Use IERC7399

.gitmodules

@@ -12,6 +12,6 @@
 [submodule "lib/erc3156"]
 	path = lib/erc3156
 	url = https://github.com/alcueca/erc3156
-[submodule "lib/erc3156pp"]
-	path = lib/erc3156pp
-	url = https://github.com/alcueca/erc3156pp
+[submodule "lib/erc7399"]
+	path = lib/erc7399
+	url = https://github.com/alcueca/erc7399

remappings.txt

@@ -1,2 +1,4 @@
 @prb/test/=lib/prb-test/src/
 forge-std/=lib/forge-std/src/
+erc7399/=lib/erc7399/src/
+solmate/=lib/solmate/src/

src/BaseWrapper.sol

@@ -2,30 +2,29 @@
 // Thanks to ultrasecr.eth
 pragma solidity ^0.8.0;
 
-import { IERC3156PPFlashLender } from "lib/erc3156pp/src/interfaces/IERC3156PPFlashLender.sol";
-import { IERC20 } from "lib/erc3156pp/src/interfaces/IERC20.sol";
+import "erc7399/IERC7399.sol";
 
-import { TransferHelper } from "./utils/TransferHelper.sol";
+import { TransferHelper, ERC20 } from "./utils/TransferHelper.sol";
 
-abstract contract BaseWrapper is IERC3156PPFlashLender {
-    using TransferHelper for IERC20;
+abstract contract BaseWrapper is IERC7399 {
+    using TransferHelper for address;
 
     struct Data {
         address loanReceiver;
         address initiator;
-        function(address, address, IERC20, uint256, uint256, bytes memory) external returns (bytes memory) callback;
+        function(address, address, address, uint256, uint256, bytes memory) external returns (bytes memory) callback;
         bytes initiatorData;
     }
 
     bytes internal _callbackResult;
 
-    /// @inheritdoc IERC3156PPFlashLender
-    function flashLoan(
+    /// @inheritdoc IERC7399
+    function flash(
         address loanReceiver,
-        IERC20 asset,
+        address asset,
         uint256 amount,
         bytes calldata initiatorData,
-        function(address, address, IERC20, uint256, uint256, bytes memory) external returns (bytes memory) callback
+        function(address, address, address, uint256, uint256, bytes memory) external returns (bytes memory) callback
     )
         external
         returns (bytes memory result)
@@ -48,15 +47,15 @@
     }
 
     /// @dev Call the flashloan function in the child contract
-    function _flashLoan(IERC20 asset, uint256 amount, bytes memory params) internal virtual;
+    function _flashLoan(address asset, uint256 amount, bytes memory params) internal virtual;
 
     /// @dev Handle the common parts of bridging the callback
-    function bridgeToCallback(IERC20 asset, uint256 amount, uint256 fee, bytes memory params) internal {
+    function bridgeToCallback(address asset, uint256 amount, uint256 fee, bytes memory params) internal {
         Data memory data = abi.decode(params, (Data));
         _transferAssets(asset, amount, data.loanReceiver);
 
         // call the callback and tell the callback receiver to repay the loan to this contract
-        bytes memory result = data.callback(data.initiator, _repayTo(), IERC20(asset), amount, fee, data.initiatorData);
+        bytes memory result = data.callback(data.initiator, _repayTo(), address(asset), amount, fee, data.initiatorData);
 
         _approveRepayment(asset, amount, fee);
 
@@ -68,15 +67,15 @@
 
     /// @dev Transfer the assets to the loan receiver.
     /// Override it if the provider can send the funds directly
-    function _transferAssets(IERC20 asset, uint256 amount, address loanReceiver) internal virtual {
+    function _transferAssets(address asset, uint256 amount, address loanReceiver) internal virtual {
         asset.safeTransfer(loanReceiver, amount);
     }
 
     /// @dev Approve the repayment of the loan to the provider if needed.
     /// Override it if the provider can receive the funds directly and you want to avoid the if condition
-    function _approveRepayment(IERC20 asset, uint256 amount, uint256 fee) internal virtual {
+    function _approveRepayment(address asset, uint256 amount, uint256 fee) internal virtual {
         if (_repayTo() == address(this)) {
-            asset.approve(msg.sender, amount + fee);
+            ERC20(asset).approve(msg.sender, amount + fee);
         }
     }
 

src/aave/AaveWrapper.sol

@@ -1,6 +1,6 @@
 // SPDX-License-Identifier: MIT
 // Thanks to ultrasecr.eth
 pragma solidity ^0.8.0;
 
 import { IPool } from "./interfaces/IPool.sol";
 import { DataTypes } from "./interfaces/DataTypes.sol";
@@ -8,49 +8,41 @@
 import { IPoolAddressesProvider } from "./interfaces/IPoolAddressesProvider.sol";
 import { IFlashLoanSimpleReceiver } from "./interfaces/IFlashLoanSimpleReceiver.sol";
 
