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SeanJCaseySeanJCasey
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feat: aave v3 flash loan asset manager
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‎contracts/external-interfaces/IAaveV3FlashLoanReceiver.sol

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// SPDX-License-Identifier: GPL-3.0
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/*
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This file is part of the Enzyme Protocol.
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(c) Enzyme Foundation <security@enzyme.finance>
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For the full license information, please view the LICENSE
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file that was distributed with this source code.
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*/
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pragma solidity >=0.6.0 <0.9.0;
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/// @title IAaveV3FlashLoanReceiver interface
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/// @author Enzyme Foundation <security@enzyme.finance>
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interface IAaveV3FlashLoanReceiver {
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function executeOperation(
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address[] calldata assets,
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uint256[] calldata amounts,
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uint256[] calldata premiums,
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address initiator,
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bytes calldata params
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) external returns (bool success_);
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function ADDRESSES_PROVIDER() external view returns (address poolAddressProviderAddress_);
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function POOL() external view returns (address poolAddress_);
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}

‎contracts/external-interfaces/IAaveV3Pool.sol

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address _onBehalfOf
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) external;
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function flashLoan(
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address _receiverAddress,
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address[] calldata _assets,
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uint256[] calldata _amounts,
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uint256[] calldata _interestRateModes,
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address _onBehalfOf,
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bytes calldata _params,
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uint16 _referralCode
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) external;
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function getReserveData(address _asset) external returns (ReserveData memory reserveData_);
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function repay(address _asset, uint256 _amount, uint256 _interestRateMode, address _onBehalfOf) external;

‎contracts/persistent/smart-accounts/aave-v3-flash-loan-asset-manager/AaveV3FlashLoanAssetManagerLib.sol

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// SPDX-License-Identifier: GPL-3.0
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/*
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This file is part of the Enzyme Protocol.
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(c) Enzyme Foundation <security@enzyme.finance>
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For the full license information, please view the LICENSE
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file that was distributed with this source code.
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*/
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pragma solidity 0.8.19;
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import {Address} from "openzeppelin-solc-0.8/utils/Address.sol";
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import {IAaveV3FlashLoanReceiver} from "../../../external-interfaces/IAaveV3FlashLoanReceiver.sol";
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import {IAaveV3Pool} from "../../../external-interfaces/IAaveV3Pool.sol";
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import {IAaveV3PoolAddressProvider} from "../../../external-interfaces/IAaveV3PoolAddressProvider.sol";
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import {IERC20} from "../../../external-interfaces/IERC20.sol";
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import {WrappedSafeERC20 as SafeERC20} from "../../../utils/0.8.19/open-zeppelin/WrappedSafeERC20.sol";
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import {IAaveV3FlashLoanAssetManager} from "./IAaveV3FlashLoanAssetManager.sol";
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/// @title AaveV3FlashLoanAssetManagerLib Contract
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/// @author Enzyme Foundation <security@enzyme.finance>
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/// @notice An asset manager contract for executing flash loans on Aave V3
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/// @dev Intended as implementation contract for a proxy.
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/// Must add this contract instance as an asset manager on the intended Enzyme vault.
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contract AaveV3FlashLoanAssetManagerLib is IAaveV3FlashLoanAssetManager, IAaveV3FlashLoanReceiver {
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using SafeERC20 for IERC20;
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// `REPAYMENT_BALANCE_BUFFER`: A small tolerance for repayment balance dust, e.g., in case of rebasing tokens
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uint256 internal constant REPAYMENT_BALANCE_BUFFER = 2;
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uint16 public immutable AAVE_REFERRAL_CODE;
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address public immutable override ADDRESSES_PROVIDER;
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// `owner`: The authorized caller of this contract instance
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address internal owner;
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// `borrowedAssetsRecipient`: The address where all borrowed assets are transferred. Generally the VaultProxy.
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address internal borrowedAssetsRecipient;
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error AaveV3FlashLoanAssetManager__ExecuteOperation__BalanceExceedsRepayment(uint256 balance);
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error AaveV3FlashLoanAssetManager__ExecuteOperation__UnauthorizedCaller();
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error AaveV3FlashLoanAssetManager__ExecuteOperation__UnauthorizedInitiator();
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error AaveV3FlashLoanAssetManager__FlashLoan__Unauthorized();
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error AaveV3FlashLoanAssetManager__Init__AlreadyInitialized();
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event BorrowedAssetsRecipientSet(address borrowedAssetsRecipient);
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event OwnerSet(address owner);
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constructor(address _aavePoolAddressProviderAddress, uint16 _aaveReferralCode) {
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AAVE_REFERRAL_CODE = _aaveReferralCode;
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ADDRESSES_PROVIDER = _aavePoolAddressProviderAddress;
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}
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/// @notice Initializes the contract
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/// @param _owner The owner (authorized caller) of the contract
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/// @param _borrowedAssetsRecipient The recipient of the flash loan borrowed assets
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function init(address _owner, address _borrowedAssetsRecipient) external {
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if (getOwner() != address(0)) revert AaveV3FlashLoanAssetManager__Init__AlreadyInitialized();
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__setOwner(_owner);
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__setBorrowedAssetsRecipient(_borrowedAssetsRecipient);
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}
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/// @notice Executes a flash loan on Aave V3
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/// @param _assets The assets to borrow
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/// @param _amounts The amounts to borrow
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/// @param _encodedCalls Encoded Call[] items to execute during the flash loan
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function flashLoan(address[] calldata _assets, uint256[] calldata _amounts, bytes calldata _encodedCalls)
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external
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override
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{
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if (msg.sender != getOwner()) revert AaveV3FlashLoanAssetManager__FlashLoan__Unauthorized();
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IAaveV3Pool(POOL()).flashLoan({
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_receiverAddress: address(this),
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_assets: _assets,
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_amounts: _amounts,
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_interestRateModes: new uint256[](_assets.length), // 0 is "no open debt"
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_onBehalfOf: address(0), // unused when interest mode = 0
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_params: _encodedCalls,
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_referralCode: AAVE_REFERRAL_CODE
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});
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}
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/// @dev Helper to set `borrowedAssetsRecipient`
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function __setBorrowedAssetsRecipient(address _borrowedAssetsRecipient) internal {
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borrowedAssetsRecipient = _borrowedAssetsRecipient;
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emit BorrowedAssetsRecipientSet(_borrowedAssetsRecipient);
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}
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/// @dev Helper to set `owner`
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function __setOwner(address _owner) internal {
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owner = _owner;
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emit OwnerSet(_owner);
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}
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//==================================================================================================================
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// IAaveV3FlashLoanReceiver
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//==================================================================================================================
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/// @notice Required callback function for Aave V3 flash loans
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function executeOperation(
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address[] calldata _assets,
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uint256[] calldata _amounts,
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uint256[] calldata _premiums,
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address _initiator,
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bytes calldata _params
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) external override returns (bool success_) {
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if (_initiator != address(this)) revert AaveV3FlashLoanAssetManager__ExecuteOperation__UnauthorizedInitiator();
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address poolAddress = POOL();
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if (msg.sender != poolAddress) revert AaveV3FlashLoanAssetManager__ExecuteOperation__UnauthorizedCaller();
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// Send full balances of all borrowed assets to vault.
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// Leaving 0-balance for all assets makes calculating repayment amounts to transfer simpler,
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// and prevents griefing by sending surplus assets here.
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{
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address recipient = getBorrowedAssetsRecipient();
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for (uint256 i; i < _assets.length; i++) {
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IERC20 asset = IERC20(_assets[i]);
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asset.safeTransfer(recipient, asset.balanceOf(address(this)));
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}
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}
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// Execute calls.
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// The final `Call[]` items should transfer exact "asset + premium" amounts to this contract to repay the loan.
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{
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Call[] memory calls = abi.decode(_params, (Call[]));
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for (uint256 i; i < calls.length; i++) {
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Call memory call = calls[i];
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Address.functionCall({target: call.target, data: call.data});
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}
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}
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// Validate that this contract has no more than the exact expected amounts to repay loan + interest,
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// and grant allowances to Aave Pool to reclaim those amounts.
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// Protects against unexpected lowering of premiums.
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for (uint256 i; i < _assets.length; i++) {
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IERC20 asset = IERC20(_assets[i]);
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uint256 repaymentAmount = _amounts[i] + _premiums[i];
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uint256 balance = asset.balanceOf(address(this));
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if (balance > repaymentAmount + REPAYMENT_BALANCE_BUFFER) {
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revert AaveV3FlashLoanAssetManager__ExecuteOperation__BalanceExceedsRepayment(balance);
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}
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asset.safeApprove(poolAddress, repaymentAmount);
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}
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return true;
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}
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/// @notice Returns the Aave V3 pool
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function POOL() public view override returns (address poolAddress_) {
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return IAaveV3PoolAddressProvider(ADDRESSES_PROVIDER).getPool();
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}
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//==================================================================================================================
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// Storage getters
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//==================================================================================================================
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/// @notice Gets the recipient of the flash loan borrowed assets
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/// @return borrowedAssetsRecipient_ The recipient
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function getBorrowedAssetsRecipient() public view returns (address borrowedAssetsRecipient_) {
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return borrowedAssetsRecipient;
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}
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/// @notice Gets the owner (authorized caller) of the contract
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/// @return owner_ The owner
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function getOwner() public view returns (address owner_) {
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return owner;
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}
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}

