Add Python 3.15 test coverage (#4565)

* Add Python 3.15 test coverage

* Install Python 3.15 build dependencies

* Complete Python 3.15 build toolchain

* Skip codeflash on Python 3.15

* Avoid private dataclasses APIs

* Preserve ClassVar detection across Python versions

---------

Co-authored-by: Amp <amp@ampcode.com>

Author: patrick91

.github/workflows/test.yml

@@ -34,6 +34,7 @@ jobs:
             jq 'map(
               {
                 session,
+                python: .python,
                 name: "\( .name ) on \( .python )\( if .call_spec != {} then " (\(.call_spec | to_entries | map("\(.key)=\(.value)") | join(", ")))" else "" end )"
               }
             )'
@@ -52,6 +53,11 @@ jobs:
       - uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1 # v7.0.1
         with:
           persist-credentials: false
+      - name: Set up Python
+        uses: actions/setup-python@5fda3b95a4ea91299a34e894583c3862153e4b97 # v7.0.0
+        with:
+          python-version: ${{ matrix.session.python }}
+          allow-prereleases: true
       - name: Install uv
         uses: astral-sh/setup-uv@20cfd1bf945f4377ade1205e4dbc17946fc9a30d # v10.0.1
         with:

RELEASE.md

@@ -0,0 +1,14 @@
+---
+release type: patch
+social_messages:
+  x: >-
+    {project_name} {version} is out! This release adds support for the upcoming
+    Python 3.15. 🍓 https://strawberry.rocks/release/{version}
+  linkedin: >-
+    {project_name} {version} is out. This release adds support for the upcoming
+    Python 3.15, keeping Strawberry tested across the latest Python release. 🍓
+---
+
+This release adds support for the upcoming Python 3.15.
+
+Strawberry's test suite now runs on Python 3.15.

noxfile.py

@@ -8,7 +8,7 @@
 nox.options.error_on_external_run = True
 nox.options.default_venv_backend = "uv"
 
-PYTHON_VERSIONS = ["3.14", "3.13", "3.12", "3.11", "3.10"]
+PYTHON_VERSIONS = ["3.15", "3.14", "3.13", "3.12", "3.11", "3.10"]
 
 GQL_CORE_VERSIONS = [
     "3.2.6",

pyproject.toml

@@ -39,7 +39,7 @@ strawberry = "strawberry.cli:run"
 [project.optional-dependencies]
 aiohttp = ["aiohttp>=3.7.4.post0,<4"]
 asgi = ["starlette>=0.18.0", "python-multipart>=0.0.7"]
-debug = ["rich>=12.0.0", "libcst"]
+debug = ["rich>=12.0.0", "libcst>=1.9.0"]
 django = ["Django>=5.2", "asgiref>=3.2"]
 channels = ["channels>=4.0.0", "Django>=5.2", "asgiref>=3.2"]
 flask = ["flask>=1.1"]
@@ -54,7 +54,7 @@ cli = [
   "typer>=0.12.4",
   "pygments>=2.3",
   "rich>=12.0.0",
-  "libcst",
+  "libcst>=1.9.0",
   "starlette>=0.18.0",
   "uvicorn>=0.11.6",
   "websockets>=15.0.1,<17",
@@ -69,7 +69,7 @@ dev = [
   "asgiref>=3.2,<4.0",
   "email-validator>=1.1.3,<3.0.0",
   "freezegun>=1.2.1,<2.0.0",
-  "libcst>=1.8.2,<2.0.0",
+  "libcst>=1.9.0,<2.0.0",
   "markupsafe~=3.0.3",
   "nox>=2025.11.12,<2026.8.0",
   "opentelemetry-api<2",
@@ -103,7 +103,7 @@ dev = [
   "types-pyyaml>=6.0.12.20240917,<7.0.0.0",
   "mypy>=1.15.0,<3.0.0",
   "pyright~=1.1.408",
-  "codeflash>=0.19.1",
+  "codeflash>=0.19.1; python_version < '3.15'",
   "pre-commit",
   "protobuf (>=7.34.1,<8.0.0)",
 ]

strawberry/utils/typing.py

@@ -1,5 +1,5 @@
 import ast
-import dataclasses
+import re
 import sys
 import typing
 from collections.abc import AsyncGenerator
@@ -22,6 +22,8 @@
     get_origin,
 )
 