-import { IERC20 } from "lib/erc3156pp/src/interfaces/IERC20.sol";
 import { FixedPointMathLib } from "lib/solmate/src/utils/FixedPointMathLib.sol";
 
-import { BaseWrapper } from "../BaseWrapper.sol";
+import { BaseWrapper, IERC7399, ERC20 } from "../BaseWrapper.sol";
 
 contract AaveWrapper is BaseWrapper, IFlashLoanSimpleReceiver {
     using FixedPointMathLib for uint256;
     using ReserveConfiguration for DataTypes.ReserveConfigurationMap;
 
     IPoolAddressesProvider public immutable ADDRESSES_PROVIDER;
-    IPool public POOL;
+    IPool public immutable POOL;
 
     constructor(IPoolAddressesProvider provider) {
         ADDRESSES_PROVIDER = provider;
         POOL = IPool(provider.getPool());
     }
 
-    function updatePool() external {
-        POOL = IPool(ADDRESSES_PROVIDER.getPool());
-    }
-
-    /**
-     * @dev From ERC-3156. The fee to be charged for a given loan.
-     * @param asset The loan currency.
-     * @param amount The amount of assets lent.
-     * @return fee The amount of `asset` to be charged for the loan, on top of the returned principal.
-     * type(uint256).max if the loan is not possible.
-     */
-    function flashFee(IERC20 asset, uint256 amount) external view returns (uint256 fee) {
-        DataTypes.ReserveData memory reserve = POOL.getReserveData(address(asset));
+    /// @inheritdoc IERC7399
+    function maxFlashLoan(address asset) external view returns (uint256 max) {
+        DataTypes.ReserveData memory reserve = POOL.getReserveData(asset);
         DataTypes.ReserveConfigurationMap memory configuration = reserve.configuration;
 
-        if (
-            !configuration.getPaused() && configuration.getActive() && configuration.getFlashLoanEnabled()
-                && amount < asset.balanceOf(reserve.aTokenAddress)
-        ) fee = amount.mulWadUp(POOL.FLASHLOAN_PREMIUM_TOTAL() * 0.0001e18);
-        else fee = type(uint256).max;
+        max = !configuration.getPaused() && configuration.getActive() && configuration.getFlashLoanEnabled()
+            ? ERC20(asset).balanceOf(reserve.aTokenAddress)
+            : 0;
+    }
+
+    /// @inheritdoc IERC7399
+    function flashFee(address, uint256 amount) external view returns (uint256) {
+        return amount.mulWadUp(POOL.FLASHLOAN_PREMIUM_TOTAL() * 0.0001e18);
     }
 
-    function _flashLoan(IERC20 asset, uint256 amount, bytes memory data) internal override {
+    function _flashLoan(address asset, uint256 amount, bytes memory data) internal override {
         POOL.flashLoanSimple({
             receiverAddress: address(this),
-            asset: address(asset),
+            asset: asset,
             amount: amount,
             params: data,
             referralCode: 0
@@ -70,9 +62,9 @@
         returns (bool)
     {
         require(msg.sender == address(POOL), "AaveFlashLoanProvider: not pool");
         require(initiator == address(this), "AaveFlashLoanProvider: not initiator");
 
-        bridgeToCallback(IERC20(asset), amount, fee, params);
+        bridgeToCallback(asset, amount, fee, params);
 
         return true;
     }

src/balancer/BalancerWrapper.sol

@@ -8,9 +8,8 @@
 import { Arrays } from "../utils/Arrays.sol";
 
 import { FixedPointMathLib } from "lib/solmate/src/utils/FixedPointMathLib.sol";
-import { IERC20 } from "lib/erc3156pp/src/interfaces/IERC20.sol";
 
-import { BaseWrapper } from "../BaseWrapper.sol";
+import { BaseWrapper, IERC7399, ERC20 } from "../BaseWrapper.sol";
 
 contract BalancerWrapper is BaseWrapper, IFlashLoanRecipient {
     using Arrays for uint256;
@@ -25,21 +24,19 @@
         balancer = _balancer;
     }
 
-    /**
-     * @dev From ERC-3156. The fee to be charged for a given loan.
-     * @param asset The loan currency.
-     * @param amount The amount of assets lent.
-     * @return fee The amount of `asset` to be charged for the loan, on top of the returned principal.
-     * type(uint256).max if the loan is not possible.
-     */
-    function flashFee(IERC20 asset, uint256 amount) external view returns (uint256 fee) {
-        if (amount >= asset.balanceOf(address(balancer))) fee = type(uint256).max;
-        else fee = amount.mulWadUp(balancer.getProtocolFeesCollector().getFlashLoanFeePercentage());
+    /// @inheritdoc IERC7399
+    function maxFlashLoan(address asset) external view returns (uint256) {
+        return ERC20(asset).balanceOf(address(balancer));
     }
 
