chadex

chadex is a non-custodial peer-to-peer ERC-20/ERC-20 decentralised exchange protocol.

• Users permit the chadex smart contract to perform ERC-20 token transfers
• Users express their desire to exchange ERC-20 tokens to other ERC-20 tokens by adding orders to the exchange
• If the prices match between users, the exchange takes place.

Fully on-chain ERC-20/ERC-20 DEX using Red-Black Trees and queues for sorted orderbook executions.

Status: Work in progress

https://bokkypoobah.github.io/chadex/

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Notes

npm install --save-dev @nomiclabs/hardhat-truffle5 @nomiclabs/hardhat-web3 web3

https://docs.openzeppelin.com/test-helpers/0.5/

npm install --save-dev @openzeppelin/test-helpers npm install --save-dev solidity-coverage

npm install --save-dev @nomiclabs/hardhat-ethers 'ethers@^5.0.0'

Coverage

Run coverage reports using the command

npx hardhat coverage

Output will be in the generated coverage directory

If you are using yarn, you can run

yarn hardhat coverage

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Old Stuff

Token incompatibilities - An Incompatibility in Ethereum Smart Contract Threatening dApp Ecosystem

• Token registry includes rating
  • 0 scam, 1 suspect, 2 unrated, 3 OK, 5 reputable
• Prevent front running

hash(ccy1/ccy2) => Orderbook

Orderbook RedBlackTree index by price buyOrders - Expiring Queue => Order * OrderType orderType; * address baseToken; // GNT * address quoteToken; // ETH * uint price; // GNT/ETH = 0.00054087 = #quoteToken per unit baseToken * uint expiry; * uint amount; // GNT - baseToken sellOrders

TODO:

• Move past consumed orders, graceful gas limit exit
• Handle canTransferFrom() - ethereum/EIPs#1594 `function canTransferFrom(address _from, address _to, uint256 _value, bytes _data) external view returns (bool, byte, bytes32);``

Function Calls

trade

function trade(uint orderFlag, address baseToken, address quoteToken, uint price, uint expiry, uint baseTokens, address uiFeeAccount) public payable returns (uint _baseTokensFilled, uint _quoteTokensFilled, uint _baseTokensOnOrder, bytes32 _orderKey);

Parameters	Notes
orderFlag	uint256
baseToken	address of the baseToken
quoteToken	address of the quoteToken
price	uint256
expiry	uint256
baseTokens	uint256
uiFeeAccount	address

And orderFlag is constructed using the following bitmasks

// Note that the BUY and SELL flags are used as indices
uint constant public ORDERTYPE_BUY = 0x00;
uint constant public ORDERTYPE_SELL = 0x01;
uint constant public ORDERFLAG_BUYSELL_MASK = 0x01;
// BK Default is to fill as much as possible
uint constant public ORDERFLAG_FILL = 0x00;
uint constant public ORDERFLAG_FILLALL_OR_REVERT = 0x10;
uint constant public ORDERFLAG_FILL_AND_ADD_ORDER = 0x20;