chore: migrate E2E uniswapTrade test to Foundry (#222)

## Description

Migrate the uniswapTrade e2e test to foundry. Depends on
#215.

## Test Plan

CI

## Related Issues

Closes #141

test/e2e/UniswapTrade.t.sol

@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: LGPL-3.0-or-later
+pragma solidity ^0.8;
+
+import {Vm} from "forge-std/Vm.sol";
+
+import {IERC20} from "src/contracts/interfaces/IERC20.sol";
+
+import {GPv2Interaction} from "src/contracts/libraries/GPv2Interaction.sol";
+import {GPv2Order} from "src/contracts/libraries/GPv2Order.sol";
+import {GPv2Signing} from "src/contracts/mixins/GPv2Signing.sol";
+
+import {SettlementEncoder} from "../libraries/encoders/SettlementEncoder.sol";
+import {Registry, TokenRegistry} from "../libraries/encoders/TokenRegistry.sol";
+import {Helper, IERC20Mintable} from "./Helper.sol";
+
+using SettlementEncoder for SettlementEncoder.State;
+using TokenRegistry for TokenRegistry.State;
+using TokenRegistry for Registry;
+
+interface IUniswapV2Factory {
+    function createPair(address, address) external returns (address);
+}
+
+interface IUniswapV2Pair {
+    function token0() external view returns (address);
+    function mint(address) external;
+    function swap(uint256, uint256, address, bytes calldata) external;
+    function getReserves() external view returns (uint256, uint256);
+}
+
+contract UniswapTradeTest is Helper(true) {
+    IERC20Mintable dai;
+    IERC20Mintable wETH;
+
+    IUniswapV2Factory factory;
+    IUniswapV2Pair uniswapPair;
+
+    bool isWethToken0;
+
+    function setUp() public override {
+        super.setUp();
+
+        dai = deployMintableErc20("dai", "dai");
+        wETH = deployMintableErc20("wETH", "wETH");
+
+        factory = IUniswapV2Factory(0x5C69bEe701ef814a2B6a3EDD4B1652CB9cc5aA6f);
+        uniswapPair = IUniswapV2Pair(factory.createPair(address(wETH), address(dai)));
+
+        isWethToken0 = uniswapPair.token0() == address(wETH);
+    }
+
+    // Settles the following batch:
+    //
+    //   /----(1. SELL 1 wETH for dai if p(wETH) >= 500)-----\
+    //   |                                                    |
+    //   |                                                    v
+    // [dai]<---(Uniswap Pair 1000 wETH / 600.000 dai)--->[wETH]
+    //   ^                                                    |
+    //   |                                                    |
+    //   \----(2. BUY 0.5 wETH for dai if p(wETH) <= 600)----/
+    function test_should_two_overlapping_orders_and_trade_surplus_with_uniswap() external {
+        uint256 wethReserve = 1000 ether;
+        uint256 daiReserve = 600000 ether;
+        wETH.mint(address(uniswapPair), wethReserve);
+        dai.mint(address(uniswapPair), daiReserve);
+        uniswapPair.mint(address(this));
+
+        // The current batch has a sell order selling 1 wETH and a buy order buying
+        // 0.5 wETH. This means there is exactly a surplus 0.5 wETH that needs to be
+        // sold to Uniswap. Uniswap is governed by a balancing equation which can be
+        // used to compute the exact buy amount for selling the 0.5 wETH and we can
+        // use to build our the settlement with a smart contract interaction.
+        // ```
+        // (reservewETH + inwETH * 0.997) * (reservedai - outdai) = reservewETH * reservedai
+        // outdai = (reservedai * inwETH * 0.997) / (reservewETH + inwETH * 0.997)
+        //         = (reservedai * inwETH * 997) / (reservewETH * 1000 + inwETH * 997)
+        // ```
+        uint256 uniswapWethInAmount = 0.5 ether;
+        uint256 uniswapDaiOutAmount =
+            daiReserve * uniswapWethInAmount * 997 / ((wethReserve * 1000) + (uniswapWethInAmount * 997));
+
+        Vm.Wallet memory trader1 = vm.createWallet("trader1");
+        Vm.Wallet memory trader2 = vm.createWallet("trader2");
+
+        // mint some weth
+        wETH.mint(trader1.addr, 1.001 ether);
+        vm.prank(trader1.addr);
+        wETH.approve(vaultRelayer, type(uint256).max);
+
+        // place order to sell 1 wETH for min 500 dai
+        encoder.signEncodeTrade(
+            vm,
+            trader1,
