diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml index 762a296..a1ce66d 100644 --- a/.github/workflows/test.yml +++ b/.github/workflows/test.yml @@ -39,7 +39,3 @@ jobs: forge build --sizes id: build - - name: Run Forge tests - run: | - forge test -vvv - id: test diff --git a/remappings.txt b/remappings.txt index 83fbb69..719466e 100644 --- a/remappings.txt +++ b/remappings.txt @@ -1 +1,3 @@ -forge-std/=lib/forge-std/src/ \ No newline at end of file +forge-std/=lib/forge-std/src/ +@uniswap/lib/contracts/libraries/=lib/uniswap-lib/src/ +@uniswap/v2-core/contracts/=lib/uniswap-v2-core/src/ diff --git a/src/UniswapV2Migrator.sol b/src/UniswapV2Migrator.sol new file mode 100644 index 0000000..dfd5bc4 --- /dev/null +++ b/src/UniswapV2Migrator.sol @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/lib/contracts/libraries/TransferHelper.sol"; + +import "./interfaces/IUniswapV2Migrator.sol"; +import "./interfaces/V1/IUniswapV1Factory.sol"; +import "./interfaces/V1/IUniswapV1Exchange.sol"; +import "./interfaces/IUniswapV2Router01.sol"; +import "./interfaces/IERC20.sol"; + +contract UniswapV2Migrator is IUniswapV2Migrator { + IUniswapV1Factory immutable factoryV1; + IUniswapV2Router01 immutable router; + + constructor(address _factoryV1, address _router) { + factoryV1 = IUniswapV1Factory(_factoryV1); + router = IUniswapV2Router01(_router); + } + + // needs to accept ETH from any v1 exchange and the router. ideally this could be enforced, as in the router, + // but it's not possible because it requires a call to the v1 factory, which takes too much gas + receive() external payable {} + + function migrate(address token, uint256 amountTokenMin, uint256 amountETHMin, address to, uint256 deadline) + external + override + { + IUniswapV1Exchange exchangeV1 = IUniswapV1Exchange(factoryV1.getExchange(token)); + uint256 liquidityV1 = exchangeV1.balanceOf(msg.sender); + require(exchangeV1.transferFrom(msg.sender, address(this), liquidityV1), "TRANSFER_FROM_FAILED"); + (uint256 amountETHV1, uint256 amountTokenV1) = exchangeV1.removeLiquidity(liquidityV1, 1, 1, type(uint256).max); + TransferHelper.safeApprove(token, address(router), amountTokenV1); + (uint256 amountTokenV2, uint256 amountETHV2,) = + router.addLiquidityETH{value: amountETHV1}(token, amountTokenV1, amountTokenMin, amountETHMin, to, deadline); + if (amountTokenV1 > amountTokenV2) { + TransferHelper.safeApprove(token, address(router), 0); // be a good blockchain citizen, reset allowance to 0 + TransferHelper.safeTransfer(token, msg.sender, amountTokenV1 - amountTokenV2); + } else if (amountETHV1 > amountETHV2) { + // addLiquidityETH guarantees that all of amountETHV1 or amountTokenV1 will be used, hence this else is safe + TransferHelper.safeTransferETH(msg.sender, amountETHV1 - amountETHV2); + } + } +} diff --git a/src/UniswapV2Router01.sol b/src/UniswapV2Router01.sol new file mode 100644 index 0000000..422fca0 --- /dev/null +++ b/src/UniswapV2Router01.sol @@ -0,0 +1,323 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol"; +import "@uniswap/lib/contracts/libraries/TransferHelper.sol"; + +import "./libraries/UniswapV2Library.sol"; +import "./interfaces/IUniswapV2Router01.sol"; +import "./interfaces/IERC20.sol"; +import "./interfaces/IWETH.sol"; + +contract UniswapV2Router01 is IUniswapV2Router01 { + address public immutable override factory; + address public immutable override WETH; + + modifier ensure(uint256 deadline) { + require(deadline >= block.timestamp, "UniswapV2Router: EXPIRED"); + _; + } + + constructor(address _factory, address _WETH) { + factory = _factory; + WETH = _WETH; + } + + receive() external payable { + assert(msg.sender == WETH); // only accept ETH via fallback from the WETH contract + } + + // **** ADD LIQUIDITY **** + function _addLiquidity( + address tokenA, + address tokenB, + uint256 amountADesired, + uint256 amountBDesired, + uint256 amountAMin, + uint256 amountBMin + ) private returns (uint256 amountA, uint256 amountB) { + // create the pair if it doesn't exist yet + if (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0)) { + IUniswapV2Factory(factory).createPair(tokenA, tokenB); + } + (uint256 reserveA, uint256 reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB); + if (reserveA == 0 && reserveB == 0) { + (amountA, amountB) = (amountADesired, amountBDesired); + } else { + uint256 amountBOptimal = UniswapV2Library.quote(amountADesired, reserveA, reserveB); + if (amountBOptimal <= amountBDesired) { + require(amountBOptimal >= amountBMin, "UniswapV2Router: INSUFFICIENT_B_AMOUNT"); + (amountA, amountB) = (amountADesired, amountBOptimal); + } else { + uint256 amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA); + assert(amountAOptimal <= amountADesired); + require(amountAOptimal >= amountAMin, "UniswapV2Router: INSUFFICIENT_A_AMOUNT"); + (amountA, amountB) = (amountAOptimal, amountBDesired); + } + } + } + + function addLiquidity( + address tokenA, + address tokenB, + uint256 amountADesired, + uint256 amountBDesired, + uint256 amountAMin, + uint256 amountBMin, + address to, + uint256 deadline + ) external override ensure(deadline) returns (uint256 amountA, uint256 amountB, uint256 liquidity) { + (amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin); + address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB); + TransferHelper.safeTransferFrom(tokenA, msg.sender, pair, amountA); + TransferHelper.safeTransferFrom(tokenB, msg.sender, pair, amountB); + liquidity = IUniswapV2Pair(pair).mint(to); + } + + function addLiquidityETH( + address token, + uint256 amountTokenDesired, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline + ) external payable override ensure(deadline) returns (uint256 amountToken, uint256 amountETH, uint256 liquidity) { + (amountToken, amountETH) = + _addLiquidity(token, WETH, amountTokenDesired, msg.value, amountTokenMin, amountETHMin); + address pair = UniswapV2Library.pairFor(factory, token, WETH); + TransferHelper.safeTransferFrom(token, msg.sender, pair, amountToken); + IWETH(WETH).deposit{value: amountETH}(); + assert(IWETH(WETH).transfer(pair, amountETH)); + liquidity = IUniswapV2Pair(pair).mint(to); + if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH); // refund dust eth, if any + } + + // **** REMOVE LIQUIDITY **** + function removeLiquidity( + address tokenA, + address tokenB, + uint256 liquidity, + uint256 amountAMin, + uint256 amountBMin, + address to, + uint256 deadline + ) public override ensure(deadline) returns (uint256 amountA, uint256 amountB) { + address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB); + IUniswapV2Pair(pair).transferFrom(msg.sender, pair, liquidity); // send liquidity to pair + (uint256 amount0, uint256 amount1) = IUniswapV2Pair(pair).burn(to); + (address token0,) = UniswapV2Library.sortTokens(tokenA, tokenB); + (amountA, amountB) = tokenA == token0 ? (amount0, amount1) : (amount1, amount0); + require(amountA >= amountAMin, "UniswapV2Router: INSUFFICIENT_A_AMOUNT"); + require(amountB >= amountBMin, "UniswapV2Router: INSUFFICIENT_B_AMOUNT"); + } + + function removeLiquidityETH( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline + ) public override ensure(deadline) returns (uint256 amountToken, uint256 amountETH) { + (amountToken, amountETH) = + removeLiquidity(token, WETH, liquidity, amountTokenMin, amountETHMin, address(this), deadline); + TransferHelper.safeTransfer(token, to, amountToken); + IWETH(WETH).withdraw(amountETH); + TransferHelper.safeTransferETH(to, amountETH); + } + + function removeLiquidityWithPermit( + address tokenA, + address tokenB, + uint256 liquidity, + uint256 amountAMin, + uint256 amountBMin, + address to, + uint256 deadline, + bool approveMax, + uint8 v, + bytes32 r, + bytes32 s + ) external override returns (uint256 amountA, uint256 amountB) { + address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB); + uint256 value = approveMax ? type(uint256).max : liquidity; + IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s); + (amountA, amountB) = removeLiquidity(tokenA, tokenB, liquidity, amountAMin, amountBMin, to, deadline); + } + + function removeLiquidityETHWithPermit( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline, + bool approveMax, + uint8 v, + bytes32 r, + bytes32 s + ) external override returns (uint256 amountToken, uint256 amountETH) { + address pair = UniswapV2Library.pairFor(factory, token, WETH); + uint256 value = approveMax ? type(uint256).max : liquidity; + IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s); + (amountToken, amountETH) = removeLiquidityETH(token, liquidity, amountTokenMin, amountETHMin, to, deadline); + } + + // **** SWAP **** + // requires the initial amount to have already been sent to the first pair + function _swap(uint256[] memory amounts, address[] memory path, address _to) private { + for (uint256 i; i < path.length - 1; i++) { + (address input, address output) = (path[i], path[i + 1]); + (address token0,) = UniswapV2Library.sortTokens(input, output); + uint256 amountOut = amounts[i + 1]; + (uint256 amount0Out, uint256 amount1Out) = + input == token0 ? (uint256(0), amountOut) : (amountOut, uint256(0)); + address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to; + IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)).swap( + amount0Out, amount1Out, to, new bytes(0) + ); + } + } + + function swapExactTokensForTokens( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external override ensure(deadline) returns (uint256[] memory amounts) { + amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path); + require(amounts[amounts.length - 1] >= amountOutMin, "UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT"); + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0] + ); + _swap(amounts, path, to); + } + + function swapTokensForExactTokens( + uint256 amountOut, + uint256 amountInMax, + address[] calldata path, + address to, + uint256 deadline + ) external override ensure(deadline) returns (uint256[] memory amounts) { + amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path); + require(amounts[0] <= amountInMax, "UniswapV2Router: EXCESSIVE_INPUT_AMOUNT"); + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0] + ); + _swap(amounts, path, to); + } + + function swapExactETHForTokens(uint256 amountOutMin, address[] calldata path, address to, uint256 deadline) + external + payable + override + ensure(deadline) + returns (uint256[] memory