chore: import upstream snapshot with attribution

test/marshal/__init__.py

@@ -0,0 +1,3 @@
+# SPDX-FileCopyrightText: 2022-present deepset GmbH <info@deepset.ai>
+#
+# SPDX-License-Identifier: Apache-2.0

test/marshal/test_yaml.py

@@ -0,0 +1,61 @@
+# SPDX-FileCopyrightText: 2022-present deepset GmbH <info@deepset.ai>
+#
+# SPDX-License-Identifier: Apache-2.0
+
+import pytest
+
+from haystack.marshal.yaml import YamlMarshaller
+
+
+class InvalidClass:
+    def __init__(self) -> None:
+        self.a = 1
+        self.b = None
+        self.c = "string"
+
+
+@pytest.fixture
+def yaml_data():
+    return {"key": "value", 1: 0.221, "list": [1, 2, 3], "tuple": (1, None, True), "dict": {"set": {False}}}
+
+
+@pytest.fixture
+def invalid_yaml_data():
+    return {"key": "value", 1: 0.221, "list": [1, 2, 3], "tuple": (1, InvalidClass(), True), "dict": {"set": {False}}}
+
+
+@pytest.fixture
+def serialized_yaml_str():
+    return """key: value
+1: 0.221
+list:
+- 1
+- 2
+- 3
+tuple: !!python/tuple
+- 1
+- null
+- true
+dict:
+  set: !!set
+    false: null
+"""
+
+
+def test_yaml_marshal(yaml_data, serialized_yaml_str):
+    marshaller = YamlMarshaller()
+    marshalled = marshaller.marshal(yaml_data)
+    assert isinstance(marshalled, str)
+    assert marshalled.strip().replace("\n", "") == serialized_yaml_str.strip().replace("\n", "")
+
+
+def test_yaml_marshal_invalid_type(invalid_yaml_data):
+    with pytest.raises(TypeError, match="basic Python types"):
+        marshaller = YamlMarshaller()
+        _ = marshaller.marshal(invalid_yaml_data)
+
+
+def test_yaml_unmarshal(yaml_data, serialized_yaml_str):
+    marshaller = YamlMarshaller()
+    unmarshalled = marshaller.unmarshal(serialized_yaml_str)
+    assert unmarshalled == yaml_data