feat!: migrate MongoEngine to native async PyMongo (>= 4.14)

- Refactored the core ORM to support PyMongo’s native async API
- Unified sync and async code paths across documents, querysets, and transactions
- Replaced legacy async implementations
- Removed deprecated and compatibility code

BREAKING CHANGE:
- Removed legacy async behavior
- Removed LazyReferenceField
- Removed GenericLazyReferenceField
- GenericReferenceField now requires `choices`
- Dropped support for PyMongo < 4.14
- Dropped support for MongoDB < 4.2

Author: arunsureshkumar

docs/apireference.rst

@@ -92,9 +92,7 @@ Fields
 .. autoclass:: mongoengine.fields.DictField
 .. autoclass:: mongoengine.fields.MapField
 .. autoclass:: mongoengine.fields.ReferenceField
-.. autoclass:: mongoengine.fields.LazyReferenceField
 .. autoclass:: mongoengine.fields.GenericReferenceField
-.. autoclass:: mongoengine.fields.GenericLazyReferenceField
 .. autoclass:: mongoengine.fields.CachedReferenceField
 .. autoclass:: mongoengine.fields.BinaryField
 .. autoclass:: mongoengine.fields.FileField

mongoengine/__init__.py

@@ -1,34 +1,31 @@
 # Import submodules so that we can expose their __all__
 from mongoengine import (
-    connection,
     document,
     errors,
     fields,
-    queryset,
     signals,
 )
+from mongoengine.synchronous import connection
+from mongoengine.base import queryset
 
 # Import everything from each submodule so that it can be accessed via
 # mongoengine, e.g. instead of `from mongoengine.connection import connect`,
 # users can simply use `from mongoengine import connect`, or even
 # `from mongoengine import *` and then `connect('testdb')`.
-from mongoengine.connection import *  # noqa: F401
+from mongoengine.synchronous.connection import *  # noqa: F401
 from mongoengine.document import *  # noqa: F401
 from mongoengine.errors import *  # noqa: F401
 from mongoengine.fields import *  # noqa: F401
-from mongoengine.queryset import *  # noqa: F401
 from mongoengine.signals import *  # noqa: F401
 
 __all__ = (
-    list(document.__all__)
-    + list(fields.__all__)
-    + list(connection.__all__)
-    + list(queryset.__all__)
-    + list(signals.__all__)
-    + list(errors.__all__)
+        list(document.__all__)
+        + list(fields.__all__)
+        + list(connection.__all__)
+        + list(signals.__all__)
+        + list(errors.__all__)
 )
 
-
 VERSION = (0, 29, 0)
 
 

mongoengine/asynchronous/__init__.py

@@ -0,0 +1,7 @@
+from .connection import *
+from .queryset import *
+
+__all__ = [
+    list(connection.__all__) +
+    list(queryset.__all__),
+]