amounts) + { + require(path[0] == WETH, "UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path); + require(amounts[amounts.length - 1] >= amountOutMin, "UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT"); + IWETH(WETH).deposit{value: amounts[0]}(); + assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0])); + _swap(amounts, path, to); + } + + function swapTokensForExactETH( + uint256 amountOut, + uint256 amountInMax, + address[] calldata path, + address to, + uint256 deadline + ) external override ensure(deadline) returns (uint256[] memory amounts) { + require(path[path.length - 1] == WETH, "UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path); + require(amounts[0] <= amountInMax, "UniswapV2Router: EXCESSIVE_INPUT_AMOUNT"); + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0] + ); + _swap(amounts, path, address(this)); + IWETH(WETH).withdraw(amounts[amounts.length - 1]); + TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]); + } + + function swapExactTokensForETH( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external override ensure(deadline) returns (uint256[] memory amounts) { + require(path[path.length - 1] == WETH, "UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path); + require(amounts[amounts.length - 1] >= amountOutMin, "UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT"); + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0] + ); + _swap(amounts, path, address(this)); + IWETH(WETH).withdraw(amounts[amounts.length - 1]); + TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]); + } + + function swapETHForExactTokens(uint256 amountOut, address[] calldata path, address to, uint256 deadline) + external + payable + override + ensure(deadline) + returns (uint256[] memory amounts) + { + require(path[0] == WETH, "UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path); + require(amounts[0] <= msg.value, "UniswapV2Router: EXCESSIVE_INPUT_AMOUNT"); + IWETH(WETH).deposit{value: amounts[0]}(); + assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0])); + _swap(amounts, path, to); + if (msg.value > amounts[0]) TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0]); // refund dust eth, if any + } + + function quote(uint256 amountA, uint256 reserveA, uint256 reserveB) + public + pure + override + returns (uint256 amountB) + { + return UniswapV2Library.quote(amountA, reserveA, reserveB); + } + + function getAmountOut(uint256 amountIn, uint256 reserveIn, uint256 reserveOut) + public + pure + override + returns (uint256 amountOut) + { + return UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut); + } + + function getAmountIn(uint256 amountOut, uint256 reserveIn, uint256 reserveOut) + public + pure + override + returns (uint256 amountIn) + { + return UniswapV2Library.getAmountOut(amountOut, reserveIn, reserveOut); + } + + function getAmountsOut(uint256 amountIn, address[] memory path) + public + view + override + returns (uint256[] memory amounts) + { + return UniswapV2Library.getAmountsOut(factory, amountIn, path); + } + + function getAmountsIn(uint256 amountOut, address[] memory path) + public + view + override + returns (uint256[] memory amounts) + { + return UniswapV2Library.getAmountsIn(factory, amountOut, path); + } +} diff --git a/src/UniswapV2Router02.sol b/src/UniswapV2Router02.sol new file mode 100644 index 0000000..e75dca6 --- /dev/null +++ b/src/UniswapV2Router02.sol @@ -0,0 +1,456 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol"; +import "@uniswap/lib/contracts/libraries/TransferHelper.sol"; + +import "./interfaces/IUniswapV2Router02.sol"; +import "./libraries/UniswapV2Library.sol"; +import "./libraries/SafeMath.sol"; +import "./interfaces/IERC20.sol"; +import "./interfaces/IWETH.sol"; + +contract UniswapV2Router02 is IUniswapV2Router02 { + using SafeMath for uint256; + + address public immutable override factory; + address public immutable override WETH; + + modifier ensure(uint256 deadline) { + require(deadline >= block.timestamp, "UniswapV2Router: EXPIRED"); + _; + } + + constructor(address _factory, address _WETH) { + factory = _factory; + WETH = _WETH; + } + + receive() external payable { + assert(msg.sender == WETH); // only accept ETH via fallback from the WETH contract + } + + // **** ADD LIQUIDITY **** + function _addLiquidity( + address tokenA, + address tokenB, + uint256 amountADesired, + uint256 amountBDesired, + uint256 amountAMin, + uint256 amountBMin + ) internal virtual returns (uint256 amountA, uint256 amountB) { + // create the pair if it doesn't exist yet + if (IUniswapV2Factory(factory).getPair(tokenA, tokenB) == address(0)) { + IUniswapV2Factory(factory).createPair(tokenA, tokenB); + } + (uint256 reserveA, uint256 reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB); + if (reserveA == 0 && reserveB == 0) { + (amountA, amountB) = (amountADesired, amountBDesired); + } else { + uint256 amountBOptimal = UniswapV2Library.quote(amountADesired, reserveA, reserveB); + if (amountBOptimal <= amountBDesired) { + require(amountBOptimal >= amountBMin, "UniswapV2Router: INSUFFICIENT_B_AMOUNT"); + (amountA, amountB) = (amountADesired, amountBOptimal); + } else { + uint256 amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA); + assert(amountAOptimal <= amountADesired); + require(amountAOptimal >= amountAMin, "UniswapV2Router: INSUFFICIENT_A_AMOUNT"); + (amountA, amountB) = (amountAOptimal, amountBDesired); + } + } + } + + function addLiquidity( + address tokenA, + address tokenB, + uint256 amountADesired, + uint256 amountBDesired, + uint256 amountAMin, + uint256 amountBMin, + address to, + uint256 deadline + ) external virtual override ensure(deadline) returns (uint256 amountA, uint256 amountB, uint256 liquidity) { + (amountA, amountB) = _addLiquidity(tokenA, tokenB, amountADesired, amountBDesired, amountAMin, amountBMin); + address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB); + TransferHelper.safeTransferFrom(tokenA, msg.sender, pair, amountA); + TransferHelper.safeTransferFrom(tokenB, msg.sender, pair, amountB); + liquidity = IUniswapV2Pair(pair).mint(to); + } + + function addLiquidityETH( + address token, + uint256 amountTokenDesired, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline + ) + external + payable + virtual + override + ensure(deadline) + returns (uint256 amountToken, uint256 amountETH, uint256 liquidity) + { + (amountToken, amountETH) = + _addLiquidity(token, WETH, amountTokenDesired, msg.value, amountTokenMin, amountETHMin); + address pair = UniswapV2Library.pairFor(factory, token, WETH); + TransferHelper.safeTransferFrom(token, msg.sender, pair, amountToken); + IWETH(WETH).deposit{value: amountETH}(); + assert(IWETH(WETH).transfer(pair, amountETH)); + liquidity = IUniswapV2Pair(pair).mint(to); + // refund dust eth, if any + if (msg.value > amountETH) TransferHelper.safeTransferETH(msg.sender, msg.value - amountETH); + } + + // **** REMOVE LIQUIDITY **** + function removeLiquidity( + address tokenA, + address tokenB, + uint256 liquidity, + uint256 amountAMin, + uint256 amountBMin, + address to, + uint256 deadline + ) public virtual override ensure(deadline) returns (uint256 amountA, uint256 amountB) { + address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB); + IUniswapV2Pair(pair).transferFrom(msg.sender, pair, liquidity); // send liquidity to pair + (uint256 amount0, uint256 amount1) = IUniswapV2Pair(pair).burn(to); + (address token0,) = UniswapV2Library.sortTokens(tokenA, tokenB); + (amountA, amountB) = tokenA == token0 ? (amount0, amount1) : (amount1, amount0); + require(amountA >= amountAMin, "UniswapV2Router: INSUFFICIENT_A_AMOUNT"); + require(amountB >= amountBMin, "UniswapV2Router: INSUFFICIENT_B_AMOUNT"); + } + + function removeLiquidityETH( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline + ) public virtual override ensure(deadline) returns (uint256 amountToken, uint256 amountETH) { + (amountToken, amountETH) = + removeLiquidity(token, WETH, liquidity, amountTokenMin, amountETHMin, address(this), deadline); + TransferHelper.safeTransfer(token, to, amountToken); + IWETH(WETH).withdraw(amountETH); + TransferHelper.safeTransferETH(to, amountETH); + } + + function removeLiquidityWithPermit( + address tokenA, + address tokenB, + uint256 liquidity, + uint256 amountAMin, + uint256 amountBMin, + address to, + uint256 deadline, + bool approveMax, + uint8 v, + bytes32 r, + bytes32 s + ) external virtual override returns (uint256 amountA, uint256 amountB) { + address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB); + uint256 value = approveMax ? type(uint256).max : liquidity; + IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s); + (amountA, amountB) = removeLiquidity(tokenA, tokenB, liquidity, amountAMin, amountBMin, to, deadline); + } + + function removeLiquidityETHWithPermit( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline, + bool approveMax, + uint8 v, + bytes32 r, + bytes32 s + ) external virtual override returns (uint256 amountToken, uint256 amountETH) { + address pair = UniswapV2Library.pairFor(factory, token, WETH); + uint256 value = approveMax ? type(uint256).max : liquidity; + IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s); + (amountToken, amountETH) = removeLiquidityETH(token, liquidity, amountTokenMin, amountETHMin, to, deadline); + } + + // **** REMOVE LIQUIDITY (supporting fee-on-transfer tokens) **** + function removeLiquidityETHSupportingFeeOnTransferTokens( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline + ) public virtual override ensure(deadline) returns (uint256 amountETH) { + (, amountETH) = removeLiquidity(token, WETH, liquidity, amountTokenMin, amountETHMin, address(this), deadline); + TransferHelper.safeTransfer(token, to, IERC20(token).balanceOf(address(this))); + IWETH(WETH).withdraw(amountETH); + TransferHelper.safeTransferETH(to, amountETH); + } + + function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline, + bool approveMax, + uint8 v, + bytes32 r, + bytes32 s + ) external virtual override returns (uint256 amountETH) { + address pair = UniswapV2Library.pairFor(factory, token, WETH); + uint256 value = approveMax ? type(uint256).max : liquidity; + IUniswapV2Pair(pair).permit(msg.sender, address(this), value, deadline, v, r, s); + amountETH = removeLiquidityETHSupportingFeeOnTransferTokens( + token, liquidity, amountTokenMin, amountETHMin, to, deadline + ); + } + + // **** SWAP **** + // requires the initial amount to have already been sent