fix: improved message when nonexisting trade is deleted

part of freqtrade#11967

Author: xmatthias

freqtrade/rpc/rpc.py

@@ -1094,7 +1094,7 @@ def _rpc_delete(self, trade_id: int) -> dict[str, str | int]:
             trade = Trade.get_trades(trade_filter=[Trade.id == trade_id]).first()
             if not trade:
                 logger.warning("delete trade: Invalid argument received")
-                raise RPCException("invalid argument")
+                raise RPCException(f"Trade with id '{trade_id}' not found.")
 
             # Try cancelling regular order if that exists
             for open_order in trade.open_orders:

tests/rpc/test_rpc.py

@@ -393,7 +393,7 @@ def test_rpc_delete_trade(mocker, default_conf, fee, markets, caplog, is_short):
     freqtradebot.strategy.order_types["stoploss_on_exchange"] = True
     create_mock_trades(fee, is_short)
     rpc = RPC(freqtradebot)
-    with pytest.raises(RPCException, match="invalid argument"):
+    with pytest.raises(RPCException, match="Trade with id '200' not found."):
         rpc._rpc_delete("200")
 
     trades = Trade.session.scalars(select(Trade)).all()