diff --git a/contracts/mocks/docs/ERC4626Fees.sol b/contracts/mocks/docs/ERC4626Fees.sol index 49c1095ab..ab1151cd7 100644 --- a/contracts/mocks/docs/ERC4626Fees.sol +++ b/contracts/mocks/docs/ERC4626Fees.sol @@ -7,36 +7,41 @@ import {ERC4626} from "../../token/ERC20/extensions/ERC4626.sol"; import {SafeERC20} from "../../token/ERC20/utils/SafeERC20.sol"; import {Math} from "../../utils/math/Math.sol"; +/// @dev ERC4626 vault with entry/exit fees expressed in https://en.wikipedia.org/wiki/Basis_point[basis point (bp)]. abstract contract ERC4626Fees is ERC4626 { using Math for uint256; - /** @dev See {IERC4626-previewDeposit}. */ + uint256 private constant _BASIS_POINT_SCALE = 1e4; + + // === Overrides === /// + + /// @dev Preview taking an entry fee on deposit. See {IERC4626-previewDeposit}. function previewDeposit(uint256 assets) public view virtual override returns (uint256) { - uint256 fee = _feeOnTotal(assets, _entryFeeBasePoint()); + uint256 fee = _feeOnTotal(assets, _entryFeeBasisPoints()); return super.previewDeposit(assets - fee); } - /** @dev See {IERC4626-previewMint}. */ + /// @dev Preview adding an entry fee on mint. See {IERC4626-previewMint}. function previewMint(uint256 shares) public view virtual override returns (uint256) { uint256 assets = super.previewMint(shares); - return assets + _feeOnRaw(assets, _entryFeeBasePoint()); + return assets + _feeOnRaw(assets, _entryFeeBasisPoints()); } - /** @dev See {IERC4626-previewWithdraw}. */ + /// @dev Preview adding an exit fee on withdraw. See {IERC4626-previewWithdraw}. function previewWithdraw(uint256 assets) public view virtual override returns (uint256) { - uint256 fee = _feeOnRaw(assets, _exitFeeBasePoint()); + uint256 fee = _feeOnRaw(assets, _exitFeeBasisPoints()); return super.previewWithdraw(assets + fee); } - /** @dev See {IERC4626-previewRedeem}. */ + /// @dev Preview taking an exit fee on redeem. See {IERC4626-previewRedeem}. function previewRedeem(uint256 shares) public view virtual override returns (uint256) { uint256 assets = super.previewRedeem(shares); - return assets - _feeOnTotal(assets, _exitFeeBasePoint()); + return assets - _feeOnTotal(assets, _exitFeeBasisPoints()); } - /** @dev See {IERC4626-_deposit}. */ + /// @dev Send entry fee to {_entryFeeRecipient}. See {IERC4626-_deposit}. function _deposit(address caller, address receiver, uint256 assets, uint256 shares) internal virtual override { - uint256 fee = _feeOnTotal(assets, _entryFeeBasePoint()); + uint256 fee = _feeOnTotal(assets, _entryFeeBasisPoints()); address recipient = _entryFeeRecipient(); super._deposit(caller, receiver, assets, shares); @@ -46,7 +51,7 @@ abstract contract ERC4626Fees is ERC4626 { } } - /** @dev See {IERC4626-_deposit}. */ + /// @dev Send exit fee to {_exitFeeRecipient}. See {IERC4626-_deposit}. function _withdraw( address caller, address receiver, @@ -54,7 +59,7 @@ abstract contract ERC4626Fees is ERC4626 { uint256 assets, uint256 shares ) internal virtual override { - uint256 fee = _feeOnRaw(assets, _exitFeeBasePoint()); + uint256 fee = _feeOnRaw(assets, _exitFeeBasisPoints()); address recipient = _exitFeeRecipient(); super._withdraw(caller, receiver, owner, assets, shares); @@ -64,27 +69,35 @@ abstract contract ERC4626Fees is ERC4626 { } } - function _entryFeeBasePoint() internal view virtual returns (uint256) { - return 0; + // === Fee configuration === /// + + function _entryFeeBasisPoints() internal view virtual returns (uint256) { + return 0; // replace with e.g. 1_000 for 1% + } + + function _exitFeeBasisPoints() internal view virtual returns (uint256) { + return 0; // replace with e.g. 1_000 for 1% } function _entryFeeRecipient() internal view virtual returns (address) { - return address(0); - } - - function _exitFeeBasePoint() internal view virtual returns (uint256) { - return 0; + return address(0); // replace with e.g. a treasury address } function _exitFeeRecipient() internal view virtual returns (address) { - return address(0); + return address(0); // replace with e.g. a treasury address } - function _feeOnRaw(uint256 assets, uint256 feeBasePoint) private pure returns (uint256) { - return assets.mulDiv(feeBasePoint, 1e5, Math.Rounding.Ceil); + // === Fee operations === /// + + /// @dev Calculates the fees that should be added to an amount `assets` that does not already include fees. + /// Used in {IERC4626-mint} and {IERC4626-withdraw} operations. + function _feeOnRaw(uint256 assets, uint256 feeBasisPoints) private pure returns (uint256) { + return assets.mulDiv(feeBasisPoints, _BASIS_POINT_SCALE, Math.Rounding.Ceil); } - function _feeOnTotal(uint256 assets, uint256 feeBasePoint) private pure returns (uint256) { - return assets.mulDiv(feeBasePoint, feeBasePoint + 1e5, Math.Rounding.Ceil); + /// @dev Calculates the fee part of an amount `assets` that already includes fees. + /// Used in {IERC4626-deposit} and {IERC4626-redeem} operations. + function _feeOnTotal(uint256 assets, uint256 feeBasisPoints) private pure returns (uint256) { + return assets.mulDiv(feeBasisPoints, feeBasisPoints + _BASIS_POINT_SCALE, Math.Rounding.Ceil); } } diff --git a/contracts/mocks/token/ERC4646FeesMock.sol b/contracts/mocks/token/ERC4646FeesMock.sol index f8fde293c..081b03a61 100644 --- a/contracts/mocks/token/ERC4646FeesMock.sol +++ b/contracts/mocks/token/ERC4646FeesMock.sol @@ -5,33 +5,33 @@ pragma solidity ^0.8.19; import {ERC4626Fees} from "../docs/ERC4626Fees.sol"; abstract contract ERC4626FeesMock is ERC4626Fees { - uint256 private immutable _entryFeeBasePointValue; + uint256 private immutable _entryFeeBasisPointValue; address private immutable _entryFeeRecipientValue; - uint256 private immutable _exitFeeBasePointValue; + uint256 private immutable _exitFeeBasisPointValue; address private immutable _exitFeeRecipientValue; constructor( - uint256 entryFeeBasePoint, + uint256 entryFeeBasisPoints, address entryFeeRecipient, - uint256 exitFeeBasePoint, + uint256 exitFeeBasisPoints, address exitFeeRecipient ) { - _entryFeeBasePointValue = entryFeeBasePoint; + _entryFeeBasisPointValue = entryFeeBasisPoints; _entryFeeRecipientValue = entryFeeRecipient; - _exitFeeBasePointValue = exitFeeBasePoint; + _exitFeeBasisPointValue = exitFeeBasisPoints; _exitFeeRecipientValue = exitFeeRecipient; } - function _entryFeeBasePoint() internal view virtual override returns (uint256) { - return _entryFeeBasePointValue; + function _entryFeeBasisPoints() internal view virtual override returns (uint256) { + return _entryFeeBasisPointValue; } function _entryFeeRecipient() internal view virtual override returns (address) { return _entryFeeRecipientValue; } - function _exitFeeBasePoint() internal view virtual override returns (uint256) { - return _exitFeeBasePointValue; + function _exitFeeBasisPoints() internal view virtual override returns (uint256) { + return _exitFeeBasisPointValue; } function _exitFeeRecipient() internal view virtual override returns (address) { diff --git a/test/token/ERC20/extensions/ERC4626.test.js b/test/token/ERC20/extensions/ERC4626.test.js index aead1d50a..499cf0628 100644 --- a/test/token/ERC20/extensions/ERC4626.test.js +++ b/test/token/ERC20/extensions/ERC4626.test.js @@ -737,9 +737,9 @@ contract('ERC4626', function (accounts) { } describe('ERC4626Fees', function () { - const feeBasePoint = web3.utils.toBN(5e3); + const feeBasisPoints = web3.utils.toBN(5e3); const valueWithoutFees = web3.utils.toBN(10000); - const fees = valueWithoutFees.mul(feeBasePoint).divn(1e5); + const fees = valueWithoutFees.mul(feeBasisPoints).divn(1e4); const valueWithFees = valueWithoutFees.add(fees); describe('input fees', function () { @@ -749,7 +749,7 @@ contract('ERC4626', function (accounts) { name + ' Vault', symbol + 'V', this.token.address, - feeBasePoint, + feeBasisPoints, other, 0, constants.ZERO_ADDRESS,