module
             namespace = module.__dict__
-            Page = nested_get(namespace, main_name, None)
+            Page = nested_get(namespace, main_name, Page)
             if Page is None:
                 # app is for backwards compatibility
-                Page = namespace.get("page", namespace.get("app"))
+                Page = namespace.get("page", namespace.get("app", Page))
                 Page = nested_get(namespace, main_name, Page)
-        else:
-            Page = route_current.component
+
+        if Page is None and route_current.children:
+            # we we did not get a component, but we recursively render
+            Page = RenderPage
         if isinstance(Page, ipywidgets.Widget):
             # If we have a widget, we need to execute this again for each
             # connection, since we cannot share widgets between connections/users.
@@ -393,7 +401,7 @@ def generate_routes(module: ModuleType) -> List[solara.Route]:
                     continue
             else:
                 # skip empty modules
-                if get_renderable(submod) is None:
+                if get_renderable(submod) is None and not hasattr(submod, "routes"):
                     continue
                 children = getattr(submod, "routes", [])
                 if subfile:

tests/unit/autorouting_test.py

@@ -134,7 +134,7 @@ def test_routes_examples_docs():
 
 def test_routes_directory():
     routes = solara.autorouting.generate_routes_directory(HERE.parent / "solara_test_apps" / "multipage")
-    assert len(routes) == 7
+    assert len(routes) == 8
     assert routes[0].path == "/"
     assert routes[0].label == "Home"
 
@@ -152,11 +152,18 @@ def test_routes_directory():
     assert routes[4].path == "and-notebooks"
     assert routes[4].label == "And Notebooks"
 
-    assert routes[5].path == "single-file-directory"
-    assert routes[5].label == "Single File Directory"
+    assert routes[5].path == "custom-routes"
+    assert routes[5].label == "Custom Routes"
+    assert routes[5].children[0].path == "/"
+    assert routes[5].children[0].label == "Hi1"
+    assert routes[5].children[1].path == "page2"
+    assert routes[5].children[1].label == "Hi2"
 
-    assert routes[6].path == "some-other-python-script"
-    assert routes[6].label == "Some Other Python Script"
+    assert routes[6].path == "single-file-directory"
+    assert routes[6].label == "Single File Directory"
+
+    assert routes[7].path == "some-other-python-script"
+    assert routes[7].label == "Some Other Python Script"
 
     main_object = solara.autorouting.RenderPage()
     solara_context = solara.RoutingProvider(children=[main_object], routes=routes, pathname="/")
@@ -201,6 +208,16 @@ def test_routes_directory():
     nav.location = "/a-directory/wrong-path"
     assert "Page not found" in rc._find(v.Alert).widget.children[0]
 
+    # custom routes in a single file
+
+    nav.location = "/custom-routes"
+    button = rc._find(v.Btn, children=["hi1"]).widget
+    assert button.children[0] == "hi1"
+
+    nav.location = "/custom-routes/page2"
+    button = rc._find(v.Btn, children=["hi2"]).widget
+    assert button.children[0] == "hi2"
+
 
 def test_routes_regular_widgets():
     # routes = solara.autorouting.generate_routes_directory(HERE.parent / "solara_test_apps" / "multipage")