Bitmex exchange metadata and use of currency pairs is inconsistent

If I do the following:

 Exchange exchange = ExchangeFactory.INSTANCE.createExchange(BitmexExchange.class.getName());
 System.out.println(exchange.getExchangeMetaData().getCurrencyPairs().keySet());

I get:

[BTC/BTC, EOS/BTC, BCH/BTC, ADA/BTC, ETH/USD, ZEC/BTC, TRX/BTC, XLM/BTC, LTC/BTC, \
XRP/BTC, BTC/USD, ETH/BTC, DASH/BTC, XMR/BTC, ETC/BTC]

There a a few problems here

• Several of these pairs aren’t actually supported by Bitmex (looks like bitmex.json is just a copy & paste. I can fix that easily)
• BTC/BTC?
• The fact that BTC is used instead of XBT.

This last bit is interesting. The code in org.knowm.xchange.bitmex.BitmexAdapters.adaptToExchangeMetaData seems to do this deliberately, but…

System.out.println(exchange.getMarketDataService().getTicker(CurrencyPair.BTC_USD));

… returns null, whereas…

System.out.println(exchange.getMarketDataService().getTicker(new CurrencyPair("XBT", "USD")));

… works (as I would expect, to be honest!)

How should this work? Should Bitmex accept XBT as one might expect (in which case it’s the exchange metadata implementation that’s wrong), or should it translate BTC to XBT internally (in which case the first of those two examples should work, but not the second)?

My inclination is to remove all the cleverness in org.knowm.xchange.bitmex.BitmexAdapters.adaptToExchangeMetaData and make it use Bitmex-native currency codes throughout.

[jakubkalicki]

Second issue is solved, now BitmexMarketDataService is consistent with other services. I have also added few integration tests. Probably tomorrow i will take care of meta data.

[jakubkalicki]

Ok, i’m starting then 😃