Fix import for jupyter_server 1 (#1359)

* Fix import for jupyter_server 1

* Force jupyter server version on CI

JupyterLab 4 being a build requirement, jupyter server 2 gets pulled. We
need to pin jupyter server for the test runtime.

* Fix name error server 1

* Fix import

.github/workflows/main.yml

@@ -33,7 +33,7 @@ jobs:
 
     - name: Create the conda environment
       shell: bash -l {0}
-      run: mamba install -q python=${{ matrix.python_version }} pip jupyterlab_pygments==0.1.0 pytest-cov pytest-rerunfailures nodejs=18 yarn=1 ipywidgets matplotlib xeus-cling  "traitlets>=5.0.3,<6" ipykernel jupyter_server=${{ matrix.server_version }}
+      run: mamba install -q python=${{ matrix.python_version }} pip jupyterlab_pygments==0.1.0 pytest-cov pytest-rerunfailures nodejs=18 yarn=1 ipywidgets matplotlib xeus-cling  "traitlets>=5.0.3,<6" ipykernel
 
     - name: Install dependencies
       shell: bash -l {0}
@@ -45,6 +45,10 @@ jobs:
         (cd tests/test_template; pip install .)
         (cd tests/skip_template; pip install .)
 
+    - name: Install proper jupyter server version
+      shell: bash -l {0}
+      run: pip install jupyter_server==${{ matrix.server_version }}
+
     - name: Run tests
       shell: bash -l {0}
       run: |

voila/app.py

@@ -21,8 +21,6 @@
 import errno
 import random
 
-from .voila_identity_provider import VoilaLoginHandler
-
 try:
     from urllib.parse import urljoin
     from urllib.request import pathname2url
@@ -65,14 +63,15 @@
     from jupyter_core.utils import run_sync
     from jupyter_server.services.config.manager import ConfigManager
 
-    from jupyterlab_server.themes_handler import ThemesHandler
+    from .voila_identity_provider import VoilaLoginHandler
 except ImportError:
     JUPYTER_SERVER_2 = False
 
     from jupyter_server.services.kernels.handlers import ZMQChannelsHandler
     from jupyter_server.utils import url_path_join, run_sync
     from jupyter_server.services.config import ConfigManager
 
+from jupyterlab_server.themes_handler import ThemesHandler
 
 from jupyter_client.kernelspec import KernelSpecManager
 
@@ -502,7 +501,8 @@ def setup_template_dirs(self):
             template_name = self.voila_configuration.template
             self.template_paths = collect_template_paths(['voila', 'nbconvert'], template_name, prune=True)
             self.static_paths = collect_static_paths(['voila', 'nbconvert'], template_name)
-            self.static_paths.append(DEFAULT_STATIC_FILES_PATH)
+            if JUPYTER_SERVER_2:
+                self.static_paths.append(DEFAULT_STATIC_FILES_PATH)
             conf_paths = [os.path.join(d, 'conf.json') for d in self.template_paths]
             for p in conf_paths:
                 # see if config file exists
@@ -650,6 +650,8 @@ def init_handlers(self) -> List:
         ])
 
         if JUPYTER_SERVER_2:
+
+
             handlers.extend(self.identity_provider.get_handlers())
 
         if self.voila_configuration.preheat_kernel: