Update tree handler

voila/server_extension.py

@@ -28,7 +28,7 @@
 from .utils import get_server_root_dir
 
 
-def _jupyter_server_extension_paths():
+def _jupyter_server_extension_points():
     """
     Returns a list of dictionaries with metadata describing
     where to find the `_load_jupyter_server_extension` function.
@@ -38,7 +38,6 @@ def _jupyter_server_extension_paths():
 
 def _load_jupyter_server_extension(server_app):
     web_app = server_app.web_app
-
     # common configuration options between the server extension and the application
     voila_configuration = VoilaConfiguration(parent=server_app)
     template_name = voila_configuration.template

voila/treehandler.py

@@ -13,6 +13,7 @@
 
 from .handler import BaseVoilaHandler
 from .utils import get_server_root_dir
+from nbclient.util import ensure_async
 
 
 class VoilaTreeHandler(BaseVoilaHandler):
@@ -51,16 +52,18 @@ def generate_page_title(self, path):
             return "Voilà Home"
 
     @web.authenticated
-    def get(self, path=""):
+    async def get(self, path=""):
         cm = self.contents_manager
-
-        if cm.dir_exists(path=path):
-            if cm.is_hidden(path) and not cm.allow_hidden:
+        dir_exists = await ensure_async(cm.dir_exists(path=path))
+        file_exists = await ensure_async(cm.file_exists(path))
+        if dir_exists:
+            is_hidden = await ensure_async(cm.is_hidden(path))
+            if is_hidden and not cm.allow_hidden:
                 self.log.info("Refusing to serve hidden directory, via 404 Error")
                 raise web.HTTPError(404)
             breadcrumbs = self.generate_breadcrumbs(path)
             page_title = self.generate_page_title(path)
-            contents = cm.get(path)
+            contents = await ensure_async(cm.get(path))
 
             def allowed_content(content):
                 if content["type"] in ["directory", "notebook"]:
@@ -85,9 +88,9 @@ def allowed_content(content):
                     query=self.request.query,
                 )
             )
-        elif cm.file_exists(path):
+        elif file_exists:
             # it's not a directory, we have redirecting to do
-            model = cm.get(path, content=False)
+            model = await ensure_async(cm.get(path, content=False))
             # redirect to /api/notebooks if it's a notebook, otherwise /api/files
             service = "notebooks" if model["type"] == "notebook" else "files"
             url = url_path_join(