chore: implement initial support for CPython 3.14 (#2412)

This patch implements rudimentary support for CPython 3.14, adapting our
monkey-patching of Morsel attributes to a new optimization in 3.14 stdlib.

In addition, the monkey patching of the SameSite attribute was removed,
since it is no longer needed on 3.8+.

.github/workflows/tests.yaml

@@ -59,6 +59,8 @@ jobs:
             python-version: "3.13"
           - env: py313_cython
             python-version: "3.13"
+          - env: py314
+            python-version: "3.14.0-alpha.2 - 3.14.0"
           - env: py312_nocover
             os: macos-latest
             platform-label: ' (macos)'

docs/api/cookies.rst

@@ -155,13 +155,6 @@ at least set this attribute to ``'Lax'`` in order to mitigate
 Currently, :meth:`~falcon.Response.set_cookie` does not set `SameSite` by
 default, although this may change in a future release.
 
-.. note::
-
-    The standard ``http.cookies`` module does not support the `SameSite`
-    attribute in versions prior to Python 3.8. Therefore, Falcon performs a
-    simple monkey-patch on the standard library module to backport this
-    feature for apps running on older Python versions.
-
 .. _RFC 6265, Section 4.1.2.5:
     https://tools.ietf.org/html/rfc6265#section-4.1.2.5
 
@@ -172,7 +165,7 @@ by setting the 'samesite' kwarg.
 The Partitioned Attribute
 ~~~~~~~~~~~~~~~~~~~~~~~~~
 
-Starting from Q1 2024, Google Chrome will start to
+Starting from Q1 2024, Google Chrome started to
 `phase out support for third-party cookies
 <https://developers.google.com/privacy-sandbox/3pcd/prepare/prepare-for-phaseout>`__.
 If your site is relying on cross-site cookies, it might be necessary to set the
@@ -187,7 +180,7 @@ automatically depending on other attributes (like ``SameSite``),
 although this may change in a future release.
 
 .. note::
-    Similar to ``SameSite`` on older Python versions, the standard
-    :mod:`http.cookies` module does not support the ``Partitioned`` attribute
-    yet, and Falcon performs the same monkey-patching as it did for
-    ``SameSite``.
+    The standard :mod:`http.cookies` module does not support the `Partitioned`
+    attribute in versions prior to Python 3.14. Therefore, Falcon performs a
+    simple monkey-patch on the standard library module to backport this
+    feature for apps running on older Python versions.

falcon/util/__init__.py

@@ -52,17 +52,23 @@
 from falcon.util.sync import wrap_sync_to_async_unsafe
 from falcon.util.time import TimezoneGMT
 
-# NOTE(kgriffs): Backport support for the new 'SameSite' attribute
-#   for Python versions prior to 3.8. We do it this way because
-#   SimpleCookie does not give us a simple way to specify our own
-#   subclass of Morsel.
+# NOTE(kgriffs, m-mueller): Monkey-patch support for the new 'Partitioned'
+#   attribute that will probably be added in Python 3.14.
+#   We do it this way because SimpleCookie does not give us a simple way to
+#   specify our own subclass of Morsel.
 _reserved_cookie_attrs = http_cookies.Morsel._reserved  # type: ignore
-if 'samesite' not in _reserved_cookie_attrs:  # pragma: no cover
-    _reserved_cookie_attrs['samesite'] = 'SameSite'
-# NOTE(m-mueller): Same for the 'partitioned' attribute that will
-#   probably be added in Python 3.13 or 3.14.
 if 'partitioned' not in _reserved_cookie_attrs:  # pragma: no cover
     _reserved_cookie_attrs['partitioned'] = 'Partitioned'
+# NOTE(vytas): Morsel._reserved_defaults is a new optimization in Python 3.14+
+#   for faster initialization of Morsel instances.
+# TODO(vytas): Remove this part of monkey-patching in the case CPython 3.14
+#   adds the Partitioned attribute to Morsel.
+_reserved_cookie_defaults = getattr(http_cookies.Morsel, '_reserved_defaults', None)
+if (
+    _reserved_cookie_defaults is not None
+    and 'partitioned' not in _reserved_cookie_defaults
+):  # pragma: no cover
+    _reserved_cookie_defaults['partitioned'] = ''
 
 
 IS_64_BITS = sys.maxsize > 2**32

requirements/tests

@@ -26,4 +26,5 @@ ujson
 python-rapidjson; platform_python_implementation != 'PyPy' and platform_machine != 's390x' and platform_machine != 'aarch64'
 
 # wheels are missing some EoL interpreters and non-x86 platforms; build would fail unless rust is available
-orjson; platform_python_implementation != 'PyPy' and platform_machine != 's390x' and platform_machine != 'aarch64'
+# (not available for CPython 3.14 either yet)
+orjson; python_version < '3.14' and platform_python_implementation != 'PyPy' and platform_machine != 's390x' and platform_machine != 'aarch64'