Merge pull request 'feat(social): conversation topic memory (Issue #299)' (#304) from sl-jetson/issue-299-topic-memory into main

jetson/ros2_ws/src/saltybot_social/config/topic_memory_params.yaml

@@ -0,0 +1,14 @@
+topic_memory_node:
+  ros__parameters:
+    conversation_topic: "/social/conversation_text"   # Input: JSON String {person_id, text}
+    output_topic: "/saltybot/conversation_topics"     # Output: JSON String per utterance
+
+    # Keyword extraction
+    min_word_length: 3          # Skip words shorter than this
+    max_keywords_per_msg: 10    # Extract at most this many keywords per utterance
+
+    # Per-person rolling window
+    max_topics_per_person: 30   # Keep last N unique topics per person
+
+    # Stale-person pruning (0 = disabled)
+    prune_after_s: 1800.0       # Forget person after 30 min of inactivity

jetson/ros2_ws/src/saltybot_social/launch/topic_memory.launch.py

@@ -0,0 +1,42 @@
+"""topic_memory.launch.py — Launch conversation topic memory node (Issue #299).
+
+Usage:
+  ros2 launch saltybot_social topic_memory.launch.py
+  ros2 launch saltybot_social topic_memory.launch.py max_topics_per_person:=50
+"""
+
+import os
+from ament_index_python.packages import get_package_share_directory
+from launch import LaunchDescription
+from launch.actions import DeclareLaunchArgument
+from launch.substitutions import LaunchConfiguration
+from launch_ros.actions import Node
+
+
+def generate_launch_description():
+    pkg = get_package_share_directory("saltybot_social")
+    cfg = os.path.join(pkg, "config", "topic_memory_params.yaml")
+
+    return LaunchDescription([
+        DeclareLaunchArgument("max_topics_per_person", default_value="30",
+                              description="Rolling topic window per person"),
+        DeclareLaunchArgument("max_keywords_per_msg",  default_value="10",
+                              description="Max keywords extracted per utterance"),
+        DeclareLaunchArgument("prune_after_s",         default_value="1800.0",
+                              description="Forget persons idle this long (0=off)"),
+
+        Node(
+            package="saltybot_social",
+            executable="topic_memory_node",
+            name="topic_memory_node",
+            output="screen",
+            parameters=[
+                cfg,
+                {
+                    "max_topics_per_person": LaunchConfiguration("max_topics_per_person"),
+                    "max_keywords_per_msg":  LaunchConfiguration("max_keywords_per_msg"),
+                    "prune_after_s":         LaunchConfiguration("prune_after_s"),
+                },
+            ],
+        ),
+    ])

jetson/ros2_ws/src/saltybot_social/saltybot_social/topic_memory_node.py

@@ -0,0 +1,268 @@
+"""topic_memory_node.py — Conversation topic memory.
+Issue #299
+
+Subscribes to /social/conversation_text (std_msgs/String, JSON payload
+{"person_id": "...", "text": "..."}), extracts key topics via stop-word
+filtered keyword extraction, and maintains a per-person rolling topic
+history.
+
+On every message that yields at least one new keyword the node publishes
+an updated topic snapshot on /saltybot/conversation_topics (std_msgs/String,
+JSON) — enabling recall like "last time you mentioned coffee" or "you talked
+about the weather with alice".
+
+Published JSON format
+─────────────────────
+  {
+    "person_id":     "alice",
+    "recent_topics": ["coffee", "weather", "robot"],   // most-recent first
+    "new_topics":    ["coffee"],                        // keywords added this turn
+    "ts":            1234567890.123
+  }
+
+Keyword extraction pipeline
+────────────────────────────
+  1. Lowercase + tokenise on non-word characters
+  2. Filter: length >= min_word_length, alphabetic only
+  3. Remove stop words (built-in English list)
+  4. Deduplicate within the utterance
+  5. Take first max_keywords_per_msg tokens
+
+Per-person storage
+──────────────────
+  Ordered list (insertion order), capped at max_topics_per_person.
+  Duplicate keywords are promoted to the front (most-recent position).
+  Persons not seen for prune_after_s seconds are pruned on next publish
+  (set to 0 to disable pruning).