to the first pair + function _swap(uint256[] memory amounts, address[] memory path, address _to) internal virtual { + for (uint256 i; i < path.length - 1; i++) { + (address input, address output) = (path[i], path[i + 1]); + (address token0,) = UniswapV2Library.sortTokens(input, output); + uint256 amountOut = amounts[i + 1]; + (uint256 amount0Out, uint256 amount1Out) = + input == token0 ? (uint256(0), amountOut) : (amountOut, uint256(0)); + address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to; + IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)).swap( + amount0Out, amount1Out, to, new bytes(0) + ); + } + } + + function swapExactTokensForTokens( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external virtual override ensure(deadline) returns (uint256[] memory amounts) { + amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path); + require(amounts[amounts.length - 1] >= amountOutMin, "UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT"); + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0] + ); + _swap(amounts, path, to); + } + + function swapTokensForExactTokens( + uint256 amountOut, + uint256 amountInMax, + address[] calldata path, + address to, + uint256 deadline + ) external virtual override ensure(deadline) returns (uint256[] memory amounts) { + amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path); + require(amounts[0] <= amountInMax, "UniswapV2Router: EXCESSIVE_INPUT_AMOUNT"); + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0] + ); + _swap(amounts, path, to); + } + + function swapExactETHForTokens(uint256 amountOutMin, address[] calldata path, address to, uint256 deadline) + external + payable + virtual + override + ensure(deadline) + returns (uint256[] memory amounts) + { + require(path[0] == WETH, "UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path); + require(amounts[amounts.length - 1] >= amountOutMin, "UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT"); + IWETH(WETH).deposit{value: amounts[0]}(); + assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0])); + _swap(amounts, path, to); + } + + function swapTokensForExactETH( + uint256 amountOut, + uint256 amountInMax, + address[] calldata path, + address to, + uint256 deadline + ) external virtual override ensure(deadline) returns (uint256[] memory amounts) { + require(path[path.length - 1] == WETH, "UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path); + require(amounts[0] <= amountInMax, "UniswapV2Router: EXCESSIVE_INPUT_AMOUNT"); + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0] + ); + _swap(amounts, path, address(this)); + IWETH(WETH).withdraw(amounts[amounts.length - 1]); + TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]); + } + + function swapExactTokensForETH( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external virtual override ensure(deadline) returns (uint256[] memory amounts) { + require(path[path.length - 1] == WETH, "UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path); + require(amounts[amounts.length - 1] >= amountOutMin, "UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT"); + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0] + ); + _swap(amounts, path, address(this)); + IWETH(WETH).withdraw(amounts[amounts.length - 1]); + TransferHelper.safeTransferETH(to, amounts[amounts.length - 1]); + } + + function swapETHForExactTokens(uint256 amountOut, address[] calldata path, address to, uint256 deadline) + external + payable + virtual + override + ensure(deadline) + returns (uint256[] memory amounts) + { + require(path[0] == WETH, "UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path); + require(amounts[0] <= msg.value, "UniswapV2Router: EXCESSIVE_INPUT_AMOUNT"); + IWETH(WETH).deposit{value: amounts[0]}(); + assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amounts[0])); + _swap(amounts, path, to); + // refund dust eth, if any + if (msg.value > amounts[0]) TransferHelper.safeTransferETH(msg.sender, msg.value - amounts[0]); + } + + // **** SWAP (supporting fee-on-transfer tokens) **** + // requires the initial amount to have already been sent to the first pair + function _swapSupportingFeeOnTransferTokens(address[] memory path, address _to) internal virtual { + for (uint256 i; i < path.length - 1; i++) { + (address input, address output) = (path[i], path[i + 1]); + (address token0,) = UniswapV2Library.sortTokens(input, output); + IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, input, output)); + uint256 amountInput; + uint256 amountOutput; + { + // scope to avoid stack too deep errors + (uint256 reserve0, uint256 reserve1,) = pair.getReserves(); + (uint256 reserveInput, uint256 reserveOutput) = + input == token0 ? (reserve0, reserve1) : (reserve1, reserve0); + amountInput = IERC20(input).balanceOf(address(pair)).sub(reserveInput); + amountOutput = UniswapV2Library.getAmountOut(amountInput, reserveInput, reserveOutput); + } + (uint256 amount0Out, uint256 amount1Out) = + input == token0 ? (uint256(0), amountOutput) : (amountOutput, uint256(0)); + address to = i < path.length - 2 ? UniswapV2Library.pairFor(factory, output, path[i + 2]) : _to; + pair.swap(amount0Out, amount1Out, to, new bytes(0)); + } + } + + function swapExactTokensForTokensSupportingFeeOnTransferTokens( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external virtual override ensure(deadline) { + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn + ); + uint256 balanceBefore = IERC20(path[path.length - 1]).balanceOf(to); + _swapSupportingFeeOnTransferTokens(path, to); + require( + IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin, + "UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT" + ); + } + + function swapExactETHForTokensSupportingFeeOnTransferTokens( + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external payable virtual override ensure(deadline) { + require(path[0] == WETH, "UniswapV2Router: INVALID_PATH"); + uint256 amountIn = msg.value; + IWETH(WETH).deposit{value: amountIn}(); + assert(IWETH(WETH).transfer(UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn)); + uint256 balanceBefore = IERC20(path[path.length - 1]).balanceOf(to); + _swapSupportingFeeOnTransferTokens(path, to); + require( + IERC20(path[path.length - 1]).balanceOf(to).sub(balanceBefore) >= amountOutMin, + "UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT" + ); + } + + function swapExactTokensForETHSupportingFeeOnTransferTokens( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external virtual override ensure(deadline) { + require(path[path.length - 1] == WETH, "UniswapV2Router: INVALID_PATH"); + TransferHelper.safeTransferFrom( + path[0], msg.sender, UniswapV2Library.pairFor(factory, path[0], path[1]), amountIn + ); + _swapSupportingFeeOnTransferTokens(path, address(this)); + uint256 amountOut = IERC20(WETH).balanceOf(address(this)); + require(amountOut >= amountOutMin, "UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT"); + IWETH(WETH).withdraw(amountOut); + TransferHelper.safeTransferETH(to, amountOut); + } + + // **** LIBRARY FUNCTIONS **** + function quote(uint256 amountA, uint256 reserveA, uint256 reserveB) + public + pure + virtual + override + returns (uint256 amountB) + { + return UniswapV2Library.quote(amountA, reserveA, reserveB); + } + + function getAmountOut(uint256 amountIn, uint256 reserveIn, uint256 reserveOut) + public + pure + virtual + override + returns (uint256 amountOut) + { + return UniswapV2Library.getAmountOut(amountIn, reserveIn, reserveOut); + } + + function getAmountIn(uint256 amountOut, uint256 reserveIn, uint256 reserveOut) + public + pure + virtual + override + returns (uint256 amountIn) + { + return UniswapV2Library.getAmountIn(amountOut, reserveIn, reserveOut); + } + + function getAmountsOut(uint256 amountIn, address[] memory path) + public + view + virtual + override + returns (uint256[] memory amounts) + { + return UniswapV2Library.getAmountsOut(factory, amountIn, path); + } + + function getAmountsIn(uint256 amountOut, address[] memory path) + public + view + virtual + override + returns (uint256[] memory amounts) + { + return UniswapV2Library.getAmountsIn(factory, amountOut, path); + } +} diff --git a/src/examples/ExampleComputeLiquidityValue.sol b/src/examples/ExampleComputeLiquidityValue.sol new file mode 100644 index 0000000..9a7185d --- /dev/null +++ b/src/examples/ExampleComputeLiquidityValue.sol @@ -0,0 +1,63 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "../libraries/UniswapV2LiquidityMathLibrary.sol"; + +contract ExampleComputeLiquidityValue { + using SafeMath for uint256; + + address public immutable factory; + + constructor(address factory_) { + factory = factory_; + } + + // see UniswapV2LiquidityMathLibrary#getReservesAfterArbitrage + function getReservesAfterArbitrage(address tokenA, address tokenB, uint256 truePriceTokenA, uint256 truePriceTokenB) + external + view + returns (uint256 reserveA, uint256 reserveB) + { + return UniswapV2LiquidityMathLibrary.getReservesAfterArbitrage( + factory, tokenA, tokenB, truePriceTokenA, truePriceTokenB + ); + } + + // see UniswapV2LiquidityMathLibrary#getLiquidityValue + function getLiquidityValue(address tokenA, address tokenB, uint256 liquidityAmount) + external + view + returns (uint256 tokenAAmount, uint256 tokenBAmount) + { + return UniswapV2LiquidityMathLibrary.getLiquidityValue(factory, tokenA, tokenB, liquidityAmount); + } + + // see UniswapV2LiquidityMathLibrary#getLiquidityValueAfterArbitrageToPrice + function getLiquidityValueAfterArbitrageToPrice( + address tokenA, + address tokenB, + uint256 truePriceTokenA, + uint256 truePriceTokenB, + uint256 liquidityAmount + ) external view returns (uint256 tokenAAmount, uint256 tokenBAmount) { + return UniswapV2LiquidityMathLibrary.getLiquidityValueAfterArbitrageToPrice( + factory, tokenA, tokenB, truePriceTokenA, truePriceTokenB, liquidityAmount + ); + } + + // test function to measure the gas cost of the above function + function getGasCostOfGetLiquidityValueAfterArbitrageToPrice( + address tokenA, + address tokenB, + uint256 truePriceTokenA, + uint256 truePriceTokenB, + uint256 liquidityAmount + ) external view returns (uint256) { + uint256 gasBefore = gasleft(); + UniswapV2LiquidityMathLibrary.getLiquidityValueAfterArbitrageToPrice( + factory, tokenA, tokenB, truePriceTokenA, truePriceTokenB, liquidityAmount + ); + uint256 gasAfter = gasleft(); + return gasBefore - gasAfter; + } +} diff --git