Roll back withdraw and deposit logic

src/MetaMorpho.sol

@@ -374,6 +374,11 @@ contract MetaMorpho is ERC4626, Ownable2Step, IMetaMorpho {
     }
 
     /// @dev Used in redeem or withdraw to withdraw the underlying asset from Blue markets.
+    /// @dev When withdrawing "too much", the error logged depends on 3 cases:
+    /// 1. when withdrawing more than balance but less than vault's total assets "ERC20: burn amount exceeds balance" is
+    /// logged.
+    /// 2. when withdrawing more than vault's total assets "withdraw failed on Morpho" is logged.
+    /// 3. when withdrawing more than balance but less than liquidity "withdraw failed on Morpho" is logged.
     function _withdraw(address caller, address receiver, address owner, uint256 assets, uint256 shares)
         internal
         override

test/forge/ERC4626Test.sol

@@ -167,7 +167,7 @@ contract ERC4626Test is BaseTest {
         vault.transferFrom(ONBEHALF, RECEIVER, shares);
     }
 
-    function testWithdrawTooMuch(uint256 deposited, uint256 assets) public {
+    function testWithdrawMoreThanBalanceButLessThanTotalAssets(uint256 deposited, uint256 assets) public {
         deposited = bound(deposited, MIN_TEST_ASSETS, MAX_TEST_ASSETS);
 
         borrowableToken.setBalance(SUPPLIER, deposited);
@@ -177,6 +177,50 @@ contract ERC4626Test is BaseTest {
 
         assets = bound(assets, deposited + 1, type(uint256).max / (deposited + 10 ** DECIMALS_OFFSET));
 
+        uint256 toAdd = assets - deposited + 1;
+        borrowableToken.setBalance(SUPPLIER, toAdd);
+
+        vm.prank(SUPPLIER);
+        vault.deposit(toAdd, SUPPLIER);
+
+        vm.prank(ONBEHALF);
+        vm.expectRevert("ERC20: burn amount exceeds balance");
+        vault.withdraw(assets, RECEIVER, ONBEHALF);
+    }
+
+    function testWithdrawMoreThanTotalAssets(uint256 deposited, uint256 assets) public {
+        deposited = bound(deposited, MIN_TEST_ASSETS, MAX_TEST_ASSETS);
+
+        borrowableToken.setBalance(SUPPLIER, deposited);
+
+        vm.prank(SUPPLIER);
+        vault.deposit(deposited, ONBEHALF);
+
+        assets = bound(assets, deposited + 1, type(uint256).max / (deposited + 10 ** DECIMALS_OFFSET));
+
+        vm.prank(ONBEHALF);
+        vm.expectRevert(bytes(ErrorsLib.WITHDRAW_FAILED_MORPHO));
+        vault.withdraw(assets, RECEIVER, ONBEHALF);
+    }
+
+    function testWithdrawMoreThanBalanceButLessThanLiquidity(uint256 deposited, uint256 assets) public {
+        deposited = bound(deposited, MIN_TEST_ASSETS, MAX_TEST_ASSETS);
+
+        borrowableToken.setBalance(SUPPLIER, deposited);
+
+        vm.prank(SUPPLIER);
+        vault.deposit(deposited, ONBEHALF);
+
+        assets = bound(assets, deposited + 1, type(uint256).max / (deposited + 10 ** DECIMALS_OFFSET));
+
+        collateralToken.setBalance(BORROWER, type(uint128).max);
+
+        // Borrow liquidity.
+        vm.startPrank(BORROWER);
+        morpho.supplyCollateral(allMarkets[0], type(uint128).max, BORROWER, hex"");
+        morpho.borrow(allMarkets[0], 1, 0, BORROWER, BORROWER);
+        vm.stopPrank();
+
         vm.prank(ONBEHALF);
         vm.expectRevert(bytes(ErrorsLib.WITHDRAW_FAILED_MORPHO));
         vault.withdraw(assets, RECEIVER, ONBEHALF);