From cfd9857dc0fe8d1acbcab1f2fc3a9700160a791a Mon Sep 17 00:00:00 2001 From: Uncle Fatso Date: Sun, 11 May 2025 16:04:09 +0300 Subject: [PATCH] initial commit Signed-off-by: Uncle Fatso --- .env.template | 7 + .gitignore | 4 + deployer.sh | 79 +++ foundry.toml | 24 +- remappings.txt | 2 + script/AddressFileRW.sol | 56 ++ script/Counter.s.sol | 19 - script/UniswapV2Factory.s.sol | 24 + script/UniswapV2Router.s.sol | 32 ++ script/WETH9.s.sol | 19 + soldeer.lock | 13 + src/Counter.sol | 14 - src/UniswapV2ERC20.sol | 113 ++++ src/UniswapV2Factory.sol | 56 ++ src/UniswapV2Pair.sol | 195 +++++++ src/UniswapV2Router.sol | 604 ++++++++++++++++++++ src/WETH9.sol | 760 ++++++++++++++++++++++++++ src/interfaces/IERC20.sol | 26 + src/interfaces/IUniswapV2Callee.sol | 11 + src/interfaces/IUniswapV2ERC20.sol | 37 ++ src/interfaces/IUniswapV2Factory.sol | 17 + src/interfaces/IUniswapV2Pair.sol | 46 ++ src/interfaces/IUniswapV2Router.sol | 51 ++ src/interfaces/IUniswapV2Router01.sol | 151 +++++ src/interfaces/IWETH.sol | 8 + src/libraries/Math.sol | 22 + src/libraries/TransferHelper.sol | 44 ++ src/libraries/UQ112x112.sol | 17 + src/libraries/UniswapV2Library.sol | 134 +++++ src/mock/MockERC20.sol | 57 ++ test/Counter.t.sol | 24 - test/UniswapV2Factory.t.sol | 86 +++ test/UniswapV2Pair.t.sol | 441 +++++++++++++++ test/UniswapV2Router.t.sol | 295 ++++++++++ 34 files changed, 3429 insertions(+), 59 deletions(-) create mode 100644 .env.template create mode 100644 deployer.sh create mode 100644 remappings.txt create mode 100644 script/AddressFileRW.sol delete mode 100644 script/Counter.s.sol create mode 100644 script/UniswapV2Factory.s.sol create mode 100644 script/UniswapV2Router.s.sol create mode 100644 script/WETH9.s.sol create mode 100644 soldeer.lock delete mode 100644 src/Counter.sol create mode 100644 src/UniswapV2ERC20.sol create mode 100644 src/UniswapV2Factory.sol create mode 100644 src/UniswapV2Pair.sol create mode 100644 src/UniswapV2Router.sol create mode 100644 src/WETH9.sol create mode 100644 src/interfaces/IERC20.sol create mode 100644 src/interfaces/IUniswapV2Callee.sol create mode 100644 src/interfaces/IUniswapV2ERC20.sol create mode 100644 src/interfaces/IUniswapV2Factory.sol create mode 100644 src/interfaces/IUniswapV2Pair.sol create mode 100644 src/interfaces/IUniswapV2Router.sol create mode 100644 src/interfaces/IUniswapV2Router01.sol create mode 100644 src/interfaces/IWETH.sol create mode 100644 src/libraries/Math.sol create mode 100644 src/libraries/TransferHelper.sol create mode 100644 src/libraries/UQ112x112.sol create mode 100644 src/libraries/UniswapV2Library.sol create mode 100644 src/mock/MockERC20.sol delete mode 100644 test/Counter.t.sol create mode 100644 test/UniswapV2Factory.t.sol create mode 100644 test/UniswapV2Pair.t.sol create mode 100644 test/UniswapV2Router.t.sol diff --git a/.env.template b/.env.template new file mode 100644 index 0000000..b1102ac --- /dev/null +++ b/.env.template @@ -0,0 +1,7 @@ +DEPLOYMENT_PRIVATE_KEY=0xac0974bec39a17e36ba4a6b4d238ff944bacb478cbed5efcae784d7bf4f2ff80 +WETH_ADDRESS= +FEE_TO_ADDRESS=0x0000000000000000000000000000000000000000 + +SEPOLIA_TEST_RPC_URL= +SEPOLIA_TEST_API_KEY= +SEPOLIA_TEST_ENDPOINT=https://api-sepolia.etherscan.io/api diff --git a/.gitignore b/.gitignore index 85198aa..052b88b 100644 --- a/.gitignore +++ b/.gitignore @@ -12,3 +12,7 @@ docs/ # Dotenv file .env + + +# Soldeer +/dependencies diff --git a/deployer.sh b/deployer.sh new file mode 100644 index 0000000..6cdf4ec --- /dev/null +++ b/deployer.sh @@ -0,0 +1,79 @@ +set -e + +AVAILIABLE_NETWORKS=(anvil-localnet sepolia-testnet) +NETWORK="${AVAILIABLE_NETWORKS[0]}" +START=1 +END=4 +VERIFY_NEEDED="--verify" + +while [[ $# -gt 0 ]]; +do + case "${1}" in + -s|--start) + START="$2" + shift + shift + ;; + -e|--end) + END="$2" + shift + shift + ;; + -n|--network) + NETWORK="$2" + shift + shift + ;; + esac +done + +if [ "$NETWORK" == "anvil-localnet" ]; then + VERIFY_NEEDED="" +fi + +found=false +for i in "${AVAILIABLE_NETWORKS[@]}" +do + if [ "$i" == "$NETWORK" ] ; then + found=true + fi +done + +if [ $found == false ] ; then + echo "ERROR: '${NETWORK}' is incorrect network for deployment, valid networks are:" + for i in "${AVAILIABLE_NETWORKS[@]}" + do + echo -e "\t${i}" + done + exit +fi + +for i in $(seq $START $END); do + if [ "0" == "$i" ]; then + CONTRACT="WETH9" + elif [ "1" == "$i" ] ; then + CONTRACT="UniswapV2Factory" + elif [ "2" == "$i" ]; then + CONTRACT="UniswapV2Router" + else + echo "No contract found for index $i" + exit + fi + + forge script script/${CONTRACT}.s.sol:${CONTRACT}Script --rpc-url $NETWORK + if [ "$NETWORK" == "anvil-localnet" ]; then + answer="y" + else + read -p "Do you want to broadcast '${CONTRACT}' to ${NETWORK} (y/N)? " answer + fi + + if [ "$answer" != "${answer#[Yy]}" ] ; then + forge script script/${CONTRACT}.s.sol:${CONTRACT}Script \ + --rpc-url $NETWORK \ + --broadcast \ + ${VERIFY_NEEDED} \ + -vvv + else + exit + fi +done diff --git a/foundry.toml b/foundry.toml index 25b918f..0199705 100644 --- a/foundry.toml +++ b/foundry.toml @@ -1,6 +1,26 @@ [profile.default] src = "src" out = "out" -libs = ["lib"] +libs = ["lib", "dependencies"] +solc_version = "0.8.20" -# See more config options https://github.com/foundry-rs/foundry/blob/master/crates/config/README.md#all-options +optimizer = true +optimizer_runs = 4294967295 + +remappings = [ + "@openzeppelin-contracts/=dependencies/@openzeppelin-contracts-5.3.0/", + "forge-std-1.9.2/=dependencies/forge-std-1.9.2/", +] +fs_permissions = [{ access = "read", path = "./broadcast"}] +allow_internal_expect_revert = true + +[dependencies] +forge-std = "1.9.7" +"@openzeppelin-contracts" = "5.3.0" + +[rpc_endpoints] +anvil-localnet = "http://127.0.0.1:8545" +sepolia-testnet = "${SEPOLIA_TEST_RPC_URL}" + +[etherscan] +sepolia-testnet = { key = "${SEPOLIA_TEST_API_KEY}", url = "${SEPOLIA_TEST_ENDPOINT}" } diff --git a/remappings.txt b/remappings.txt new file mode 100644 index 0000000..97c31a7 --- /dev/null +++ b/remappings.txt @@ -0,0 +1,2 @@ +@openzeppelin-contracts-5.3.0/=dependencies/@openzeppelin-contracts-5.3.0/ +forge-std-1.9.7/=dependencies/forge-std-1.9.7/ diff --git a/script/AddressFileRW.sol b/script/AddressFileRW.sol new file mode 100644 index 0000000..f79c9e3 --- /dev/null +++ b/script/AddressFileRW.sol @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.20; + +import {Script} from "forge-std/Script.sol"; +import {stdJson} from "forge-std/StdJson.sol"; +import "@openzeppelin-contracts/utils/Strings.sol"; + +contract AddressFileRWScript is Script { + using stdJson for string; + + function _readFromFile(string memory fileName) internal view returns (address) { + string memory root = vm.projectRoot(); + string memory path = string.concat( + root, + "/broadcast/", + fileName, + ".s.sol/", + Strings.toString(block.chainid), + "/run-latest.json" + ); + string memory json = vm.readFile(path); + bytes memory contractAddress = stdJson.parseRaw( + json, + ".transactions[0].contractAddress" + ); + return _bytesToAddress(contractAddress); + } + + function _uint2str(uint256 _i) internal pure returns (string memory str) { + if (_i == 0) { + return "0"; + } + + uint256 j = _i; + uint256 length; + while (j != 0) { + length++; + j /= 10; + } + + bytes memory bstr = new bytes(length); + uint256 k = length; + j = _i; + while (j != 0) { + bstr[--k] = bytes1(uint8(48 + j % 10)); + j /= 10; + } + str = string(bstr); + } + + function _bytesToAddress(bytes memory bys) internal pure returns (address addr) { + assembly { + addr := mload(add(bys, 32)) + } + } +} diff --git a/script/Counter.s.sol b/script/Counter.s.sol deleted file mode 100644 index cdc1fe9..0000000 --- a/script/Counter.s.sol +++ /dev/null @@ -1,19 +0,0 @@ -// SPDX-License-Identifier: UNLICENSED -pragma solidity ^0.8.13; - -import {Script, console} from "forge-std/Script.sol"; -import {Counter} from "../src/Counter.sol"; - -contract CounterScript is Script { - Counter public counter; - - function setUp() public {} - - function run() public { - vm.startBroadcast(); - - counter = new