rework exception handling (fixes #108)

freqtrade/tests/test_main.py

@@ -9,7 +9,7 @@ from sqlalchemy import create_engine
 from freqtrade.exchange import Exchanges
 from freqtrade.main import create_trade, handle_trade, close_trade_if_fulfilled, init, \
     get_target_bid, _process
-from freqtrade.misc import get_state, State
+from freqtrade.misc import get_state, State, FreqtradeException
 from freqtrade.persistence import Trade
 
 
@@ -139,7 +139,7 @@ def test_create_trade_no_stake_amount(default_conf, ticker, mocker):
                           get_ticker=ticker,
                           buy=MagicMock(return_value='mocked_limit_buy'),
                           get_balance=MagicMock(return_value=default_conf['stake_amount'] * 0.5))
-    with pytest.raises(ValueError, match=r'.*stake amount.*'):
+    with pytest.raises(FreqtradeException, match=r'.*stake amount.*'):
         create_trade(default_conf['stake_amount'])
 
 
@@ -152,7 +152,7 @@ def test_create_trade_no_pairs(default_conf, ticker, mocker):
                           get_ticker=ticker,
                           buy=MagicMock(return_value='mocked_limit_buy'))
 
-    with pytest.raises(ValueError, match=r'.*No pair in whitelist.*'):
+    with pytest.raises(FreqtradeException, match=r'.*No pair in whitelist.*'):
         conf = copy.deepcopy(default_conf)
         conf['exchange']['pair_whitelist'] = []
         mocker.patch.dict('freqtrade.main._CONF', conf)