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plm-lottery/tests/unit/test_db_base.py
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"""Regression tests for B-39: SQLite must run in WAL mode with a busy_timeout,
since this app has five concurrent background tasks plus every HTTP handler
sharing one database file, and the default rollback-journal mode lets a writer
block every reader and fails a second writer immediately instead of waiting."""
import pytest
from sqlalchemy.ext.asyncio import create_async_engine
from app.db.base import _SQLITE_BUSY_TIMEOUT_MS, _register_sqlite_pragmas
@pytest.fixture
async def sqlite_engine(tmp_path):
# WAL needs a real file (it writes a companion -wal/-shm file alongside it) —
# ":memory:" wouldn't exercise the same path.
engine = create_async_engine(f"sqlite+aiosqlite:///{tmp_path}/test.db")
yield engine
await engine.dispose()
async def _pragma(engine, name: str):
async with engine.connect() as conn:
result = await conn.exec_driver_sql(f"PRAGMA {name}")
return result.fetchone()[0]
async def test_register_sqlite_pragmas_enables_wal_and_busy_timeout(sqlite_engine):
_register_sqlite_pragmas(sqlite_engine)
assert (await _pragma(sqlite_engine, "journal_mode")).lower() == "wal"
assert await _pragma(sqlite_engine, "busy_timeout") == _SQLITE_BUSY_TIMEOUT_MS
assert await _pragma(sqlite_engine, "synchronous") == 1 # NORMAL
async def test_register_sqlite_pragmas_applies_to_every_new_connection(sqlite_engine):
"""The pool can open more than one underlying DBAPI connection over the
engine's lifetime — the pragmas must be re-applied to each one, not just
the first, or a later connection would silently fall back to SQLite's
defaults."""
_register_sqlite_pragmas(sqlite_engine)
async with sqlite_engine.connect() as first:
await first.exec_driver_sql("PRAGMA journal_mode")
async with sqlite_engine.connect() as second:
result = await second.exec_driver_sql("PRAGMA busy_timeout")
assert result.fetchone()[0] == _SQLITE_BUSY_TIMEOUT_MS
def test_register_sqlite_pragmas_is_a_noop_for_other_dialects():
"""Must not touch (or crash on) a non-sqlite engine — e.g. a future
PostgreSQL DATABASE_URL, which neither needs nor understands these
pragmas."""
class _FakeDialect:
name = "postgresql"
class _FakeEngine:
dialect = _FakeDialect()
_register_sqlite_pragmas(_FakeEngine()) # must not raise