Counter(); - - vm.stopBroadcast(); - } -} diff --git a/script/UniswapV2Factory.s.sol b/script/UniswapV2Factory.s.sol new file mode 100644 index 0000000..2cc31bf --- /dev/null +++ b/script/UniswapV2Factory.s.sol @@ -0,0 +1,24 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.20; + +import {Script,console} from "forge-std/Script.sol"; +import "../src/UniswapV2Factory.sol"; + +import "./AddressFileRW.sol"; + +contract UniswapV2FactoryScript is Script { + function setUp() public {} + + function run() public { + uint256 privateKey = vm.envUint("DEPLOYMENT_PRIVATE_KEY"); + address feeToAddress = vm.envAddress("FEE_TO_ADDRESS"); + address account = vm.addr(privateKey); + + console.log("Deployment Account : ", account); + console.log("Fee to Address : ", feeToAddress); + + vm.broadcast(privateKey); + UniswapV2Factory factory = new UniswapV2Factory(feeToAddress); + console.log("\n\tFactory Address: ", address(factory)); + } +} diff --git a/script/UniswapV2Router.s.sol b/script/UniswapV2Router.s.sol new file mode 100644 index 0000000..f237aa7 --- /dev/null +++ b/script/UniswapV2Router.s.sol @@ -0,0 +1,32 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.20; + +import {console} from "forge-std/Script.sol"; +import "../src/UniswapV2Router.sol"; + +import "./AddressFileRW.sol"; + +contract UniswapV2RouterScript is AddressFileRWScript { + function setUp() public {} + + function run() public { + uint256 privateKey = vm.envUint("DEPLOYMENT_PRIVATE_KEY"); + address account = vm.addr(privateKey); + + address factoryAddress = _readFromFile("UniswapV2Factory"); + address wethAddress; + try vm.envAddress("WETH_ADDRESS") returns (address maybeWethAddress) { + wethAddress = maybeWethAddress; + } catch { + wethAddress = _readFromFile("WETH9"); + } + + console.log("Deployment Account : ", account); + console.log("WETH9 Address : ", wethAddress); + console.log("UniswapV2 Factory : ", factoryAddress); + + vm.broadcast(privateKey); + UniswapV2Router router = new UniswapV2Router(factoryAddress, wethAddress); + console.log("\n\tRouter Address: ", address(router)); + } +} diff --git a/script/WETH9.s.sol b/script/WETH9.s.sol new file mode 100644 index 0000000..32a7ac8 --- /dev/null +++ b/script/WETH9.s.sol @@ -0,0 +1,19 @@ +// SPDX-License-Identifier: MIT +pragma solidity ^0.8.20; + +import {Script,console} from "forge-std/Script.sol"; +import "../src/WETH9.sol"; + +contract WETH9Script is Script { + function setUp() public {} + + function run() public { + uint256 privateKey = vm.envUint("DEPLOYMENT_PRIVATE_KEY"); + address account = vm.addr(privateKey); + console.log("Deployment Account : ", account); + + vm.broadcast(privateKey); + WETH9 weth = new WETH9(); + console.log("\n\tWETH9 Address: ", address(weth)); + } +} diff --git a/soldeer.lock b/soldeer.lock new file mode 100644 index 0000000..f274bd0 --- /dev/null +++ b/soldeer.lock @@ -0,0 +1,13 @@ +[[dependencies]] +name = "@openzeppelin-contracts" +version = "5.3.0" +url = "https://soldeer-revisions.s3.amazonaws.com/@openzeppelin-contracts/5_3_0_10-04-2025_10:51:50_contracts.zip" +checksum = "fa2bc3db351137c4d5eb32b738a814a541b78e87fbcbfeca825e189c4c787153" +integrity = "d69addf252dfe0688dcd893a7821cbee2421f8ce53d95ca0845a59530043cfd1" + +[[dependencies]] +name = "forge-std" +version = "1.9.7" +url = "https://soldeer-revisions.s3.amazonaws.com/forge-std/1_9_7_28-04-2025_15:55:08_forge-std-1.9.zip" +checksum = "8d9e0a885fa8ee6429a4d344aeb6799119f6a94c7c4fe6f188df79b0dce294ba" +integrity = "9e60fdba82bc374df80db7f2951faff6467b9091873004a3d314cf0c084b3c7d" diff --git a/src/Counter.sol b/src/Counter.sol deleted file mode 100644 index aded799..0000000 --- a/src/Counter.sol +++ /dev/null @@ -1,14 +0,0 @@ -// SPDX-License-Identifier: UNLICENSED -pragma solidity ^0.8.13; - -contract Counter { - uint256 public number; - - function setNumber(uint256 newNumber) public { - number = newNumber; - } - - function increment() public { - number++; - } -} diff --git a/src/UniswapV2ERC20.sol b/src/UniswapV2ERC20.sol new file mode 100644 index 0000000..219e955 --- /dev/null +++ b/src/UniswapV2ERC20.sol @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import "./interfaces/IUniswapV2ERC20.sol"; + +contract UniswapV2ERC20 is IUniswapV2ERC20 { + string public constant override name = "Uniswap V2"; + string public constant override symbol = "UNI-V2"; + uint8 public constant override decimals = 18; + uint256 public override totalSupply; + mapping(address => uint256) public override balanceOf; + mapping(address => mapping(address => uint256)) public override allowance; + + bytes32 public override DOMAIN_SEPARATOR; + // keccak256("Permit(address owner,address spender,uint256 value,uint256 nonce,uint256 deadline)"); + bytes32 public constant override PERMIT_TYPEHASH = + 0x6e71edae12b1b97f4d1f60370fef10105fa2faae0126114a169c64845d6126c9; + mapping(address => uint256) public override nonces; + + constructor() { + DOMAIN_SEPARATOR = keccak256( + abi.encode( + keccak256("EIP712Domain(string name,string version,uint256 chainId,address verifyingContract)"), + keccak256(bytes(name)), + keccak256(bytes("1")), + block.chainid, + address(this) + ) + ); + } + + function _mint(address to, uint256 value) internal { + totalSupply += value; + balanceOf[to] += value; + emit Transfer(address(0), to, value); + } + + function _burn(address from, uint256 value) internal { + balanceOf[from] -= value; + totalSupply -= 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] -= value; + balanceOf[to] += value; + emit Transfer(from, to, value); + } + + function approve( + address spender, + uint256 value + ) external override returns (bool) { + _approve(msg.sender, spender, value); + return true; + } + + function transfer( + address to, + uint256 value + ) external override returns (bool) { + _transfer(msg.sender, to, value); + return true; + } + + function transferFrom( + address from, + address to, + uint256 value + ) external override returns (bool) { + if (allowance[from][msg.sender] != type(uint256).max) { + allowance[from][msg.sender] -= value; + } + _transfer(from, to, value); + return true; + } + + function permit( + address owner, + address spender, + uint256 value, + uint256 deadline, + uint8 v, + bytes32 r, + bytes32 s + ) external override { + if (deadline < block.timestamp) revert("UniswapV2: 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); + if (recoveredAddress == address(0) || recoveredAddress != owner) revert("UniswapV2: INVALID_SIGNATURE"); + _approve(owner, spender, value); + } +} diff --git a/src/UniswapV2Factory.sol b/src/UniswapV2Factory.sol new file mode 100644 index 0000000..cf335e4 --- /dev/null +++ b/src/UniswapV2Factory.sol @@ -0,0 +1,56 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import "./interfaces/IUniswapV2Factory.sol"; +import "./interfaces/IUniswapV2Pair.sol"; +import "./UniswapV2Pair.sol"; + +contract UniswapV2Factory is IUniswapV2Factory { + bytes32 public constant PAIR_HASH = keccak256(type(UniswapV2Pair).creationCode); + + address public override feeTo; + address public override feeToSetter; + + mapping(address => mapping(address => address)) public override getPair; + address[] public override allPairs; + + constructor(address _feeToSetter) { + feeToSetter = _feeToSetter; + } + + function allPairsLength() external view override returns (uint256) { + return allPairs.length; + } + + function createPair( + address tokenA, + address tokenB + ) external override returns (address pair) { + if (tokenA == tokenB) revert("UniswapV2: IDENTICAL_ADDRESSES"); + (address token0, address token1) = tokenA < tokenB ? (tokenA, tokenB) : (tokenB, tokenA); + if (token0 == address(0)) revert("UniswapV2: ZERO_ADDRESS"); + if (getPair[token0][token1] != address(0)) revert("UniswapV2: PAIR_EXISTS"); + + bytes memory bytecode = type(UniswapV2Pair).creationCode; + bytes32 salt = keccak256(abi.encodePacked(token0, token1)); + assembly { + pair := create2(0, add(bytecode, 32), mload(bytecode), salt) + } + + IUniswapV2Pair(pair).initialize(token0, token1); + getPair[token0][token1] = pair; + getPair[token1][token0] = pair; // populate mapping in