test: add test for DelistFilter

freqtrade/plugins/pairlist/DelistFilter.py

@@ -8,6 +8,7 @@ from datetime import UTC, datetime, timedelta
 from freqtrade.exceptions import ConfigurationError
 from freqtrade.exchange.exchange_types import Ticker
 from freqtrade.plugins.pairlist.IPairList import IPairList, PairlistParameter, SupportsBacktesting
+from freqtrade.util import format_date
 
 
 logger = logging.getLogger(__name__)
@@ -85,7 +86,7 @@ class DelistFilter(IPairList):
 
             if remove_pair:
                 self.log_once(
-                    f"Removed {pair} from whitelist, because it will be delisted on {delist_date}.",
+                    f"Removed {pair} from whitelist, because it will be delisted on {format_date(delist_date)}.",
                     logger.info,
                 )
                 return False

tests/plugins/test_pairlist.py

@@ -18,7 +18,7 @@ from freqtrade.persistence import LocalTrade, Trade
 from freqtrade.plugins.pairlist.pairlist_helpers import dynamic_expand_pairlist, expand_pairlist
 from freqtrade.plugins.pairlistmanager import PairListManager
 from freqtrade.resolvers import PairListResolver
-from freqtrade.util.datetime_helpers import dt_now
+from freqtrade.util import dt_now, dt_utc
 from tests.conftest import (
     EXMS,
     create_mock_trades_usdt,
@@ -2611,3 +2611,63 @@ def test_backtesting_modes(
 
     if expected_warning:
         assert log_has_re(f"Pairlist Handlers {expected_warning}", caplog)
+
+
+def test_DelistFilter_error(whitelist_conf) -> None:
+    whitelist_conf["pairlists"] = [{"method": "StaticPairList"}, {"method": "DelistFilter"}]
+    exchange_mock = MagicMock()
+    exchange_mock._ft_has = {"has_delisting": False}
+    with pytest.raises(
+        OperationalException,
+        match=r"DelistFilter doesn't support this exchange and trading mode combination\.",
+    ):
+        PairListManager(exchange_mock, whitelist_conf, MagicMock())
+
+
+@pytest.mark.usefixtures("init_persistence")
+def test_DelistFilter(mocker, default_conf_usdt, time_machine, caplog) -> None:
+    default_conf_usdt["exchange"]["pair_whitelist"] = [
+        "ETH/USDT",
+        "XRP/USDT",
+        "BTC/USDT",
+        "NEO/USDT",
+    ]
+    default_conf_usdt["pairlists"] = [
+        {"method": "StaticPairList"},
+        {"method": "DelistFilter", "max_days_from_now": 3},
+    ]
+    default_conf_usdt["max_open_trades"] = -1
+    exchange = get_patched_exchange(mocker, default_conf_usdt)
+
+    def delist_mock(pair: str):
+        mock_delist = {
+            "XRP/USDT": dt_utc(2025, 9, 1) + timedelta(days=1),  # Delisting in 1 day
+            "NEO/USDT": dt_utc(2025, 9, 1) + timedelta(days=5, hours=2),  # Delisting in 5 days
+        }
+        return mock_delist.get(pair, None)
+
+    time_machine.move_to("2025-09-01 01:00:00 +00:00", tick=False)
+
+    mocker.patch.object(exchange, "check_delisting_time", delist_mock)
+    pm = PairListManager(exchange, default_conf_usdt)
+    pm.refresh_pairlist()
+    assert pm.whitelist == ["ETH/USDT", "BTC/USDT", "NEO/USDT"]
+    assert log_has(
+        "Removed XRP/USDT from whitelist, because it will be delisted on 2025-09-02 00:00:00.",
+        caplog,
+    )
+    # NEO is kept initially as delisting is in 5 days, but config is 3 days
+
+    time_machine.move_to("2025-09-03 01:00:00 +00:00", tick=False)
+    pm.refresh_pairlist()
+    assert pm.whitelist == ["ETH/USDT", "BTC/USDT", "NEO/USDT"]
+    # NEO not removed yet, expiry falls into the window 1 hour later
+
+    time_machine.move_to("2025-09-03 02:00:00 +00:00", tick=False)
+    pm.refresh_pairlist()
+    assert pm.whitelist == ["ETH/USDT", "BTC/USDT"]
+
+    assert log_has(
+        "Removed NEO/USDT from whitelist, because it will be delisted on 2025-09-06 02:00:00.",
+        caplog,
+    )