# Market Swap Exercises In this exercise, you'll implement a smart contract that interacts with GMX V2 to create a market swap order converting WETH to DAI. You need to complete the implementation of the `MarketSwap.sol` contract. ## Task 1: Implement the `receive` function The contract needs to be able to receive ETH when GMX refunds execution fees. Enable this contract to receive ETH. ## Task 2: Implement the `createOrder` function ```solidity // Task 2 - Create an order to swap WETH to DAI function createOrder(uint256 wethAmount) external payable returns (bytes32 key) { uint256 executionFee = 0.1 * 1e18; weth.transferFrom(msg.sender, address(this), wethAmount); // Task 2.1 - Send execution fee to the order vault // Task 2.2 - Send WETH to the order vault // Task 2.3 - Create an order to swap WETH to DAI } ``` This function should: 1. Accept WETH from the caller 2. Send an execution fee to the GMX order vault 3. Send WETH to the order vault 4. Create a market swap order to convert WETH to DAI The function is partially implemented. You need to complete tasks 2.1, 2.2, and 2.3: ### Task 2.1: Send execution fee to order vault 1. Send ETH (the execution fee) to the `ORDER_VAULT` using the function `exchangeRouter.sendWnt` 2. The execution fee is already set as 0.1 ETH ### Task 2.2: Send WETH to order vault 1. Approve the `ROUTER` to spend `WETH` 2. Use `exchangeRouter.sendTokens` to send `WETH` to the `ORDER_VAULT` ### Task 2.3: Create an order to swap WETH to DAI 1. Define the swap path that the order will take (using GM tokens `GM_TOKEN_ETH_WETH_USDC` and `GM_TOKEN_SWAP_ONLY_USDC_DAI`) 2. Call `exchangeRouter.createOrder` with the appropriate parameters 3. Return the key (order ID) that is generated > Hint: Set `initialCollateralToken` to `WETH` ## Task 3: Implement the `getOrder` function ```solidity // Task 3 - Get order function getOrder(bytes32 key) external view returns (Order.Props memory) {} ``` This function should retrieve order details from the GMX reader contract: ## Test ```shell forge test --fork-url $FORK_URL --fork-block-number $FORK_BLOCK_NUM --match-path test/MarketSwap.test.sol -vvv ```