the reverse direction + allPairs.push(pair); + emit PairCreated(token0, token1, pair, allPairs.length); + } + + function setFeeTo(address _feeTo) external override { + if (msg.sender != feeToSetter) revert("UniswapV2: FORBIDDEN"); + feeTo = _feeTo; + } + + function setFeeToSetter(address _feeToSetter) external override { + if (msg.sender != feeToSetter) revert("UniswapV2: FORBIDDEN"); + feeToSetter = _feeToSetter; + } +} diff --git a/src/UniswapV2Pair.sol b/src/UniswapV2Pair.sol new file mode 100644 index 0000000..043b6f8 --- /dev/null +++ b/src/UniswapV2Pair.sol @@ -0,0 +1,195 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import "./UniswapV2ERC20.sol"; + +import "./interfaces/IUniswapV2Pair.sol"; +import "./interfaces/IUniswapV2Factory.sol"; +import "./interfaces/IUniswapV2Callee.sol"; +import "./interfaces/IERC20.sol"; + +import "./libraries/Math.sol"; +import "./libraries/UQ112x112.sol"; +import "./libraries/TransferHelper.sol"; + +contract UniswapV2Pair is IUniswapV2Pair, UniswapV2ERC20 { + using UQ112x112 for uint224; + + uint256 public constant override MINIMUM_LIQUIDITY = 10 ** 3; + + address public override factory; + address public override token0; + address public override token1; + + uint112 private reserve0; // uses single storage slot, accessible via getReserves + uint112 private reserve1; // uses single storage slot, accessible via getReserves + uint32 private blockTimestampLast; // uses single storage slot, accessible via getReserves + + uint256 public override price0CumulativeLast; + uint256 public override price1CumulativeLast; + uint256 public override kLast; // reserve0 * reserve1, as of immediately after the most recent liquidity event + + uint256 private unlocked = 1; + modifier lock() { + if (unlocked == 0) revert("UniswapV2: LOCKED"); + unlocked = 0; + _; + unlocked = 1; + } + + function getReserves() + public + view + override + returns ( + uint112 _reserve0, + uint112 _reserve1, + uint32 _blockTimestampLast + ) + { + _reserve0 = reserve0; + _reserve1 = reserve1; + _blockTimestampLast = blockTimestampLast; + } + + constructor() { + factory = msg.sender; + } + + function initialize(address _token0, address _token1) external override { + if (msg.sender != factory) revert("UniswapV2: FORBIDDEN"); // sufficient check + token0 = _token0; + token1 = _token1; + } + + function _update(uint256 balance0, uint256 balance1, uint112 _reserve0, uint112 _reserve1) private { + if (balance0 > type(uint112).max || balance1 > type(uint112).max) revert("UniswapV2: OVERFLOW"); + uint32 blockTimestamp = uint32(block.timestamp % 2 ** 32); + unchecked { + uint32 timeElapsed = blockTimestamp - blockTimestampLast; // overflow is desired + if (timeElapsed > 0 && _reserve0 != 0 && _reserve1 != 0) { + price0CumulativeLast += uint256(UQ112x112.encode(_reserve1).uqdiv(_reserve0)) * timeElapsed; + price1CumulativeLast += uint256(UQ112x112.encode(_reserve0).uqdiv(_reserve1)) * timeElapsed; + } + } + reserve0 = uint112(balance0); + reserve1 = uint112(balance1); + blockTimestampLast = blockTimestamp; + emit Sync(reserve0, reserve1); + } + + function _mintFee( + uint112 _reserve0, + uint112 _reserve1 + ) private returns (bool feeOn) { + address feeTo = IUniswapV2Factory(factory).feeTo(); + feeOn = feeTo != address(0); + uint256 _kLast = kLast; // gas savings + if (feeOn) { + if (_kLast != 0) { + uint256 rootK = UniswapV2Math.sqrt(uint256(_reserve0) * _reserve1); + uint256 rootKLast = UniswapV2Math.sqrt(_kLast); + if (rootK > rootKLast) { + uint256 numerator = totalSupply * (rootK - rootKLast); + uint256 denominator = rootK * 5 + rootKLast; + uint256 liquidity = numerator / denominator; + if (liquidity > 0) _mint(feeTo, liquidity); + } + } + } else if (_kLast != 0) { + kLast = 0; + } + } + + function mint(address to) external override lock returns (uint256 liquidity) { + (uint112 _reserve0, uint112 _reserve1, ) = getReserves(); // gas savings + uint256 balance0 = IERC20(token0).balanceOf(address(this)); + uint256 balance1 = IERC20(token1).balanceOf(address(this)); + uint256 amount0 = balance0 - _reserve0; + uint256 amount1 = balance1 - _reserve1; + + bool feeOn = _mintFee(_reserve0, _reserve1); + uint256 _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee + if (_totalSupply == 0) { + liquidity = UniswapV2Math.sqrt(amount0 * amount1) - MINIMUM_LIQUIDITY; + _mint(address(0), MINIMUM_LIQUIDITY); // permanently lock the first MINIMUM_LIQUIDITY tokens + } else { + liquidity = UniswapV2Math.min(amount0 * _totalSupply / _reserve0, amount1 * _totalSupply / _reserve1); + } + if (liquidity == 0) revert("UniswapV2: INSUFFICIENT_LIQUIDITY_MINTED"); + _mint(to, liquidity); + _update(balance0, balance1, _reserve0, _reserve1); + + if (feeOn) kLast = uint256(reserve0) * reserve1; // reserve0 and reserve1 are up-to-date + emit Mint(msg.sender, amount0, amount1); + } + + function burn(address to) external override lock returns (uint256 amount0, uint256 amount1) { + (uint112 _reserve0, uint112 _reserve1, ) = getReserves(); // gas savings + address _token0 = token0; // gas savings + address _token1 = token1; // gas savings + uint256 balance0 = IERC20(_token0).balanceOf(address(this)); + uint256 balance1 = IERC20(_token1).balanceOf(address(this)); + uint256 liquidity = balanceOf[address(this)]; + + bool feeOn = _mintFee(_reserve0, _reserve1); + uint256 _totalSupply = totalSupply; // gas savings, must be defined here since totalSupply can update in _mintFee + amount0 = (liquidity * balance0) / _totalSupply; // using balances ensures pro-rata distribution + amount1 = (liquidity * balance1) / _totalSupply; // using balances ensures pro-rata distribution + if (amount0 == 0 || amount1 == 0) revert("UniswapV2: INSUFFICIENT_LIQUIDITY_BURNED"); + _burn(address(this), liquidity); + TransferHelper.safeTransfer(_token0, to, amount0); + TransferHelper.safeTransfer(_token1, to, amount1); + balance0 = IERC20(_token0).balanceOf(address(this)); + balance1 = IERC20(_token1).balanceOf(address(this)); + + _update(balance0, balance1, _reserve0, _reserve1); + if (feeOn) kLast = uint256(reserve0) * reserve1; // reserve0 and reserve1 are up-to-date + emit Burn(msg.sender, amount0, amount1, to); + } + + function swap(uint256 amount0Out, uint256 amount1Out, address to, bytes calldata data) external override lock { + if (amount0Out == 0 && amount1Out == 0) revert("UniswapV2: INSUFFICIENT_OUTPUT_AMOUNT"); + (uint112 _reserve0, uint112 _reserve1, ) = getReserves(); // gas savings + if (amount0Out >= _reserve0 || amount1Out >= _reserve1) revert("UniswapV2: INSUFFICIENT_LIQUIDITY"); + + uint256 balance0; + uint256 balance1; + { + // scope for _token{0,1}, avoids stack too deep errors + address _token0 = token0; + address _token1 = token1; + if (to == _token0 || to == _token1) revert("UniswapV2: INVALID_TO"); + if (amount0Out > 0) TransferHelper.safeTransfer(_token0, to, amount0Out); // optimistically transfer tokens + if (amount1Out > 0) TransferHelper.safeTransfer(_token1, to, amount1Out); // optimistically transfer tokens + if (data.length > 0) IUniswapV2Callee(to).uniswapV2Call(msg.sender, amount0Out, amount1Out, data); + balance0 = IERC20(_token0).balanceOf(address(this)); + balance1 = IERC20(_token1).balanceOf(address(this)); + } + uint256 amount0In = balance0 > _reserve0 - amount0Out ? balance0 - (_reserve0 - amount0Out) : 0; + uint256 amount1In = balance1 > _reserve1 - amount1Out ? balance1 - (_reserve1 - amount1Out) : 0; + if (amount0In == 0 && amount1In == 0) revert("UniswapV2: INSUFFICIENT_INPUT_AMOUNT"); + { + // scope for reserve{0,1}Adjusted, avoids stack too deep errors + uint256 balance0Adjusted = balance0 * 1000 - amount0In * 3; + uint256 balance1Adjusted = balance1 * 1000 - amount1In * 3; + if (balance0Adjusted * balance1Adjusted < uint256(_reserve0) * uint256(_reserve1) * 1e6) { + revert("UniswapV2: K"); + } + } + + _update(balance0, balance1, _reserve0, _reserve1); + emit Swap(msg.sender, amount0In, amount1In, amount0Out, amount1Out, to); + } + + function skim(address to) external override lock { + address _token0 = token0; // gas savings + address _token1 = token1; // gas