+_CLASSVAR_RE = re.compile(r"^\s*(\w+(?:\s*\.\s*\w+)*)")
+
 
 @lru_cache
 def get_generic_alias(type_: type) -> type:
@@ -144,24 +146,29 @@ def is_type_var(annotation: type) -> bool:
     return isinstance(annotation, TypeVar)
 
 
-def is_classvar(cls: type, annotation: ForwardRef | str) -> bool:
+def is_classvar(cls: type, annotation: object) -> bool:
     """Returns True if the annotation is a ClassVar."""
-    # This code was copied from the dataclassses cpython implementation to check
-    # if a field is annotated with ClassVar or not, taking future annotations
-    # in consideration.
-    if dataclasses._is_classvar(annotation, typing):  # type: ignore
+    if annotation is ClassVar or get_origin(annotation) is ClassVar:
         return True
 
     annotation_str = (
         annotation.__forward_arg__ if isinstance(annotation, ForwardRef) else annotation
     )
-    return isinstance(annotation_str, str) and dataclasses._is_type(  # type: ignore
-        annotation_str,
-        cls,
-        typing,
-        typing.ClassVar,
-        dataclasses._is_classvar,  # type: ignore
-    )
+    module = sys.modules.get(cls.__module__)
+    if not isinstance(annotation_str, str) or module is None:
+        return False
+
+    match = _CLASSVAR_RE.match(annotation_str)
+    if match is None:
+        return False
+
+    resolved: object | None = module
+    for path_item in match.group(1).split("."):
+        resolved = getattr(resolved, path_item.strip(), None)
+        if resolved is None:
+            return False
+
+    return resolved is ClassVar or get_origin(resolved) is ClassVar
 
 
 def type_has_annotation(type_: object, annotation: type) -> bool:

tests/relay/test_types.py

@@ -1,3 +1,4 @@
+import typing_extensions
 from collections.abc import AsyncGenerator, AsyncIterable
 from typing import Any, Optional, Union, cast
 from typing_extensions import assert_type
@@ -259,6 +260,18 @@ def fruit(self) -> Fruit:
     strawberry.Schema(query=Query)
 
 
+def test_resolve_id_attr_ignores_qualified_classvar():
+    @strawberry.type
+    class Fruit(relay.Node):
+        id: relay.NodeID[int]
+
+    Fruit.__annotations__["registry"] = (
+        f"{typing_extensions.__name__}.ClassVar[MissingType]"
+    )
+
+    assert Fruit.resolve_id_attr() == "id"
+
+
 def test_list_connection_without_edges_or_page_info(mocker: MagicMock):
     @strawberry.type(name="Connection", description="A connection to a list of items.")
     class DummyListConnectionWithTotalCount(relay.ListConnection[relay.NodeType]):

tests/utils/test_typing_forward_refs.py

@@ -1,11 +1,17 @@
 from __future__ import annotations
 
 import typing
+import typing_extensions
+from types import SimpleNamespace
 from typing import ClassVar, ForwardRef, Optional, Union
 
 from strawberry.scalars import JSON
 from strawberry.utils.typing import eval_type, is_classvar
 
+_classvar_proxy = SimpleNamespace(
+    nested=SimpleNamespace(ClassVar=ClassVar),
+)
+
 
 def test_eval_type():
     class Foo: ...
@@ -51,7 +57,12 @@ class Foo:
         attr1: str
         attr2: ClassVar[str]
         attr3: typing.ClassVar[str]
+        attr4: typing_extensions.ClassVar[str]
+
+    Foo.__annotations__["attr5"] = "_classvar_proxy.nested.ClassVar[str]"
 
     assert not is_classvar(Foo, Foo.__annotations__["attr1"])
     assert is_classvar(Foo, Foo.__annotations__["attr2"])
     assert is_classvar(Foo, Foo.__annotations__["attr3"])
+    assert is_classvar(Foo, Foo.__annotations__["attr4"])
+    assert is_classvar(Foo, Foo.__annotations__["attr5"])