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Fix Felix internal audit comments #105

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Merged
ncitron merged 1 commit into from
Jun 25, 2021
Merged

Fix Felix internal audit comments #105

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34 changes: 24 additions & 10 deletions contracts/product/AMMSplitter.sol
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Original file line number Diff line number Diff line change
Expand Up @@ -108,7 +108,9 @@ contract AMMSplitter {
/* ============ External Functions ============= */

/**
* Executes an exact input trade. Splits trade efficiently between Uniswap and Sushiswap
* Executes an exact input trade split between Uniswap and Sushiswap. This function is for when one wants to trade with the optimal split between Uniswap
* and Sushiswap. This function's interface matches the Uniswap V2 swapExactTokensForTokens function. Input/output tokens are inferred implicitly from
* the trade path with first token as input and last as output.
*
* @param _amountIn the exact input amount
* @param _amountOutMin the minimum output amount that must be received
Expand All @@ -128,7 +130,7 @@ contract AMMSplitter {
external
returns (uint256 totalOutput)
{
require(_path.length <= 3 && _path.length != 0, "AMMSplitter: incorrect path length");
_checkPath(_path);

IERC20 inputToken = IERC20(_path[0]);
inputToken.transferFrom(msg.sender, address(this), _amountIn);
Expand All @@ -155,7 +157,9 @@ contract AMMSplitter {
}

/**
* Executes an exact output trade. Splits trade efficiently between Uniswap and Sushiswap
* Executes an exact output trade split between Uniswap and Sushiswap. This function is for when one wants to trade with the optimal split between Uniswap
* and Sushiswap. This function's interface matches the Uniswap V2 swapTokensForExactTokens function. Input/output tokens are inferred implicitly from
* the trade path with first token as input and last as output.
*
* @param _amountOut the exact output amount
* @param _amountInMax the maximum input amount that can be spent
Expand All @@ -175,7 +179,7 @@ contract AMMSplitter {
external
returns (uint256 totalInput)
{
require(_path.length <= 3 && _path.length != 0, "AMMSplitter: incorrect path length");
_checkPath(_path);

TradeInfo memory tradeInfo = _getTradeSizes(_path, _amountOut);

Expand Down Expand Up @@ -214,7 +218,7 @@ contract AMMSplitter {
* @param _amountIn input amount
* @param _path the trade path to use
*
* @return uint256[] array of input amounts, intermiary amounts, and output amounts
* @return uint256[] array of input amounts, intermediary amounts, and output amounts
*/
function getAmountsOut(uint256 _amountIn, address[] calldata _path) external view returns (uint256[] memory) {
return _getAmounts(_amountIn, _path, true);
Expand Down Expand Up @@ -245,7 +249,7 @@ contract AMMSplitter {
*/
function _getAmounts(uint256 _size, address[] calldata _path, bool _isExactInput) internal view returns (uint256[] memory amounts) {

require(_path.length <= 3 && _path.length != 0, "AMMSplitter: incorrect path length");
_checkPath(_path);

TradeInfo memory tradeInfo = _getTradeSizes(_path, _size);

Expand All @@ -259,8 +263,8 @@ contract AMMSplitter {
}

/**
* Calculates the optimal trade sizes for Uniswap and Sushiswap. Pool vaules must be measured in the same token. For single hop trades
* this is the balance of the output token. For two hop trades, it is measured as the balance of the intermidiary token. The equation to
* Calculates the optimal trade sizes for Uniswap and Sushiswap. Pool values must be measured in the same token. For single hop trades
* this is the balance of the output token. For two hop trades, it is measured as the balance of the intermediary token. The equation to
* calculate the ratio for two hop trades is documented under _calculateTwoHopRatio. For single hop trades, this equation is:
*
* Tu/Ts = Pu / Ps
Expand All @@ -273,7 +277,7 @@ contract AMMSplitter {
* @param _path the trade path that will be used
* @param _size the total size of the trade
*
* @return tradeInfo TradeInfo struct containing Uniswap and Sushiswap tarde sizes
* @return tradeInfo TradeInfo struct containing Uniswap and Sushiswap trade sizes
*/
function _getTradeSizes(address[] calldata _path, uint256 _size) internal view returns (TradeInfo memory tradeInfo) {

Expand Down Expand Up @@ -369,6 +373,16 @@ contract AMMSplitter {
}
}

/**
* Confirms that the path length is either two or three. Reverts if it does not fall within these bounds. When paths are greater than three in
* length, the calculation for the optimal split between Uniswap and Sushiswap becomes much more difficult, so it is disallowed.
*
* @param _path trade path to check
*/
function _checkPath(address[] calldata _path) internal pure {
require(_path.length == 2 || _path.length == 3, "AMMSplitter: incorrect path length");
}

/**
* Gets the balance of a component token in a Uniswap / Sushiswap pool
*
Expand All @@ -392,7 +406,7 @@ contract AMMSplitter {
* @param _path Path for the trade
* @param _to Address to redirect trade output to
* @param _deadline Timestamp that trade must execute before
* @param _isExactInput Whether to perfrom an exact input or exact output swap
* @param _isExactInput Whether to perform an exact input or exact output swap
*
* @return uint256 the actual input / output amount of the trade
*/
Expand Down