Fix SessionHandler call to start kernel

Author: kevin-bates

jupyter_server/services/sessions/handlers.py

@@ -132,9 +132,9 @@ def patch(self, session_id):
                 changes['kernel_id'] = kernel_id
             elif model['kernel'].get('name') is not None:
                 kernel_name = model['kernel']['name']
-                kernel_id = sm.start_kernel_for_session(
+                kernel_id = yield maybe_future(sm.start_kernel_for_session(
                     session_id, kernel_name=kernel_name, name=before['name'],
-                    path=before['path'], type=before['type'])
+                    path=before['path'], type=before['type']))
                 changes['kernel_id'] = kernel_id
 
         yield maybe_future(sm.update_session(session_id, **changes))

jupyter_server/services/sessions/tests/test_sessions_api.py

@@ -132,9 +132,15 @@ def test_create(self):
         sid = newsession['id']
         got = self.sess_api.get(sid).json()
 
-        # Kernel state may have changed from 'starting' to 'idle'
-        del got['kernel']['execution_state']
-        del newsession['kernel']['execution_state']
+        # Kernel state may have changed from 'starting' to 'idle',
+        # but let's only clean up if that's the case
+        if got['kernel']['execution_state'] == 'starting' and newsession['kernel']['execution_state'] == 'idle':
+            del got['kernel']['execution_state']
+            del newsession['kernel']['execution_state']
+            # include their last_activity as well
+            del got['kernel']['last_activity']
+            del newsession['kernel']['last_activity']
+
         self.assertEqual(got, newsession)
 
     def test_create_file_session(self):