savings + TransferHelper.safeTransfer(_token0, to, IERC20(_token0).balanceOf(address(this)) - reserve0); + TransferHelper.safeTransfer(_token1, to, IERC20(_token1).balanceOf(address(this)) - reserve1); + } + + function sync() external override lock { + _update(IERC20(token0).balanceOf(address(this)), IERC20(token1).balanceOf(address(this)), reserve0, reserve1); + } +} diff --git a/src/UniswapV2Router.sol b/src/UniswapV2Router.sol new file mode 100644 index 0000000..00962e8 --- /dev/null +++ b/src/UniswapV2Router.sol @@ -0,0 +1,604 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import "./interfaces/IUniswapV2Factory.sol"; +import "./interfaces/IUniswapV2Router.sol"; +import "./interfaces/IUniswapV2Pair.sol"; +import "./interfaces/IWETH.sol"; +import "./interfaces/IERC20.sol"; + +import {TransferHelper} from "./libraries/TransferHelper.sol"; +import {UniswapV2Library} from "./libraries/UniswapV2Library.sol"; + +contract UniswapV2Router is IUniswapV2Router { + //solhint-disable-next-line immutable-vars-naming + address public immutable override factory; + address public immutable override WETH; + + modifier ensure(uint256 deadline) { + if (deadline < block.timestamp) revert("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) { + if (amountBOptimal < amountBMin) revert("UniswapV2Router: INSUFFICIENT_B_AMOUNT"); + (amountA, amountB) = (amountADesired, amountBOptimal); + } else { + uint256 amountAOptimal = UniswapV2Library.quote(amountBDesired, reserveB, reserveA); + assert(amountAOptimal <= amountADesired); + if (amountAOptimal < amountAMin) revert("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); + if (amountA < amountAMin) revert("UniswapV2Router: INSUFFICIENT_A_AMOUNT"); + if (amountB < amountBMin) revert("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); + if (amounts[amounts.length - 1] < amountOutMin) + revert("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); + if (amounts[0] > amountInMax) revert("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) + { + if (path[0] != WETH) revert("UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsOut(factory, msg.value, path); + if (amounts[amounts.length - 1] < amountOutMin) revert("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) + { + if (path[path.length - 1] != WETH) revert("UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path); + if (amounts[0] > amountInMax) revert("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) + { + if (path[path.length - 1] != WETH) revert("UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsOut(factory, amountIn, path); + if (amounts[amounts.length - 1] < amountOutMin) revert("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) + { + if (path[0] != WETH) revert("UniswapV2Router: INVALID_PATH"); + amounts = UniswapV2Library.getAmountsIn(factory, amountOut, path); + if (amounts[0] > msg.value) revert("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)) - + 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); + if (IERC20(path[path.length - 1]).balanceOf(to) - balanceBefore < amountOutMin) { + revert("UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT"); + } + } + + function swapExactETHForTokensSupportingFeeOnTransferTokens( + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external payable virtual override ensure(deadline) { + if (path[0] != WETH) revert("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); + if (IERC20(path[path.length - 1]).balanceOf(to) - balanceBefore < amountOutMin) { + revert("UniswapV2Router: INSUFFICIENT_OUTPUT_AMOUNT"); + } + } + + function swapExactTokensForETHSupportingFeeOnTransferTokens( + uint256 amountIn, + uint256 amountOutMin, + address[] calldata path, + address to, + uint256 deadline + ) external virtual override ensure(deadline) { + if (path[path.length - 1] != WETH) revert("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)); + if (amountOut < amountOutMin) revert("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/WETH9.sol b/src/WETH9.sol new file mode 100644 index 0000000..bf2c70c --- /dev/null +++ b/src/WETH9.sol @@ -0,0 +1,760 @@ +// 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 . + +pragma solidity =0.8.20; + +contract WETH9 { + string public name = "Wrapped Ether"; + string public symbol = "WETH"; + uint8 public decimals = 18; + + event Approval(address indexed src, address indexed guy, uint wad); + event Transfer(address indexed src, address indexed dst, uint wad); + event Deposit(address indexed dst, uint wad); + event Withdrawal(address indexed src, uint wad); + + mapping (address => uint) public balanceOf; + mapping (address => mapping (address => uint)) public allowance; + + fallback() external payable { + deposit(); + } + receive() external payable { + deposit(); + } + function deposit() public payable { + balanceOf[msg.sender] += msg.value; + emit Deposit(msg.sender, msg.value); + } + function withdraw(uint wad) public { + require(balanceOf[msg.sender] >= wad); + balanceOf[msg.sender] -= wad; + (bool sent,) = msg.sender.call{value: wad}(""); + require(sent); + emit Withdrawal(msg.sender, wad); + } + + function totalSupply() public view returns (uint) { + return address(this).balance; + } + + function approve(address guy, uint wad) public returns (bool) { + allowance[msg.sender][guy] = wad; + emit Approval(msg.sender, guy, wad); + return true; + } + + function transfer(address dst, uint wad) public returns (bool) { + return transferFrom(msg.sender, dst, wad); + } + + function transferFrom(address src, address dst, uint 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. By contrast, +the GNU General Public License is intended to guarantee your freedom to +share and change all versions of a program--to make sure it remains free +software for all its users. We, the Free Software Foundation, use the +GNU General Public License for most of our software; it applies also to +any other work released this way by its authors. You can apply it to +your programs, too. + + When we speak of free software, we are referring to freedom, not +price. Our General Public Licenses are designed to make sure that you +have the freedom to distribute copies of free software (and charge for +them if you wish), that you receive source code or can get it if you +want it, that you can change the software or use pieces of it in new +free programs, and that you know you can do these things. + + To protect your rights, we need to prevent others from denying you +these rights or asking you to surrender the rights. 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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 +. + +*/ diff --git a/src/interfaces/IERC20.sol b/src/interfaces/IERC20.sol new file mode 100644 index 0000000..5a511d3 --- /dev/null +++ b/src/interfaces/IERC20.sol @@ -0,0 +1,26 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +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/IUniswapV2Callee.sol b/src/interfaces/IUniswapV2Callee.sol new file mode 100644 index 0000000..1c25e84 --- /dev/null +++ b/src/interfaces/IUniswapV2Callee.sol @@ -0,0 +1,11 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +interface IUniswapV2Callee { + function uniswapV2Call( + address sender, + uint256 amount0, + uint256 amount1, + bytes calldata data + ) external; +} diff --git a/src/interfaces/IUniswapV2ERC20.sol b/src/interfaces/IUniswapV2ERC20.sol new file mode 100644 index 0000000..525b3af --- /dev/null +++ b/src/interfaces/IUniswapV2ERC20.sol @@ -0,0 +1,37 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +interface IUniswapV2ERC20 { + event Approval(address indexed owner, address indexed spender, uint256 value); + event Transfer(address indexed from, address indexed to, uint256 value); + + function name() external pure returns (string memory); + function symbol() external pure returns (string memory); + function decimals() external pure 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); + + function DOMAIN_SEPARATOR() external view returns (bytes32); + function PERMIT_TYPEHASH() external pure returns (bytes32); + function nonces(address