+
+Parameters
+──────────
+  conversation_topic   (str, "/social/conversation_text")
+  output_topic         (str, "/saltybot/conversation_topics")
+  min_word_length      (int, 3)    minimum character length to keep
+  max_keywords_per_msg (int, 10)   max keywords extracted per utterance
+  max_topics_per_person(int, 30)   rolling window per person
+  prune_after_s        (float, 1800.0)  forget persons idle this long (0=off)
+"""
+
+from __future__ import annotations
+
+import json
+import re
+import string
+import time
+import threading
+from typing import Dict, List, Optional
+
+import rclpy
+from rclpy.node import Node
+from rclpy.qos import QoSProfile
+from std_msgs.msg import String
+
+
+# ── Stop-word list (English) ───────────────────────────────────────────────────
+
+STOP_WORDS: frozenset = frozenset({
+    "the", "a", "an", "and", "or", "but", "nor", "not", "so", "yet",
+    "for", "with", "from", "into", "onto", "upon", "about", "above",
+    "after", "before", "between", "during", "through", "under", "over",
+    "at", "by", "in", "of", "on", "to", "up", "as",
+    "is", "are", "was", "were", "be", "been", "being",
+    "have", "has", "had", "do", "does", "did",
+    "will", "would", "could", "should", "may", "might", "shall", "can",
+    "it", "its", "this", "that", "these", "those",
+    "i", "me", "my", "myself", "we", "our", "ours",
+    "you", "your", "yours", "he", "him", "his", "she", "her", "hers",
+    "they", "them", "their", "theirs",
+    "what", "which", "who", "whom", "when", "where", "why", "how",
+    "all", "each", "every", "both", "few", "more", "most",
+    "other", "some", "such", "no", "only", "own", "same",
+    "than", "then", "too", "very", "just", "also",
+    "get", "got", "say", "said", "know", "think", "go", "going", "come",
+    "like", "want", "see", "take", "make", "give", "look",
+    "yes", "yeah", "okay", "ok", "oh", "ah", "um", "uh", "well",
+    "now", "here", "there", "hi", "hey", "hello",
+})
+
+_PUNCT_RE = re.compile(r"[^\w\s]")
+
+
+# ── Keyword extraction ────────────────────────────────────────────────────────
+
+def extract_keywords(text: str,
+                     min_length: int = 3,
+                     max_keywords: int = 10) -> List[str]:
+    """Return a deduplicated list of meaningful keywords from *text*.
+
+    Steps: lowercase -> strip punctuation -> split -> filter stop words &
+    length -> deduplicate -> cap at max_keywords.
+    """
+    cleaned = _PUNCT_RE.sub(" ", text.lower())
+    seen: dict = {}            # ordered-set via insertion-order dict
+    for tok in cleaned.split():
+        tok = tok.strip(string.punctuation + "_")
+        if (len(tok) >= min_length
+                and tok.isalpha()
+                and tok not in STOP_WORDS
+                and tok not in seen):
+            seen[tok] = None
+            if len(seen) >= max_keywords:
+                break
+    return list(seen)
+
+
+# ── Per-person topic memory ───────────────────────────────────────────────────
+
+class PersonTopicMemory:
+    """Rolling, deduplicated topic list for one person."""
+
+    def __init__(self, max_topics: int = 30) -> None:
+        self._max       = max_topics
+        self._topics: List[str] = []   # oldest -> newest order
+        self._topic_set: set   = set()
+        self.last_updated: float = 0.0
+
+    def add(self, keywords: List[str]) -> List[str]:
+        """Add *keywords*; promote duplicates to front, evict oldest over cap.
+
+        Returns the list of newly added (previously unseen) keywords.
+        """
+        added: List[str] = []
+        for kw in keywords:
+            if kw in self._topic_set:
+                # Promote to most-recent position
+                self._topics.remove(kw)
+                self._topics.append(kw)
+            else:
+                self._topics.append(kw)
+                self._topic_set.add(kw)
+                added.append(kw)
+            # Trim oldest if over cap
+            while len(self._topics) > self._max:
+                evicted = self._topics.pop(0)
+                self._topic_set.discard(evicted)
+        self.last_updated = time.monotonic()
+        return added
+
+    @property
+    def recent_topics(self) -> List[str]:
+        """Most-recent topics first."""
