implement NativeConvert.deconvert

src/NativeConverter.sol

@@ -21,6 +21,7 @@ contract NativeConverter is CommonAdminOwner {
     using SafeERC20Upgradeable for IUSDC;
 
     event Convert(address indexed from, address indexed to, uint256 amount);
+    event Deconvert(address indexed from, address indexed to, uint256 amount);
     event Migrate(uint256 amount);
 
     /// @notice the PolygonZkEVMBridge deployed on the zkEVM
@@ -106,11 +107,33 @@ contract NativeConverter is CommonAdminOwner {
         emit Convert(msg.sender, receiver, amount);
     }
 
+    function deconvert(
+        address receiver,
+        uint256 amount,
+        bytes calldata permitData
+    ) external whenNotPaused {
+        require(receiver != address(0), "INVALID_RECEIVER");
+        require(amount > 0, "INVALID_AMOUNT");
+        require(amount <= zkBWUSDC.balanceOf(address(this)), "AMOUNT_TOO_LARGE");
+
+        if (permitData.length > 0)
+            LibPermit.permit(address(zkUSDCe), amount, permitData);
+
+        // transfer native usdc from user to the converter, and burn it
+        zkUSDCe.safeTransferFrom(msg.sender, address(this), amount);
+        zkUSDCe.burn(amount);
+
+        // and then send bridge wrapped usdc to the user
+        zkBWUSDC.safeTransfer(receiver, amount);
+
+        emit Deconvert(msg.sender, receiver, amount);
+    }
+
     /// @notice Migrates L2 BridgeWrappedUSDC USDC to L1 USDC
     /// @dev Any BridgeWrappedUSDC transfered in by previous calls to
     /// `convert` will be burned and the corresponding
     /// L1 USDC will be sent to the L1Escrow via a message to the bridge
-    function migrate() external whenNotPaused {
+    function migrate() external onlyOwner whenNotPaused {
         // Anyone can call migrate() on NativeConverter to
         // have all zkBridgeWrappedUSDC withdrawn via the PolygonZkEVMBridge
         // moving the L1_USDC held in the PolygonZkEVMBridge to L1Escrow

test/Base.sol

@@ -32,6 +32,9 @@ library Events {
     // copy of NativeConverter.Convert
     event Convert(address indexed from, address indexed to, uint256 amount);
 
+    // copy of NativeConverter.Deconvert
+    event Deconvert(address indexed from, address indexed to, uint256 amount);
+
     // copy of L1Escrow.Deposit
     event Deposit(address indexed from, address indexed to, uint256 amount);
 

test/integration/ConvertFlows.t.sol

@@ -186,4 +186,38 @@ contract ConvertFlows is Base {
 
         _assertUsdcSupplyAndBalancesMatch();
     }
+
+    function testConverNativeUsdcToWrappedUsdc() public {
+        vm.selectFork(_l2Fork);
+        vm.startPrank(_alice);
+
+        // setup: alice converts wrapped to native ("seeding" the nativeconverter) and sends to bob
+        uint256 amount = _toUSDC(10000);
+        _erc20L2Wusdc.approve(address(_nativeConverter), amount);
+        _nativeConverter.convert(_bob, amount, _emptyBytes);
+        vm.stopPrank();
+
+        // deconvert
+        vm.startPrank(_bob);
+
+        // frank has no wrapped
+        uint256 wrappedBalance1 = _erc20L2Wusdc.balanceOf(_frank);
+        assertEq(wrappedBalance1, 0);
+
+        // bob converts 8k native to wrapped, with frank as the receiver
+        uint256 amount2 = _toUSDC(8000);
+        _erc20L2Usdc.approve(address(_nativeConverter), amount2);
+
+        // check that our convert event is emitted
+        vm.expectEmit(address(_nativeConverter));
+        emit Events.Deconvert(_bob, _frank, amount2);
+
+        _nativeConverter.deconvert(_frank, amount2, _emptyBytes);
+
+        // frank has 8k wrapped
+        uint256 wrappedBalance2 = _erc20L2Wusdc.balanceOf(_frank);
+        assertEq(wrappedBalance2, amount2);
+
+        _assertUsdcSupplyAndBalancesMatch();
+    }
 }