Fix lint errors

Author: Mariko Wakabayashi

jupyter_server/services/contents/filecheckpoints.py

@@ -15,7 +15,6 @@
 
 from anyio import run_sync_in_worker_thread
 from jupyter_core.utils import ensure_dir_exists
-from jupyter_server.utils import ensure_async
 from ipython_genutils.py3compat import getcwd
 from traitlets import Unicode
 

jupyter_server/services/contents/fileio.py

@@ -12,7 +12,7 @@
 import os
 import shutil
 
-from anyio import open_file, run_sync_in_worker_thread
+from anyio import run_sync_in_worker_thread
 from tornado.web import HTTPError
 
 from jupyter_server.utils import (

jupyter_server/services/contents/filemanager.py

@@ -10,7 +10,6 @@
 import shutil
 import stat
 import sys
-import warnings
 import mimetypes
 import nbformat
 

jupyter_server/services/contents/manager.py

@@ -30,7 +30,6 @@
     default,
 )
 from ipython_genutils.py3compat import string_types
-from jupyter_server.base.handlers import JupyterHandler
 from jupyter_server.transutils import _
 from jupyter_server.utils import ensure_async
 

tests/services/contents/test_api.py

@@ -12,7 +12,6 @@
 )
 
 from jupyter_server.utils import url_path_join
-from jupyter_server.services.contents.filecheckpoints import AsyncFileCheckpoints, FileCheckpoints
 
 from base64 import encodebytes, decodebytes
 

tests/services/contents/test_config.py

@@ -1,6 +1,5 @@
 import pytest
 
-from traitlets.config import Config
 from jupyter_server.services.contents.checkpoints import AsyncCheckpoints
 from jupyter_server.services.contents.filecheckpoints import GenericFileCheckpoints
 from jupyter_server.services.contents.manager import AsyncContentsManager

tests/services/contents/test_manager.py

@@ -10,7 +10,6 @@
 
 from nbformat import v4 as nbformat
 
-from jupyter_server.services.contents.filecheckpoints import AsyncFileCheckpoints, FileCheckpoints
 from jupyter_server.services.contents.filemanager import AsyncFileContentsManager, FileContentsManager
 from jupyter_server.utils import ensure_async
 from ...utils import expected_http_error
@@ -335,7 +334,7 @@ async def test_get(jp_contents_manager):
     # Test in sub-directory
     sub_dir = '/foo/'
     _make_dir(cm, 'foo')
-    model = await ensure_async(cm.new_untitled(path=sub_dir, ext='.ipynb'))
+    await ensure_async(cm.new_untitled(path=sub_dir, ext='.ipynb'))
     model2 = await ensure_async(cm.get(sub_dir + name))
     assert isinstance(model2, dict)
     assert 'name' in model2
@@ -461,7 +460,6 @@ async def test_save(jp_contents_manager):
     sub_dir = '/foo/'
     _make_dir(cm, 'foo')
     model = await ensure_async(cm.new_untitled(path=sub_dir, type='notebook'))
-    name = model['name']
     path = model['path']
     model = await ensure_async(cm.get(path))