From 4b55a62aed57e18f53108055ef4689fd864a6f59 Mon Sep 17 00:00:00 2001
From: Remco de Boer <29308176+redeboer@users.noreply.github.com>
Date: Thu, 20 Mar 2025 17:28:15 +0100
Subject: [PATCH] DX: import pickling example from #471

---
 tests/helicity/test_pickle.py | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 tests/helicity/test_pickle.py

diff --git a/tests/helicity/test_pickle.py b/tests/helicity/test_pickle.py
new file mode 100644
index 000000000..99a458ed6
--- /dev/null
+++ b/tests/helicity/test_pickle.py
@@ -0,0 +1,23 @@
+from __future__ import annotations
+
+import io
+import pickle  # noqa: S403
+from typing import TYPE_CHECKING
+
+import ampform
+
+if TYPE_CHECKING:
+    from qrules import ReactionInfo
+
+    from ampform.helicity import HelicityModel
+
+
+def test_model_pickling(reaction: ReactionInfo):
+    """See https://github.com/ComPWA/ampform/issues/471."""
+    builder = ampform.get_builder(reaction)
+    model = builder.formulate()
+    stream = io.BytesIO()
+    pickle.dump(model, stream)
+    stream.seek(0)
+    loaded_model: HelicityModel = pickle.load(stream)  # noqa: S301
+    assert loaded_model.kinematic_variables == model.kinematic_variables