supplyToCompound.js

// contract instance
CErc20 immutable cDai;

// constructor() {
cDaiAddress = 0x6D7F0754FFeb405d23C51CE938289d4835bE3b14;
cDai = CErc20(cDaiAddress);
// }

function swapETHToDaiToCompound() public payable returns(bool){
    address[] memory _paths = new address[](2);
    _paths[0] = WETHAddress;
    _paths[1] = DaiAddress;
    uint[] memory _result = uniswapV2Router01.swapExactETHForTokens{value: msg.value}(0, _paths, address(this), now + 120);
    uint _DaiAmount = _result[1];
    Dai.approve(cDaiAddress, _DaiAmount); 
    assert(cDai.mint(_DaiAmount) == 0);
    return true;
}
    
function redeemFromCompoundAndReturnETH() public returns(uint[] memory){
    assert(cDai.redeem(cDai.balanceOf(address(this))) == 0);
    address[] memory _paths = new address[](2);
    _paths[0] = DaiAddress;
    _paths[1] = WETHAddress;
    uint _DaiAmount = Dai.balanceOf(address(this));
    Dai.approve(address(uniswapV2Router01), _DaiAmount);
    return uniswapV2Router01.swapExactTokensForETH(_DaiAmount, 0, _paths, msg.sender, now + 120);
}