refactor: deduplicate pool close() by calling _drain_idle(), fix is True style

pool.close() had a drain loop character-for-character identical to
_drain_idle(). Replace with a call to _drain_idle().

Also change _reset_connection's `conn._in_transaction is True` to
the truthiness check `if conn._in_transaction:` for consistency with
the rest of the codebase. Fix two mock tests that relied on the
`is True` behavior (MagicMock attributes are truthy but not `is True`).

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: antoineleclair

src/dqliteclient/pool.py

@@ -180,7 +180,7 @@ async def _reset_connection(self, conn: DqliteConnection) -> bool:
         Returns True if the connection is clean and can be reused,
         False if it should be destroyed.
         """
-        if conn._in_transaction is True:
+        if conn._in_transaction:
             try:
                 await conn.execute("ROLLBACK")
             except Exception:
@@ -248,19 +248,7 @@ async def close(self) -> None:
         in-flight tasks before calling close().
         """
         self._closed = True
-
-        # Close idle connections
-        while not self._pool.empty():
-            try:
-                conn = self._pool.get_nowait()
-            except asyncio.QueueEmpty:
-                break
-            try:
-                await conn.close()
-            except BaseException:
-                pass
-            finally:
-                self._size -= 1
+        await self._drain_idle()
 
         # In-use connections are closed by acquire()'s cleanup when they
         # return — the else branch checks _closed and closes instead of

tests/test_pool.py

@@ -142,6 +142,7 @@ async def test_cancellation_returns_healthy_connection_to_pool(self) -> None:
         mock_conn.is_connected = True
         mock_conn.connect = AsyncMock()
         mock_conn.close = AsyncMock()
+        mock_conn._in_transaction = False
 
         with patch.object(pool._cluster, "connect", return_value=mock_conn):
             await pool.initialize()
@@ -437,6 +438,7 @@ async def test_user_exception_preserves_healthy_connection(self) -> None:
         mock_conn.is_connected = True
         mock_conn.connect = AsyncMock()
         mock_conn.close = AsyncMock()
+        mock_conn._in_transaction = False
 
         with patch.object(pool._cluster, "connect", return_value=mock_conn):
             await pool.initialize()