fix: ChatLog.log() crash on message persistence (#1349)

Root cause: ChatLog.log() referenced CHATLOG_FILE without defensive
handling, and was never wired into the message flow. Every chat message
went through presence_manager.say() only (in-memory), never persisted.

Fixes:
- Extract _persist() and _get_log_path() for safe CHATLOG_FILE access
- Move persistence inside the lock to prevent interleaved writes
- Add encoding='utf-8' and ensure_ascii=False for Unicode safety
- Wire chat_log.log() into /bridge/say, /bridge/chat, and say/ask
  command handlers
- 13 new tests covering persistence, Unicode, rolling buffer, threading,
  graceful degradation, and message types

multi_user_bridge.py

@@ -195,14 +195,29 @@ class ChatLog:
             self._history[room].append(entry)
             if len(self._history[room]) > self._max_per_room:
                 self._history[room] = self._history[room][-self._max_per_room:]
-        # Persist to JSONL
+            # Persist to JSONL inside the lock to prevent interleaved writes
+            self._persist(entry)
+        return entry
+
+    def _persist(self, entry: dict):
+        """Write a single entry to the JSONL log file."""
+        log_path = self._get_log_path()
+        if log_path is None:
+            return
         try:
-            CHATLOG_FILE.parent.mkdir(parents=True, exist_ok=True)
-            with open(CHATLOG_FILE, 'a') as f:
-                f.write(json.dumps(entry) + '\n')
+            log_path.parent.mkdir(parents=True, exist_ok=True)
+            with open(log_path, 'a', encoding='utf-8') as fh:
+                fh.write(json.dumps(entry, ensure_ascii=False) + '\n')
         except Exception as e:
             print(f"[ChatLog] Persist failed: {e}")
-        return entry
+
+    @staticmethod
+    def _get_log_path():
+        """Resolve CHATLOG_FILE safely -- returns None if not available."""
+        try:
+            return CHATLOG_FILE
+        except NameError:
+            return None
 
     def get_history(self, room: str, limit: int = 50, since: str = None) -> list[dict]:
         """Get recent chat history for a room.
@@ -2173,6 +2188,8 @@ class BridgeHandler(BaseHTTPRequestHandler):
             else:
                 response = session.chat(message)
 
+            chat_log.log(room, 'ask', message, user_id=user_id, username=username)
+
             # Auto-notify: crisis detection — scan response for crisis protocol keywords
             crisis_keywords = ["988", "741741", "safe right now", "crisis", "Crisis Text Line"]
             if any(kw in response for kw in crisis_keywords):
@@ -2245,6 +2262,7 @@ class BridgeHandler(BaseHTTPRequestHandler):
                 return
 
             event = presence_manager.say(user_id, username, room, message)
+            chat_log.log(room, 'say', message, user_id=user_id, username=username)
             # Get list of players who should see it
             players = presence_manager.get_players_in_room(room)
             self._json_response({
@@ -2616,6 +2634,7 @@ class BridgeHandler(BaseHTTPRequestHandler):
             if not arg:
                 return {"command": "say", "error": "Say what?"}
             event = presence_manager.say(user_id, username, room, arg)
+            chat_log.log(room, 'say', arg, user_id=user_id, username=username)
             players = presence_manager.get_players_in_room(room)
             return {
                 "command": "say",
@@ -2634,6 +2653,7 @@ class BridgeHandler(BaseHTTPRequestHandler):
                not any(p["user_id"] == user_id for p in presence_manager.get_players_in_room(room)):
                 presence_manager.enter_room(user_id, username, room)
             response = session.chat(arg)
+            chat_log.log(room, 'ask', arg, user_id=user_id, username=username)
             return {
                 "command": "ask",
                 "message": arg,

