Allow holders to burn unit tokens only on L1

src/unit/ERC20Mintable.sol

@@ -91,27 +91,9 @@ contract ERC20Mintable is IERC20Mintable, Ownable2Step, ERC20Permit {
      * @custom:security Owner-only access prevents unauthorized deflation
      */
     function burn(address from, address spender, uint256 amount) external onlyOwner {
-        _burn(from, spender, amount);
-    }
-
-    /**
-     * @notice Burns tokens from the specified address, decreasing total supply.
-     * @dev Callable by any address. Decreases both total supply and target balance.
-     *
-     * Requirements:
-     * - `from` cannot be the zero address
-     * - `from` must have sufficient balance
-     * - If caller is different from `from`, caller must have allowance for `from`'s tokens
-     *
-     * Emits:
-     * - {Burn} event with source address and amount
-     * - {Transfer} event from source address to zero address
-     *
-     * @param from Address to burn tokens from
-     * @param amount Amount of tokens to burn
-     */
-    function burn(address from, uint256 amount) external {
-        _burn(from, _msgSender(), amount);
+        _burn(from, amount);
+        if (from != spender) _spendAllowance(from, spender, amount);
+        emit Burn(from, amount);
     }
 
     /**
@@ -125,16 +107,4 @@ contract ERC20Mintable is IERC20Mintable, Ownable2Step, ERC20Permit {
     function renounceOwnership() public pure override {
         revert RenounceOwnershipDisabled();
     }
-
-    /**
-     * @dev Internal function to burn tokens, handling allowance checks if necessary.
-     * @param from Address to burn tokens from
-     * @param spender Address initiating the burn (for allowance checks if different from `from`)
-     * @param amount Amount of tokens to burn
-     */
-    function _burn(address from, address spender, uint256 amount) internal {
-        _burn(from, amount);
-        if (from != spender) _spendAllowance(from, spender, amount);
-        emit Burn(from, amount);
-    }
 }

src/unit/GenericUnit.sol

@@ -31,6 +31,28 @@ contract GenericUnit is IGenericShare, ERC20Mintable {
         ERC20Mintable(controller, name, symbol)
     { }
 
+    /**
+     * @notice Burns tokens from the specified address, decreasing total supply.
+     * @dev Callable by any address. Decreases both total supply and target balance.
+     *
+     * Requirements:
+     * - `from` cannot be the zero address
+     * - `from` must have sufficient balance
+     * - If caller is different from `from`, caller must have allowance for `from`'s tokens
+     *
+     * Emits:
+     * - {Burn} event with source address and amount
+     * - {Transfer} event from source address to zero address
+     *
+     * @param from Address to burn tokens from
+     * @param amount Amount of tokens to burn
+     */
+    function burn(address from, uint256 amount) external {
+        _burn(from, amount);
+        if (from != _msgSender()) _spendAllowance(from, _msgSender(), amount);
+        emit Burn(from, amount);
+    }
+
     /**
      * @notice Returns the address of the Vault for the given asset.
      * @dev Vault changes do not emit VaultChange event as this is handled by the Controller.

tests/unit/unit/ERC20Mintable.t.sol

@@ -54,7 +54,7 @@ contract ERC20Mintable_Mint_Test is ERC20MintableTest {
     }
 }
 
-contract ERC20Mintable_BurnOnlyOwner_Test is ERC20MintableTest {
+contract ERC20Mintable_Burn_Test is ERC20MintableTest {
     address from = makeAddr("from");
     address spender = from;
     uint256 initialBalance = 100 ether;
@@ -136,79 +136,6 @@ contract ERC20Mintable_BurnOnlyOwner_Test is ERC20MintableTest {
     }
 }
 
