From 5c2481082ef11633c56bd5d631550b746b18d271 Mon Sep 17 00:00:00 2001
From: hroff-1902 <hroff_raeyd9tzpttf@mail.ru>
Date: Wed, 22 Jul 2020 22:46:30 +0300
Subject: [PATCH] Add tests for PriceFilter

---
 tests/pairlist/test_pairlist.py | 56 +++++++++++++++++++++++----------
 1 file changed, 40 insertions(+), 16 deletions(-)

diff --git a/tests/pairlist/test_pairlist.py b/tests/pairlist/test_pairlist.py
index efe4a784b..5a9472ef9 100644
--- a/tests/pairlist/test_pairlist.py
+++ b/tests/pairlist/test_pairlist.py
@@ -590,34 +590,58 @@ def test_agefilter_caching(mocker, markets, whitelist_conf_3, tickers, ohlcv_his
     assert freqtrade.exchange.get_historic_ohlcv.call_count == previous_call_count
 
 
-@pytest.mark.parametrize("pairlistconfig,expected", [
+@pytest.mark.parametrize("pairlistconfig,desc_expected,exception_expected", [
     ({"method": "PriceFilter", "low_price_ratio": 0.001, "min_price": 0.00000010,
-      "max_price": 1.0}, "[{'PriceFilter': 'PriceFilter - Filtering pairs priced below "
-                         "0.1% or below 0.00000010 or above 1.00000000.'}]"
-     ),
+      "max_price": 1.0},
+     "[{'PriceFilter': 'PriceFilter - Filtering pairs priced below "
+     "0.1% or below 0.00000010 or above 1.00000000.'}]",
+     None
+    ),
     ({"method": "PriceFilter", "low_price_ratio": 0.001, "min_price": 0.00000010},
-     "[{'PriceFilter': 'PriceFilter - Filtering pairs priced below 0.1% or below 0.00000010.'}]"
-     ),
+     "[{'PriceFilter': 'PriceFilter - Filtering pairs priced below 0.1% or below 0.00000010.'}]",
+     None
+    ),
     ({"method": "PriceFilter", "low_price_ratio": 0.001, "max_price": 1.00010000},
-     "[{'PriceFilter': 'PriceFilter - Filtering pairs priced below 0.1% or above 1.00010000.'}]"
-     ),
+     "[{'PriceFilter': 'PriceFilter - Filtering pairs priced below 0.1% or above 1.00010000.'}]",
+     None
+    ),
     ({"method": "PriceFilter", "min_price": 0.00002000},
-     "[{'PriceFilter': 'PriceFilter - Filtering pairs priced below 0.00002000.'}]"
-     ),
+     "[{'PriceFilter': 'PriceFilter - Filtering pairs priced below 0.00002000.'}]",
+     None
+    ),
     ({"method": "PriceFilter"},
-     "[{'PriceFilter': 'PriceFilter - No price filters configured.'}]"
-     ),
+     "[{'PriceFilter': 'PriceFilter - No price filters configured.'}]",
+     None
+    ),
+    ({"method": "PriceFilter", "low_price_ratio": -0.001},
+     None,
+     "PriceFilter requires low_price_ratio be >= 0"
+    ), # OperationalException expected
+    ({"method": "PriceFilter", "min_price": -0.00000010},
+     None,
+     "PriceFilter requires min_price be >= 0"
+    ), # OperationalException expected
+    ({"method": "PriceFilter", "max_price": -1.00010000},
+     None,
+     "PriceFilter requires max_price be >= 0"
+    ), # OperationalException expected
 ])
-def test_pricefilter_desc(mocker, whitelist_conf, markets, pairlistconfig, expected):
+def test_pricefilter_desc(mocker, whitelist_conf, markets, pairlistconfig,
+                          desc_expected, exception_expected):
     mocker.patch.multiple('freqtrade.exchange.Exchange',
                           markets=PropertyMock(return_value=markets),
                           exchange_has=MagicMock(return_value=True)
                           )
     whitelist_conf['pairlists'] = [pairlistconfig]
 
-    freqtrade = get_patched_freqtradebot(mocker, whitelist_conf)
-    short_desc = str(freqtrade.pairlists.short_desc())
-    assert short_desc == expected
+    if desc_expected is not None:
+        freqtrade = get_patched_freqtradebot(mocker, whitelist_conf)
+        short_desc = str(freqtrade.pairlists.short_desc())
+        assert short_desc == desc_expected
+    else: # # OperationalException expected
+        with pytest.raises(OperationalException,
+                           match=exception_expected):
+            freqtrade = get_patched_freqtradebot(mocker, whitelist_conf)
 
 
 def test_pairlistmanager_no_pairlist(mocker, markets, whitelist_conf, caplog):