SWAP calculations

[kilrau]

@moshababo discovered:

I was looking at the swaps code for something, and there’s something in the currency/amount calculations that I don’t understand. Considering i’m on pair LTC/BTC and the price is 0.01. we have 2 scenarios:

1)

maker order: buy quantity 5 taker order: sell quantity 5

swap amounts: maker: 5 LTC taker: 0.05 BTC

• if the maker is buy, then he wants to buy LTC. so why he’s the one sending LTC?

2)

maker order: sell quantity 5 taker order: buy quantity 5

swap amounts maker: 5 BTC taker: 0.05 LTC

• same like my previous question for the currency, and the amount also doesn’t seem correct.

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My calculations are based on: https://github.com/ExchangeUnion/xud/blob/master/lib/swaps/Swaps.ts#L91 https://github.com/ExchangeUnion/xud/blob/master/lib/swaps/Swaps.ts#L241

[sangaman]

Thanks for catching and describing this, it's indeed a bug and it's possible for the amounts to get switched. I opened a PR to fix this and also a similar bug in the logic for deriving the SwapResult from a completed swap.