feat(fee): add max fee

src/MetaMorpho.sol

@@ -152,13 +152,13 @@ contract MetaMorpho is ERC4626, ERC20Permit, Ownable2Step, Multicall, IMetaMorph
     }
 
     function submitFee(uint256 newFee) external onlyOwner {
-        require(newFee <= WAD, ErrorsLib.MAX_FEE_EXCEEDED);
+        require(newFee <= MAX_FEE, ErrorsLib.MAX_FEE_EXCEEDED);
         require(newFee != fee, ErrorsLib.ALREADY_SET);
 
         if (newFee < fee || timelock == 0) {
             _setFee(newFee);
         } else {
-            // Safe "unchecked" cast because newFee <= WAD.
+            // Safe "unchecked" cast because newFee <= MAX_FEE.
             pendingFee = PendingUint192(uint192(newFee), uint64(block.timestamp));
 
             emit EventsLib.SubmitFee(newFee);
@@ -512,7 +512,7 @@ contract MetaMorpho is ERC4626, ERC20Permit, Ownable2Step, Multicall, IMetaMorph
     function _setFee(uint256 newFee) internal {
         require(newFee == 0 || feeRecipient != address(0), ErrorsLib.ZERO_FEE_RECIPIENT);
 
-        // Safe "unchecked" cast because newFee <= WAD.
+        // Safe "unchecked" cast because newFee <= MAX_FEE.
         fee = uint96(newFee);
 
         emit EventsLib.SetFee(newFee);

src/libraries/ConstantsLib.sol

@@ -14,3 +14,6 @@ uint8 constant DECIMALS_OFFSET = 6;
 /// @dev The maximum supply/withdraw queue size ensuring the cost of depositing/withdrawing from the vault fits in a
 /// block.
 uint256 constant MAX_QUEUE_SIZE = 64;
+
+/// @dev The maximum fee the vault can have (50%).
+uint256 constant MAX_FEE = 0.5e18;

test/forge/FeeTest.sol

@@ -182,7 +182,7 @@ contract FeeTest is BaseTest {
 
     function testSetFeeAccrueFee(uint256 deposited, uint256 fee, uint256 blocks) public {
         deposited = bound(deposited, MIN_TEST_ASSETS, MAX_TEST_ASSETS);
-        fee = bound(fee, 0, WAD);
+        fee = bound(fee, 0, MAX_FEE);
         blocks = _boundBlocks(blocks);
 
         vm.assume(fee != FEE);
@@ -232,8 +232,22 @@ contract FeeTest is BaseTest {
         vault.submitFee(fee);
     }
 
+    function testSubmitFeeMaxFeeExceeded(uint256 fee) public {
+        fee = bound(fee, MAX_FEE + 1, type(uint256).max);
+
+        vm.prank(OWNER);
+        vm.expectRevert(bytes(ErrorsLib.MAX_FEE_EXCEEDED));
+        vault.submitFee(fee);
+    }
+
+    function testSubmitFeeAlreadySet() public {
+        vm.prank(OWNER);
+        vm.expectRevert(bytes(ErrorsLib.ALREADY_SET));
+        vault.submitFee(FEE);
+    }
+
     function testAcceptFeeNotOwner(uint256 fee) public {
-        fee = bound(fee, FEE + 1, WAD);
+        fee = bound(fee, FEE + 1, MAX_FEE);
 
         _setTimelock(1);
 

test/forge/TimelockTest.sol

@@ -146,7 +146,7 @@ contract TimelockTest is BaseTest {
     }
 
     function testSubmitFeeIncreased(uint256 fee) public {
-        fee = bound(fee, FEE + 1, WAD);
+        fee = bound(fee, FEE + 1, MAX_FEE);
 
         vm.prank(OWNER);
         vault.submitFee(fee);
@@ -159,16 +159,8 @@ contract TimelockTest is BaseTest {
         assertEq(submittedAt, block.timestamp, "submittedAt");
     }
 
-    function testSubmitFeeIncreasedMaxFeeExceeded(uint256 fee) public {
-        fee = bound(fee, WAD + 1, type(uint256).max);
-
-        vm.prank(OWNER);
-        vm.expectRevert(bytes(ErrorsLib.MAX_FEE_EXCEEDED));
-        vault.submitFee(fee);
-    }
-
     function testAcceptFee(uint256 fee) public {
-        fee = bound(fee, FEE + 1, WAD);
+        fee = bound(fee, FEE + 1, MAX_FEE);
 
         vm.prank(OWNER);
         vault.submitFee(fee);
@@ -192,7 +184,7 @@ contract TimelockTest is BaseTest {
     }
 
     function testAcceptFeeTimelockNotElapsed(uint256 fee, uint256 elapsed) public {
-        fee = bound(fee, FEE + 1, WAD);
+        fee = bound(fee, FEE + 1, MAX_FEE);
         elapsed = bound(elapsed, 1, TIMELOCK - 1);
 
         vm.prank(OWNER);
@@ -206,7 +198,7 @@ contract TimelockTest is BaseTest {
     }
 
     function testAcceptFeeTimelockExpirationExceeded(uint256 fee, uint256 elapsed) public {
-        fee = bound(fee, FEE + 1, WAD);
+        fee = bound(fee, FEE + 1, MAX_FEE);
         elapsed = bound(elapsed, TIMELOCK + TIMELOCK_EXPIRATION + 1, type(uint64).max);
 
         vm.prank(OWNER);

test/forge/helpers/BaseTest.sol

@@ -10,7 +10,7 @@ import {MorphoLib} from "@morpho-blue/libraries/periphery/MorphoLib.sol";
 import {MorphoBalancesLib} from "@morpho-blue/libraries/periphery/MorphoBalancesLib.sol";
 
 import "src/libraries/ConstantsLib.sol";
-import "@morpho-blue/libraries/ConstantsLib.sol";
+import {ORACLE_PRICE_SCALE} from "@morpho-blue/libraries/ConstantsLib.sol";
 
 import {IrmMock} from "src/mocks/IrmMock.sol";
 import {ERC20Mock} from "src/mocks/ERC20Mock.sol";