Add test for ohlcv_as_df

tests/exchange/test_exchange.py

@@ -1307,6 +1307,57 @@ def test_get_historic_ohlcv(default_conf, mocker, caplog, exchange_name):
     assert log_has_re(r"Async code raised an exception: .*", caplog)
 
 
+@pytest.mark.parametrize("exchange_name", EXCHANGES)
+def test_get_historic_ohlcv_as_df(default_conf, mocker, exchange_name):
+    exchange = get_patched_exchange(mocker, default_conf, id=exchange_name)
+    ohlcv = [
+        [
+            arrow.utcnow().int_timestamp * 1000,  # unix timestamp ms
+            1,  # open
+            2,  # high
+            3,  # low
+            4,  # close
+            5,  # volume (in quote currency)
+        ],
+        [
+            arrow.utcnow().shift(minutes=5).int_timestamp * 1000,  # unix timestamp ms
+            1,  # open
+            2,  # high
+            3,  # low
+            4,  # close
+            5,  # volume (in quote currency)
+        ],
+        [
+            arrow.utcnow().shift(minutes=10).int_timestamp * 1000,  # unix timestamp ms
+            1,  # open
+            2,  # high
+            3,  # low
+            4,  # close
+            5,  # volume (in quote currency)
+        ]
+    ]
+    pair = 'ETH/BTC'
+
+    async def mock_candle_hist(pair, timeframe, since_ms):
+        return pair, timeframe, ohlcv
+
+    exchange._async_get_candle_history = Mock(wraps=mock_candle_hist)
+    # one_call calculation * 1.8 should do 2 calls
+
+    since = 5 * 60 * exchange._ft_has['ohlcv_candle_limit'] * 1.8
+    ret = exchange.get_historic_ohlcv_as_df(pair, "5m", int((
+        arrow.utcnow().int_timestamp - since) * 1000))
+
+    assert exchange._async_get_candle_history.call_count == 2
+    # Returns twice the above OHLCV data
+    assert len(ret) == 2
+    assert isinstance(ret, DataFrame)
+    assert 'date' in ret.columns
+    assert 'open' in ret.columns
+    assert 'close' in ret.columns
+    assert 'high' in ret.columns
+
+
 def test_refresh_latest_ohlcv(mocker, default_conf, caplog) -> None:
     ohlcv = [
         [