FixUp Friday: Exchange Proxies and Exchange Handling

[fredo]

There are some issues related to the exchange classes which increase the likelihood of errors or mistakes in further development. Also the logic for quering exchange rates is kind of falsy.

This is a proposal to take advantage of a fix up friday to refactor the exchange classes, making the code more readable, less likely to introduce new errors and improve the transaction speed for swaps.

What is to be done:

• remove redundancy between the classes uniswap and kyber
• remove redundancy of calculating transaction costs
• do a proper gas estimation and gas price calculation to save money for the user
• Remove the EthereumAmount class as it is only useful for printing values not for actual logic
• Implement a proper exchange rate calculation as it is falsy (at least for kyber)
• Increase Swap speed (It takes about a minute and a half to even send the transaction)

[konradkonrad]

• add: proper error handling (user facing) so users can confidently retry

[konradkonrad]

• try direct deposit from swap contract: https://etherscan.io/address/0x15ac371adE21c4F31Da36A4Cf9A0ef35aFdE7a9F#writeContract

[fredo]

• try direct deposit from swap contract: https://etherscan.io/address/0x15ac371adE21c4F31Da36A4Cf9A0ef35aFdE7a9F#writeContract

This does not work as desired but I already found a good tradeoff sending RDN directly to the UDC automatically. Looks very smooth and user doesnt notice