From b80cef964e5461fd19a7329982d97402e2ca3333 Mon Sep 17 00:00:00 2001
From: hroff-1902 <hroff_raeyd9tzpttf@mail.ru>
Date: Wed, 3 Jul 2019 01:03:38 +0300
Subject: [PATCH] fix validate_timeframes(); test added

---
 freqtrade/exchange/exchange.py            | 11 ++++++----
 freqtrade/tests/exchange/test_exchange.py | 26 +++++++++++++++++++++--
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/freqtrade/exchange/exchange.py b/freqtrade/exchange/exchange.py
index 2350c752f..71055460b 100644
--- a/freqtrade/exchange/exchange.py
+++ b/freqtrade/exchange/exchange.py
@@ -269,12 +269,15 @@ class Exchange(object):
         """
         Checks if ticker interval from config is a supported timeframe on the exchange
         """
-        if not hasattr(self._api, "timeframes"):
-            # If timeframes is missing, the exchange probably has no fetchOHLCV method.
+        if not hasattr(self._api, "timeframes") or self._api.timeframes is None:
+            # If timeframes attribute is missing (or is None), the exchange probably
+            # has no fetchOHLCV method.
             # Therefore we also show that.
             raise OperationalException(
-                f"This exchange ({self.name}) does not have a `timeframes` attribute and "
-                f"is therefore not supported. fetchOHLCV: {self.exchange_has('fetchOHLCV')}")
+                f"The ccxt library does not provide the list of timeframes "
+                f"for the exchange \"{self.name}\" and this exchange "
+                f"is therefore not supported. ccxt fetchOHLCV: {self.exchange_has('fetchOHLCV')}")
+
         timeframes = self._api.timeframes
         if timeframe not in timeframes:
             raise OperationalException(
diff --git a/freqtrade/tests/exchange/test_exchange.py b/freqtrade/tests/exchange/test_exchange.py
index b74882ad4..1d4b0bb11 100644
--- a/freqtrade/tests/exchange/test_exchange.py
+++ b/freqtrade/tests/exchange/test_exchange.py
@@ -396,7 +396,7 @@ def test_validate_timeframes_failed(default_conf, mocker):
         Exchange(default_conf)
 
 
-def test_validate_timeframes_emulated_ohlcv(default_conf, mocker):
+def test_validate_timeframes_emulated_ohlcv_1(default_conf, mocker):
     default_conf["ticker_interval"] = "3m"
     api_mock = MagicMock()
     id_mock = PropertyMock(return_value='test_exchange')
@@ -409,7 +409,29 @@ def test_validate_timeframes_emulated_ohlcv(default_conf, mocker):
     mocker.patch('freqtrade.exchange.Exchange._load_markets', MagicMock(return_value={}))
     mocker.patch('freqtrade.exchange.Exchange.validate_pairs', MagicMock())
     with pytest.raises(OperationalException,
-                       match=r'This exchange (.*) does not have a `timeframes` attribute and*'):
+                       match=r'The ccxt library does not provide the list of timeframes '
+                             r'for the exchange ".*" and this exchange '
+                             r'is therefore not supported. *'):
+        Exchange(default_conf)
+
+
+def test_validate_timeframes_emulated_ohlcvi_2(default_conf, mocker):
+    default_conf["ticker_interval"] = "3m"
+    api_mock = MagicMock()
+    id_mock = PropertyMock(return_value='test_exchange')
+    type(api_mock).id = id_mock
+
+    # delete timeframes so magicmock does not autocreate it
+    del api_mock.timeframes
+
+    mocker.patch('freqtrade.exchange.Exchange._init_ccxt', MagicMock(return_value=api_mock))
+    mocker.patch('freqtrade.exchange.Exchange._load_markets',
+                 MagicMock(return_value={'timeframes': None}))
+    mocker.patch('freqtrade.exchange.Exchange.validate_pairs', MagicMock())
+    with pytest.raises(OperationalException,
+                       match=r'The ccxt library does not provide the list of timeframes '
+                             r'for the exchange ".*" and this exchange '
+                             r'is therefore not supported. *'):
         Exchange(default_conf)