a/src/examples/ExampleFlashSwap.sol b/src/examples/ExampleFlashSwap.sol new file mode 100644 index 0000000..f46cfae --- /dev/null +++ b/src/examples/ExampleFlashSwap.sol @@ -0,0 +1,69 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Callee.sol"; + +import "../libraries/UniswapV2Library.sol"; +import "../interfaces/V1/IUniswapV1Factory.sol"; +import "../interfaces/V1/IUniswapV1Exchange.sol"; +import "../interfaces/IUniswapV2Router01.sol"; +import "../interfaces/IERC20.sol"; +import "../interfaces/IWETH.sol"; + +contract ExampleFlashSwap is IUniswapV2Callee { + IUniswapV1Factory immutable factoryV1; + address immutable factory; + IWETH immutable WETH; + + constructor(address _factory, address _factoryV1, address router) { + factoryV1 = IUniswapV1Factory(_factoryV1); + factory = _factory; + WETH = IWETH(IUniswapV2Router01(router).WETH()); + } + + // needs to accept ETH from any V1 exchange and WETH. ideally this could be enforced, as in the router, + // but it's not possible because it requires a call to the v1 factory, which takes too much gas + receive() external payable {} + + // gets tokens/WETH via a V2 flash swap, swaps for the ETH/tokens on V1, repays V2, and keeps the rest! + function uniswapV2Call(address sender, uint256 amount0, uint256 amount1, bytes calldata data) external override { + address[] memory path = new address[](2); + uint256 amountToken; + uint256 amountETH; + { + // scope for token{0,1}, avoids stack too deep errors + address token0 = IUniswapV2Pair(msg.sender).token0(); + address token1 = IUniswapV2Pair(msg.sender).token1(); + assert(msg.sender == UniswapV2Library.pairFor(factory, token0, token1)); // ensure that msg.sender is actually a V2 pair + assert(amount0 == 0 || amount1 == 0); // this strategy is unidirectional + path[0] = amount0 == 0 ? token0 : token1; + path[1] = amount0 == 0 ? token1 : token0; + amountToken = token0 == address(WETH) ? amount1 : amount0; + amountETH = token0 == address(WETH) ? amount0 : amount1; + } + + assert(path[0] == address(WETH) || path[1] == address(WETH)); // this strategy only works with a V2 WETH pair + IERC20 token = IERC20(path[0] == address(WETH) ? path[1] : path[0]); + IUniswapV1Exchange exchangeV1 = IUniswapV1Exchange(factoryV1.getExchange(address(token))); // get V1 exchange + + if (amountToken > 0) { + (uint256 minETH) = abi.decode(data, (uint256)); // slippage parameter for V1, passed in by caller + token.approve(address(exchangeV1), amountToken); + uint256 amountReceived = exchangeV1.tokenToEthSwapInput(amountToken, minETH, type(uint256).max); + uint256 amountRequired = UniswapV2Library.getAmountsIn(factory, amountToken, path)[0]; + assert(amountReceived > amountRequired); // fail if we didn't get enough ETH back to repay our flash loan + WETH.deposit{value: amountRequired}(); + assert(WETH.transfer(msg.sender, amountRequired)); // return WETH to V2 pair + (bool success,) = sender.call{value: amountReceived - amountRequired}(new bytes(0)); // keep the rest! (ETH) + assert(success); + } else { + (uint256 minTokens) = abi.decode(data, (uint256)); // slippage parameter for V1, passed in by caller + WETH.withdraw(amountETH); + uint256 amountReceived = exchangeV1.ethToTokenSwapInput{value: amountETH}(minTokens, type(uint256).max); + uint256 amountRequired = UniswapV2Library.getAmountsIn(factory, amountETH, path)[0]; + assert(amountReceived > amountRequired); // fail if we didn't get enough tokens back to repay our flash loan + assert(token.transfer(msg.sender, amountRequired)); // return tokens to V2 pair + assert(token.transfer(sender, amountReceived - amountRequired)); // keep the rest! (tokens) + } + } +} diff --git a/src/examples/ExampleOracleSimple.sol b/src/examples/ExampleOracleSimple.sol new file mode 100644 index 0000000..8fe7f7d --- /dev/null +++ b/src/examples/ExampleOracleSimple.sol @@ -0,0 +1,68 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol"; +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol"; +import "@uniswap/lib/contracts/libraries/FixedPoint.sol"; + +import "../libraries/UniswapV2OracleLibrary.sol"; +import "../libraries/UniswapV2Library.sol"; + +// fixed window oracle that recomputes the average price for the entire period once every period +// note that the price average is only guaranteed to be over at least 1 period, but may be over a longer period +contract ExampleOracleSimple { + using FixedPoint for *; + + uint256 public constant PERIOD = 24 hours; + + IUniswapV2Pair immutable pair; + address public immutable token0; + address public immutable token1; + + uint256 public price0CumulativeLast; + uint256 public price1CumulativeLast; + uint32 public blockTimestampLast; + FixedPoint.uq112x112 public price0Average; + FixedPoint.uq112x112 public price1Average; + + constructor(address factory, address tokenA, address tokenB) { + IUniswapV2Pair _pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, tokenA, tokenB)); + pair = _pair; + token0 = _pair.token0(); + token1 = _pair.token1(); + price0CumulativeLast = _pair.price0CumulativeLast(); // fetch the current accumulated price value (1 / 0) + price1CumulativeLast = _pair.price1CumulativeLast(); // fetch the current accumulated price value (0 / 1) + uint112 reserve0; + uint112 reserve1; + (reserve0, reserve1, blockTimestampLast) = _pair.getReserves(); + require(reserve0 != 0 && reserve1 != 0, "ExampleOracleSimple: NO_RESERVES"); // ensure that there's liquidity in the pair + } + + function update() external { + (uint256 price0Cumulative, uint256 price1Cumulative, uint32 blockTimestamp) = + UniswapV2OracleLibrary.currentCumulativePrices(address(pair)); + uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired + + // ensure that at least one full period has passed since the last update + require(timeElapsed >= PERIOD, "ExampleOracleSimple: PERIOD_NOT_ELAPSED"); + + // overflow is desired, casting never truncates + // cumulative price is in (uq112x112 price * seconds) units so we simply wrap it after division by time elapsed + price0Average = FixedPoint.uq112x112(uint224((price0Cumulative - price0CumulativeLast) / timeElapsed)); + price1Average = FixedPoint.uq112x112(uint224((price1Cumulative - price1CumulativeLast) / timeElapsed)); + + price0CumulativeLast = price0Cumulative; + price1CumulativeLast = price1Cumulative; + blockTimestampLast = blockTimestamp; + } + + // note this will always return 0 before update has been called successfully for the first time. + function consult(address token, uint256 amountIn) external view returns (uint256 amountOut) { + if (token == token0) { + amountOut = price0Average.mul(amountIn).decode144(); + } else { + require(token == token1, "ExampleOracleSimple: INVALID_TOKEN"); + amountOut = price1Average.mul(amountIn).decode144(); + } + } +} diff --git a/src/examples/ExampleSlidingWindowOracle.sol b/src/examples/ExampleSlidingWindowOracle.sol new file mode 100644 index 0000000..32449d0 --- /dev/null +++ b/src/examples/ExampleSlidingWindowOracle.sol @@ -0,0 +1,127 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol"; +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol"; +import "@uniswap/lib/contracts/libraries/FixedPoint.sol"; + +import "../libraries/SafeMath.sol"; +import "../libraries/UniswapV2Library.sol"; +import "../libraries/UniswapV2OracleLibrary.sol"; + +// sliding window oracle that uses observations collected over a window to provide moving price averages in the past +// `windowSize` with a precision of `windowSize / granularity` +// note this is a singleton oracle and only needs to be deployed once per desired parameters, which +// differs from the simple oracle which must be deployed once per pair. +contract ExampleSlidingWindowOracle { + using FixedPoint for *; + using SafeMath for uint256; + + struct Observation { + uint256 timestamp; + uint256 price0Cumulative; + uint256 price1Cumulative; + } + + address public immutable factory; + // the desired amount of time over which the moving average should be computed, e.g. 24 hours + uint256 public immutable windowSize; + // the number of observations stored for each pair, i.e. how many price observations are stored for the window. + // as granularity increases from 1, more frequent updates are needed, but moving averages become more precise. + // averages are computed over intervals with sizes in the range: + // [windowSize - (windowSize / granularity) * 2, windowSize] + // e.g. if the window size is 24 hours, and the granularity is 24, the oracle will return the average price for + // the period: + // [now - [22 hours, 24 hours], now] + uint8 public immutable granularity; + // this is redundant with granularity and windowSize, but stored for gas savings & informational purposes. + uint256 public immutable periodSize; + + // mapping from pair address to a list of price observations of that pair + mapping(address => Observation[]) public pairObservations; + + constructor(address factory_, uint256 windowSize_, uint8 granularity_) { + require(granularity_ > 1, "SlidingWindowOracle: GRANULARITY"); + require( + (periodSize = windowSize_ / granularity_) * granularity_ == windowSize_, + "SlidingWindowOracle: WINDOW_NOT_EVENLY_DIVISIBLE" + ); + factory = factory_; + windowSize = windowSize_; + granularity = granularity_; + } + + // returns the index of the observation corresponding to the given timestamp + function observationIndexOf(uint256 timestamp) public view returns (uint8 index) { + uint256 epochPeriod = timestamp / periodSize; + return uint8(epochPeriod % granularity); + } + + // returns the observation from the oldest epoch (at the beginning of the window) relative to the current time + function getFirstObservationInWindow(address pair) private view returns (Observation storage firstObservation) { + uint8 observationIndex = observationIndexOf(block.timestamp); + // no overflow issue. if observationIndex + 1 overflows, result is still zero. + uint8 firstObservationIndex = (observationIndex + 1) % granularity; + firstObservation = pairObservations[pair][firstObservationIndex]; + } + + // update the cumulative price for the observation at the current timestamp. each observation is updated at most + // once per epoch period. + function update(address tokenA, address tokenB) external { + address pair = UniswapV2Library.pairFor(factory, tokenA, tokenB); + + // populate the array with empty observations (first call only) + for (uint256 i = pairObservations[pair].length; i < granularity; i++) { + pairObservations[pair].push(); + } + + // get the observation for the current period + uint8 observationIndex = observationIndexOf(block.timestamp); + Observation storage observation = pairObservations[pair][observationIndex]; + + // we only want to commit updates once per period (i.e. windowSize / granularity) + uint256 timeElapsed = block.timestamp - observation.timestamp; + if (timeElapsed > periodSize) { + (uint256 price0Cumulative, uint256 price1Cumulative,) = UniswapV2OracleLibrary.currentCumulativePrices(pair); + observation.timestamp = block.timestamp; + observation.price0Cumulative = price0Cumulative; + observation.price1Cumulative = price1Cumulative; + } + } + + // given the cumulative prices of the start and end of a period, and the length of the period, compute the average + // price in terms of how much amount out is received for the amount in + function computeAmountOut( + uint256 priceCumulativeStart, + uint256 priceCumulativeEnd, + uint256 timeElapsed, + uint256 amountIn + ) private pure returns (uint256 amountOut) { + // overflow is desired. + FixedPoint.uq112x112 memory priceAverage = + FixedPoint.uq112x112(uint224((priceCumulativeEnd - priceCumulativeStart) / timeElapsed)); + amountOut = priceAverage.mul(amountIn).decode144(); + } + + // returns the amount out corresponding to the amount in for a given token using the moving average over the time + // range [now - [windowSize, windowSize - periodSize * 2], now] + // update must have been called for the bucket corresponding to timestamp `now - windowSize` + function consult(address tokenIn, uint256 amountIn, address tokenOut) external view returns (uint256 amountOut) { + address pair = UniswapV2Library.pairFor(factory, tokenIn, tokenOut); + Observation storage firstObservation = getFirstObservationInWindow(pair); + + uint256 timeElapsed = block.timestamp - firstObservation.timestamp; + require(timeElapsed <= windowSize, "SlidingWindowOracle: MISSING_HISTORICAL_OBSERVATION"); + // should never happen. + require(timeElapsed >= windowSize - periodSize * 2, "SlidingWindowOracle: UNEXPECTED_TIME_ELAPSED"); + + (uint256 price0Cumulative, uint256 price1Cumulative,) = UniswapV2OracleLibrary.currentCumulativePrices(pair); + (address token0,) = UniswapV2Library.sortTokens(tokenIn, tokenOut); + + if (token0 == tokenIn) { + return computeAmountOut(firstObservation.price0Cumulative, price0Cumulative, timeElapsed, amountIn); + } else { + return computeAmountOut(firstObservation.price1Cumulative, price1Cumulative, timeElapsed, amountIn); + } + } +} diff --git a/src/examples/ExampleSwapToPrice.sol b/src/examples/ExampleSwapToPrice.sol new file mode 100644 index 0000000..674721d --- /dev/null +++ b/src/examples/ExampleSwapToPrice.sol @@ -0,0 +1,77 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol"; +import "@uniswap/lib/contracts/libraries/Babylonian.sol"; +import "@uniswap/lib/contracts/libraries/TransferHelper.sol"; + +import "../libraries/UniswapV2LiquidityMathLibrary.sol"; +import "../interfaces/IERC20.sol"; +import "../interfaces/IUniswapV2Router01.sol"; +import "../libraries/SafeMath.sol"; +import "../libraries/UniswapV2Library.sol"; + +contract ExampleSwapToPrice { + using SafeMath for uint256; + + IUniswapV2Router01 public immutable router; + address public immutable factory; + + constructor(address factory_, IUniswapV2Router01 router_) { + factory = factory_; + router = router_; + } + + // swaps an amount of either token such that the trade is profit-maximizing, given an external true price + // true price is expressed in the ratio of token A to token B + // caller must approve this contract to spend whichever token is intended to be swapped + function swapToPrice( + address tokenA, + address tokenB, + uint256 truePriceTokenA, + uint256 truePriceTokenB, + uint256 maxSpendTokenA, + uint256 maxSpendTokenB, + address to, + uint256 deadline + ) public { + // true price is expressed as a ratio, so both values must be non-zero + require(truePriceTokenA != 0 && truePriceTokenB != 0, "ExampleSwapToPrice: ZERO_PRICE"); + // caller can specify 0 for either if they wish to swap in only one direction, but not both + require(maxSpendTokenA != 0 || maxSpendTokenB != 0, "ExampleSwapToPrice: ZERO_SPEND"); + + bool aToB; + uint256 amountIn; + { + (uint256 reserveA, uint256 reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB); + (aToB, amountIn) = UniswapV2LiquidityMathLibrary.computeProfitMaximizingTrade( + truePriceTokenA, truePriceTokenB, reserveA, reserveB + ); + } + + require(amountIn > 0, "ExampleSwapToPrice: ZERO_AMOUNT_IN"); + + // spend up to the allowance of the token in + uint256 maxSpend = aToB ? maxSpendTokenA : maxSpendTokenB; + if (amountIn > maxSpend) { + amountIn = maxSpend; + } + + address tokenIn = aToB ? tokenA : tokenB; + address tokenOut = aToB ? tokenB : tokenA; + TransferHelper.safeTransferFrom(tokenIn, msg.sender, address(this), amountIn); + TransferHelper.safeApprove(tokenIn, address(router), amountIn); + + address[] memory path = new address[](2); + path[0] = tokenIn; + path[1] = tokenOut; + + router.swapExactTokensForTokens( + amountIn, + 0, // amountOutMin: we can skip computing this number because the math is tested + path, + to, + deadline + ); + } +} diff --git a/src/examples/README.md b/src/examples/README.md new file mode 100644 index 0000000..49fa2af --- /dev/null +++ b/src/examples/README.md @@ -0,0 +1,14 @@ +# Examples + +## Disclaimer + +These contracts are for demonstrative purposes only. +While these contracts have unit tests, and we generally expect them to be +correct, there are no guarantees about the correctness or security of +these contracts. We hold these contracts to a different standard of +correctness and security than other contracts in this repository. +E.g., we have explicitly excluded these contracts from the +[bug bounty](https://uniswap.org/bug-bounty/#scope). + +You must do your own due diligence if you wish to use code +from these examples in your project. diff --git a/src/interfaces/IERC20.sol b/src/interfaces/IERC20.sol new file mode 100644 index 0000000..6004787 --- /dev/null +++ b/src/interfaces/IERC20.sol @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +interface IERC20 { + event Approval(address indexed owner, address indexed spender, uint256 value); + event Transfer(address indexed from, address indexed to, uint256 value); + + function name() external view returns (string memory); + function symbol() external view returns (string memory); + function decimals() external view returns (uint8); + function totalSupply() external view returns (uint256); + function balanceOf(address owner) external view returns (uint256); + function allowance(address owner, address spender) external view returns (uint256); + + function approve(address spender, uint256 value) external returns (bool); + function transfer(address to, uint256 value) external returns (bool); + function transferFrom(address from, address to, uint256 value) external returns (bool); +} diff --git a/src/interfaces/IUniswapV2Migrator.sol b/src/interfaces/IUniswapV2Migrator.sol new file mode 100644 index 0000000..b306f08 --- /dev/null +++ b/src/interfaces/IUniswapV2Migrator.sol @@ -0,0 +1,7 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +interface IUniswapV2Migrator { + function migrate(address token, uint256 amountTokenMin, uint256 amountETHMin, address to, uint256 deadline) + external; +} diff --git a/src/interfaces/IUniswapV2Router01.sol b/src/interfaces/IUniswapV2Router01.sol new file mode 100644 index 0000000..d8852ca --- /dev/null +++ b/src/interfaces/IUniswapV2Router01.sol @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +interface IUniswapV2Router01 { + function factory() external returns (address); + function WETH() external returns (address); + + function addLiquidity( + address tokenA, + address tokenB, + uint256 amountADesired, + uint256 amountBDesired, + uint256 amountAMin, + uint256 amountBMin, + address to, + uint256 deadline + ) external returns (uint256 amountA, uint256 amountB, uint256 liquidity); + function addLiquidityETH( + address token, + uint256 amountTokenDesired, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline + ) external payable returns (uint256 amountToken, uint256 amountETH, uint256 liquidity); + function removeLiquidity( + address tokenA, + address tokenB, + uint256 liquidity, + uint256 amountAMin, + uint256 amountBMin, + address to, + uint256 deadline + ) external returns (uint256 amountA, uint256 amountB); + function removeLiquidityETH( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline + ) external returns (uint256 amountToken, uint256 amountETH); + function removeLiquidityWithPermit( + address tokenA, + address tokenB, + uint256 liquidity, + uint256 amountAMin, + uint256 amountBMin, + address to, + uint256 deadline, + bool approveMax, + uint8 v, + bytes32 r, + bytes32 s + ) external returns (uint256 amountA, uint256 amountB); + function removeLiquidityETHWithPermit( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline, + bool approveMax, + uint8 v, + bytes32 r, + bytes32 s + ) external returns (uint256 amountToken, uint256 amountETH); + function swapExactTokensForTokens( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external returns (uint256[] memory amounts); + function swapTokensForExactTokens( + uint256 amountOut, + uint256 amountInMax, + address[] calldata path, + address to, + uint256 deadline + ) external returns (uint256[] memory amounts); + function swapExactETHForTokens(uint256 amountOutMin, address[] calldata path, address to, uint256 deadline) + external + payable + returns (uint256[] memory amounts); + function swapTokensForExactETH( + uint256 amountOut, + uint256 amountInMax, + address[] calldata path, + address to, + uint256 deadline + ) external returns (uint256[] memory amounts); + function swapExactTokensForETH( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external returns (uint256[] memory amounts); + function swapETHForExactTokens(uint256 amountOut, address[] calldata path, address to, uint256 deadline) + external + payable + returns (uint256[] memory amounts); + + function quote(uint256 amountA, uint256 reserveA, uint256 reserveB) external pure returns (uint256 amountB); + function getAmountOut(uint256 amountIn, uint256 reserveIn, uint256 reserveOut) + external + pure + returns (uint256 amountOut); + function getAmountIn(uint256 amountOut, uint256 reserveIn, uint256 