chore: import upstream snapshot with attribution

test/core/sample_components/test_fstring.py

@@ -0,0 +1,43 @@
+# SPDX-FileCopyrightText: 2022-present deepset GmbH <info@deepset.ai>
+#
+# SPDX-License-Identifier: Apache-2.0
+
+import pytest
+
+from haystack.testing.sample_components import FString
+
+
+def test_fstring_with_one_var():
+    fstring = FString(template="Hello, {name}!", variables=["name"])
+    output = fstring.run(name="Alice")
+    assert output == {"string": "Hello, Alice!"}
+
+
+def test_fstring_with_no_vars():
+    fstring = FString(template="No variables in this template.", variables=[])
+    output = fstring.run()
+    assert output == {"string": "No variables in this template."}
+
+
+def test_fstring_with_template_at_runtime():
+    fstring = FString(template="Hello {name}", variables=["name"])
+    output = fstring.run(template="Goodbye {name}!", name="Alice")
+    assert output == {"string": "Goodbye Alice!"}
+
+
+def test_fstring_with_vars_mismatch():
+    fstring = FString(template="Hello {name}", variables=["name"])
+    with pytest.raises(KeyError):
+        fstring.run(template="Goodbye {person}!", name="Alice")
+
+
+def test_fstring_with_vars_in_excess():
+    fstring = FString(template="Hello {name}", variables=["name"])
+    output = fstring.run(template="Goodbye!", name="Alice")
+    assert output == {"string": "Goodbye!"}
+
+
+def test_fstring_with_vars_missing():
+    fstring = FString(template="{greeting}, {name}!", variables=["name"])
+    with pytest.raises(KeyError):
+        fstring.run(greeting="Hello")