owner) external view returns (uint256); + + function permit( + address owner, + address spender, + uint256 value, + uint256 deadline, + uint8 v, + bytes32 r, + bytes32 s + ) external; +} diff --git a/src/interfaces/IUniswapV2Factory.sol b/src/interfaces/IUniswapV2Factory.sol new file mode 100644 index 0000000..62c4516 --- /dev/null +++ b/src/interfaces/IUniswapV2Factory.sol @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +interface IUniswapV2Factory { + event PairCreated(address indexed token0, address indexed token1, address pair, uint256); + + function feeTo() external view returns (address); + function feeToSetter() external view returns (address); + + function getPair(address tokenA, address tokenB) external view returns (address pair); + function allPairs(uint256) external view returns (address pair); + function allPairsLength() external view returns (uint256); + function createPair(address tokenA, address tokenB) external returns (address pair); + + function setFeeTo(address) external; + function setFeeToSetter(address) external; +} diff --git a/src/interfaces/IUniswapV2Pair.sol b/src/interfaces/IUniswapV2Pair.sol new file mode 100644 index 0000000..eaba6bf --- /dev/null +++ b/src/interfaces/IUniswapV2Pair.sol @@ -0,0 +1,46 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import "./IUniswapV2ERC20.sol"; + +interface IUniswapV2Pair is IUniswapV2ERC20 { + event Mint(address indexed sender, uint256 amount0, uint256 amount1); + event Burn(address indexed sender, uint256 amount0, uint256 amount1, address indexed to); + event Swap( + address indexed sender, + uint256 amount0In, + uint256 amount1In, + uint256 amount0Out, + uint256 amount1Out, + address indexed to + ); + event Sync(uint112 reserve0, uint112 reserve1); + + function MINIMUM_LIQUIDITY() external pure returns (uint256); + function factory() external view returns (address); + function token0() external view returns (address); + function token1() external view returns (address); + + function getReserves() + external + view + returns (uint112 reserve0, uint112 reserve1, uint32 blockTimestampLast); + + function price0CumulativeLast() external view returns (uint256); + function price1CumulativeLast() external view returns (uint256); + function kLast() external view returns (uint256); + + function mint(address to) external returns (uint256 liquidity); + function burn(address to) external returns (uint256 amount0, uint256 amount1); + + function swap( + uint256 amount0Out, + uint256 amount1Out, + address to, + bytes calldata data + ) external; + + function skim(address to) external; + function sync() external; + function initialize(address, address) external; +} diff --git a/src/interfaces/IUniswapV2Router.sol b/src/interfaces/IUniswapV2Router.sol new file mode 100644 index 0000000..e7d71e0 --- /dev/null +++ b/src/interfaces/IUniswapV2Router.sol @@ -0,0 +1,51 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import {IUniswapV2Router01} from "./IUniswapV2Router01.sol"; + +interface IUniswapV2Router 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/IUniswapV2Router01.sol b/src/interfaces/IUniswapV2Router01.sol new file mode 100644 index 0000000..ada6380 --- /dev/null +++ b/src/interfaces/IUniswapV2Router01.sol @@ -0,0 +1,151 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +interface IUniswapV2Router01 { + function factory() external view returns (address); + + function WETH() external view 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/IWETH.sol b/src/interfaces/IWETH.sol new file mode 100644 index 0000000..99ed6d6 --- /dev/null +++ b/src/interfaces/IWETH.sol @@ -0,0 +1,8 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +interface IWETH { + function deposit() external payable; + function withdraw(uint256) external; + function transfer(address to, uint256 value) external returns (bool); +} diff --git a/src/libraries/Math.sol b/src/libraries/Math.sol new file mode 100644 index 0000000..ec853c3 --- /dev/null +++ b/src/libraries/Math.sol @@ -0,0 +1,22 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +library UniswapV2Math { + function min(uint256 x, uint256 y) internal pure returns (uint256 z) { + z = x < y ? x : y; + } + + // babylonian method (https://en.wikipedia.org/wiki/Methods_of_computing_square_roots#Babylonian_method) + function sqrt(uint256 y) internal pure returns (uint256 z) { + if (y > 3) { + z = y; + uint256 x = y / 2 + 1; + while (x < z) { + z = x; + x = (y / x + x) / 2; + } + } else if (y != 0) { + z = 1; + } + } +} diff --git a/src/libraries/TransferHelper.sol b/src/libraries/TransferHelper.sol new file mode 100644 index 0000000..2b3bf3d --- /dev/null +++ b/src/libraries/TransferHelper.sol @@ -0,0 +1,44 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +library TransferHelper { + function safeApprove(address token, address to, uint256 value) internal { + // bytes4(keccak256(bytes('approve(address,uint256)'))); + (bool success, bytes memory data) = token.call( + abi.encodeWithSelector(0x095ea7b3, to, value) + ); + if (!success || (data.length > 0 && !abi.decode(data, (bool)))) { + revert("TransferHelper::safeApprove: approve failed"); + } + } + + function safeTransfer(address token, address to, uint256 value) internal { + // bytes4(keccak256(bytes('transfer(address,uint256)'))); + (bool success, bytes memory data) = token.call( + abi.encodeWithSelector(0xa9059cbb, to, value) + ); + if (!success || (data.length > 0 && !abi.decode(data, (bool)))) { + revert("TransferHelper::safeTransfer: transfer failed"); + } + } + + function safeTransferFrom( + address token, + address from, + address to, + uint256 value + ) internal { + // bytes4(keccak256(bytes('transferFrom(address,address,uint256)'))); + (bool success, bytes memory data) = token.call( + abi.encodeWithSelector(0x23b872dd, from, to, value) + ); + if (!success || (data.length > 0 && !abi.decode(data, (bool)))) { + revert("TransferHelper::transferFrom: transferFrom failed"); + } + } + + function safeTransferETH(address to, uint256 value) internal { + (bool success, ) = to.call{value: value}(new bytes(0)); + if (!success) revert("TransferHelper::safeTransferETH: ETH transfer failed"); + } +} diff --git a/src/libraries/UQ112x112.sol b/src/libraries/UQ112x112.sol new file mode 100644 index 0000000..0b76c1d --- /dev/null +++ b/src/libraries/UQ112x112.sol @@ -0,0 +1,17 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +library UQ112x112 { + //solhint-disable-next-line state-visibility + uint224 constant Q112 = 2 ** 112; + + // encode a uint112 as a UQ112x112 + function encode(uint112 y) internal pure returns (uint224 z) { + z = uint224(y) * Q112; // never overflows + } + + // divide a UQ112x112 by a uint112, returning a UQ112x112 + function uqdiv(uint224 x, uint112 y) internal pure returns (uint224 z) { + z = x / uint224(y); + } +} diff --git a/src/libraries/UniswapV2Library.sol b/src/libraries/UniswapV2Library.sol new file mode 100644 index 0000000..0f01c5d --- /dev/null +++ b/src/libraries/UniswapV2Library.sol @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import "../interfaces/IUniswapV2Pair.sol"; + +library UniswapV2Library { + // 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) { + if (tokenA == tokenB) revert("UniswapV2Library: IDENTICAL_ADDRESSES"); + (token0, token1) = tokenA < tokenB + ? (tokenA, tokenB) + : (tokenB, tokenA); + if (token0 == address(0)) revert("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( + bytes1(0xff), + factory, + keccak256(abi.encodePacked(token0, token1)), + // hex"443533a897cfad2762695078bf6ee9b78b4edcda64ec31e1c83066cee4c90a7e" // init code hash + // hex"7b5d0bf8129b1dafc6a0c5ca9822522c5c0c69ebc66d6af886ae16fa5b9db6ef" // init code hash + hex"2512d6f091a7cc78ba777ddd98c57630a8cbbf9e4afca50e51170141f5029973" // 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) { + if (amountA == 0) revert("UniswapV2Library: INSUFFICIENT_AMOUNT"); + if (reserveA == 0 || reserveB == 0) revert("UniswapV2Library: INSUFFICIENT_LIQUIDITY"); + amountB = (amountA * 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) { + if (amountIn == 