+        return list(reversed(self._topics))
+
+    def __len__(self) -> int:
+        return len(self._topics)
+
+
+# ── ROS2 node ─────────────────────────────────────────────────────────────────
+
+class TopicMemoryNode(Node):
+    """Extracts and remembers conversation topics per person."""
+
+    def __init__(self) -> None:
+        super().__init__("topic_memory_node")
+
+        self.declare_parameter("conversation_topic",    "/social/conversation_text")
+        self.declare_parameter("output_topic",          "/saltybot/conversation_topics")
+        self.declare_parameter("min_word_length",       3)
+        self.declare_parameter("max_keywords_per_msg",  10)
+        self.declare_parameter("max_topics_per_person", 30)
+        self.declare_parameter("prune_after_s",         1800.0)
+
+        conv_topic     = self.get_parameter("conversation_topic").value
+        out_topic      = self.get_parameter("output_topic").value
+        self._min_len  = self.get_parameter("min_word_length").value
+        self._max_kw   = self.get_parameter("max_keywords_per_msg").value
+        self._max_tp   = self.get_parameter("max_topics_per_person").value
+        self._prune_s  = self.get_parameter("prune_after_s").value
+
+        # person_id -> PersonTopicMemory
+        self._memory: Dict[str, PersonTopicMemory] = {}
+        self._lock = threading.Lock()
+
+        qos = QoSProfile(depth=10)
+        self._pub = self.create_publisher(String, out_topic, qos)
+        self._sub = self.create_subscription(
+            String, conv_topic, self._on_conversation, qos
+        )
+
+        self.get_logger().info(
+            f"TopicMemoryNode ready "
+            f"(min_len={self._min_len}, max_kw={self._max_kw}, "
+            f"max_topics={self._max_tp}, prune_after={self._prune_s}s)"
+        )
+
+    # ── Subscription ───────────────────────────────────────────────────────
+
+    def _on_conversation(self, msg: String) -> None:
+        try:
+            payload = json.loads(msg.data)
+            person_id: str = str(payload.get("person_id", "unknown"))
+            text: str      = str(payload.get("text", ""))
+        except (json.JSONDecodeError, AttributeError) as exc:
+            self.get_logger().warn(f"Bad conversation_text payload: {exc}")
+            return
+
+        if not text.strip():
+            return
+
+        keywords = extract_keywords(text, self._min_len, self._max_kw)
+        if not keywords:
+            return
+
+        with self._lock:
+            self._prune_stale()
+            if person_id not in self._memory:
+                self._memory[person_id] = PersonTopicMemory(self._max_tp)
+            mem = self._memory[person_id]
+            new_topics = mem.add(keywords)
+            recent = mem.recent_topics
+
+        out = String()
+        out.data = json.dumps({
+            "person_id":     person_id,
+            "recent_topics": recent,
+            "new_topics":    new_topics,
+            "ts":            time.time(),
+        })
+        self._pub.publish(out)
+
+        if new_topics:
+            self.get_logger().info(
+                f"[{person_id}] new topics: {new_topics} | "
+                f"memory: {recent[:5]}{'...' if len(recent) > 5 else ''}"
+            )
+
+    # ── Helpers ────────────────────────────────────────────────────────────
+
+    def _prune_stale(self) -> None:
+        """Remove persons not seen for prune_after_s seconds (call under lock)."""
+        if self._prune_s <= 0:
+            return
+        now = time.monotonic()
+        stale = [pid for pid, m in self._memory.items()
+                 if (now - m.last_updated) > self._prune_s]
+        for pid in stale:
+            del self._memory[pid]
+            self.get_logger().info(f"Pruned stale person: {pid}")
+
+    def get_memory(self, person_id: str) -> Optional[PersonTopicMemory]:
+        """Return topic memory for a person (None if not seen)."""
+        with self._lock:
+            return self._memory.get(person_id)
+
+    def all_persons(self) -> Dict[str, List[str]]:
+        """Return {person_id: recent_topics} snapshot for all known persons."""