-    function _flashLoan(IERC20 asset, uint256 amount, bytes memory data) internal override {
+    /// @inheritdoc IERC7399
+    function flashFee(address, uint256 amount) external view returns (uint256) {
+        return amount.mulWadUp(balancer.getProtocolFeesCollector().getFlashLoanFeePercentage());
+    }
+
+    function _flashLoan(address asset, uint256 amount, bytes memory data) internal override {
         flashLoanDataHash = keccak256(data);
-        balancer.flashLoan(this, address(asset).toArray(), amount.toArray(), data);
+        balancer.flashLoan(this, asset.toArray(), amount.toArray(), data);
     }
 
     /// @inheritdoc IFlashLoanRecipient
@@ -53,10 +50,10 @@
         override
     {
         require(msg.sender == address(balancer), "BalancerWrapper: not balancer");
         require(keccak256(params) == flashLoanDataHash, "BalancerWrapper: params hash mismatch");
         delete flashLoanDataHash;
 
-        bridgeToCallback(IERC20(assets[0]), amounts[0], fees[0], params);
+        bridgeToCallback(assets[0], amounts[0], fees[0], params);
     }
 
     function _repayTo() internal view override returns (address) {

src/erc3156/ERC3156Wrapper.sol

@@ -4,9 +4,7 @@
 import { IERC3156FlashLender } from "lib/erc3156/contracts/interfaces/IERC3156FlashLender.sol";
 import { IERC3156FlashBorrower } from "lib/erc3156/contracts/interfaces/IERC3156FlashBorrower.sol";
 
-import { IERC20 } from "lib/erc3156pp/src/interfaces/IERC20.sol";
-
-import { BaseWrapper } from "../BaseWrapper.sol";
+import { BaseWrapper, IERC7399 } from "../BaseWrapper.sol";
 
 /**
  * @author Alberto Cuesta Cañada
@@ -15,34 +13,34 @@
 contract ERC3156Wrapper is BaseWrapper, IERC3156FlashBorrower {
     bytes32 public constant CALLBACK_SUCCESS = keccak256("ERC3156FlashBorrower.onFlashLoan");
 
-    mapping(IERC20 => IERC3156FlashLender) public lenders;
+    mapping(address => IERC3156FlashLender) public lenders;
 
     /**
      * @param assets_ Asset contracts supported for flash lending.
      * @param lenders_ The flash lenders that will be used for each asset.
      */
-    constructor(IERC20[] memory assets_, IERC3156FlashLender[] memory lenders_) {
+    constructor(address[] memory assets_, IERC3156FlashLender[] memory lenders_) {
         require(assets_.length == lenders_.length, "Arrays must be the same length");
         for (uint256 i = 0; i < assets_.length; i++) {
             lenders[assets_[i]] = IERC3156FlashLender(address(lenders_[i]));
         }
     }
 
-    /**
-     * @dev From ERC-3156. The fee to be charged for a given loan.
-     * @param asset The loan currency.
-     * @param amount The amount of assets lent.
-     * @return The amount of `asset` to be charged for the loan, on top of the returned principal.
-     * type(uint256).max if the loan is not possible.
-     */
-    function flashFee(IERC20 asset, uint256 amount) external view returns (uint256) {
+    /// @inheritdoc IERC7399
+    function maxFlashLoan(address asset) external view returns (uint256) {
+        IERC3156FlashLender lender = lenders[asset];
+        require(address(lender) != address(0), "Unsupported currency");
+        return lender.maxFlashLoan(asset);
+    }
+
+    /// @inheritdoc IERC7399
+    function flashFee(address asset, uint256 amount) external view returns (uint256) {
         IERC3156FlashLender lender = lenders[asset];
         require(address(lender) != address(0), "Unsupported currency");
-        if (lender.maxFlashLoan(address(asset)) < amount) return type(uint256).max;
-        else return lender.flashFee(address(asset), amount);
+        return lender.flashFee(asset, amount);
     }
 
-    function _flashLoan(IERC20 asset, uint256 amount, bytes memory data) internal override {
+    function _flashLoan(address asset, uint256 amount, bytes memory data) internal override {
         IERC3156FlashLender lender = lenders[asset];
         require(address(lender) != address(0), "Unsupported currency");
 
@@ -62,9 +60,9 @@
         returns (bytes32)
     {
         require(erc3156initiator == address(this), "External loan initiator");
-        require(msg.sender == address(lenders[IERC20(asset)]), "Unknown lender");
+        require(msg.sender == address(lenders[asset]), "Unknown lender");
 
-        bridgeToCallback(IERC20(asset), amount, fee, params);
+        bridgeToCallback(asset, amount, fee, params);
 
         return CALLBACK_SUCCESS;
     }