# `Vault` Exercises `Vault` is a contract that users deposit and withdraw WETH from. Authorized accounts will be able to transfer WETH in this contract into the strategy by calling `transfer`. You need to complete the implementation of the `Vault.sol` contract. ## Task 1: Implement `totalValueInToken` ```solidity function totalValueInToken() public view returns (uint256) {} ``` Return the amount of WETH in this contract plus the amount of WETH managed by the strategy. > Hint: > > - `strategy.totalValueInToken()` returns the total amount of WETH managed by the strategy. ## Task 2: Implement `deposit` ```solidity function deposit(uint256 wethAmount) external guard returns (uint256 shares) {} ``` This function will deposit WETH from `msg.sender` and mint shares. - Call the function `strategy.claim` to claim funding fees - Calculate the shares to mint and then transfer `WETH` from `msg.sender`. > Hints > > - Call `_convertToShares` to calculate the amount of shares to mint ## Task 3: Implement `withdraw` ```solidity function withdraw(uint256 shares) external payable guard returns (uint256 wethSent, bytes32 withdrawOrderKey) {} ``` This function will withdraw WETH to `msg.sender`. If not enough WETH can be withdrawn this function will create a market decrease order. - Call the function `strategy.claim` to claim funding fees - Calculate the amount of WETH to withdraw by calling `_convertToWeth` - If there are enough WETH in vault or strategy - Send the appropriate amount of WETH to `msg.sender` - Burn `shares` - Refund ETH if `msg.value` is greater than 0. - If there are not enough WETH in vault and strategy - Withdraw all of WETH from the vault and the strategy to `msg.sender` - Calculate and burn the appropriate amount of shares - Lock the rest of the shares by calling `_lock` - Make sure that `withdrawCallback` is a contract. - Call `strategy.decrease` to create a withdraw order. Send `msg.value` as execution fee. - Store `WithdrawOrder` ## Task 4: Implement `cancelWithdrawOrder` ```solidity function cancelWithdrawOrder(bytes32 key) external guard {} ``` This function allows users to cancel their withdraw order. - Check that only the user that created the withdraw order can cancel their own order. - Make sure that `withdrawCallback` is a contract. - Call `strategy.cancel` to cancel the order. ## Task 5: Implement `removeWithdrawOrder` ```solidity function removeWithdrawOrder(bytes32 key, bool ok) external auth {} ``` This function is called by `WithdrawCallback` to remove the withdraw order in 2 situations. 1. Withdraw order executed successfully. `ok` will be `true`. 2. There was an error executing the order or the order was cancelled. `ok` will be `false`. - Get the withdraw order stored in the mapping `withdrawOrders`. - Unlock the shares of the user who created the withdraw order. - If `ok` is `true`, burn the remaining shares. - Delete the withdraw order. ## Test ```shell forge test --fork-url $FORK_URL --fork-block-number $FORK_BLOCK_NUM --match-path test/app/Vault.test.sol -vvv ``` ## Integration test Test all contracts (`Vault`, `Strategy` and `WithdrawCallback`). ```shell forge test --fork-url $FORK_URL --fork-block-number $FORK_BLOCK_NUM --match-path test/app/VaultAndStrategy.test.sol -vvv ```