chore: import upstream snapshot with attribution

python/tests/test_cross_sdk_compatibility.py

@@ -0,0 +1,40 @@
+"""Cross-SDK compatibility tests.
+
+These tests verify that the Python SDK uses identical fixtures
+to the TypeScript SDK, ensuring webhook verification works consistently
+across both SDKs.
+"""
+
+import json
+
+import pytest
+
+from tests.conftest import get_py_fixtures_dir, get_ts_fixtures_dir
+
+
+class TestCrossSDKFixtureCompatibility:
+    """Tests verifying Python and TypeScript fixtures are synchronized."""
+
+    @pytest.mark.parametrize(
+        "fixture_name",
+        [
+            "golden-signatures.json",
+            "v1-github-push.json",
+            "v2-github-push.json",
+            "v3-github-push.json",
+        ],
+    )
+    def test_fixtures_are_identical(self, fixture_name: str) -> None:
+        """Verify TypeScript and Python fixtures are byte-identical."""
+        ts_path = get_ts_fixtures_dir() / fixture_name
+        py_path = get_py_fixtures_dir() / fixture_name
+
+        with open(ts_path) as f:
+            ts_content = json.load(f)
+        with open(py_path) as f:
+            py_content = json.load(f)
+
+        assert ts_content == py_content, (
+            f"Fixture {fixture_name} differs between TypeScript and Python SDKs. "
+            "Ensure fixtures are kept in sync."
+        )