fix: guard against non-LLM recipients in speak_to tool(#158)

Author: BhoomiAgrawal12

mesa_llm/tools/inbuilt_tools.py

@@ -1,3 +1,4 @@
+import logging
 from typing import TYPE_CHECKING, Any
 
 from mesa.discrete_space import (
@@ -15,6 +16,8 @@
 if TYPE_CHECKING:
     from mesa_llm.llm_agent import LLMAgent
 
+logger = logging.getLogger(__name__)
+
 # Mapping directions to (dx, dy) for Cartesian-style spaces.
 direction_map_xy = {
     "North": (0, 1),
@@ -208,6 +211,12 @@ def speak_to(
     ]
 
     for recipient in listener_agents:
+        if not hasattr(recipient, "memory"):
+            logger.warning(
+                "Agent %s has no memory attribute; skipping speak_to.",
+                recipient.unique_id,
+            )
+            continue
         recipient.memory.add_to_memory(
             type="message",
             content={

tests/test_tools/test_inbuilt_tools.py

@@ -582,3 +582,30 @@ class _DummyOrthogonalGrid(OrthogonalMooreGrid):
 
     assert agent.cell is wrapped_cell
     assert result == "agent 29 moved to (2, 2)."
+
+
+def test_speak_to_skips_non_llm_recipient(mocker):
+    """
+    speak_to must not crash when a recipient has no memory attribute.
+
+    This covers the case where a non-LLM (rule-based) agent is listed as a
+    recipient.
+    """
+    model = DummyModel()
+
+    sender = DummyAgent(unique_id=1, model=model)
+    llm_recipient = DummyAgent(unique_id=2, model=model)
+    rule_recipient = DummyAgent(unique_id=3, model=model) 
+
+    llm_recipient.memory = SimpleNamespace(add_to_memory=mocker.Mock())
+
+    model.agents = [sender, llm_recipient, rule_recipient]
+
+    ret = speak_to(sender, [2, 3], "Hello both")
+
+    llm_recipient.memory.add_to_memory.assert_called_once()
+    call_kwargs = llm_recipient.memory.add_to_memory.call_args[1]
+    assert call_kwargs["type"] == "message"
+    assert call_kwargs["content"]["message"] == "Hello both"
+
+    assert "2" in ret and "3" in ret