Add exchange_ws test case

tests/exchange/test_exchange_ws.py

@@ -0,0 +1,30 @@
+
+
+from time import sleep
+from unittest.mock import MagicMock
+
+from freqtrade.exchange.exchange_ws import ExchangeWS
+
+
+def test_exchangews_init(mocker):
+
+    config = MagicMock()
+    ccxt_object = MagicMock()
+    mocker.patch("freqtrade.exchange.exchange_ws.ExchangeWS._start_forever", MagicMock())
+
+    exchange_ws = ExchangeWS(config, ccxt_object)
+
+    assert exchange_ws.config == config
+    assert exchange_ws.ccxt_object == ccxt_object
+    assert exchange_ws._thread.name == "ccxt_ws"
+    assert exchange_ws._background_tasks == set()
+    assert exchange_ws._klines_watching == set()
+    assert exchange_ws._klines_scheduled == set()
+    assert exchange_ws.klines_last_refresh == {}
+    assert exchange_ws.klines_last_request == {}
+    assert exchange_ws._ob_watching == set()
+    assert exchange_ws._ob_scheduled == set()
+    assert exchange_ws.ob_last_request == {}
+    sleep(0.1)
+    # Cleanup
+    exchange_ws.cleanup()