‎contracts/persistent/smart-accounts/aave-v3-flash-loan-asset-manager/IAaveV3FlashLoanAssetManager.sol

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// SPDX-License-Identifier: GPL-3.0
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/*
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This file is part of the Enzyme Protocol.
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(c) Enzyme Foundation <security@enzyme.finance>
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For the full license information, please view the LICENSE
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file that was distributed with this source code.
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*/
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pragma solidity >=0.6.0 <0.9.0;
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/// @title IAaveV3FlashLoanAssetManager Interface
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/// @author Enzyme Foundation <security@enzyme.finance>
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interface IAaveV3FlashLoanAssetManager {
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struct Call {
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address target;
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bytes data;
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}
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function flashLoan(address[] calldata _assets, uint256[] calldata _amounts, bytes calldata _encodedCalls)
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external;
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function init(address _owner, address _vaultProxyAddress) external;
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}

‎tests/interfaces/external/IAaveV3Pool.sol

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uint256 data;
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}
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function FLASHLOAN_PREMIUM_TOTAL() external view returns (uint256 premiumInBps_);
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function getReserveData(address _asset) external view returns (ReserveData memory reserveData_);
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function getUserConfiguration(address _user)

‎tests/interfaces/interfaces.txt

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ISingleAssetRedemptionQueueLib.sol: SingleAssetRedemptionQueueLib.abi.json
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# Smart accounts
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IAaveV3FlashLoanAssetManager.sol: AaveV3FlashLoanAssetManagerLib.abi.json
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IMultiCallAccountMixin.sol: MultiCallAccountMixin.abi.json
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IMultiCallAccountMixinHarness.sol: MultiCallAccountMixinHarness.abi.json
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ISharePriceThrottledAssetManagerLib.sol: SharePriceThrottledAssetManagerLib.abi.json

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