+        with self._lock:
+            return {pid: m.recent_topics for pid, m in self._memory.items()}
+
+
+def main(args=None) -> None:
+    rclpy.init(args=args)
+    node = TopicMemoryNode()
+    try:
+        rclpy.spin(node)
+    except KeyboardInterrupt:
+        pass
+    finally:
+        node.destroy_node()
+        rclpy.shutdown()

jetson/ros2_ws/src/saltybot_social/setup.py

@@ -53,6 +53,8 @@ setup(
             'face_track_servo_node = saltybot_social.face_track_servo_node:main',
             # Speech volume auto-adjuster (Issue #289)
             'volume_adjust_node = saltybot_social.volume_adjust_node:main',
+            # Conversation topic memory (Issue #299)
+            'topic_memory_node = saltybot_social.topic_memory_node:main',
         ],
     },
 )

jetson/ros2_ws/src/saltybot_social/test/test_topic_memory.py

@@ -0,0 +1,522 @@
+"""test_topic_memory.py — Offline tests for topic_memory_node (Issue #299).
+
+Stubs out rclpy so tests run without a ROS install.
+"""
+
+import importlib.util
+import json
+import sys
+import time
+import types
+import unittest
+
+
+# ── ROS2 stubs ────────────────────────────────────────────────────────────────
+
+def _make_ros_stubs():
+    for mod_name in ("rclpy", "rclpy.node", "rclpy.qos",
+                     "std_msgs", "std_msgs.msg"):
+        if mod_name not in sys.modules:
+            sys.modules[mod_name] = types.ModuleType(mod_name)
+
+    class _Node:
+        def __init__(self, name="node"):
+            self._name = name
+            if not hasattr(self, "_params"):
+                self._params = {}
+            self._pubs  = {}
+            self._subs  = {}
+            self._logs  = []
+
+        def declare_parameter(self, name, default):
+            if name not in self._params:
+                self._params[name] = default
+
+        def get_parameter(self, name):
+            class _P:
+                def __init__(self, v): self.value = v
+            return _P(self._params.get(name))
+
+        def create_publisher(self, msg_type, topic, qos):
+            pub = _FakePub()
+            self._pubs[topic] = pub
+            return pub
+
+        def create_subscription(self, msg_type, topic, cb, qos):
+            self._subs[topic] = cb
+            return object()
+
+        def get_logger(self):
+            node = self
+            class _L:
+                def info(self, m):  node._logs.append(("INFO",  m))
+                def warn(self, m):  node._logs.append(("WARN",  m))
+                def error(self, m): node._logs.append(("ERROR", m))
+            return _L()
+
+        def destroy_node(self): pass
+
+    class _FakePub:
+        def __init__(self):
+            self.msgs = []
+        def publish(self, msg):
+            self.msgs.append(msg)
+
+    class _QoSProfile:
+        def __init__(self, depth=10): self.depth = depth
+
+    class _String:
+        def __init__(self): self.data = ""
+
+    rclpy_mod = sys.modules["rclpy"]
+    rclpy_mod.init     = lambda args=None: None
+    rclpy_mod.spin     = lambda node: None
+    rclpy_mod.shutdown = lambda: None
+
+    sys.modules["rclpy.node"].Node      = _Node
+    sys.modules["rclpy.qos"].QoSProfile = _QoSProfile
+    sys.modules["std_msgs.msg"].String  = _String
+
+    return _Node, _FakePub, _String
+
+
+_Node, _FakePub, _String = _make_ros_stubs()
+
+
+# ── Module loader ─────────────────────────────────────────────────────────────
+
+_SRC = (
+    "/Users/seb/AI/saltylab-firmware/jetson/ros2_ws/src/"
+    "saltybot_social/saltybot_social/topic_memory_node.py"
+)
+
+
+def _load_mod():
+    spec = importlib.util.spec_from_file_location("topic_memory_testmod", _SRC)
+    mod  = importlib.util.module_from_spec(spec)
+    spec.loader.exec_module(mod)
+    return mod
+
+
+def _make_node(mod, **kwargs):
+    node = mod.TopicMemoryNode.__new__(mod.TopicMemoryNode)
+    defaults = {
+        "conversation_topic":    "/social/conversation_text",
+        "output_topic":          "/saltybot/conversation_topics",
+        "min_word_length":       3,
+        "max_keywords_per_msg":  10,
+        "max_topics_per_person": 30,
+        "prune_after_s":         1800.0,
+    }
+    defaults.update(kwargs)
+    node._params = dict(defaults)
+    mod.TopicMemoryNode.__init__(node)
+    return node
+
+
+def _msg(person_id, text):
+    m = _String()
+    m.data = json.dumps({"person_id": person_id, "text": text})
+    return m
+
+
+def _send(node, person_id, text):
+    """Deliver a conversation message to the node."""
