"""Retry of transient 'no more rows available' engine errors (#74934 port). Under dual gateway/agent WAL contention (FTS5 trigram sync holding the write lock on large appends), the SQLite engine can raise a transient 'no more rows available' error. The exception CLASS varies with the SQLite build — some surface it as ``sqlite3.InterfaceError``, which is a sibling of ``DatabaseError`` (not a subclass) and therefore escaped both existing retry branches in ``_execute_write`` on attempt 0, killing the turn as ``session_persistence_failed`` while the identical write would have succeeded milliseconds later. The fix is message-scoped, not class-scoped: any ``sqlite3.Error`` whose text contains 'no more rows available' retries within the existing deadline/patience loop; every other error propagates untouched. """ import sqlite3 import pytest from hermes_state import SessionDB @pytest.fixture def db(tmp_path, monkeypatch): # Keep retries fast: tiny jitter, short-but-sufficient patience. monkeypatch.setattr(SessionDB, "_WRITE_PATIENCE_S", 2.0) monkeypatch.setattr(SessionDB, "_WRITE_RETRY_MIN_S", 0.001) monkeypatch.setattr(SessionDB, "_WRITE_RETRY_MAX_S", 0.005) d = SessionDB(db_path=tmp_path / "state.db") yield d d.close() class TestNoMoreRowsRetry: def test_transient_interface_error_is_retried_to_success(self, db): """InterfaceError('no more rows available') must be retried inside the deadline/patience loop and succeed once the contention clears.""" calls = {"n": 0} def flaky(conn): calls["n"] += 1 if calls["n"] <= 3: raise sqlite3.InterfaceError("no more rows available") conn.execute( "INSERT INTO state_meta (key, value) VALUES ('nmr', 'ok') " "ON CONFLICT(key) DO UPDATE SET value=excluded.value" ) return "done" assert db._execute_write(flaky) == "done" assert calls["n"] == 4 assert db.get_meta("nmr") == "ok" def test_unrelated_interface_error_propagates_immediately(self, db): """The catch-all is message-scoped: an InterfaceError with any other text must escape on the first attempt, not be swallowed/retried.""" calls = {"n": 0} def broken(conn): calls["n"] += 1 raise sqlite3.InterfaceError("bad parameter or other API misuse") with pytest.raises(sqlite3.InterfaceError, match="bad parameter"): db._execute_write(broken) assert calls["n"] == 1 def test_no_more_rows_via_database_error_is_retried(self, db): """Some builds raise the same transient message through the generic DatabaseError class — it must ride the same retry loop instead of being misrouted into the FTS-corruption rebuild path.""" calls = {"n": 0} def flaky(conn): calls["n"] += 1 if calls["n"] <= 2: raise sqlite3.DatabaseError("no more rows available") return "ok" assert db._execute_write(flaky) == "ok" assert calls["n"] == 3 def test_exhausted_patience_propagates_the_transient_error(self, db, monkeypatch): """If contention never clears within the patience budget, the original error must surface rather than looping forever.""" monkeypatch.setattr(SessionDB, "_WRITE_PATIENCE_S", 0.05) def always(conn): raise sqlite3.InterfaceError("no more rows available") with pytest.raises(sqlite3.InterfaceError, match="no more rows"): db._execute_write(always)