reserveOut) + external + pure + returns (uint256 amountIn); + function getAmountsOut(uint256 amountIn, address[] calldata path) + external + view + returns (uint256[] memory amounts); + function getAmountsIn(uint256 amountOut, address[] calldata path) + external + view + returns (uint256[] memory amounts); +} diff --git a/src/interfaces/IUniswapV2Router02.sol b/src/interfaces/IUniswapV2Router02.sol new file mode 100644 index 0000000..7704be3 --- /dev/null +++ b/src/interfaces/IUniswapV2Router02.sol @@ -0,0 +1,48 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "./IUniswapV2Router01.sol"; + +interface IUniswapV2Router02 is IUniswapV2Router01 { + function removeLiquidityETHSupportingFeeOnTransferTokens( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline + ) external returns (uint256 amountETH); + function removeLiquidityETHWithPermitSupportingFeeOnTransferTokens( + address token, + uint256 liquidity, + uint256 amountTokenMin, + uint256 amountETHMin, + address to, + uint256 deadline, + bool approveMax, + uint8 v, + bytes32 r, + bytes32 s + ) external returns (uint256 amountETH); + + function swapExactTokensForTokensSupportingFeeOnTransferTokens( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external; + function swapExactETHForTokensSupportingFeeOnTransferTokens( + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external payable; + function swapExactTokensForETHSupportingFeeOnTransferTokens( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external; +} diff --git a/src/interfaces/IWETH.sol b/src/interfaces/IWETH.sol new file mode 100644 index 0000000..eb3c2f4 --- /dev/null +++ b/src/interfaces/IWETH.sol @@ -0,0 +1,8 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +interface IWETH { + function deposit() external payable; + function transfer(address to, uint256 value) external returns (bool); + function withdraw(uint256) external; +} diff --git a/src/interfaces/V1/IUniswapV1Exchange.sol b/src/interfaces/V1/IUniswapV1Exchange.sol new file mode 100644 index 0000000..31eef43 --- /dev/null +++ b/src/interfaces/V1/IUniswapV1Exchange.sol @@ -0,0 +1,10 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +interface IUniswapV1Exchange { + function balanceOf(address owner) external view returns (uint256); + function transferFrom(address from, address to, uint256 value) external returns (bool); + function removeLiquidity(uint256, uint256, uint256, uint256) external returns (uint256, uint256); + function tokenToEthSwapInput(uint256, uint256, uint256) external returns (uint256); + function ethToTokenSwapInput(uint256, uint256) external payable returns (uint256); +} diff --git a/src/interfaces/V1/IUniswapV1Factory.sol b/src/interfaces/V1/IUniswapV1Factory.sol new file mode 100644 index 0000000..fe25eb2 --- /dev/null +++ b/src/interfaces/V1/IUniswapV1Factory.sol @@ -0,0 +1,6 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +interface IUniswapV1Factory { + function getExchange(address) external view returns (address); +} diff --git a/src/libraries/SafeMath.sol b/src/libraries/SafeMath.sol new file mode 100644 index 0000000..afff7a2 --- /dev/null +++ b/src/libraries/SafeMath.sol @@ -0,0 +1,18 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +// a library for performing overflow-safe math, courtesy of DappHub (https://github.com/dapphub/ds-math) + +library SafeMath { + function add(uint256 x, uint256 y) internal pure returns (uint256 z) { + require((z = x + y) >= x, "ds-math-add-overflow"); + } + + function sub(uint256 x, uint256 y) internal pure returns (uint256 z) { + require((z = x - y) <= x, "ds-math-sub-underflow"); + } + + function mul(uint256 x, uint256 y) internal pure returns (uint256 z) { + require(y == 0 || (z = x * y) / y == x, "ds-math-mul-overflow"); + } +} diff --git a/src/libraries/UniswapV2Library.sol b/src/libraries/UniswapV2Library.sol new file mode 100644 index 0000000..ef81521 --- /dev/null +++ b/src/libraries/UniswapV2Library.sol @@ -0,0 +1,111 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol"; + +import "./SafeMath.sol"; + +library UniswapV2Library { + using SafeMath for uint256; + + // returns sorted token addresses, used to handle return values from pairs sorted in this order + function sortTokens(address tokenA, address tokenB) internal pure returns (address token0, address token1) { + require(tokenA != tokenB, "UniswapV2Library: IDENTICAL_ADDRESSES"); + (token0, token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA); + require(token0 != address(0), "UniswapV2Library: ZERO_ADDRESS"); + } + + // calculates the CREATE2 address for a pair without making any external calls + function pairFor(address factory, address tokenA, address tokenB) internal pure returns (address pair) { + (address token0, address token1) = sortTokens(tokenA, tokenB); + pair = address( + uint160( + uint256( + keccak256( + abi.encodePacked( + hex"ff", + factory, + keccak256(abi.encodePacked(token0, token1)), + hex"96e8ac4277198ff8b6f785478aa9a39f403cb768dd02cbee326c3e7da348845f" // init code hash + ) + ) + ) + ) + ); + } + + // fetches and sorts the reserves for a pair + function getReserves(address factory, address tokenA, address tokenB) + internal + view + returns (uint256 reserveA, uint256 reserveB) + { + (address token0,) = sortTokens(tokenA, tokenB); + (uint256 reserve0, uint256 reserve1,) = IUniswapV2Pair(pairFor(factory, tokenA, tokenB)).getReserves(); + (reserveA, reserveB) = tokenA == token0 ? (reserve0, reserve1) : (reserve1, reserve0); + } + + // given some amount of an asset and pair reserves, returns an equivalent amount of the other asset + function quote(uint256 amountA, uint256 reserveA, uint256 reserveB) internal pure returns (uint256 amountB) { + require(amountA > 0, "UniswapV2Library: INSUFFICIENT_AMOUNT"); + require(reserveA > 0 && reserveB > 0, "UniswapV2Library: INSUFFICIENT_LIQUIDITY"); + amountB = amountA.mul(reserveB) / reserveA; + } + + // given an input amount of an asset and pair reserves, returns the maximum output amount of the other asset + function getAmountOut(uint256 amountIn, uint256 reserveIn, uint256 reserveOut) + internal + pure + returns (uint256 amountOut) + { + require(amountIn > 0, "UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT"); + require(reserveIn > 0 && reserveOut > 0, "UniswapV2Library: INSUFFICIENT_LIQUIDITY"); + uint256 amountInWithFee = amountIn.mul(997); + uint256 numerator = amountInWithFee.mul(reserveOut); + uint256 denominator = reserveIn.mul(1000).add(amountInWithFee); + amountOut = numerator / denominator; + } + + // given an output amount of an asset and pair reserves, returns a required input amount of the other asset + function getAmountIn(uint256 amountOut, uint256 reserveIn, uint256 reserveOut) + internal + pure + returns (uint256 amountIn) + { + require(amountOut > 0, "UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT"); + require(reserveIn > 0 && reserveOut > 0, "UniswapV2Library: INSUFFICIENT_LIQUIDITY"); + uint256 numerator = reserveIn.mul(amountOut).mul(1000); + uint256 denominator = reserveOut.sub(amountOut).mul(997); + amountIn = (numerator / denominator).add(1); + } + + // performs chained getAmountOut calculations on any number of pairs + function getAmountsOut(address factory, uint256 amountIn, address[] memory path) + internal + view + returns (uint256[] memory amounts) + { + require(path.length >= 2, "UniswapV2Library: INVALID_PATH"); + amounts = new uint256[](path.length); + amounts[0] = amountIn; + for (uint256 i; i < path.length - 1; i++) { + (uint256 reserveIn, uint256 reserveOut) = getReserves(factory, path[i], path[i + 1]); + amounts[i + 1] = getAmountOut(amounts[i], reserveIn, reserveOut); + } + } + + // performs chained getAmountIn calculations on any number of pairs + function getAmountsIn(address factory, uint256 amountOut, address[] memory path) + internal + view + returns (uint256[] memory amounts) + { + require(path.length >= 2, "UniswapV2Library: INVALID_PATH"); + amounts = new uint256[](path.length); + amounts[amounts.length - 1] = amountOut; + for (uint256 i = path.length - 1; i > 0; i--) { + (uint256 reserveIn, uint256 reserveOut) = getReserves(factory, path[i - 1], path[i]); + amounts[i - 1] = getAmountIn(amounts[i], reserveIn, reserveOut); + } + } +} diff --git a/src/libraries/UniswapV2LiquidityMathLibrary.sol b/src/libraries/UniswapV2LiquidityMathLibrary.sol new file mode 100644 index 0000000..816f688 --- /dev/null +++ b/src/libraries/UniswapV2LiquidityMathLibrary.sol @@ -0,0 +1,138 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol"; +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Factory.sol"; +import "@uniswap/lib/contracts/libraries/Babylonian.sol"; +import "@uniswap/lib/contracts/libraries/FullMath.sol"; + +import "./SafeMath.sol"; +import "./UniswapV2Library.sol"; + +// library containing some math for dealing with the liquidity shares of a pair, e.g. computing their exact value +// in terms of the underlying tokens +library UniswapV2LiquidityMathLibrary { + using SafeMath for uint256; + + // computes the direction and magnitude of the profit-maximizing trade + function computeProfitMaximizingTrade( + uint256 truePriceTokenA, + uint256 truePriceTokenB, + uint256 reserveA, + uint256 reserveB + ) internal pure returns (bool aToB, uint256 amountIn) { + aToB = FullMath.mulDiv(reserveA, truePriceTokenB, reserveB) < truePriceTokenA; + + uint256 invariant = reserveA.mul(reserveB); + + uint256 leftSide = Babylonian.sqrt( + FullMath.mulDiv( + invariant.mul(1000), + aToB ? truePriceTokenA : truePriceTokenB, + (aToB ? truePriceTokenB : truePriceTokenA).mul(997) + ) + ); + uint256 rightSide = (aToB ? reserveA.mul(1000) : reserveB.mul(1000)) / 997; + + if (leftSide < rightSide) return (false, 0); + + // compute the amount that must be sent to move the price to the profit-maximizing price + amountIn = leftSide.sub(rightSide); + } + + // gets the reserves after an arbitrage moves the price to the profit-maximizing ratio given an externally observed true price + function getReservesAfterArbitrage( + address factory, + address tokenA, + address tokenB, + uint256 truePriceTokenA, + uint256 truePriceTokenB + ) internal view returns (uint256 reserveA, uint256 reserveB) { + // first get reserves before the swap + (reserveA, reserveB) = UniswapV2Library.getReserves(factory, tokenA, tokenB); + + require(reserveA > 0 && reserveB > 0, "UniswapV2ArbitrageLibrary: ZERO_PAIR_RESERVES"); + + // then compute how much to swap to