+    cb = node._subs["/social/conversation_text"]
+    cb(_msg(person_id, text))
+
+
+# ── Tests: extract_keywords ───────────────────────────────────────────────────
+
+class TestExtractKeywords(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls): cls.mod = _load_mod()
+
+    def _kw(self, text, min_len=3, max_kw=10):
+        return self.mod.extract_keywords(text, min_len, max_kw)
+
+    def test_basic(self):
+        kws = self._kw("I love drinking coffee")
+        self.assertIn("love", kws)
+        self.assertIn("drinking", kws)
+        self.assertIn("coffee", kws)
+
+    def test_stop_words_removed(self):
+        kws = self._kw("the quick brown fox")
+        self.assertNotIn("the", kws)
+
+    def test_short_words_removed(self):
+        kws = self._kw("go to the museum now", min_len=4)
+        self.assertNotIn("go", kws)
+        self.assertNotIn("to", kws)
+        self.assertNotIn("the", kws)
+
+    def test_deduplication(self):
+        kws = self._kw("coffee coffee coffee")
+        self.assertEqual(kws.count("coffee"), 1)
+
+    def test_max_keywords_cap(self):
+        text = " ".join(f"word{i}" for i in range(20))
+        kws = self._kw(text, max_kw=5)
+        self.assertLessEqual(len(kws), 5)
+
+    def test_punctuation_stripped(self):
+        kws = self._kw("Hello, world! How's weather?")
+        # "world" and "weather" should be found, punctuation removed
+        self.assertIn("world", kws)
+        self.assertIn("weather", kws)
+
+    def test_case_insensitive(self):
+        kws = self._kw("Robot ROBOT robot")
+        self.assertEqual(kws.count("robot"), 1)
+
+    def test_empty_text(self):
+        self.assertEqual(self._kw(""), [])
+
+    def test_all_stop_words(self):
+        self.assertEqual(self._kw("the is a and"), [])
+
+    def test_non_alpha_excluded(self):
+        kws = self._kw("model42 123 price500")
+        # alphanumeric tokens like "model42" contain digits → excluded
+        self.assertEqual(kws, [])
+
+    def test_preserves_order(self):
+        kws = self._kw("zebra apple mango")
+        self.assertEqual(kws, ["zebra", "apple", "mango"])
+
+    def test_min_length_three(self):
+        kws = self._kw("cat dog elephant", min_len=3)
+        self.assertIn("cat", kws)
+        self.assertIn("dog", kws)
+        self.assertIn("elephant", kws)
+
+    def test_min_length_four_excludes_short(self):
+        kws = self._kw("cat dog elephant", min_len=4)
+        self.assertNotIn("cat", kws)
+        self.assertNotIn("dog", kws)
+        self.assertIn("elephant", kws)
+
+
+# ── Tests: PersonTopicMemory ──────────────────────────────────────────────────
+
+class TestPersonTopicMemory(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls): cls.mod = _load_mod()
+
+    def _mem(self, max_topics=10):
+        return self.mod.PersonTopicMemory(max_topics)
+
+    def test_empty_initially(self):
+        self.assertEqual(len(self._mem()), 0)
+
+    def test_add_returns_new(self):
+        m = self._mem()
+        added = m.add(["coffee", "weather"])
+        self.assertEqual(added, ["coffee", "weather"])
+
+    def test_duplicate_not_in_added(self):
+        m = self._mem()
+        m.add(["coffee"])
+        added = m.add(["coffee", "weather"])
+        self.assertNotIn("coffee", added)
+        self.assertIn("weather", added)
+
+    def test_recent_topics_most_recent_first(self):
+        m = self._mem()
+        m.add(["coffee"])
+        m.add(["weather"])
+        topics = m.recent_topics
+        self.assertEqual(topics[0], "weather")
+        self.assertEqual(topics[1], "coffee")
+
+    def test_duplicate_promoted_to_front(self):
+        m = self._mem()
+        m.add(["coffee", "weather", "robot"])
+        m.add(["coffee"])  # promote coffee to front