0) revert("UniswapV2Library: INSUFFICIENT_INPUT_AMOUNT"); + if (reserveIn == 0 || reserveOut == 0) revert("UniswapV2Library: INSUFFICIENT_LIQUIDITY"); + uint256 amountInWithFee = amountIn * 997; + uint256 numerator = amountInWithFee * reserveOut; + uint256 denominator = reserveIn * 1000 + 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) { + if (amountOut == 0) revert("UniswapV2Library: INSUFFICIENT_OUTPUT_AMOUNT"); + if (reserveIn == 0 || reserveOut == 0) revert("UniswapV2Library: INSUFFICIENT_LIQUIDITY"); + uint256 numerator = reserveIn * amountOut * 1000; + uint256 denominator = (reserveOut - amountOut) * 997; + amountIn = numerator / denominator + 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) { + if (path.length < 2) revert("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) { + if (path.length < 2) revert("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/mock/MockERC20.sol b/src/mock/MockERC20.sol new file mode 100644 index 0000000..7428ac4 --- /dev/null +++ b/src/mock/MockERC20.sol @@ -0,0 +1,57 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +contract MockERC20 { + string public name; + string public symbol; + uint8 public decimals; + uint256 public totalSupply; + + 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; + + constructor(string memory _name, string memory _symbol, uint8 _decimals) { + name = _name; + symbol = _symbol; + decimals = _decimals; + } + + function mint(address guy, uint256 wad) public { + balanceOf[guy] += wad; + totalSupply += wad; + } + + 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; + } +} diff --git a/test/Counter.t.sol b/test/Counter.t.sol deleted file mode 100644 index 54b724f..0000000 --- a/test/Counter.t.sol +++ /dev/null @@ -1,24 +0,0 @@ -// SPDX-License-Identifier: UNLICENSED -pragma solidity ^0.8.13; - -import {Test, console} from "forge-std/Test.sol"; -import {Counter} from "../src/Counter.sol"; - -contract CounterTest is Test { - Counter public counter; - - function setUp() public { - counter = new Counter(); - counter.setNumber(0); - } - - function test_Increment() public { - counter.increment(); - assertEq(counter.number(), 1); - } - - function testFuzz_SetNumber(uint256 x) public { - counter.setNumber(x); - assertEq(counter.number(), x); - } -} diff --git a/test/UniswapV2Factory.t.sol b/test/UniswapV2Factory.t.sol new file mode 100644 index 0000000..2c4ac07 --- /dev/null +++ b/test/UniswapV2Factory.t.sol @@ -0,0 +1,86 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import {Test} from "forge-std/Test.sol"; + +import "../src/UniswapV2Factory.sol"; +import "../src/UniswapV2Pair.sol"; +import "../src/mock/MockERC20.sol"; + +import "../src/libraries/UniswapV2Library.sol"; + +contract UniswapV2FactoryTest is Test { + UniswapV2Factory public factory; + MockERC20 public token0; + MockERC20 public token1; + MockERC20 public token2; + MockERC20 public token3; + + function setUp() public { + factory = new UniswapV2Factory(address(0)); + + token0 = new MockERC20("SomeToken0", "ST0", 18); + token1 = new MockERC20("SomeToken1", "ST1", 18); + token2 = new MockERC20("SomeToken2", "ST2", 9); + token3 = new MockERC20("SomeToken3", "ST3", 6); + } + + function testCreatePair() public { + address tokenPair = factory.createPair(address(token0), address(token1)); + (address _token0, address _token1) = UniswapV2Library.sortTokens( + address(token0), + address(token1) + ); + + assertEq(factory.allPairsLength(), 1); + assertEq(factory.getPair(address(token0), address(token1)), tokenPair); + assertEq(UniswapV2Pair(tokenPair).token0(), _token0); + assertEq(UniswapV2Pair(tokenPair).token1(), _token1); + } + + function testCreatePairMultipleTokens() public { + address tokenPair0 = factory.createPair(address(token0), address(token1)); + address tokenPair1 = factory.createPair(address(token2), address(token3)); + + (address _token0, address _token1) = UniswapV2Library.sortTokens(address(token0), address(token1)); + (address _token2, address _token3) = UniswapV2Library.sortTokens(address(token2), address(token3)); + + assertEq(factory.allPairsLength(), 2); + assertEq(factory.getPair(address(token0), address(token1)), tokenPair0); + assertEq(factory.getPair(address(token2), address(token3)), tokenPair1); + assertEq(UniswapV2Pair(tokenPair0).token0(), _token0); + assertEq(UniswapV2Pair(tokenPair0).token1(), _token1); + assertEq(UniswapV2Pair(tokenPair1).token0(), _token2); + assertEq(UniswapV2Pair(tokenPair1).token1(), _token3); + } + + function testCreatePairChained() public { + address tokenPair0 = factory.createPair(address(token0), address(token1)); + address tokenPair1 = factory.createPair(address(token1), address(token2)); + address tokenPair2 = factory.createPair(address(token2), address(token3)); + + assertEq(factory.allPairsLength(), 3); + assertEq(factory.getPair(address(token0), address(token1)), tokenPair0); + assertEq(factory.getPair(address(token1), address(token2)), tokenPair1); + assertEq(factory.getPair(address(token2), address(token3)), tokenPair2); + } + + function testCreatePairIdenticalTokens() public { + vm.expectRevert(); + factory.createPair(address(token0), address(token0)); + } + + function testCreatePairInvalidToken() public { + vm.expectRevert(); + factory.createPair(address(0), address(token1)); + + vm.expectRevert(); + factory.createPair(address(token0), address(0)); + } + + function testCreatePairDuplicatePair() public { + factory.createPair(address(token0), address(token1)); + vm.expectRevert(); + factory.createPair(address(token0), address(token1)); + } +} diff --git a/test/UniswapV2Pair.t.sol b/test/UniswapV2Pair.t.sol new file mode 100644 index 0000000..bb373a8 --- /dev/null +++ b/test/UniswapV2Pair.t.sol @@ -0,0 +1,441 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import {Test} from "forge-std/Test.sol"; + +import "../src/mock/MockERC20.sol"; +import "../src/UniswapV2Pair.sol"; +import "../src/UniswapV2Factory.sol"; +import "../src/libraries/UQ112x112.sol"; + +contract MockUser { + function addLiquidity( + address pair, + address _token0, + address _token1, + uint256 _amount0, + uint256 _amount1 + ) public returns (uint256) { + MockERC20(_token0).transfer(pair, _amount0); + MockERC20(_token1).transfer(pair, _amount1); + return UniswapV2Pair(pair).mint(address(this)); + } + + function removeLiquidity(address pair, uint256 liquidity) + public + returns (uint256, uint256) + { + UniswapV2Pair(pair).transfer(pair, liquidity); + + return UniswapV2Pair(pair).burn(address(this)); + } +} + +contract TestUniswapV2Pair is Test { + MockERC20 public token0; + MockERC20 public token1; + UniswapV2Pair public pair; + UniswapV2Factory public factory; + MockUser public user; + + function setUp() public { + token0 = new MockERC20("SomeToken0", "ST0", 18); + token1 = new MockERC20("SomeToken1", "ST1", 9); + + factory = new UniswapV2Factory(address(0)); + address tokenAddress = factory.createPair(address(token0), address(token1)); + pair = UniswapV2Pair(tokenAddress); + // pair.initialize(address(token0), address(token1)); + + token0.mint(address(this), 10 ether); + token1.mint(address(this), 10 ether); + + user = new MockUser(); + token0.mint(address(user), 10 ether); + token1.mint(address(user), 10 ether); + } + + function assertBlockTimestampLast(uint256 timestamp) public view { + (, , uint32 lastBlockTimestamp) = pair.getReserves(); + assertEq(timestamp, lastBlockTimestamp); + } + + function getCurrentMarginalPrices() + public + view + returns (uint256 price0, uint256 price1) + { + (uint112 reserve0, uint112 reserve1, ) = pair.getReserves(); + + price0 = reserve0 > 0 + ? uint256(UQ112x112.encode(reserve1)) / reserve0 + : 0; + price1 = reserve1 > 0 + ? uint256(UQ112x112.encode(reserve0)) / reserve1 + : 0; + } + + function sortAmountsByTokens(uint256 amount0, uint256 amount1) public view returns (uint256, uint256) { + if (token0 < token1) { + return (amount0, amount1); + } else { + return (amount1, amount0); + } + } + + function assertCumulativePrices(uint256 price0, uint256 price1) public view { + assertEq( + price0, + pair.price0CumulativeLast(), + "unexpected cumulative