test: _reduce_messages in LangChainAgent

Author: boczekbartek

src/rai_core/rai/agents/langchain/agent.py

@@ -33,25 +33,28 @@ class BaseState(TypedDict):
     messages: List[BaseMessage]
 
 
+newMessageBehaviorType = Literal[
+    "take_all",
+    "keep_last",
+    "queue",
+    "interuppt_take_all",
+    "interuppt_keep_last",
+]
+
+
 class LangChainAgent(BaseAgent):
     def __init__(
         self,
         target_connectors: Dict[str, HRIConnector[HRIMessage]],
         runnable: Runnable,
         state: BaseState | None = None,
-        new_message_behavior: Literal[
-            "take_all",
-            "keep_last",
-            "queue",
-            "interuppt_take_all",
-            "interuppt_keep_last",
-        ] = "interuppt_keep_last",
+        new_message_behavior: newMessageBehaviorType = "interuppt_keep_last",
         max_size: int = 100,
     ):
         super().__init__()
         self.logger = logging.getLogger(__name__)
         self.agent = runnable
-        self.new_message_behavior = new_message_behavior
+        self.new_message_behavior: newMessageBehaviorType = new_message_behavior
         self.tracing_callbacks = get_tracing_callbacks()
         self.state = state or ReActAgentState(messages=[])
         self._langchain_callback = HRICallbackHandler(
@@ -141,26 +144,33 @@ def stop(self):
             self.thread = None
             self.logger.info("Agent stopped")
 
-    def _reduce_messages(self) -> HRIMessage:
-        text = ""
-        images = []
-        audios = []
-        source_messages = list()
-        if "take_all" in self.new_message_behavior:
+    @staticmethod
+    def _apply_reduction_behavior(
+        method: newMessageBehaviorType, buffer: Deque
+    ) -> List:
+        output = list()
+        if "take_all" in method:
             # Take all starting from the oldest
-            while len(self._received_messages) > 0:
-                source_messages.append(self._received_messages.popleft())
-        elif "keep_last" in self.new_message_behavior:
+            while len(buffer) > 0:
+                output.append(buffer.popleft())
+        elif "keep_last" in method:
             # Take the recently added message
-            source_messages.append(self._received_messages.pop())
-            self._received_messages.clear()
-        elif self.new_message_behavior == "queue":
+            output.append(buffer.pop())
+            buffer.clear()
+        elif method == "queue":
             # Take the first message from the queue. Let other messages wait.
-            source_messages.append(self._received_messages.popleft())
+            output.append(buffer.popleft())
         else:
-            raise ValueError(
-                f"Invalid new_message_behavior: {self.new_message_behavior}"
-            )
+            raise ValueError(f"Invalid new_message_behavior: {method}")
+        return output
+
+    def _reduce_messages(self) -> HRIMessage:
+        text = ""
+        images = []
+        audios = []
+        source_messages = self._apply_reduction_behavior(
+            self.new_message_behavior, self._received_messages
+        )
         for source_message in source_messages:
             text += f"{source_message.text}\n"
             images.extend(source_message.images)

tests/agents/test_langchain_agent.py

@@ -0,0 +1,41 @@
+# Copyright (C) 2025 Robotec.AI
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from collections import deque
+from typing import List
+
+import pytest
+from rai.agents.langchain.agent import LangChainAgent, newMessageBehaviorType
+
+
+@pytest.mark.parametrize(
+    "new_message_behavior,in_buffer,out_buffer,output",
+    [
+        ("take_all", [1, 2, 3], [], [1, 2, 3]),
+        ("keep_last", [1, 2, 3], [], [3]),
+        ("queue", [1, 2, 3], [2, 3], [1]),
+        ("interuppt_take_all", [1, 2, 3], [], [1, 2, 3]),
+        ("interuppt_keep_last", [1, 2, 3], [], [3]),
+    ],
+)
+def test_reduce_messages(
+    new_message_behavior: newMessageBehaviorType,
+    in_buffer: List,
+    out_buffer: List,
+    output: List,
+):
+    buffer = deque(in_buffer)
+    output = LangChainAgent._apply_reduction_behavior(new_message_behavior, buffer)
+    assert output == output
+    assert buffer == deque(out_buffer)