+        topics = m.recent_topics
+        self.assertEqual(topics[0], "coffee")
+
+    def test_cap_evicts_oldest(self):
+        m = self._mem(max_topics=3)
+        m.add(["alpha", "beta", "gamma"])
+        m.add(["delta"])  # alpha should be evicted
+        topics = m.recent_topics
+        self.assertNotIn("alpha", topics)
+        self.assertIn("delta", topics)
+        self.assertEqual(len(topics), 3)
+
+    def test_len(self):
+        m = self._mem()
+        m.add(["coffee", "weather", "robot"])
+        self.assertEqual(len(m), 3)
+
+    def test_last_updated_set(self):
+        m = self._mem()
+        before = time.monotonic()
+        m.add(["test"])
+        self.assertGreaterEqual(m.last_updated, before)
+
+    def test_empty_add(self):
+        m = self._mem()
+        added = m.add([])
+        self.assertEqual(added, [])
+        self.assertEqual(len(m), 0)
+
+    def test_many_duplicates_stay_within_cap(self):
+        m = self._mem(max_topics=5)
+        for _ in range(10):
+            m.add(["coffee"])
+        self.assertEqual(len(m), 1)
+        self.assertIn("coffee", m.recent_topics)
+
+
+# ── Tests: node init ──────────────────────────────────────────────────────────
+
+class TestNodeInit(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls): cls.mod = _load_mod()
+
+    def test_instantiates(self):
+        self.assertIsNotNone(_make_node(self.mod))
+
+    def test_pub_registered(self):
+        node = _make_node(self.mod)
+        self.assertIn("/saltybot/conversation_topics", node._pubs)
+
+    def test_sub_registered(self):
+        node = _make_node(self.mod)
+        self.assertIn("/social/conversation_text", node._subs)
+
+    def test_memory_empty(self):
+        node = _make_node(self.mod)
+        self.assertEqual(node.all_persons(), {})
+
+    def test_custom_topics(self):
+        node = _make_node(self.mod,
+                          conversation_topic="/my/conv",
+                          output_topic="/my/topics")
+        self.assertIn("/my/conv", node._subs)
+        self.assertIn("/my/topics", node._pubs)
+
+
+# ── Tests: on_conversation callback ──────────────────────────────────────────
+
+class TestOnConversation(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls): cls.mod = _load_mod()
+
+    def setUp(self):
+        self.node = _make_node(self.mod)
+        self.pub  = self.node._pubs["/saltybot/conversation_topics"]
+
+    def test_publishes_on_keyword(self):
+        _send(self.node, "alice", "I love drinking coffee")
+        self.assertEqual(len(self.pub.msgs), 1)
+
+    def test_payload_is_json(self):
+        _send(self.node, "alice", "I love drinking coffee")
+        payload = json.loads(self.pub.msgs[-1].data)
+        self.assertIsInstance(payload, dict)
+
+    def test_payload_person_id(self):
+        _send(self.node, "bob", "I enjoy hiking mountains")
+        payload = json.loads(self.pub.msgs[-1].data)
+        self.assertEqual(payload["person_id"], "bob")
+
+    def test_payload_recent_topics(self):
+        _send(self.node, "alice", "I love coffee weather robots")
+        payload = json.loads(self.pub.msgs[-1].data)
+        self.assertIsInstance(payload["recent_topics"], list)
+        self.assertGreater(len(payload["recent_topics"]), 0)
+
+    def test_payload_new_topics(self):
+        _send(self.node, "alice", "I love coffee")
+        payload = json.loads(self.pub.msgs[-1].data)
+        self.assertIn("coffee", payload["new_topics"])
+
+    def test_payload_has_ts(self):
+        _send(self.node, "alice", "I love coffee")
+        payload = json.loads(self.pub.msgs[-1].data)
+        self.assertIn("ts", payload)
+
+    def test_all_stop_words_no_publish(self):
+        _send(self.node, "alice", "the is and or")
