Prevent load of disabled (or disabling) extension modules

jupyter_server/extension/manager.py

@@ -163,6 +163,10 @@ def __init__(self, *args, **kwargs):
         """Initialize an extension package."""
         # Store extension points that have been linked.
         self._linked_points = {}
+        self._extension_points = {}
+        self._module = None
+        self._metadata = []
+        self._action = kwargs.pop("action", "")
         super().__init__(*args, **kwargs)
 
     _linked_points: dict = {}
@@ -172,7 +176,9 @@ def _validate_name(self, proposed):
         name = proposed["value"]
         self._extension_points = {}
         try:
-            self._module, self._metadata = get_metadata(name, self.log)
+            # Perform load if we're enabling, or it's already enabled and not disabling the module
+            if (self.enabled and self._action != "disabling") or self._action == "enabling":
+                self._module, self._metadata = get_metadata(name, self.log)
         except ImportError as e:
             msg = (
                 f"The module '{name}' could not be found ({e}). Are you "

jupyter_server/extension/serverextension.py

@@ -246,14 +246,17 @@ def toggle_server_extension(self, import_name):
         )
         try:
             self.log.info(f"{self._toggle_pre_message.capitalize()}: {import_name}")
-            self.log.info(f"- Writing config: {config_dir}")
-            # Validate the server extension.
-            self.log.info(f"    - Validating {import_name}...")
-            # Interface with the Extension Package and validate.
-            extpkg = ExtensionPackage(name=import_name)
-            extpkg.validate()
-            version = extpkg.version
-            self.log.info(f"      {import_name} {version} {GREEN_OK}")
+            self.log.info(f"    - Writing config: {config_dir}")
+            # If enabling, validate the server extension.
+            if self._toggle_pre_message == "enabling":
+                self.log.info(f"    - Validating {import_name}...")
+                # Interface with the Extension Package and validate.
+                extpkg = ExtensionPackage(name=import_name, action=self._toggle_pre_message)
+                extpkg.validate()
+                version = extpkg.version
+                self.log.info(f"      {import_name} {version} {GREEN_OK}")
+            else:
+                self.log.info(f"    - Validation of {import_name} skipped due to acton to disable.")
 
             # Toggle extension config.
             config = extension_manager.config_manager
@@ -335,19 +338,22 @@ def list_server_extensions(self):
             for name, enabled in jpserver_extensions.items():
                 # Attempt to get extension metadata
                 self.log.info(f"    {name} {GREEN_ENABLED if enabled else RED_DISABLED}")
-                try:
-                    self.log.info(f"    - Validating {name}...")
-                    extension = ExtensionPackage(name=name, enabled=enabled)
-                    if not extension.validate():
-                        msg = "validation failed"
-                        raise ValueError(msg)
-                    version = extension.version
-                    self.log.info(f"      {name} {version} {GREEN_OK}")
-                except Exception as err:
-                    exc_info = False
-                    if int(self.log_level) <= logging.DEBUG:
-                        exc_info = True
-                    self.log.warning(f"      {RED_X} {err}", exc_info=exc_info)
+                if enabled:
+                    try:
+                        self.log.info(f"    - Validating {name}...")
+                        extension = ExtensionPackage(name=name, enabled=enabled)
+                        if not extension.validate():
+                            msg = "validation failed"
+                            raise ValueError(msg)
+                        version = extension.version
+                        self.log.info(f"      {name} {version} {GREEN_OK}")
+                    except Exception as err:
+                        exc_info = False
+                        if int(self.log_level) <= logging.DEBUG:
+                            exc_info = True
+                        self.log.warning(f"      {RED_X} {err}", exc_info=exc_info)
+                else:
+                    self.log.info(f"    - Validation of {name} skipped.")
             # Add a blank line between paths.
             self.log.info("")
 

jupyter_server/extension/utils.py

@@ -71,7 +71,7 @@ def get_metadata(package_name, logger=None):
     # each module took to import. This makes it much easier for users to report
     # slow loading modules upstream, as slow loading modules will block server startup
     if logger:
-        logger.info(f"Package {package_name} took {duration:.4f}s to import")
+        logger.info(f"    - Package {package_name} took {duration:.4f}s to import")
 
     try:
         return module, module._jupyter_server_extension_points()