From 30979577bad3ef4cf41ac23d4f1eeee626332318 Mon Sep 17 00:00:00 2001
From: James Snewin <james.snewin@immutable.com>
Date: Wed, 22 Nov 2023 14:34:29 +1000
Subject: [PATCH] refactor deposit

---
 src/child/ChildERC20Bridge.sol         | 54 +++++++++++++++-----------
 test/unit/child/ChildERC20Bridge.t.sol |  1 +
 2 files changed, 32 insertions(+), 23 deletions(-)

diff --git a/src/child/ChildERC20Bridge.sol b/src/child/ChildERC20Bridge.sol
index 22124e0a..79287c87 100644
--- a/src/child/ChildERC20Bridge.sol
+++ b/src/child/ChildERC20Bridge.sol
@@ -129,6 +129,9 @@ contract ChildERC20Bridge is BridgeRoles, IChildERC20BridgeErrors, IChildERC20Br
         // Initialize
         clonedETHToken.initialize(NATIVE_ETH, "Ethereum", "ETH", 18);
         childETHToken = address(clonedETHToken);
+
+        // Map the supported tokens by default
+        rootTokenToChildToken[NATIVE_ETH] = childETHToken;
     }
 
     /**
@@ -436,33 +439,38 @@ contract ChildERC20Bridge is BridgeRoles, IChildERC20BridgeErrors, IChildERC20Br
             revert ZeroAddress();
         }
 
-        IChildERC20 childToken;
-        if (rootToken != rootIMXToken) {
-            if (rootToken == NATIVE_ETH) {
-                childToken = IChildERC20(childETHToken);
-            } else {
-                childToken = IChildERC20(rootTokenToChildToken[rootToken]);
-                if (address(childToken) == address(0)) {
-                    revert NotMapped();
-                }
-            }
+        _emitDepositEventAndHandleTransfer(rootToken, rootTokenToChildToken[rootToken], sender, receiver, amount);
+    }
 
-            if (address(childToken).code.length == 0) {
-                revert EmptyTokenContract();
-            }
+    function _emitDepositEventAndHandleTransfer(
+        address rootToken,
+        address childToken,
+        address sender,
+        address receiver,
+        uint256 amount
+    ) private {
+        if (rootToken == rootIMXToken) {
+            Address.sendValue(payable(receiver), amount);
+            emit IMXDeposit(rootToken, sender, receiver, amount);
+            return;
+        }
 
-            if (!childToken.mint(receiver, amount)) {
-                revert MintFailed();
-            }
+        if (childToken == address(0)) {
+            revert NotMapped();
+        }
 
-            if (rootToken == NATIVE_ETH) {
-                emit NativeEthDeposit(rootToken, address(childToken), sender, receiver, amount);
-            } else {
-                emit ChildChainERC20Deposit(rootToken, address(childToken), sender, receiver, amount);
-            }
+        if (childToken.code.length == 0) {
+            revert EmptyTokenContract();
+        }
+
+        if (!IChildERC20(childToken).mint(receiver, amount)) {
+            revert MintFailed();
+        }
+
+        if (rootToken == NATIVE_ETH) {
+            emit NativeEthDeposit(rootToken, address(childToken), sender, receiver, amount);
         } else {
-            Address.sendValue(payable(receiver), amount);
-            emit IMXDeposit(rootToken, sender, receiver, amount);
+            emit ChildChainERC20Deposit(rootToken, address(childToken), sender, receiver, amount);
         }
     }
 
diff --git a/test/unit/child/ChildERC20Bridge.t.sol b/test/unit/child/ChildERC20Bridge.t.sol
index d7d24400..a5a954b2 100644
--- a/test/unit/child/ChildERC20Bridge.t.sol
+++ b/test/unit/child/ChildERC20Bridge.t.sol
@@ -155,6 +155,7 @@ contract ChildERC20BridgeUnitTest is Test, IChildERC20BridgeEvents, IChildERC20B
         assertTrue(childBridge.hasRole(childBridge.ADAPTOR_MANAGER_ROLE(), address(this)), "adaptorManager not set");
         assertFalse(address(childBridge.childETHToken()) == address(0), "childETHToken not set");
         assertFalse(address(childBridge.childETHToken()).code.length == 0, "childETHToken contract empty");
+        assert(childBridge.rootTokenToChildToken(NATIVE_ETH) != address(0));
     }
 
     function test_RevertIfInitializeTwice() public {