+        self.assertEqual(len(self.pub.msgs), 0)
+
+    def test_empty_text_no_publish(self):
+        _send(self.node, "alice", "")
+        self.assertEqual(len(self.pub.msgs), 0)
+
+    def test_bad_json_no_crash(self):
+        m = _String(); m.data = "not json at all"
+        self.node._subs["/social/conversation_text"](m)
+        self.assertEqual(len(self.pub.msgs), 0)
+        warns = [l for l in self.node._logs if l[0] == "WARN"]
+        self.assertEqual(len(warns), 1)
+
+    def test_missing_person_id_defaults_unknown(self):
+        m = _String(); m.data = json.dumps({"text": "coffee weather hiking"})
+        self.node._subs["/social/conversation_text"](m)
+        payload = json.loads(self.pub.msgs[-1].data)
+        self.assertEqual(payload["person_id"], "unknown")
+
+    def test_duplicate_topic_not_in_new(self):
+        _send(self.node, "alice", "coffee mountains weather")
+        _send(self.node, "alice", "coffee")   # coffee already known
+        payload = json.loads(self.pub.msgs[-1].data)
+        self.assertNotIn("coffee", payload["new_topics"])
+
+    def test_topics_accumulate_across_turns(self):
+        _send(self.node, "alice", "coffee weather")
+        _send(self.node, "alice", "mountains hiking")
+        mem = self.node.get_memory("alice")
+        topics = mem.recent_topics
+        self.assertIn("coffee", topics)
+        self.assertIn("mountains", topics)
+
+    def test_separate_persons_independent(self):
+        _send(self.node, "alice", "coffee weather")
+        _send(self.node, "bob",   "robots motors")
+        alice = self.node.get_memory("alice").recent_topics
+        bob   = self.node.get_memory("bob").recent_topics
+        self.assertIn("coffee",  alice)
+        self.assertNotIn("robots", alice)
+        self.assertIn("robots",  bob)
+        self.assertNotIn("coffee", bob)
+
+    def test_all_persons_snapshot(self):
+        _send(self.node, "alice", "coffee weather")
+        _send(self.node, "bob",   "robots motors")
+        persons = self.node.all_persons()
+        self.assertIn("alice", persons)
+        self.assertIn("bob",   persons)
+
+    def test_recent_topics_most_recent_first(self):
+        _send(self.node, "alice", "alpha")
+        _send(self.node, "alice", "beta")
+        _send(self.node, "alice", "gamma")
+        topics = self.node.get_memory("alice").recent_topics
+        self.assertEqual(topics[0], "gamma")
+
+    def test_stop_words_not_stored(self):
+        _send(self.node, "alice", "the weather and coffee")
+        topics = self.node.get_memory("alice").recent_topics
+        self.assertNotIn("the", topics)
+        self.assertNotIn("and", topics)
+
+    def test_max_keywords_respected(self):
+        node = _make_node(self.mod, max_keywords_per_msg=3)
+        _send(node, "alice",
+              "coffee weather hiking mountains ocean desert forest lake")
+        mem = node.get_memory("alice")
+        # Only 3 keywords should have been extracted per message
+        self.assertLessEqual(len(mem), 3)
+
+    def test_max_topics_cap(self):
+        node = _make_node(self.mod, max_topics_per_person=5, max_keywords_per_msg=20)
+        words = ["alpha", "beta", "gamma", "delta", "epsilon",
+                 "zeta", "eta", "theta"]
+        for i, w in enumerate(words):
+            _send(node, "alice", w)
+        mem = node.get_memory("alice")
+        self.assertLessEqual(len(mem), 5)
+
+
+# ── Tests: prune ──────────────────────────────────────────────────────────────
+
+class TestPrune(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls): cls.mod = _load_mod()
+
+    def test_no_prune_when_disabled(self):
+        node = _make_node(self.mod, prune_after_s=0.0)
+        _send(node, "alice", "coffee weather")