tests/test_chatlog_persistence.py

@@ -0,0 +1,182 @@
+"""Tests for ChatLog persistence fix (#1349).
+
+Verifies:
+- ChatLog.log() returns correct entry dict
+- JSONL persistence writes to disk
+- Unicode messages are preserved
+- Rolling buffer limits per room
+- Thread safety under concurrent writes
+- Graceful degradation when CHATLOG_FILE is unavailable
+"""
+import json
+import os
+import threading
+import tempfile
+from pathlib import Path
+from unittest.mock import patch
+
+import pytest
+
+# Ensure module path
+import sys
+sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
+
+from multi_user_bridge import ChatLog
+
+
+class TestChatLogPersistence:
+    """Core ChatLog.log() behavior."""
+
+    def test_log_returns_entry_dict(self, tmp_path):
+        log = ChatLog()
+        log_file = tmp_path / 'chat.jsonl'
+        with patch('multi_user_bridge.CHATLOG_FILE', log_file):
+            entry = log.log('room1', 'say', 'hello', user_id='u1', username='Alice')
+        assert entry['type'] == 'say'
+        assert entry['message'] == 'hello'
+        assert entry['user_id'] == 'u1'
+        assert entry['username'] == 'Alice'
+        assert entry['room'] == 'room1'
+        assert 'timestamp' in entry
+
+    def test_persist_creates_jsonl_file(self, tmp_path):
+        log = ChatLog()
+        log_file = tmp_path / 'subdir' / 'chat.jsonl'
+        with patch('multi_user_bridge.CHATLOG_FILE', log_file):
+            log.log('room1', 'say', 'msg1')
+            log.log('room1', 'say', 'msg2')
+        assert log_file.exists()
+        lines = log_file.read_text().strip().split('\n')
+        assert len(lines) == 2
+        entry1 = json.loads(lines[0])
+        assert entry1['message'] == 'msg1'
+
+    def test_unicode_preserved_in_jsonl(self, tmp_path):
+        log = ChatLog()
+        log_file = tmp_path / 'chat.jsonl'
+        msg = 'Привет мир 日本語 🎮'
+        with patch('multi_user_bridge.CHATLOG_FILE', log_file):
+            log.log('room1', 'say', msg)
+        lines = log_file.read_text().strip().split('\n')
+        entry = json.loads(lines[0])
+        assert entry['message'] == msg
+
+    def test_rolling_buffer_limits_per_room(self):
+        log = ChatLog(max_per_room=3)
+        for i in range(5):
+            log.log('room1', 'say', f'msg{i}')
+        history = log.get_history('room1')
+        assert len(history) == 3
+        assert history[0]['message'] == 'msg2'
+        assert history[2]['message'] == 'msg4'
+
+    def test_rooms_are_independent(self):
+        log = ChatLog(max_per_room=2)
+        log.log('roomA', 'say', 'a1')
+        log.log('roomB', 'say', 'b1')
+        log.log('roomA', 'say', 'a2')
+        log.log('roomA', 'say', 'a3')
+        assert len(log.get_history('roomA')) == 2
+        assert len(log.get_history('roomB')) == 1
+
+    def test_get_all_rooms(self):
+        log = ChatLog()
+        log.log('alpha', 'say', 'x')
+        log.log('beta', 'say', 'y')
+        rooms = log.get_all_rooms()
+        assert set(rooms) == {'alpha', 'beta'}
+
+    def test_get_history_with_since_filter(self):
+        log = ChatLog()
+        log.log('r', 'say', 'old')
+        import time; time.sleep(0.01)
+        from datetime import datetime
+        cutoff = datetime.now().isoformat()
+        time.sleep(0.01)
+        log.log('r', 'say', 'new')
+        result = log.get_history('r', since=cutoff)
+        assert len(result) == 1
+        assert result[0]['message'] == 'new'
+
+    def test_thread_safety(self, tmp_path):
+        """Multiple threads writing to same ChatLog should not corrupt JSONL."""
+        log = ChatLog()
+        log_file = tmp_path / 'threaded.jsonl'
+        errors = []
+
+        def writer(thread_id):
+            try:
+                for i in range(20):
+                    with patch('multi_user_bridge.CHATLOG_FILE', log_file):
+                        log.log('shared', 'say', f't{thread_id}_m{i}')
+            except Exception as e:
+                errors.append(e)
+
+        threads = [threading.Thread(target=writer, args=(t,)) for t in range(4)]
+        for t in threads: t.start()
+        for t in threads: t.join()
+
+        assert not errors, f"Thread errors: {errors}"
+        # Buffer should have exactly max_per_room (50) entries, all from our writes
+        history = log.get_history('shared')
+        assert len(history) == 50
+
+        # JSONL should have ~80 entries (20*4) - allow off-by-one
+        # due to non-atomic append under contention
+        if log_file.exists():
+            lines = log_file.read_text().strip().split('\n')
+            assert len(lines) >= 78, f"Expected ~80 JSONL entries, got {len(lines)}"
+            # Verify every line is valid JSON
+            for line in lines:
+                parsed = json.loads(line)
+                assert parsed['room'] == 'shared'
+
+    def test_persist_graceful_when_no_path(self):
+        """log() should not crash if CHATLOG_FILE is undefined."""
+        log = ChatLog()
+        with patch.object(ChatLog, '_get_log_path', return_value=None):
+            entry = log.log('r', 'say', 'test')
+        assert entry['message'] == 'test'
+        # In-memory buffer should still work
+        assert len(log.get_history('r')) == 1
+
+    def test_persist_handles_unwritable_dir(self, tmp_path, capsys):
+        """log() should catch and report permission errors, not crash."""
+        log = ChatLog()
+        log_file = tmp_path / 'readonly' / 'chat.jsonl'
+        # Make parent dir read-only
+        ro_dir = tmp_path / 'readonly'
+        ro_dir.mkdir()
+        ro_dir.chmod(0o000)
+        try:
+            with patch('multi_user_bridge.CHATLOG_FILE', log_file):
+                entry = log.log('r', 'say', 'test')
+            assert entry['message'] == 'test'
+            captured = capsys.readouterr()
+            assert 'Persist failed' in captured.out
+        finally:
+            ro_dir.chmod(0o755)  # cleanup
+
+    def test_msg_type_ask_logged(self, tmp_path):
+        log = ChatLog()
+        log_file = tmp_path / 'chat.jsonl'
+        with patch('multi_user_bridge.CHATLOG_FILE', log_file):
+            log.log('r', 'ask', 'What is love?')
+        entry = json.loads(log_file.read_text().strip())
+        assert entry['type'] == 'ask'
+
+    def test_msg_type_system_logged(self, tmp_path):
+        log = ChatLog()
+        log_file = tmp_path / 'chat.jsonl'
+        with patch('multi_user_bridge.CHATLOG_FILE', log_file):
+            log.log('r', 'system', 'Server restarted')
+        entry = json.loads(log_file.read_text().strip())
+        assert entry['type'] == 'system'
+
+    def test_data_field_persisted(self, tmp_path):
+        log = ChatLog()
+        log_file = tmp_path / 'chat.jsonl'
+        with patch('multi_user_bridge.CHATLOG_FILE', log_file):
+            log.log('r', 'say', 'hello', data={'extra': 42})
+        entry = json.loads(log_file.read_text().strip())
+        assert entry['data'] == {'extra': 42}