price 0" + ); + assertEq( + price1, + pair.price1CumulativeLast(), + "unexpected cumulative price 1" + ); + } + + function assertPairReserves(uint256 _reserve0, uint256 _reserve1) public view { + (uint256 reserve0, uint256 reserve1,) = pair.getReserves(); + // (reserve0, reserve1) = sortAmountsByTokens(reserve0, reserve1); + assertEq(reserve0, _reserve0); + assertEq(reserve1, _reserve1); + } + + function testMintNewPair() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + + uint256 liquidity = pair.mint(address(this)); + + assertPairReserves(1 ether, 1 ether); + assertEq(pair.balanceOf(address(0)), pair.MINIMUM_LIQUIDITY()); + assertEq(pair.balanceOf(address(this)), liquidity); + assertEq(pair.totalSupply(), liquidity + pair.MINIMUM_LIQUIDITY()); + } + + function testMintWithReserve() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + uint256 l1 = pair.mint(address(this)); + + token0.transfer(address(pair), 2 ether); + token1.transfer(address(pair), 2 ether); + uint256 l2 = pair.mint(address(this)); + + assertPairReserves(3 ether, 3 ether); + assertEq(pair.balanceOf(address(this)), l1 + l2); + assertEq(pair.totalSupply(), l1 + l2 + pair.MINIMUM_LIQUIDITY()); + } + + function testMintUnequalBalance() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + uint256 l1 = pair.mint(address(this)); + + token0.transfer(address(pair), 4 ether); + token1.transfer(address(pair), 1 ether); + uint256 l2 = pair.mint(address(this)); + + assertPairReserves(2 ether, 5 ether); + assertEq(pair.balanceOf(address(this)), l1 + l2); + assertEq(pair.totalSupply(), l1 + l2 + pair.MINIMUM_LIQUIDITY()); + } + + function testMintArithmeticUnderflow() public { + // 0x11: Arithmetic over/underflow + vm.expectRevert(); + pair.mint(address(this)); + } + + function testMintInsufficientLiquidity() public { + token0.transfer(address(pair), 1000); + token1.transfer(address(pair), 1000); + + vm.expectRevert(); + pair.mint(address(this)); + } + + function testMintMultipleUsers() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + uint256 l1 = pair.mint(address(this)); + + uint256 l2 = user.addLiquidity( + address(pair), + address(token0), + address(token1), + 2 ether, + 3 ether + ); + + assertPairReserves(4 ether, 3 ether); + assertEq(pair.balanceOf(address(this)), l1); + assertEq(pair.balanceOf(address(user)), l2); + assertEq(pair.totalSupply(), l1 + l2 + pair.MINIMUM_LIQUIDITY()); + } + + function testBurn() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + uint256 liquidity = pair.mint(address(this)); + + pair.transfer(address(pair), liquidity); + pair.burn(address(this)); + + assertEq(pair.balanceOf(address(this)), 0); + assertEq(pair.totalSupply(), pair.MINIMUM_LIQUIDITY()); + assertPairReserves(pair.MINIMUM_LIQUIDITY(), pair.MINIMUM_LIQUIDITY()); + assertEq( + token0.balanceOf(address(this)), + 10 ether - pair.MINIMUM_LIQUIDITY() + ); + assertEq( + token1.balanceOf(address(this)), + 10 ether - pair.MINIMUM_LIQUIDITY() + ); + } + + function testBurnUnequal() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + uint256 l0 = pair.mint(address(this)); + + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 2 ether); + uint256 l1 = pair.mint(address(this)); + + pair.transfer(address(pair), l0 + l1); + (uint256 amount0, uint256 amount1) = pair.burn(address(this)); + (amount0, amount1) = sortAmountsByTokens(amount0, amount1); + + assertEq(pair.balanceOf(address(this)), 0); + assertEq(pair.totalSupply(), pair.MINIMUM_LIQUIDITY()); + assertEq(token0.balanceOf(address(this)), 10 ether - 2 ether + amount0); + assertEq(token1.balanceOf(address(this)), 10 ether - 3 ether + amount1); + } + + function testBurnNoLiquidity() public { + // 0x12: divide/modulo by zero + vm.expectRevert(); + pair.burn(address(this)); + } + + function testBurnInsufficientLiquidityBurned() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + pair.mint(address(this)); + + vm.expectRevert(); + pair.burn(address(this)); + } + + function testBurnMultipleUsers() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + uint256 l1 = pair.mint(address(this)); + + uint256 l2 = user.addLiquidity( + address(pair), + address(token0), + address(token1), + 2 ether, + 3 ether + ); + + pair.transfer(address(pair), l1); + (uint256 amount0, uint256 amount1) = pair.burn(address(this)); + (amount0, amount1) = sortAmountsByTokens(amount0, amount1); + + assertEq(pair.balanceOf(address(this)), 0); + assertEq(pair.balanceOf(address(user)), l2); + assertEq(pair.totalSupply(), l2 + pair.MINIMUM_LIQUIDITY()); + assertPairReserves(4 ether - amount1, 3 ether - amount0); + assertEq(token0.balanceOf(address(this)), 10 ether - 1 ether + amount0); + assertEq(token1.balanceOf(address(this)), 10 ether - 1 ether + amount1); + } + + function testBurnUnbalancedMultipleUsers() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + uint256 l1 = pair.mint(address(this)); + + uint256 l2 = user.addLiquidity( + address(pair), + address(token0), + address(token1), + 2 ether, + 3 ether + ); + + (uint256 a00, uint256 a01) = user.removeLiquidity(address(pair), l2); + (a00, a01) = sortAmountsByTokens(a00, a01); + + pair.transfer(address(pair), l1); + (uint256 a10, uint256 a11) = pair.burn(address(this)); + (a10, a11) = sortAmountsByTokens(a10, a11); + + assertEq(pair.balanceOf(address(this)), 0); + assertEq(pair.balanceOf(address(user)), 0); + assertEq(pair.totalSupply(), pair.MINIMUM_LIQUIDITY()); + + // second user penalised for unbalanced liquidity, hence reserves unbalanced + assertPairReserves( + pair.MINIMUM_LIQUIDITY() * 4 / 3 + 1, + pair.MINIMUM_LIQUIDITY() + ); + assertEq(token0.balanceOf(address(this)), 10 ether - 1 ether + a10); + assertEq(token1.balanceOf(address(this)), 10 ether - 1 ether + a11); + assertEq(token0.balanceOf(address(user)), 10 ether - 2 ether + a00); + assertEq(token1.balanceOf(address(user)), 10 ether - 3 ether + a01); + } + + function testSwap() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + pair.mint(address(this)); + + // transfer to maintain K + token1.transfer(address(pair), 1 ether); + pair.swap(0.5 ether, 0 ether, address(user), ""); + + assertPairReserves(1.5 ether, 1 ether); + assertEq(token1.balanceOf(address(user)), 10 ether + 0.5 ether); + } + + function testSwapMultipleUserLiquidity() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + pair.mint(address(this)); + + user.addLiquidity( + address(pair), + address(token0), + address(token1), + 2 ether, + 3 ether + ); + + // transfer to maintain K + token0.transfer(address(pair), 2 ether); + pair.swap(0 ether, 1 ether, address(user), ""); + assertPairReserves(4 ether, 4 ether); + } + + function testSwapUnderpriced() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + pair.mint(address(this)); + + // transfer to maintain K + token1.transfer(address(pair), 1 ether); + pair.swap(0, 0.4 ether, address(user), ""); + assertPairReserves(2 ether, 0.6 ether); + } + + function testSwapInvalidAmount() public { + vm.expectRevert(); + pair.swap(0 ether, 0 ether, address(user), ""); + } + + function testSwapInsufficientLiquidity() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + pair.mint(address(this)); + + vm.expectRevert(); + pair.swap(3 ether, 0 ether, address(user), ""); + + vm.expectRevert(); + pair.swap(0 ether, 3 ether, address(user), ""); + } + + function testSwapSwapToSelf() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + pair.mint(address(this)); + + vm.expectRevert(); + pair.swap(1 ether, 0 ether, address(token0), ""); + + vm.expectRevert(); + pair.swap(0 ether, 1 ether, address(token1), ""); + } + + function testSwapInvalidConstantProductFormula() public { + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + pair.mint(address(this)); + + vm.expectRevert(); + pair.swap(1 ether, 0 ether, address(user), ""); + + vm.expectRevert(); + pair.swap(0 ether, 1 ether, address(user), ""); + } + + function testCumulativePrices() public { + vm.warp(0); + token0.transfer(address(pair), 1 ether); + token1.transfer(address(pair), 1 ether); + pair.mint(address(this)); + + pair.sync(); + assertCumulativePrices(0, 0); + + ( + uint256 currentPrice0, + uint256 