From 7ed7c0b34690479723dc1f01aca7d674773dc89f Mon Sep 17 00:00:00 2001
From: Zahari Kassabov <zaharid@protonmail.com>
Date: Wed, 17 Dec 2025 20:52:20 +0000
Subject: [PATCH] Enable ForwardRefs in dataclasses

In Python 3.14, type annotations are resolved in a delayed manner by
default, and get resolved, on demand, when accession __annotations__.
This allows writing recursive types such as a dataclass where some field
contains itself.

As a minor annoyance, accessing the type attribute of the fields, does
not resolve the delayed forward reference.

Add tests for Python 3.14
---
 .github/workflows/pythonpackage.yml        |  2 +-
 validobj/tests/__init__.py                 |  0
 validobj/tests/conftest.py                 |  6 +++++-
 validobj/tests/test_delayed_dataclasses.py | 16 ++++++++++++++++
 validobj/validation.py                     |  5 ++++-
 5 files changed, 26 insertions(+), 3 deletions(-)
 create mode 100644 validobj/tests/__init__.py
 create mode 100644 validobj/tests/test_delayed_dataclasses.py

diff --git a/.github/workflows/pythonpackage.yml b/.github/workflows/pythonpackage.yml
index 94fb4ff..ab4d44a 100644
--- a/.github/workflows/pythonpackage.yml
+++ b/.github/workflows/pythonpackage.yml
@@ -9,7 +9,7 @@ jobs:
     strategy:
       max-parallel: 4
       matrix:
-        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13']
+        python-version: ['3.8', '3.9', '3.10', '3.11', '3.12', '3.13', '3.14']
 
     steps:
     - uses: actions/checkout@v1
diff --git a/validobj/tests/__init__.py b/validobj/tests/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/validobj/tests/conftest.py b/validobj/tests/conftest.py
index 4070d50..f5dfd04 100644
--- a/validobj/tests/conftest.py
+++ b/validobj/tests/conftest.py
@@ -2,6 +2,10 @@
 
 # https://docs.pytest.org/en/6.2.x/example/pythoncollection.html#customizing-test-collection
 
+collect_ignore = []
 
 if sys.version_info < (3, 12):  # pragma: nocover
-    collect_ignore = ["test_type_syntax.py"]
+    collect_ignore += ["test_type_syntax.py"]
+
+if sys.version_info < (3, 14):  # pragma: nocover
+    collect_ignore += ["test_delayed_dataclasses.py"]
diff --git a/validobj/tests/test_delayed_dataclasses.py b/validobj/tests/test_delayed_dataclasses.py
new file mode 100644
index 0000000..7f90e59
--- /dev/null
+++ b/validobj/tests/test_delayed_dataclasses.py
@@ -0,0 +1,16 @@
+from typing import Any
+import dataclasses
+
+from validobj import parse_input
+
+@dataclasses.dataclass
+class Linked:
+    value: Any
+    parents: Linked | list[Linked] | None = None
+
+
+def test_delayed_annotations():
+    inp = {'value': 1, 'parents': {'value': 2, 'parents': [{'value': 3}, {'value': 4, 'parents': {'value': 5}}]}}
+    assert parse_input(inp, Linked).parents.value == 2
+
+
diff --git a/validobj/validation.py b/validobj/validation.py
index 47d4d22..73d2d12 100644
--- a/validobj/validation.py
+++ b/validobj/validation.py
@@ -209,10 +209,13 @@ def _parse_dataclass(value, spec):
         header=f"Cannot process value into {_typename(spec)!r} because "
         f"fields do not match.",
     )
+    # Note: We don't use field.type because of https://github.com/python/cpython/issues/137891
+    types = spec.__annotations__
+
     res = {}
     field_dict = {
         # Look inside InitVar
-        f.name: f.type if not isinstance(f.type, dataclasses.InitVar) else f.type.type
+        f.name: types[f.name] if not isinstance(f.type, dataclasses.InitVar) else f.type.type
         for f in fields
     }
     for k, v in value.items():