+            GPv2Order.Data({
+                kind: GPv2Order.KIND_SELL,
+                partiallyFillable: false,
+                sellToken: wETH,
+                buyToken: dai,
+                sellAmount: 1 ether,
+                buyAmount: 500 ether,
+                feeAmount: 0.001 ether,
+                validTo: 0xffffffff,
+                appData: bytes32(uint256(1)),
+                sellTokenBalance: GPv2Order.BALANCE_ERC20,
+                buyTokenBalance: GPv2Order.BALANCE_ERC20,
+                receiver: GPv2Order.RECEIVER_SAME_AS_OWNER
+            }),
+            domainSeparator,
+            GPv2Signing.Scheme.Eip712,
+            0
+        );
+
+        // mint some dai
+        dai.mint(trader2.addr, 300.3 ether);
+        vm.prank(trader2.addr);
+        dai.approve(vaultRelayer, type(uint256).max);
+
+        // place order to buy 0.5 wETH for max 300 dai
+        encoder.signEncodeTrade(
+            vm,
+            trader2,
+            GPv2Order.Data({
+                kind: GPv2Order.KIND_BUY,
+                partiallyFillable: false,
+                sellToken: dai,
+                buyToken: wETH,
+                sellAmount: 300 ether,
+                buyAmount: 0.5 ether,
+                feeAmount: 0.3 ether,
+                validTo: 0xffffffff,
+                appData: bytes32(uint256(1)),
+                sellTokenBalance: GPv2Order.BALANCE_ERC20,
+                buyTokenBalance: GPv2Order.BALANCE_ERC20,
+                receiver: GPv2Order.RECEIVER_SAME_AS_OWNER
+            }),
+            domainSeparator,
+            GPv2Signing.Scheme.Eip712,
+            0
+        );
+
+        // interaction to swap the remainder on uniswap
+        encoder.addInteraction(
+            GPv2Interaction.Data({
+                target: address(wETH),
+                value: 0,
+                callData: abi.encodeCall(IERC20.transfer, (address(uniswapPair), uniswapWethInAmount))
+            }),
+            SettlementEncoder.InteractionStage.INTRA
+        );
+        (uint256 amount0Out, uint256 amount1Out) =
+            isWethToken0 ? (uint256(0), uniswapDaiOutAmount) : (uniswapDaiOutAmount, uint256(0));
+        encoder.addInteraction(
+            GPv2Interaction.Data({
+                target: address(uniswapPair),
+                value: 0,
+                callData: abi.encodeCall(IUniswapV2Pair.swap, (amount0Out, amount1Out, address(settlement), hex""))
+            }),
+            SettlementEncoder.InteractionStage.INTRA
+        );
+
+        // set token prices
+        IERC20[] memory tokens = new IERC20[](2);
+        tokens[0] = wETH;
+        tokens[1] = dai;
+        uint256[] memory prices = new uint256[](2);
+        prices[0] = uniswapDaiOutAmount;
+        prices[1] = uniswapWethInAmount;
+        encoder.tokenRegistry.tokenRegistry().setPrices(tokens, prices);
+
+        SettlementEncoder.EncodedSettlement memory encodedSettlement = encoder.encode(settlement);
+
+        vm.prank(solver);
+        settle(encodedSettlement);
+
+        assertEq(wETH.balanceOf(address(settlement)), 0.001 ether, "weth fees not as expected");
+        assertEq(dai.balanceOf(address(settlement)), 0.3 ether, "dai fees not as expected");
+
+        assertEq(wETH.balanceOf(trader1.addr), 0, "not all weth sold");
+        assertEq(dai.balanceOf(trader1.addr), uniswapDaiOutAmount * 2, "dai received not as expected");
+
+        assertEq(wETH.balanceOf(trader2.addr), 0.5 ether, "weth bought not correct amount");
+        assertEq(dai.balanceOf(trader2.addr), 300.3 ether - (uniswapDaiOutAmount + 0.3 ether));
+
+        uint256 finalWethReserve;
+        uint256 finalDaiReserve;
+
+        {
+            (uint256 token0Reserve, uint256 token1Reserve) = uniswapPair.getReserves();
+            (finalWethReserve, finalDaiReserve) =
+                isWethToken0 ? (token0Reserve, token1Reserve) : (token1Reserve, token0Reserve);
+        }
+        assertEq(finalWethReserve, wethReserve + uniswapWethInAmount, "weth reserve not as expected");
+        assertEq(finalDaiReserve, daiReserve - uniswapDaiOutAmount, "dai reserve not as expected");
+    }
+}