currentPrice1 + ) = getCurrentMarginalPrices(); + + vm.warp(1); + pair.sync(); + assertBlockTimestampLast(1); + assertCumulativePrices(currentPrice0, currentPrice1); + + vm.warp(2); + pair.sync(); + assertBlockTimestampLast(2); + assertCumulativePrices(currentPrice0 * 2, currentPrice1 * 2); + + vm.warp(3); + pair.sync(); + assertBlockTimestampLast(3); + assertCumulativePrices(currentPrice0 * 3, currentPrice1 * 3); + + user.addLiquidity( + address(pair), + address(token0), + address(token1), + 2 ether, + 3 ether + ); + + (uint256 newPrice0, uint256 newPrice1) = getCurrentMarginalPrices(); + + vm.warp(4); + pair.sync(); + assertBlockTimestampLast(4); + assertCumulativePrices( + currentPrice0 * 3 + newPrice0, + currentPrice1 * 3 + newPrice1 + ); + + vm.warp(5); + pair.sync(); + assertBlockTimestampLast(5); + assertCumulativePrices( + currentPrice0 * 3 + newPrice0 * 2, + currentPrice1 * 3 + newPrice1 * 2 + ); + + vm.warp(6); + pair.sync(); + assertBlockTimestampLast(6); + assertCumulativePrices( + currentPrice0 * 3 + newPrice0 * 3, + currentPrice1 * 3 + newPrice1 * 3 + ); + } +} diff --git a/test/UniswapV2Router.t.sol b/test/UniswapV2Router.t.sol new file mode 100644 index 0000000..6a6ff46 --- /dev/null +++ b/test/UniswapV2Router.t.sol @@ -0,0 +1,295 @@ +// SPDX-License-Identifier: MIT +pragma solidity =0.8.20; + +import {Test} from "forge-std/Test.sol"; + +import "../src/mock/MockERC20.sol"; +import "../src/interfaces/IERC20.sol"; + +import "../src/UniswapV2Factory.sol"; +import "../src/UniswapV2Router.sol"; +import "../src/UniswapV2Pair.sol"; +import "../src/WETH9.sol"; + +import "../src/libraries/UniswapV2Library.sol"; + +contract TestUniswapV2Router is Test { + UniswapV2Factory public factory; + UniswapV2Router public router; + + MockERC20 public token0; + MockERC20 public token1; + + WETH9 public weth; + + function setUp() public { + weth = new WETH9(); + factory = new UniswapV2Factory(address(0)); + router = new UniswapV2Router(address(factory), address(weth)); + + token0 = new MockERC20("SomeToken0", "ST0", 18); + token1 = new MockERC20("SomeToken1", "ST1", 9); + + token0.mint(address(this), 10 ether); + token1.mint(address(this), 10 ether); + } + + function testAddLiquidityPairFor() public { + token0.approve(address(router), 10 ether); + token1.approve(address(router), 10 ether); + + (address _token0, address _token1) = UniswapV2Library.sortTokens( + address(token0), + address(token1) + ); + address pair = UniswapV2Library.pairFor( + address(factory), + _token0, + _token1 + ); + + (, , uint256 liquidity) = router.addLiquidity( + address(token0), + address(token1), + 1 ether, + 1 ether, + 1 ether, + 1 ether, + address(this), + block.timestamp + 1 + ); + + assertEq(liquidity, 1 ether - UniswapV2Pair(pair).MINIMUM_LIQUIDITY()); + assertEq(factory.getPair(address(token0), address(token1)), pair); + } + + function testAddLiquidityNoPair() public { + token0.approve(address(router), 10 ether); + token1.approve(address(router), 10 ether); + + (address _token0, address _token1) = UniswapV2Library.sortTokens( + address(token0), + address(token1) + ); + + address pair = UniswapV2Library.pairFor( + address(factory), + _token0, + _token1 + ); + + (uint256 amount0, uint256 amount1, uint256 liquidity) = router.addLiquidity( + address(token0), + address(token1), + 1 ether, + 1 ether, + 1 ether, + 1 ether, + address(this), + block.timestamp + 1 + ); + + assertEq(amount0, 1 ether); + assertEq(amount1, 1 ether); + assertEq(liquidity, 1 ether - UniswapV2Pair(pair).MINIMUM_LIQUIDITY()); + + assertEq(factory.getPair(address(token0), address(token1)), pair); + assertEq(UniswapV2Pair(pair).token0(), address(token0)); + assertEq(UniswapV2Pair(pair).token1(), address(token1)); + + (uint256 reserve0, uint256 reserve1, ) = UniswapV2Pair(pair).getReserves(); + assertEq(reserve0, 1 ether); + assertEq(reserve1, 1 ether); + assertEq(token0.balanceOf(address(pair)), 1 ether); + assertEq(token1.balanceOf(address(pair)), 1 ether); + assertEq(token0.balanceOf(address(this)), 9 ether); + assertEq(token1.balanceOf(address(this)), 9 ether); + } + + function testAddLiquidityInsufficientAmountB() public { + token0.approve(address(router), 4 ether); + token1.approve(address(router), 8 ether); + + router.addLiquidity( + address(token0), + address(token1), + 4 ether, + 8 ether, + 4 ether, + 8 ether, + address(this), + block.timestamp + 1 + ); + + token0.approve(address(router), 1 ether); + token1.approve(address(router), 2 ether); + + vm.expectRevert(); + router.addLiquidity( + address(token0), + address(token1), + 1 ether, + 2 ether, + 1 ether, + 2.3 ether, + address(this), + block.timestamp + 1 + ); + } + + function testAddLiquidityAmountBDesiredHigh() public { + token0.approve(address(router), 4 ether); + token1.approve(address(router), 8 ether); + + router.addLiquidity( + address(token0), + address(token1), + 4 ether, + 8 ether, + 4 ether, + 8 ether, + address(this), + block.timestamp + 1 + ); + + token0.approve(address(router), 1 ether); + token1.approve(address(router), 2 ether); + + (uint256 amount0, uint256 amount1, ) = router.addLiquidity( + address(token0), + address(token1), + 1 ether, + 2.3 ether, + 1 ether, + 2 ether, + address(this), + block.timestamp + 1 + ); + + assertEq(amount0, 1 ether); + assertEq(amount1, 2 ether); + } + + function testAddLiquidityAmountBDesiredLow() public { + token0.approve(address(router), 4 ether); + token1.approve(address(router), 8 ether); + + router.addLiquidity( + address(token0), + address(token1), + 4 ether, + 8 ether, + 4 ether, + 8 ether, + address(this), + block.timestamp + 1 + ); + + token0.approve(address(router), 1 ether); + token1.approve(address(router), 2 ether); + + (uint256 amount0, uint256 amount1, ) = router.addLiquidity( + address(token0), + address(token1), + 1 ether, + 1.5 ether, + 0.75 ether, + 2 ether, + address(this), + block.timestamp + 1 + ); + + assertEq(amount0, 0.75 ether); + assertEq(amount1, 1.5 ether); + } + + function testAddLiquidityInsufficientAmountA() public { + token0.approve(address(router), 4 ether); + token1.approve(address(router), 8 ether); + + router.addLiquidity( + address(token0), + address(token1), + 4 ether, + 8 ether, + 4 ether, + 8 ether, + address(this), + block.timestamp + 1 + ); + + token0.approve(address(router), 1 ether); + token1.approve(address(router), 2 ether); + + vm.expectRevert(); + router.addLiquidity( + address(token0), + address(token1), + 1 ether, + 1.5 ether, + 1 ether, + 2 ether, + address(this), + block.timestamp + 1 + ); + } + + function testAddLiquidityExpired() public { + token0.approve(address(router), 1 ether); + token1.approve(address(router), 1 ether); + + vm.warp(2); + vm.expectRevert(); + router.addLiquidity( + address(token0), + address(token1), + 1 ether, + 1 ether, + 1 ether, + 1 ether, + address(this), + 1 + ); + } + + function testRemoveLiquidity() public { + token0.approve(address(router), 1 ether); + token1.approve(address(router), 1 ether); + + (uint256 amount0, uint256 amount1, uint256 liquidity) = router.addLiquidity( + address(token0), + address(token1), + 1 ether, + 1 ether, + 1 ether, + 1 ether, + address(this), + block.timestamp + 1 + ); + + uint256 prevAmount0 = token0.balanceOf(address(this)); + uint256 prevAmount1 = token1.balanceOf(address(this)); + + address pair = factory.getPair(address(token0), address(token1)); + assertEq(IERC20(pair).balanceOf(address(this)), liquidity); + IERC20(pair).approve(address(router), liquidity); + + router.removeLiquidity( + address(token0), + address(token1), + liquidity, + 0, + 0, + address(this), + block.timestamp + 1 + ); + UniswapV2Pair(pair).skim(address(this)); + + assertEq(IERC20(pair).balanceOf(address(this)), 0); + assertEq(token0.balanceOf(address(this)), prevAmount0 + amount0 - UniswapV2Pair(pair).MINIMUM_LIQUIDITY()); + assertEq(token1.balanceOf(address(this)), prevAmount1 + amount1 - UniswapV2Pair(pair).MINIMUM_LIQUIDITY()); + + assertEq(token0.balanceOf(pair), UniswapV2Pair(pair).MINIMUM_LIQUIDITY()); + assertEq(token1.balanceOf(pair), UniswapV2Pair(pair).MINIMUM_LIQUIDITY()); + } +}