fix(memory): prune encoded Dream sessions

nanobot/agent/memory.py

@@ -16,7 +16,7 @@ from typing import TYPE_CHECKING, Any, Callable, Iterator
 from loguru import logger
 
 from nanobot.runtime_context import public_history_messages
-from nanobot.session.manager import Session
+from nanobot.session.manager import Session, SessionManager
 from nanobot.utils.gitstore import GitStore
 from nanobot.utils.helpers import (
     ensure_dir,
@@ -31,7 +31,6 @@ from nanobot.utils.helpers import (
 from nanobot.utils.prompt_templates import render_template
 
 if TYPE_CHECKING:
-    from nanobot.session.manager import SessionManager
     from nanobot.utils.llm_runtime import LLMRuntime
 
 # ---------------------------------------------------------------------------
@@ -705,12 +704,15 @@ class MemoryStore:
     def prune_dream_sessions(sessions_dir: Path, *, keep: int = 10) -> None:
         """Remove the oldest Dream session files, keeping only the N most recent.
 
-        Only files matching ``dream_*.jsonl`` are considered. Non-dream session
+        Only current base64url-encoded Dream session keys are considered.
-        files are never touched.
+        Non-dream session files are never touched.
         """
-        dream_files = sorted(
+        dream_files = []
-            sessions_dir.glob("dream_*.jsonl"), key=lambda p: p.stat().st_mtime,
+        for path in sessions_dir.glob("*.jsonl"):
-        )
+            decoded_key = SessionManager._decode_storage_key(path.stem)
+            if decoded_key is not None and decoded_key.startswith("dream:"):
+                dream_files.append(path)
+        dream_files.sort(key=lambda p: p.stat().st_mtime)
         if len(dream_files) <= keep:
             return
 

tests/agent/test_dream_session.py

@@ -1,8 +1,10 @@
 """Tests for Dream session key generation and rotation."""
+
 from datetime import datetime, timedelta
 from unittest.mock import patch
 
 from nanobot.agent.memory import MemoryStore
+from nanobot.session.manager import SessionManager
 
 
 class TestDreamSessionKey:
@@ -31,11 +33,11 @@ class TestPruneDreamSessions:
         sessions_dir.mkdir()
 
         base_time = time.time() - 100
+        dream_paths = []
 
         for i in range(15):
             key = f"dream:20260528-{100000 + i:06d}"
-            safe_key = key.replace(":", "_")
+            path = sessions_dir / f"{SessionManager._storage_key(key)}.jsonl"
-            path = sessions_dir / f"{safe_key}.jsonl"
             path.write_text(
                 f'{{"_type": "metadata", "key": "{key}", '
                 f'"created_at": "2026-05-28T10:00:{i:02d}", '
@@ -43,29 +45,57 @@ class TestPruneDreamSessions:
                 encoding="utf-8",
             )
             os.utime(path, (base_time + i, base_time + i))
+            dream_paths.append(path)
 
         normal_path = sessions_dir / "telegram_123.jsonl"
         normal_path.write_text('{"_type": "metadata"}\n', encoding="utf-8")
 
         MemoryStore.prune_dream_sessions(sessions_dir, keep=10)
 
-        dream_files = sorted(sessions_dir.glob("dream_*.jsonl"))
+        assert [path.exists() for path in dream_paths] == [False] * 5 + [True] * 10
-        assert len(dream_files) == 10
-        remaining_keys = [f.stem for f in dream_files]
-        assert "dream_20260528-100000" not in remaining_keys
-        assert "dream_20260528-100014" in remaining_keys
         assert normal_path.exists()
 
+    def test_ignores_legacy_dream_filenames(self, tmp_path):
+        import os
+        import time
+
+        sessions_dir = tmp_path / "sessions"
+        sessions_dir.mkdir()
+        base_time = time.time() - 100
+        current_paths = []
+
+        for i in range(2):
+            key = f"dream:20260713-{100000 + i:06d}"
+            path = sessions_dir / f"{SessionManager._storage_key(key)}.jsonl"
+            path.write_text(
+                f'{{"_type": "metadata", "key": "{key}"}}\n',
+                encoding="utf-8",
+            )
+            os.utime(path, (base_time + i, base_time + i))
+            current_paths.append(path)
+
+        legacy_path = sessions_dir / "dream_20260713-095959.jsonl"
+        legacy_path.write_text(
+            '{"_type": "metadata", "key": "dream:20260713-095959"}\n',
+            encoding="utf-8",
+        )
+        os.utime(legacy_path, (base_time - 1, base_time - 1))
+
+        MemoryStore.prune_dream_sessions(sessions_dir, keep=1)
+
+        assert [path.exists() for path in current_paths] == [False, True]
+        assert legacy_path.exists()
+
     def test_noop_when_under_limit(self, tmp_path):
         sessions_dir = tmp_path / "sessions"
         sessions_dir.mkdir()
         for i in range(3):
             key = f"dream:20260528-{100000 + i:06d}"
-            safe_key = key.replace(":", "_")
+            path = sessions_dir / f"{SessionManager._storage_key(key)}.jsonl"
-            (sessions_dir / f"{safe_key}.jsonl").write_text("{}", encoding="utf-8")
+            path.write_text("{}", encoding="utf-8")
 
         MemoryStore.prune_dream_sessions(sessions_dir, keep=10)
-        assert len(list(sessions_dir.glob("dream_*.jsonl"))) == 3
+        assert len(list(sessions_dir.glob("*.jsonl"))) == 3
 
     def test_empty_dir_noop(self, tmp_path):
         sessions_dir = tmp_path / "sessions"