Introduce markets_static fixture serving an immutable list of markets. Adapt pairlist/markets tests to use this new fixture.

This allows freely modifying markets in get_markets() without a need of updating pairlist/markets tests.

tests/commands/test_commands.py

@@ -208,11 +208,10 @@ def test_list_timeframes(mocker, capsys):
     assert re.search(r"^1d$", captured.out, re.MULTILINE)
 
 
-def test_list_markets(mocker, markets, capsys):
+def test_list_markets(mocker, markets_static, capsys):
 
     api_mock = MagicMock()
-    api_mock.markets = markets
+    patch_exchange(mocker, api_mock=api_mock, id='bittrex', mock_markets=markets_static)
-    patch_exchange(mocker, api_mock=api_mock, id='bittrex')
 
     # Test with no --config
     args = [
@@ -237,7 +236,7 @@ def test_list_markets(mocker, markets, capsys):
             "TKN/BTC, XLTCUSDT, XRP/BTC.\n"
             in captured.out)
 
-    patch_exchange(mocker, api_mock=api_mock, id="binance")
+    patch_exchange(mocker, api_mock=api_mock, id="binance", mock_markets=markets_static)
     # Test with --exchange
     args = [
         "list-markets",
@@ -250,7 +249,7 @@ def test_list_markets(mocker, markets, capsys):
     assert re.match("\nExchange Binance has 10 active markets:\n",
                     captured.out)
 
-    patch_exchange(mocker, api_mock=api_mock, id="bittrex")
+    patch_exchange(mocker, api_mock=api_mock, id="bittrex", mock_markets=markets_static)
     # Test with --all: all markets
     args = [
         "list-markets", "--all",

tests/conftest.py

@@ -90,8 +90,10 @@ def patch_exchange(mocker, api_mock=None, id='binance', mock_markets=True) -> No
     mocker.patch('freqtrade.exchange.Exchange.name', PropertyMock(return_value=id.title()))
     mocker.patch('freqtrade.exchange.Exchange.precisionMode', PropertyMock(return_value=2))
     if mock_markets:
+        if isinstance(mock_markets, bool):
+            mock_markets = get_markets()
         mocker.patch('freqtrade.exchange.Exchange.markets',
-                     PropertyMock(return_value=get_markets()))
+                     PropertyMock(return_value=mock_markets))
 
     if api_mock:
         mocker.patch('freqtrade.exchange.Exchange._init_ccxt', MagicMock(return_value=api_mock))
@@ -376,6 +378,8 @@ def markets():
 
 
 def get_markets():
+    # See get_markets_static() for immutable markets and do not modify them unless absolutely
+    # necessary!
     return {
         'ETH/BTC': {
             'id': 'ethbtc',
@@ -675,11 +679,22 @@ def get_markets():
 
 
 @pytest.fixture
-def shitcoinmarkets(markets):
+def markets_static():
+    # These markets are used in some tests that would need adaptation should anything change in
+    # market list. Do not modify this list without a good reason! Do not modify market parameters
+    # of listed pairs in get_markets() without a good reason either!
+    static_markets = ['BLK/BTC', 'BTT/BTC', 'ETH/BTC', 'ETH/USDT', 'LTC/BTC', 'LTC/ETH', 'LTC/USD',
+                      'LTC/USDT', 'NEO/BTC', 'TKN/BTC', 'XLTCUSDT', 'XRP/BTC']
+    all_markets = get_markets()
+    return {m: all_markets[m] for m in static_markets}
+
+
+@pytest.fixture
+def shitcoinmarkets(markets_static):
     """
     Fixture with shitcoin markets - used to test filters in pairlists
     """
-    shitmarkets = deepcopy(markets)
+    shitmarkets = deepcopy(markets_static)
     shitmarkets.update({
         'HOT/BTC': {
             'id': 'HOTBTC',

tests/exchange/test_exchange.py

@@ -2735,7 +2735,7 @@ def test_get_valid_pair_combination(default_conf, mocker, markets):
         (['LTC'], ['NONEXISTENT'], False, False,
          []),
     ])
-def test_get_markets(default_conf, mocker, markets,
+def test_get_markets(default_conf, mocker, markets_static,
                      base_currencies, quote_currencies, pairs_only, active_only,
                      expected_keys):
     mocker.patch.multiple('freqtrade.exchange.Exchange',
@@ -2743,7 +2743,7 @@ def test_get_markets(default_conf, mocker, markets,
                           _load_async_markets=MagicMock(),
                           validate_pairs=MagicMock(),
                           validate_timeframes=MagicMock(),
-                          markets=PropertyMock(return_value=markets))
+                          markets=PropertyMock(return_value=markets_static))
     ex = Exchange(default_conf)
     pairs = ex.get_markets(base_currencies, quote_currencies, pairs_only, active_only)
     assert sorted(pairs.keys()) == sorted(expected_keys)

tests/plugins/test_pairlist.py

@@ -131,9 +131,9 @@ def test_load_pairlist_noexist(mocker, markets, default_conf):
                                        default_conf, {}, 1)
 
 
-def test_load_pairlist_verify_multi(mocker, markets, default_conf):
+def test_load_pairlist_verify_multi(mocker, markets_static, default_conf):
     freqtrade = get_patched_freqtradebot(mocker, default_conf)
-    mocker.patch('freqtrade.exchange.Exchange.markets', PropertyMock(return_value=markets))
+    mocker.patch('freqtrade.exchange.Exchange.markets', PropertyMock(return_value=markets_static))
     plm = PairListManager(freqtrade.exchange, default_conf)
     # Call different versions one after the other, should always consider what was passed in
     # and have no side-effects (therefore the same check multiple times)