Test for the utils functions

Author: stellasia

src/neo4j_graphrag/llm/utils.py

@@ -18,28 +18,21 @@ def legacy_inputs_to_messages(
     system_instruction: Optional[str] = None,
 ) -> list[LLMMessage]:
     if message_history:
-        warnings.warn(
-            "Using message_history parameter is deprecated and will be removed in 2.0. Use a list of inputs or a MessageHistory instead.",
-            DeprecationWarning,
-        )
         if isinstance(message_history, MessageHistory):
             messages = message_history.messages
         else:  # list[LLMMessage]
-            messages = []
+            messages = message_history
     else:
         messages = []
     if system_instruction is not None:
-        warnings.warn(
-            "Using system_instruction parameter is deprecated and will be removed in 2.0. Use a list of inputs or a MessageHistory instead.",
-            DeprecationWarning,
-        )
         if system_instruction_from_messages(messages) is not None:
             warnings.warn(
                 "system_instruction provided but ignored as the message history already contains a system message",
-                RuntimeWarning,
+                UserWarning,
             )
         else:
-            messages.append(
+            messages.insert(
+                0,
                 LLMMessage(
                     role="system",
                     content=system_instruction,

tests/unit/llm/test_utils.py

@@ -0,0 +1,107 @@
+import pytest
+
+from neo4j_graphrag.llm.utils import system_instruction_from_messages, \
+    legacy_inputs_to_messages
+from neo4j_graphrag.message_history import InMemoryMessageHistory
+from neo4j_graphrag.types import LLMMessage
+
+
+def test_system_instruction_from_messages():
+    messages = [
+        LLMMessage(role="system", content="text"),
+    ]
+    assert system_instruction_from_messages(messages) == "text"
+
+    messages = []
+    assert system_instruction_from_messages(messages) is None
+
+    messages = [
+        LLMMessage(role="assistant", content="text"),
+    ]
+    assert system_instruction_from_messages(messages) is None
+
+
+def test_legacy_inputs_to_messages_only_input_as_llm_message_list():
+    messages = legacy_inputs_to_messages(input=[
+        LLMMessage(role="user", content="text"),
+    ])
+    assert messages == [
+        LLMMessage(role="user", content="text"),
+    ]
+
+
+def test_legacy_inputs_to_messages_only_input_as_message_history():
+    messages = legacy_inputs_to_messages(input=InMemoryMessageHistory(
+        messages=[
+            LLMMessage(role="user", content="text"),
+        ]
+    ))
+    assert messages == [
+        LLMMessage(role="user", content="text"),
+    ]
+
+
+def test_legacy_inputs_to_messages_only_input_as_str():
+    messages = legacy_inputs_to_messages(input="text")
+    assert messages == [
+        LLMMessage(role="user", content="text"),
+    ]
+
+
+def test_legacy_inputs_to_messages_input_as_str_and_message_history_as_llm_message_list():
+    messages = legacy_inputs_to_messages(
+        input="text",
+        message_history=[
+            LLMMessage(role="assistant", content="How can I assist you today?"),
+        ]
+    )
+    assert messages == [
+        LLMMessage(role="assistant", content="How can I assist you today?"),
+        LLMMessage(role="user", content="text"),
+    ]
+
+
+def test_legacy_inputs_to_messages_input_as_str_and_message_history_as_message_history():
+    messages = legacy_inputs_to_messages(
+        input="text",
+        message_history=InMemoryMessageHistory(messages=[
+            LLMMessage(role="assistant", content="How can I assist you today?"),
+        ])
+    )
+    assert messages == [
+        LLMMessage(role="assistant", content="How can I assist you today?"),
+        LLMMessage(role="user", content="text"),
+    ]
+
+
+def test_legacy_inputs_to_messages_with_explicit_system_instruction():
+    messages = legacy_inputs_to_messages(
+        input="text",
+        message_history=[
+            LLMMessage(role="assistant", content="How can I assist you today?"),
+        ],
+        system_instruction="You are a genius."
+    )
+    assert messages == [
+        LLMMessage(role="system", content="You are a genius."),
+        LLMMessage(role="assistant", content="How can I assist you today?"),
+        LLMMessage(role="user", content="text"),
+    ]
+
+
+def test_legacy_inputs_to_messages_do_not_duplicate_system_instruction():
+    with pytest.warns(
+        UserWarning,
+        match="system_instruction provided but ignored as the message history already contains a system message"
+    ):
+        messages = legacy_inputs_to_messages(
+            input="text",
+            message_history=[
+                LLMMessage(role="system", content="You are super smart."),
+            ],
+            system_instruction="You are a genius."
+        )
+        assert messages == [
+            LLMMessage(role="system", content="You are super smart."),
+            LLMMessage(role="user", content="text"),
+        ]