Add async contents manager support

jupyterlab/jupyterlab_jupytext/__init__.py

@@ -8,6 +8,10 @@
     from jupytext.contentsmanager import build_jupytext_contents_manager_class
 except ImportError as err:
     build_jupytext_contents_manager = reraise(err)
+try:
+    from jupytext.async_contentsmanager import build_jupytext_async_contents_manager_class
+except ImportError as err:
+    build_jupytext_async_contents_manager = reraise(err)
 
 
 def load_jupyter_server_extension(app):  # pragma: no cover
@@ -24,24 +28,27 @@ def load_jupyter_server_extension(app):  # pragma: no cover
 
     # If possible, we derive a Jupytext CM from the current CM
     base_class = app.contents_manager_class
-    if asyncio.iscoroutinefunction(base_class.get):
-        app.log.warning(
-            f"[Jupytext Server Extension] Async contents managers like {base_class.__name__} "
-            "are not supported at the moment "
-            "(https://github.com/mwouts/jupytext/issues/1020). "
-            "We will derive a contents manager from LargeFileManager instead."
-        )
-        from jupyter_server.services.contents.largefilemanager import (  # noqa
-            LargeFileManager,
-        )
-
-        base_class = LargeFileManager
+    # if asyncio.iscoroutinefunction(base_class.get):
+        # app.log.warning(
+        #     f"[Jupytext Server Extension] Async contents managers like {base_class.__name__} "
+        #     "are not supported at the moment "
+        #     "(https://github.com/mwouts/jupytext/issues/1020). "
+        #     "We will derive a contents manager from LargeFileManager instead."
+        # )
+        # from jupyter_server.services.contents.largefilemanager import (  # noqa
+        #     LargeFileManager,
+        # )
+
+        # base_class = LargeFileManager
 
     app.log.info(
         "[Jupytext Server Extension] Deriving a JupytextContentsManager "
         "from {}".format(base_class.__name__)
     )
-    app.contents_manager_class = build_jupytext_contents_manager_class(base_class)
+    if asyncio.iscoroutinefunction(base_class.get):
+        app.contents_manager_class = build_jupytext_async_contents_manager_class(base_class)
+    else:
+        app.contents_manager_class = build_jupytext_contents_manager_class(base_class)
 
     try:
         # And rerun selected init steps from https://github.com/jupyter/notebook/blob/

pyproject.toml

@@ -50,6 +50,7 @@ Documentation = "https://jupytext.readthedocs.io"
 # Test related dependencies
 test = [
   "pytest",
+  "pytest-asyncio",
   "pytest-xdist",
   "pytest-randomly"
 ]

src/jupytext/__init__.py

@@ -15,6 +15,11 @@
 except ImportError as err:
     TextFileContentsManager = reraise(err)
 
+try:
+    from .async_contentsmanager import AsyncTextFileContentsManager
+except ImportError as err:
+    AsyncTextFileContentsManager = reraise(err)
+
 __all__ = [
     "read",
     "write",