chore: import upstream snapshot with attribution

test/utils/test_experimental.py

@@ -0,0 +1,87 @@
+# SPDX-FileCopyrightText: 2022-present deepset GmbH <info@deepset.ai>
+#
+# SPDX-License-Identifier: Apache-2.0
+
+import pytest
+
+from haystack import component
+from haystack.utils.experimental import ExperimentalWarning, _experimental
+
+
+class TestExperimentalDecorator:
+    def test_emits_experimental_warning_on_init(self):
+        @_experimental
+        @component
+        class MyComponent:
+            @component.output_types(value=int)
+            def run(self, value: int) -> dict:
+                return {"value": value}
+
+        with pytest.warns(ExperimentalWarning):
+            MyComponent()
+
+    def test_warning_message_contains_class_name(self):
+        @_experimental
+        @component
+        class MyComponent:
+            @component.output_types(value=int)
+            def run(self, value: int) -> dict:
+                return {"value": value}
+
+        with pytest.warns(ExperimentalWarning, match="MyComponent"):
+            MyComponent()
+
+    def test_sets_experimental_attribute(self):
+        @_experimental
+        @component
+        class MyComponent:
+            @component.output_types(value=int)
+            def run(self, value: int) -> dict:
+                return {"value": value}
+
+        assert getattr(MyComponent, "__experimental__") is True  # noqa: B009
+
+    def test_passes_args_and_kwargs_to_init(self):
+        @_experimental
+        @component
+        class MyComponent:
+            def __init__(self, value: int, label: str = "default"):
+                self.value = value
+                self.label = label
+
+            @component.output_types(value=int)
+            def run(self, value: int) -> dict:
+                return {"value": value}
+
+        with pytest.warns(ExperimentalWarning):
+            instance = MyComponent(42, label="custom")
+
+        assert instance.value == 42
+        assert instance.label == "custom"
+
+    def test_preserves_init_name(self):
+        @_experimental
+        @component
+        class MyComponent:
+            @component.output_types(value=int)
+            def run(self, value: int) -> dict:
+                return {"value": value}
+
+        assert MyComponent.__init__.__name__ == "__init__"
+
+    def test_experimental_warning_is_user_warning_subclass(self):
+        assert issubclass(ExperimentalWarning, UserWarning)
+
+    def test_warning_emitted_on_every_instantiation(self):
+        @_experimental
+        @component
+        class MyComponent:
+            @component.output_types(value=int)
+            def run(self, value: int) -> dict:
+                return {"value": value}
+
+        with pytest.warns(ExperimentalWarning):
+            MyComponent()
+
+        with pytest.warns(ExperimentalWarning):
+            MyComponent()