fix: 增强 SQLite 数据库恢复与异常提示

tests/unit/test_db_stability.py

@@ -0,0 +1,65 @@
+import pytest
+
+from app.db import check_database_integrity, checkpoint_sqlite_wal, create_sqlite_engine
+
+
+def test_check_database_integrity_returns_ok_for_valid_sqlite_database():
+    engine = create_sqlite_engine("sqlite:///:memory:")
+    try:
+        assert check_database_integrity(engine) == "ok"
+    finally:
+        engine.dispose()
+
+
+def test_check_database_integrity_raises_when_sqlite_reports_problem(monkeypatch):
+    class FakeCursor:
+        def execute(self, _sql):
+            return None
+
+        def fetchone(self):
+            return ("database disk image is malformed",)
+
+        def close(self):
+            return None
+
+    class FakeConnection:
+        def cursor(self):
+            return FakeCursor()
+
+    class FakeRawConnection:
+        driver_connection = FakeConnection()
+
+        def close(self):
+            return None
+
+    class FakeEngine:
+        def raw_connection(self):
+            return FakeRawConnection()
+
+    with pytest.raises(RuntimeError, match="SQLite integrity check failed"):
+        check_database_integrity(FakeEngine())
+
+
+def test_checkpoint_sqlite_wal_truncates_wal_for_file_database(tmp_path):
+    db_path = tmp_path / "app.db"
+    engine = create_sqlite_engine(f"sqlite:///{db_path}")
+    try:
+        with engine.begin() as connection:
+            connection.exec_driver_sql("CREATE TABLE demo (id INTEGER PRIMARY KEY, name TEXT)")
+            connection.exec_driver_sql("INSERT INTO demo (name) VALUES ('ok')")
+
+        assert checkpoint_sqlite_wal(engine) is True
+
+        with engine.connect() as connection:
+            rows = connection.exec_driver_sql("SELECT name FROM demo").all()
+        assert rows == [("ok",)]
+    finally:
+        engine.dispose()
+
+
+def test_checkpoint_sqlite_wal_skips_in_memory_database():
+    engine = create_sqlite_engine("sqlite:///:memory:")
+    try:
+        assert checkpoint_sqlite_wal(engine) is False
+    finally:
+        engine.dispose()