+        # Manually expire timestamp
+        node._memory["alice"].last_updated = time.monotonic() - 9999
+        _send(node, "bob", "robots motors")   # triggers prune check
+        # alice should still be present (prune disabled)
+        self.assertIn("alice", node.all_persons())
+
+    def test_prune_stale_person(self):
+        node = _make_node(self.mod, prune_after_s=1.0)
+        _send(node, "alice", "coffee weather")
+        node._memory["alice"].last_updated = time.monotonic() - 10.0  # stale
+        _send(node, "bob", "robots motors")  # triggers prune
+        self.assertNotIn("alice", node.all_persons())
+
+    def test_fresh_person_not_pruned(self):
+        node = _make_node(self.mod, prune_after_s=1.0)
+        _send(node, "alice", "coffee weather")
+        # alice is fresh (just added)
+        _send(node, "bob", "robots motors")
+        self.assertIn("alice", node.all_persons())
+
+
+# ── Tests: source and config ──────────────────────────────────────────────────
+
+class TestNodeSrc(unittest.TestCase):
+    @classmethod
+    def setUpClass(cls):
+        with open(_SRC) as f: cls.src = f.read()
+
+    def test_issue_tag(self):         self.assertIn("#299", self.src)
+    def test_input_topic(self):       self.assertIn("/social/conversation_text", self.src)
+    def test_output_topic(self):      self.assertIn("/saltybot/conversation_topics", self.src)
+    def test_extract_keywords(self):  self.assertIn("extract_keywords", self.src)
+    def test_person_topic_memory(self):self.assertIn("PersonTopicMemory", self.src)
+    def test_stop_words(self):        self.assertIn("STOP_WORDS", self.src)
+    def test_json_output(self):       self.assertIn("json.dumps", self.src)
+    def test_person_id_in_output(self):self.assertIn("person_id", self.src)
+    def test_recent_topics_key(self): self.assertIn("recent_topics", self.src)
+    def test_new_topics_key(self):    self.assertIn("new_topics", self.src)
+    def test_threading_lock(self):    self.assertIn("threading.Lock", self.src)
+    def test_prune_method(self):      self.assertIn("_prune_stale", self.src)
+    def test_main_defined(self):      self.assertIn("def main", self.src)
+    def test_min_word_length_param(self):self.assertIn("min_word_length", self.src)
+    def test_max_topics_param(self):  self.assertIn("max_topics_per_person", self.src)
+
+
+class TestConfig(unittest.TestCase):
+    _CONFIG = (
+        "/Users/seb/AI/saltylab-firmware/jetson/ros2_ws/src/"
+        "saltybot_social/config/topic_memory_params.yaml"
+    )
+    _LAUNCH = (
+        "/Users/seb/AI/saltylab-firmware/jetson/ros2_ws/src/"
+        "saltybot_social/launch/topic_memory.launch.py"
+    )
+    _SETUP = (
+        "/Users/seb/AI/saltylab-firmware/jetson/ros2_ws/src/"
+        "saltybot_social/setup.py"
+    )
+
+    def test_config_exists(self):
+        import os; self.assertTrue(os.path.exists(self._CONFIG))
+
+    def test_config_min_word_length(self):
+        with open(self._CONFIG) as f: c = f.read()
+        self.assertIn("min_word_length", c)
+
+    def test_config_max_topics(self):
+        with open(self._CONFIG) as f: c = f.read()
+        self.assertIn("max_topics_per_person", c)
+
+    def test_config_prune(self):
+        with open(self._CONFIG) as f: c = f.read()
+        self.assertIn("prune_after_s", c)
+
+    def test_launch_exists(self):
+        import os; self.assertTrue(os.path.exists(self._LAUNCH))
+
+    def test_launch_max_topics_arg(self):
+        with open(self._LAUNCH) as f: c = f.read()
+        self.assertIn("max_topics_per_person", c)
+
+    def test_entry_point(self):
+        with open(self._SETUP) as f: c = f.read()
+        self.assertIn("topic_memory_node", c)
+
+
+if __name__ == "__main__":
+    unittest.main()