Brief Description

This project is the entry contract for butterSwap.

ButterRouter V2 consists of two main contracts.

• ButterRouterV2.sol is new version contract.
• SwapAdapter.sol is the swap aggregation adapter contract of the new version contract ,called by ButterRouterV2 to complete swap.

Main interfaces explanation(v2)

1. swapAndCall swap tokens and execute a callback method

    // 1. swap: _swapData.length > 0 and _bridgeData.length == 0
    // 2. swap and call: _swapData.length > 0 and _callbackData.length > 0
    function swapAndCall(
        bytes32 _transferId,
        address _srcToken,
        uint256 _amount,
        FeeType _feeType,
        bytes calldata _swapData,
        bytes calldata _callbackData,
        bytes calldata _permitData
    ) external payable;

2. swapAndBridge swap tokens and bridge outToken to other chain.

    // 1. bridge:  _swapData.length == 0 and _bridgeData.length > 0
    // 2. swap and bridge: _swapData.length > 0 and _bridgeData.length > 0
    function swapAndBridge(
        address _srcToken,
        uint256 _amount,
        bytes calldata _swapData,
        bytes calldata _bridgeData,
        bytes calldata _permitData
    ) external payable;

3. remoteSwapAndCall called by butter mos after bridge, to swap tokens and execute a callback on target chain.

    // At remote chain call after bridge
    // mos transfer token to router first
    //  1. swap: _swapData.length > 0 and _callbackData.length == 0
    //  2. call: _swapData.length == 0 and _callbackData.length > 0
    //  3. swap and call: _swapData.length > 0 and _callbackData.length > 0
    function remoteSwapAndCall(
        bytes32 _orderId,
        address _srcToken,
        uint256 _amount,
        uint256 _fromChain,
        bytes calldata _from,
        bytes calldata _swapAndCall
    ) external payable;

Installation

npm install --save-dev @butternetwork/router
# or
yarn add --dev @butternetwork/router

Contract Deployment and SetUp Workflow

Pre-requirement

Since all of the contracts are developed in Hardhat development environment, developers need to install Hardhat before working through our contracts. The hardhat installation tutorial can be found herehardhat

install

npm install

create an .env file and fill following in the contents

PRIVATE_KEY =
TRON_PRIVATE_KEY =
ALCHEMY_KEY =
ROUTER_DEPLOY_SALT =
SWAP_ADAPTER_DEPLOY_SALT =
FEE_RECEIVER_SAlT =

Compiling contracts

Simply useing hardhat built-in compile task to compile contracts.

$ npx hardhat compile
Compiling...
Compiled 1 contract successfully

The compiled artifacts will be saved in the artifacts/ directory by default

Testing

Compiled 6 Solidity files successfully
  ButterRouterV2
    ✔ setFee only owner (1442ms)
    ✔ setMosAddress only owner (147ms)
    ✔ setAuthorization only owner (129ms)
    ✔ setDexExecutor only owner (122ms)
    ✔ rescueFunds correct (130ms)
    ✔ rescueFunds only owner (129ms)
    ✔ setFee feeReceiver zero address (126ms)
    ✔ setFee feeRate less than 1000000 (124ms)
    ✔ setFee correct  (137ms)
    ✔ setMosAddress _mosAddress must be contract (100ms)
    ✔ setDexExecutor dexExecutor must be contract (111ms)
    ✔ setMosAddress correct (120ms)
    ✔ setDexExecutor correct (132ms)
    ✔ setAuthorization only owner (110ms)
    ✔ setAuthorization correct (135ms)
    ✔ swapAndCall (2920ms)
    ✔ swapAndCall (2826ms)
    ✔ swapAndBridge (2870ms)
    ✔ swapAndCall (2931ms)
    ✔ remoteSwapAndCall (2808ms)
    ✔ remoteSwapAndCall _makeUniV3Swap -> native (2764ms)
    ✔ remoteSwapAndCall _makeUniV3Swap -> tokens (2735ms)
    ✔ remoteSwapAndCall _makeUniV2Swap -> swapExactTokensForETH (2740ms)
    ✔ remoteSwapAndCall _makeUniV2Swap -> swapExactTokensForTokens (2911ms)
    ✔ remoteSwapAndCall _makeUniV2Swap -> swapExactETHForTokens (2813ms)
    ✔ remoteSwapAndCall _makeCurveSwap (2932ms)
    ✔ remoteSwapAndCall buy nft seaport (2799ms)


  27 passing (37s)

Deploy and setup

The deploy script is located in tasks folder . We can run the following command to deploy.

NOTE

if deploy chain is zksync or zksyncTestnet,please compile this contract use

npx hardhat compile --network  `<zkSync or zkSyncTest>`

v2

1.deploy and set up before run this task, set task/config.js

npx hardhat routerV2 --network <network>

subtasks

1.routerV2:deploy

npx hardhat routerV2:deploy --mos <mos address> --wtoken <wtoken address> --network <network>

2.routerV2:deploySwapAdapter

npx hardhat routerV2:deploySwapAdapter --network <network>

3.routerV2:setAuthorization

npx hardhat routerV2:setAuthorization --router <router address> --executors <excutor1,excutor2,..> --flag <flag> --network <network>

4.routerV2:setFee

npx hardhat routerV2:setFee --router <router address> --feereceiver <receiver address> --feerate <rate> --fixedfee <fixedfee> --network <network>