-contract ERC20Mintable_Burn_Test is ERC20MintableTest {
-    address from = makeAddr("from");
-    uint256 initialBalance = 100 ether;
-
-    function setUp() public override {
-        super.setUp();
-
-        vm.prank(owner);
-        token.mint(from, initialBalance);
-    }
-
-    function testFuzz_shouldBurn(uint256 amount) public {
-        amount = bound(amount, 0, initialBalance);
-
-        vm.prank(from);
-        token.burn(from, amount);
-
-        assertEq(token.totalSupply(), initialBalance - amount);
-        assertEq(token.balanceOf(from), initialBalance - amount);
-    }
-
-    function test_shouldSpendAllowance() public {
-        uint256 amount = initialBalance / 2;
-        address spender = makeAddr("spender");
-
-        vm.prank(from);
-        token.approve(spender, amount);
-
-        vm.prank(spender);
-        token.burn(from, amount);
-
-        assertEq(token.totalSupply(), initialBalance - amount);
-        assertEq(token.balanceOf(from), initialBalance - amount);
-        assertEq(token.allowance(from, spender), 0);
-    }
-
-    function testFuzz_shouldEmit_Burn(uint256 amount) public {
-        amount = bound(amount, 0, initialBalance);
-
-        vm.expectEmit();
-        emit IERC20Mintable.Burn(from, amount);
-
-        vm.prank(from);
-        token.burn(from, amount);
-    }
-
-    function test_shouldRevert_whenFromZero() public {
-        vm.prank(from);
-        vm.expectRevert(abi.encodeWithSelector(IERC20Errors.ERC20InvalidSender.selector, address(0)));
-        token.burn(address(0), 1);
-    }
-
-    function testFuzz_shouldRevert_whenInsufficientBalance(uint256 amount) public {
-        amount = bound(amount, initialBalance + 1, type(uint256).max);
-
-        vm.prank(from);
-        vm.expectRevert(
-            abi.encodeWithSelector(IERC20Errors.ERC20InsufficientBalance.selector, from, initialBalance, amount)
-        );
-        token.burn(from, amount);
-    }
-
-    function test_shouldRevert_whenSpenderNotApproved() public {
-        address spender = makeAddr("spender");
-
-        vm.expectRevert(
-            abi.encodeWithSelector(IERC20Errors.ERC20InsufficientAllowance.selector, spender, 0, initialBalance)
-        );
-        vm.prank(spender);
-        token.burn(from, initialBalance);
-    }
-}
-
 contract ERC20Mintable_RenounceOwnership_Test is ERC20MintableTest {
     function test_shouldRevert_whenRenounceOwnership_whenOwner() public {
         vm.prank(owner);

tests/unit/unit/GenericUnit.t.sol

@@ -4,8 +4,10 @@ pragma solidity 0.8.29;
 import { Test } from "forge-std/Test.sol";
 
 import { Ownable } from "@openzeppelin/contracts/access/Ownable.sol";
+import { IERC20Errors } from "@openzeppelin/contracts/interfaces/draft-IERC6093.sol";
 
 import { GenericUnit, IController } from "../../../src/unit/GenericUnit.sol";
+import { IERC20Mintable } from "../../../src/interfaces/IERC20Mintable.sol";
 
 abstract contract GenericUnitTest is Test {
     GenericUnit unit;
@@ -35,6 +37,79 @@ contract GenericUnit_Constructor_Test is GenericUnitTest {
     }
 }
 
+contract GenericUnit_Burn_Test is GenericUnitTest {
+    address from = makeAddr("from");
+    uint256 initialBalance = 100 ether;
+
+    function setUp() public override {
+        super.setUp();
+
+        vm.prank(owner);
+        unit.mint(from, initialBalance);
+    }
+
+    function testFuzz_shouldBurn(uint256 amount) public {
+        amount = bound(amount, 0, initialBalance);
+
+        vm.prank(from);
+        unit.burn(from, amount);
+
+        assertEq(unit.totalSupply(), initialBalance - amount);
+        assertEq(unit.balanceOf(from), initialBalance - amount);
+    }
+
+    function test_shouldSpendAllowance() public {
+        uint256 amount = initialBalance / 2;
+        address spender = makeAddr("spender");
+
+        vm.prank(from);
+        unit.approve(spender, amount);
+
+        vm.prank(spender);
+        unit.burn(from, amount);
+
+        assertEq(unit.totalSupply(), initialBalance - amount);
+        assertEq(unit.balanceOf(from), initialBalance - amount);
+        assertEq(unit.allowance(from, spender), 0);
+    }
+
+    function testFuzz_shouldEmit_Burn(uint256 amount) public {
+        amount = bound(amount, 0, initialBalance);
+
+        vm.expectEmit();
+        emit IERC20Mintable.Burn(from, amount);
+
+        vm.prank(from);
+        unit.burn(from, amount);
+    }
+
+    function test_shouldRevert_whenFromZero() public {
+        vm.prank(from);
+        vm.expectRevert(abi.encodeWithSelector(IERC20Errors.ERC20InvalidSender.selector, address(0)));
+        unit.burn(address(0), 1);
+    }
+
+    function testFuzz_shouldRevert_whenInsufficientBalance(uint256 amount) public {
+        amount = bound(amount, initialBalance + 1, type(uint256).max);
+
+        vm.prank(from);
+        vm.expectRevert(
+            abi.encodeWithSelector(IERC20Errors.ERC20InsufficientBalance.selector, from, initialBalance, amount)
+        );
+        unit.burn(from, amount);
+    }
+
+    function test_shouldRevert_whenSpenderNotApproved() public {
+        address spender = makeAddr("spender");
+
+        vm.expectRevert(
+            abi.encodeWithSelector(IERC20Errors.ERC20InsufficientAllowance.selector, spender, 0, initialBalance)
+        );
+        vm.prank(spender);
+        unit.burn(from, initialBalance);
+    }
+}
+
 contract GenericUnit_Vault_Test is GenericUnitTest {
     function setUp() public override {
         super.setUp();