From b63eda3a2b7e694a32d524c0413a30f737ef9d8d Mon Sep 17 00:00:00 2001
From: Matthias <xmatthias@outlook.com>
Date: Mon, 2 Aug 2021 07:15:09 +0200
Subject: [PATCH] Some minor cleanup and improved test coverage

---
 freqtrade/plugins/pairlist/rangestabilityfilter.py |  7 +++++--
 tests/plugins/test_pairlist.py                     | 12 +++++++++++-
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/freqtrade/plugins/pairlist/rangestabilityfilter.py b/freqtrade/plugins/pairlist/rangestabilityfilter.py
index 63184c726..ef7f2cbcb 100644
--- a/freqtrade/plugins/pairlist/rangestabilityfilter.py
+++ b/freqtrade/plugins/pairlist/rangestabilityfilter.py
@@ -51,9 +51,12 @@ class RangeStabilityFilter(IPairList):
         """
         Short whitelist method description - used for startup-messages
         """
+        max_rate_desc = ""
+        if self._max_rate_of_change:
+            max_rate_desc = (f" and above {self._max_rate_of_change}")
         return (f"{self.name} - Filtering pairs with rate of change below "
-                f"{self._min_rate_of_change} and above "
-                f"{self._max_rate_of_change} over the last {plural(self._days, 'day')}.")
+                f"{self._min_rate_of_change}{max_rate_desc} over the "
+                f"last {plural(self._days, 'day')}.")
 
     def filter_pairlist(self, pairlist: List[str], tickers: Dict) -> List[str]:
         """
diff --git a/tests/plugins/test_pairlist.py b/tests/plugins/test_pairlist.py
index a3f5b0875..5f0701a22 100644
--- a/tests/plugins/test_pairlist.py
+++ b/tests/plugins/test_pairlist.py
@@ -425,8 +425,12 @@ def test_VolumePairList_refresh_empty(mocker, markets_empty, whitelist_conf):
         "USDT", ['NANO/USDT']),
     ([{"method": "StaticPairList"},
       {"method": "RangeStabilityFilter", "lookback_days": 10,
-       "min_rate_of_change": 0.01, "max_rate_of_change": 0.99, "refresh_period": 1440}],
+       "min_rate_of_change": 0.01, "refresh_period": 1440}],
      "BTC", ['ETH/BTC', 'TKN/BTC', 'HOT/BTC']),
+    ([{"method": "StaticPairList"},
+      {"method": "RangeStabilityFilter", "lookback_days": 10,
+       "max_rate_of_change": 0.01, "refresh_period": 1440}],
+     "BTC", []),  # All removed because of max_rate_of_change being 0.017
     ([{"method": "StaticPairList"},
       {"method": "VolatilityFilter", "lookback_days": 3,
        "min_volatility": 0.002, "max_volatility": 0.004, "refresh_period": 1440}],
@@ -985,6 +989,12 @@ def test_spreadfilter_invalid_data(mocker, default_conf, markets, tickers, caplo
      None,
      "PriceFilter requires max_value to be >= 0"
      ),  # OperationalException expected
+    ({"method": "RangeStabilityFilter", "lookback_days": 10,
+      "min_rate_of_change": 0.01},
+     "[{'RangeStabilityFilter': 'RangeStabilityFilter - Filtering pairs with rate of change below "
+     "0.01 over the last days.'}]",
+        None
+     ),
     ({"method": "RangeStabilityFilter", "lookback_days": 10,
      "min_rate_of_change": 0.01, "max_rate_of_change": 0.99},
      "[{'RangeStabilityFilter': 'RangeStabilityFilter - Filtering pairs with rate of change below "