Add simple caching to get_ticker and re-enable caching test

freqtrade/exchange/__init__.py

@@ -17,6 +17,9 @@ logger = logging.getLogger(__name__)
 _API: ccxt.Exchange = None
 _CONF: dict = {}
 
+# Cache for ticker data
+_TICKER_CACHE: dict = {}
+
 # Holds all open sell orders for dry_run
 _DRY_RUN_OPEN_ORDERS: Dict[str, Any] = {}
 
@@ -190,9 +193,13 @@ def get_balances() -> dict:
 
 
 def get_ticker(pair: str, refresh: Optional[bool] = True) -> dict:
+    global _TICKER_CACHE
     try:
-        # TODO: add caching
-        return _API.fetch_ticker(pair)
+        if not refresh:
+            if _TICKER_CACHE:
+                return _TICKER_CACHE
+        _TICKER_CACHE = _API.fetch_ticker(pair)
+        return _TICKER_CACHE
     except ccxt.NetworkError as e:
         raise NetworkException(
             'Could not load tickers due to networking error. Message: {}'.format(e)

freqtrade/tests/exchange/test_exchange.py

@@ -224,9 +224,9 @@ def test_get_ticker(default_conf, mocker):
 
     # if not caching the result we should get the same ticker
     # if not fetching a new result we should get the cached ticker
-    # ticker = get_ticker(pair='ETH/BTC', refresh=False)
-    # assert ticker['bid'] == 0.00001098
-    # assert ticker['ask'] == 0.00001099
+    ticker = get_ticker(pair='ETH/BTC', refresh=False)
+    assert ticker['bid'] == 0.00001098
+    assert ticker['ask'] == 0.00001099
 
     # force ticker refresh
     ticker = get_ticker(pair='ETH/BTC', refresh=True)
@@ -259,13 +259,26 @@ def test_get_ticker_history(default_conf, mocker):
     assert ticks[0]['V'] == 5
 
     # change the ticker
-    # tick = 999
-    # api_mock.get_ticker_history = MagicMock(return_value=tick)
-    # mocker.patch('freqtrade.exchange._API', api_mock)
+    new_tick = [
+        [
+            1511686200000,  # unix timestamp ms
+            6,  # open
+            7,  # high
+            8,  # low
+            9,  # close
+            10,  # volume (in quote currency)
+        ]
+    ]
+    api_mock.get_ticker_history = MagicMock(return_value=new_tick)
+    mocker.patch('freqtrade.exchange._API', api_mock)
 
     # ensure caching will still return the original ticker
-    # ticks = get_ticker_history('ETH/BTC', default_conf['ticker_interval'])
-    # assert ticks == 123
+    ticks = get_ticker_history('ETH/BTC', default_conf['ticker_interval'])
+    assert ticks[0]['O'] == 1
+    assert ticks[0]['H'] == 2
+    assert ticks[0]['L'] == 3
+    assert ticks[0]['C'] == 4
+    assert ticks[0]['V'] == 5
 
 
 def test_cancel_order_dry_run(default_conf, mocker):