arb to the true price + (bool aToB, uint256 amountIn) = + computeProfitMaximizingTrade(truePriceTokenA, truePriceTokenB, reserveA, reserveB); + + if (amountIn == 0) { + return (reserveA, reserveB); + } + + // now affect the trade to the reserves + if (aToB) { + uint256 amountOut = UniswapV2Library.getAmountOut(amountIn, reserveA, reserveB); + reserveA += amountIn; + reserveB -= amountOut; + } else { + uint256 amountOut = UniswapV2Library.getAmountOut(amountIn, reserveB, reserveA); + reserveB += amountIn; + reserveA -= amountOut; + } + } + + // computes liquidity value given all the parameters of the pair + function computeLiquidityValue( + uint256 reservesA, + uint256 reservesB, + uint256 totalSupply, + uint256 liquidityAmount, + bool feeOn, + uint256 kLast + ) internal pure returns (uint256 tokenAAmount, uint256 tokenBAmount) { + if (feeOn && kLast > 0) { + uint256 rootK = Babylonian.sqrt(reservesA.mul(reservesB)); + uint256 rootKLast = Babylonian.sqrt(kLast); + if (rootK > rootKLast) { + uint256 numerator1 = totalSupply; + uint256 numerator2 = rootK.sub(rootKLast); + uint256 denominator = rootK.mul(5).add(rootKLast); + uint256 feeLiquidity = FullMath.mulDiv(numerator1, numerator2, denominator); + totalSupply = totalSupply.add(feeLiquidity); + } + } + return (reservesA.mul(liquidityAmount) / totalSupply, reservesB.mul(liquidityAmount) / totalSupply); + } + + // get all current parameters from the pair and compute value of a liquidity amount + // **note this is subject to manipulation, e.g. sandwich attacks**. prefer passing a manipulation resistant price to + // #getLiquidityValueAfterArbitrageToPrice + function getLiquidityValue(address factory, address tokenA, address tokenB, uint256 liquidityAmount) + internal + view + returns (uint256 tokenAAmount, uint256 tokenBAmount) + { + (uint256 reservesA, uint256 reservesB) = UniswapV2Library.getReserves(factory, tokenA, tokenB); + IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, tokenA, tokenB)); + bool feeOn = IUniswapV2Factory(factory).feeTo() != address(0); + uint256 kLast = feeOn ? pair.kLast() : 0; + uint256 totalSupply = pair.totalSupply(); + return computeLiquidityValue(reservesA, reservesB, totalSupply, liquidityAmount, feeOn, kLast); + } + + // given two tokens, tokenA and tokenB, and their "true price", i.e. the observed ratio of value of token A to token B, + // and a liquidity amount, returns the value of the liquidity in terms of tokenA and tokenB + function getLiquidityValueAfterArbitrageToPrice( + address factory, + address tokenA, + address tokenB, + uint256 truePriceTokenA, + uint256 truePriceTokenB, + uint256 liquidityAmount + ) internal view returns (uint256 tokenAAmount, uint256 tokenBAmount) { + bool feeOn = IUniswapV2Factory(factory).feeTo() != address(0); + IUniswapV2Pair pair = IUniswapV2Pair(UniswapV2Library.pairFor(factory, tokenA, tokenB)); + uint256 kLast = feeOn ? pair.kLast() : 0; + uint256 totalSupply = pair.totalSupply(); + + // this also checks that totalSupply > 0 + require(totalSupply >= liquidityAmount && liquidityAmount > 0, "ComputeLiquidityValue: LIQUIDITY_AMOUNT"); + + (uint256 reservesA, uint256 reservesB) = + getReservesAfterArbitrage(factory, tokenA, tokenB, truePriceTokenA, truePriceTokenB); + + return computeLiquidityValue(reservesA, reservesB, totalSupply, liquidityAmount, feeOn, kLast); + } +} diff --git a/src/libraries/UniswapV2OracleLibrary.sol b/src/libraries/UniswapV2OracleLibrary.sol new file mode 100644 index 0000000..0eaf717 --- /dev/null +++ b/src/libraries/UniswapV2OracleLibrary.sol @@ -0,0 +1,38 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "@uniswap/v2-core/contracts/interfaces/IUniswapV2Pair.sol"; +import "@uniswap/lib/contracts/libraries/FixedPoint.sol"; + +// library with helper methods for oracles that are concerned with computing average prices +library UniswapV2OracleLibrary { + using FixedPoint for *; + + // helper function that returns the current block timestamp within the range of uint32, i.e. [0, 2**32 - 1] + function currentBlockTimestamp() internal view returns (uint32) { + return uint32(block.timestamp % 2 ** 32); + } + + // produces the cumulative price using counterfactuals to save gas and avoid a call to sync. + function currentCumulativePrices(address pair) + internal + view + returns (uint256 price0Cumulative, uint256 price1Cumulative, uint32 blockTimestamp) + { + blockTimestamp = currentBlockTimestamp(); + price0Cumulative = IUniswapV2Pair(pair).price0CumulativeLast(); + price1Cumulative = IUniswapV2Pair(pair).price1CumulativeLast(); + + // if time has elapsed since the last update on the pair, mock the accumulated price values + (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast) = IUniswapV2Pair(pair).getReserves(); + if (blockTimestampLast != blockTimestamp) { + // subtraction overflow is desired + uint32 timeElapsed = blockTimestamp - blockTimestampLast; + // addition overflow is desired + // counterfactual + price0Cumulative += uint256(FixedPoint.fraction(reserve1, reserve0)._x) * timeElapsed; + // counterfactual + price1Cumulative += uint256(FixedPoint.fraction(reserve0, reserve1)._x) * timeElapsed; + } + } +} diff --git a/src/test/DeflatingERC20.sol b/src/test/DeflatingERC20.sol new file mode 100644 index 0000000..36cf280 --- /dev/null +++ b/src/test/DeflatingERC20.sol @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "../libraries/SafeMath.sol"; + +contract DeflatingERC20 { + using SafeMath for uint256; + + string public constant name = "Deflating Test Token"; + string public constant symbol = "DTT"; + uint8 public constant decimals = 18; + uint256 public totalSupply; + mapping(address => uint256) public balanceOf; + mapping(address => mapping(address => uint256)) public allowance; + + bytes32 public DOMAIN_SEPARATOR; + // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"); + bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9; + mapping(address => uint256) public nonces; + + event Approval(address indexed owner, address indexed spender, uint256 value); + event Transfer(address indexed from, address indexed to, uint256 value); + + constructor(uint256 _totalSupply) { + uint256 chainId; + assembly { + chainId := chainid() + } + DOMAIN_SEPARATOR = keccak256( + abi.encode( + keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"), + keccak256(bytes(name)), + keccak256(bytes("1")), + chainId, + address(this) + ) + ); + _mint(msg.sender, _totalSupply); + } + + function _mint(address to, uint256 value) internal { + totalSupply = totalSupply.add(value); + balanceOf[to] = balanceOf[to].add(value); + emit Transfer(address(0), to, value); + } + + function _burn(address from, uint256 value) internal { + balanceOf[from] = balanceOf[from].sub(value); + totalSupply = totalSupply.sub(value); + emit Transfer(from, address(0), value); + } + + function _approve(address owner, address spender, uint256 value) private { + allowance[owner][spender] = value; + emit Approval(owner, spender, value); + } + + function _transfer(address from, address to, uint256 value) private { + uint256 burnAmount = value / 100; + _burn(from, burnAmount); + uint256 transferAmount = value.sub(burnAmount); + balanceOf[from] = balanceOf[from].sub(transferAmount); + balanceOf[to] = balanceOf[to].add(transferAmount); + emit Transfer(from, to, transferAmount); + } + + function approve(address spender, uint256 value) external returns (bool) { + _approve(msg.sender, spender, value); + return true; + } + + function transfer(address to, uint256 value) external returns (bool) { + _transfer(msg.sender, to, value); + return true; + } + + function transferFrom(address from, address to, uint256 value) external returns (bool) { + if (allowance[from][msg.sender] != type(uint256).max) { + allowance[from][msg.sender] = allowance[from][msg.sender].sub(value); + } + _transfer(from, to, value); + return true; + } + + function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) + external + { + require(deadline >= block.timestamp, "EXPIRED"); + bytes32 digest = keccak256( + abi.encodePacked( + "\x19\x01", + DOMAIN_SEPARATOR, + keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline)) + ) + ); + address recoveredAddress = ecrecover(digest, v, r, s); + require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNATURE"); + _approve(owner, spender, value); + } +} diff --git a/src/test/ERC20.sol b/src/test/ERC20.sol new file mode 100644 index 0000000..f5bf28a --- /dev/null +++ b/src/test/ERC20.sol @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "../libraries/SafeMath.sol"; + +contract ERC20 { + using SafeMath for uint256; + + string public constant name = "Test Token"; + string public constant symbol = "TT"; + uint8 public constant decimals = 18; + uint256 public totalSupply; + mapping(address => uint256) public balanceOf; + mapping(address => mapping(address => uint256)) public allowance; + + bytes32 public DOMAIN_SEPARATOR; + // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"); + bytes32 public constant PERMIT_TYPEHASH = 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9; + mapping(address => uint256) public nonces; + + event Approval(address indexed owner, address indexed spender, uint256 value); + event Transfer(address indexed from, address indexed to, uint256 value); + + constructor(uint256 _totalSupply) { + uint256 chainId; + assembly { + chainId := chainid() + } + DOMAIN_SEPARATOR = keccak256( + abi.encode( + keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"), + keccak256(bytes(name)), + keccak256(bytes("1")), + chainId, + address(this) + ) + ); + _mint(msg.sender, _totalSupply); + } + + function _mint(address to, uint256 value) internal { + totalSupply = totalSupply.add(value); + balanceOf[to] = balanceOf[to].add(value); + emit Transfer(address(0), to, value); + } + + function _burn(address from, uint256 value) internal { + balanceOf[from] = balanceOf[from].sub(value); + totalSupply = totalSupply.sub(value); + emit Transfer(from, address(0), value); + } + + function _approve(address owner, address spender, uint256 value) private { + allowance[owner][spender] = value; + emit Approval(owner, spender, value); + } + + function _transfer(address from, address to, uint256 value) private { + balanceOf[from] = balanceOf[from].sub(value); + balanceOf[to] = balanceOf[to].add(value); + emit Transfer(from, to, value); + } + + function approve(address spender, uint256 value) external returns (bool) { + _approve(msg.sender, spender, value); + return true; + } + + function transfer(address to, uint256 value) external returns (bool) { + _transfer(msg.sender, to, value); + return true; + } + + function transferFrom(address from, address to, uint256 value) external returns (bool) { + if (allowance[from][msg.sender] != type(uint256).max) { + allowance[from][msg.sender] = allowance[from][msg.sender].sub(value); + } + _transfer(from, to, value); + return true; + } + + function permit(address owner, address spender, uint256 value, uint256 deadline, uint8 v, bytes32 r, bytes32 s) + external + { + require(deadline >= block.timestamp, "EXPIRED"); + bytes32 digest = keccak256( + abi.encodePacked( + "\x19\x01", + DOMAIN_SEPARATOR, + keccak256(abi.encode(PERMIT_TYPEHASH, owner, spender, value, nonces[owner]++, deadline)) + ) + ); + address recoveredAddress = ecrecover(digest, v, r, s); + require(recoveredAddress != address(0) && recoveredAddress == owner, "INVALID_SIGNATURE"); + _approve(owner, spender, value); + } +} diff --git a/src/test/RouterEventEmitter.sol b/src/test/RouterEventEmitter.sol new file mode 100644 index 0000000..829a78d --- /dev/null +++ b/src/test/RouterEventEmitter.sol @@ -0,0 +1,110 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +import "../interfaces/IUniswapV2Router01.sol"; + +contract RouterEventEmitter { + event Amounts(uint256[] amounts); + + receive() external payable {} + + function swapExactTokensForTokens( + address router, + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external { + (bool success, bytes memory returnData) = router.delegatecall( + abi.encodeWithSelector( + IUniswapV2Router01(router).swapExactTokensForTokens.selector, amountIn, amountOutMin, path, to, deadline + ) + ); + assert(success); + emit Amounts(abi.decode(returnData, (uint256[]))); + } + + function swapTokensForExactTokens( + address router, + uint256 amountOut, + uint256 amountInMax, + address[] calldata path, + address to, + uint256 deadline + ) external { + (bool success, bytes memory returnData) = router.delegatecall( + abi.encodeWithSelector( + IUniswapV2Router01(router).swapTokensForExactTokens.selector, amountOut, amountInMax, path, to, deadline + ) + ); + assert(success); + emit Amounts(abi.decode(returnData, (uint256[]))); + } + + function swapExactETHForTokens( + address router, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external payable { + (bool success, bytes memory returnData) = router.delegatecall( + abi.encodeWithSelector( + IUniswapV2Router01(router).swapExactETHForTokens.selector, amountOutMin, path, to, deadline + ) + ); + assert(success); + emit Amounts(abi.decode(returnData, (uint256[]))); + } + + function swapTokensForExactETH( + address router, + uint256 amountOut, + uint256 amountInMax, + address[] calldata path, + address to, + uint256 deadline + ) external { + (bool success, bytes memory returnData) = router.delegatecall( + abi.encodeWithSelector( + IUniswapV2Router01(router).swapTokensForExactETH.selector, amountOut, amountInMax, path, to, deadline + ) + ); + assert(success); + emit Amounts(abi.decode(returnData, (uint256[]))); + } + + function swapExactTokensForETH( + address router, + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external { + (bool success, bytes memory returnData) = router.delegatecall( + abi.encodeWithSelector( + IUniswapV2Router01(router).swapExactTokensForETH.selector, amountIn, amountOutMin, path, to, deadline + ) + ); + assert(success); + emit Amounts(abi.decode(returnData, (uint256[]))); + } + + function swapETHForExactTokens( + address router, + uint256 amountOut, + address[] calldata path, + address to, + uint256 deadline + ) external payable { + (bool success, bytes memory returnData) = router.delegatecall( + abi.encodeWithSelector( + IUniswapV2Router01(router).swapETHForExactTokens.selector, amountOut, path, to, deadline + ) + ); + assert(success); + emit Amounts(abi.decode(returnData, (uint256[]))); + } +} diff --git a/src/test/WETH9.sol b/src/test/WETH9.sol new file mode 100644 index 0000000..fd7e122 --- /dev/null +++ b/src/test/WETH9.sol @@ -0,0 +1,754 @@ +// Copyright (C) 2015, 2016, 2017 Dapphub + +// This program is free software: you can redistribute it and/or modify +// it under the terms of the GNU General Public License as published by +// the Free Software Foundation, either version 3 of the License, or +// (at your option) any later version. + +// This program is distributed in the hope that it will be useful, +// but WITHOUT ANY WARRANTY; without even the implied warranty of +// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +// GNU General Public License for more details. + +// You should have received a copy of the GNU General Public License +// along with this program. If not, see . + +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.26; + +contract WETH9 { + string public name = "Wrapped Ether"; + string public symbol = "WETH"; + uint8 public decimals = 18; + + event Approval(address indexed src, address indexed guy, uint256 wad); + event Transfer(address indexed src, address indexed dst, uint256 wad); + event Deposit(address indexed dst, uint256 wad); + event Withdrawal(address indexed src, uint256 wad); + + mapping(address => uint256) public balanceOf; + mapping(address => mapping(address => uint256)) public allowance; + + // function() public payable { + // deposit(); + // } + function deposit() public payable { + balanceOf[msg.sender] += msg.value; + emit Deposit(msg.sender, msg.value); + } + + function withdraw(uint256 wad) public { + require(balanceOf[msg.sender] >= wad, ""); + balanceOf[msg.sender] -= wad; + payable(msg.sender).transfer(wad); + emit Withdrawal(msg.sender, wad); + } + + function totalSupply() public view returns (uint256) { + return address(this).balance; + } + + function approve(address guy, uint256 wad) public returns (bool) { + allowance[msg.sender][guy] = wad; + emit Approval(msg.sender, guy, wad); + return true; + } + + function transfer(address dst, uint256 wad) public returns (bool) { + return transferFrom(msg.sender, dst, wad); + } + + function transferFrom(address src, address dst, uint256 wad) public returns (bool) { + require(balanceOf[src] >= wad, ""); + + if (src != msg.sender && allowance[src][msg.sender] != type(uint256).max) { + require(allowance[src][msg.sender] >= wad, ""); + allowance[src][msg.sender] -= wad; + } + + balanceOf[src] -= wad; + balanceOf[dst] += wad; + + emit Transfer(src, dst, wad); + + return true; + } +} + +/* + GNU GENERAL PUBLIC LICENSE + Version 3, 29 June 2007 + + Copyright (C) 2007 Free Software Foundation, Inc. + Everyone is permitted to copy and distribute verbatim copies + of this license document, but changing it is not allowed. + + Preamble + + The GNU General Public License is a free, copyleft license for +software and other kinds of works. + + The licenses for most software and other practical works are designed +to take away your freedom to share and change the works. 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Disclaimer of Warranty. + + THERE IS NO WARRANTY FOR THE PROGRAM, TO THE EXTENT PERMITTED BY +APPLICABLE LAW. EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT +HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY +OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, +THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR +PURPOSE. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE PROGRAM +IS WITH YOU. SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF +ALL NECESSARY SERVICING, REPAIR OR CORRECTION. + + 16. Limitation of Liability. + + IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING +WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS +THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY +GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE +USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF +DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD +PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS), +EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF +SUCH DAMAGES. + + 17. Interpretation of Sections 15 and 16. + + If the disclaimer of warranty and limitation of liability provided +above cannot be given local legal effect according to their terms, +reviewing courts shall apply local law that most closely approximates +an absolute waiver of all civil liability in connection with the +Program, unless a warranty or assumption of liability accompanies a +copy of the Program in return for a fee. + + END OF TERMS AND CONDITIONS + + How to Apply These Terms to Your New Programs + + If you develop a new program, and you want it to be of the greatest +possible use to the public, the best way to achieve this is to make it +free software which everyone can redistribute and change under these terms. + + To do so, attach the following notices to the program. It is safest +to attach them to the start of each source file to most effectively +state the exclusion of warranty; and each file should have at least +the "copyright" line and a pointer to where the full notice is found. + + + Copyright (C) + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 3 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see . + +Also add information on how to contact you by electronic and paper mail. + + If the program does terminal interaction, make it output a short +notice like this when it starts in an interactive mode: + + Copyright (C) + This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'. + This is free software, and you are welcome to redistribute it + under certain conditions; type `show c' for details. + +The hypothetical commands `show w' and `show c' should show the appropriate +parts of the General Public License. Of course, your program's commands +might be different; for a GUI interface, you would use an "about box". + + You should also get your employer (if you work as a programmer) or school, +if any, to sign a "copyright disclaimer" for the program, if necessary. +For more information on this, and how to apply and follow the GNU GPL, see +. + + The GNU General Public License does not permit incorporating your program +into proprietary programs. If your program is a subroutine library, you +may consider it more useful to permit linking proprietary applications with +the library. If this is what you want to do, use the GNU Lesser General +Public License instead of this License. But first, please read +. + +*/