Don't assume that resources entries are relative (#1182)

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: ojarjur

jupyter_server/gateway/managers.py

@@ -218,13 +218,16 @@ def _replace_path_kernelspec_resources(self, kernel_specs):
             for resource_name in resources:
                 original_path = resources[resource_name]
                 split_eg_base_url = str.rsplit(original_path, sep="/kernelspecs/", maxsplit=1)
-                new_path = url_path_join(self.parent.base_url, "kernelspecs", split_eg_base_url[1])
-                kernel_specs["kernelspecs"][kernel_name]["resources"][resource_name] = new_path
-                if original_path != new_path:
-                    self.log.debug(
-                        f"Replaced original kernel resource path {original_path} with new "
-                        f"path {kernel_specs['kernelspecs'][kernel_name]['resources'][resource_name]}"
+                if len(split_eg_base_url) > 1:
+                    new_path = url_path_join(
+                        self.parent.base_url, "kernelspecs", split_eg_base_url[1]
                     )
+                    kernel_specs["kernelspecs"][kernel_name]["resources"][resource_name] = new_path
+                    if original_path != new_path:
+                        self.log.debug(
+                            f"Replaced original kernel resource path {original_path} with new "
+                            f"path {kernel_specs['kernelspecs'][kernel_name]['resources'][resource_name]}"
+                        )
         return kernel_specs
 
     def _get_kernelspecs_endpoint_url(self, kernel_name=None):

tests/test_gateway.py

@@ -41,7 +41,10 @@ def generate_kernelspec(name):
     kernelspec_stanza = {
         "name": name,
         "spec": spec_stanza,
-        "resources": {"logo-64x64": f"f/kernelspecs/{name}/logo-64x64.png"},
+        "resources": {
+            "logo-64x64": f"f/kernelspecs/{name}/logo-64x64.png",
+            "url": "https://example.com/example-url",
+        },
     }
     return kernelspec_stanza