optional custom erc20 support

app/ibc-hooks/common_test.go

@@ -311,6 +311,7 @@ func _createTestInput(
 	)
 	evmParams := evmtypes.DefaultParams()
 	require.NoError(t, evmKeeper.Params.Set(ctx, evmParams))
+	require.NoError(t, evmKeeper.Initialize(ctx))
 
 	// set erc20 keeper
 	*erc20Keeper = *evmKeeper.ERC20Keeper().(*evmkeeper.ERC20Keeper)

proto/minievm/evm/v1/types.proto

@@ -21,6 +21,16 @@ message Params {
   // and an empty list is interpreted as allowing anyone to distribute.
   repeated string allowed_publishers = 2
       [(gogoproto.moretags) = "yaml:\"allowed_publishers\"", (amino.dont_omitempty) = true];
+
+  // allow_custom_erc20 defines whether the chain allows custom erc20 tokens
+  // to be registered on cosmos bank interface.
+  bool            allow_custom_erc20    = 3 [(gogoproto.customname) = "AllowCustomERC20"];
+  repeated string allowed_custom_erc20s = 4 [
+    (gogoproto.customname) = "AllowedCustomERC20s",
+    (gogoproto.moretags)   = "yaml:\"allowed_custom_erc20s\"",
+    (amino.dont_omitempty) = true
+  ];
+  ;
 }
 
 // Log represents a contract log event. These events are generated by

x/bank/keeper/common_test.go

@@ -303,6 +303,7 @@ func _createTestInput(
 	)
 	evmParams := evmtypes.DefaultParams()
 	require.NoError(t, evmKeeper.Params.Set(ctx, evmParams))
+	require.NoError(t, evmKeeper.Initialize(ctx))
 
 	// set erc20 keeper
 	*erc20Keeper = *evmKeeper.ERC20Keeper().(*evmkeeper.ERC20Keeper)

x/evm/contracts/custom_erc20/CustomERC20.sol

@@ -0,0 +1,76 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.24;
+
+import "../i_erc20/IERC20.sol";
+import "../ownable/Ownable.sol";
+import "../erc20_registry/ERC20Registry.sol";
+
+contract CustomERC20 is IERC20, Ownable, ERC20Registry {
+    event Transfer(address indexed from, address indexed to, uint256 value);
+    event Approval(
+        address indexed owner,
+        address indexed spender,
+        uint256 value
+    );
+
+    mapping(address => uint256) public balanceOf;
+    mapping(address => mapping(address => uint256)) public allowance;
+    string public name;
+    string public symbol;
+    uint8 public decimals;
+    uint256 public totalSupply;
+
+    constructor(string memory _name, string memory _symbol, uint8 _decimals) register_erc20 {
+        name = _name;
+        symbol = _symbol;
+        decimals = _decimals;
+    }
+
+    function transfer(
+        address recipient,
+        uint256 amount
+    ) external register_erc20_store(recipient) returns (bool) {
+        balanceOf[msg.sender] -= amount;
+        balanceOf[recipient] += amount;
+        emit Transfer(msg.sender, recipient, amount);
+        return true;
+    }
+
+    function approve(address spender, uint256 amount) external returns (bool) {
+        allowance[msg.sender][spender] = amount;
+        emit Approval(msg.sender, spender, amount);
+        return true;
+    }
+
+    function transferFrom(
+        address sender,
+        address recipient,
+        uint256 amount
+    ) external register_erc20_store(recipient) returns (bool) {
+        allowance[sender][msg.sender] -= amount;
+        balanceOf[sender] -= amount;
+        balanceOf[recipient] += amount;
+        emit Transfer(sender, recipient, amount);
+        return true;
+    }
+
+    function _mint(address to, uint256 amount) internal register_erc20_store(to) {
+        balanceOf[to] += amount;
+        totalSupply += amount;
+        emit Transfer(address(0), to, amount);
+    }
+
+    function _burn(address from, uint256 amount) internal {
+        balanceOf[from] -= amount;
+        totalSupply -= amount;
+        emit Transfer(from, address(0), amount);
+    }
+
+    function mint(address to, uint256 amount) external onlyOwner{
+        _mint(to, amount);
+    }
+
+    function burn(address from, uint256 amount) external onlyOwner {
+        _burn(from, amount);
+    }
+}

x/evm/contracts/erc20/ERC20.sol

@@ -20,7 +20,8 @@ contract ERC20 is IERC20, Ownable, ERC20Registry {
     uint8 public decimals;
     uint256 public totalSupply;
 
-    constructor(string memory _name, string memory _symbol, uint8 _decimals) register_erc20 {
+    // for custom erc20s, you should add `register_erc20` modifier to the constructor
+    constructor(string memory _name, string memory _symbol, uint8 _decimals) {
         name = _name;
         symbol = _symbol;
         decimals = _decimals;

x/evm/contracts/erc20_factory/ERC20Factory.sol

@@ -0,0 +1,26 @@
+// SPDX-License-Identifier: MIT
+pragma solidity ^0.8.24;
+
+import "../erc20/ERC20.sol";
+import "../i_erc20_registry/IERC20Registry.sol";
+
+contract ERC20Factory is ERC20Registry {
+    event ERC20Created(address indexed erc20, address indexed owner);
+
+    function createERC20(
+        string memory name,
+        string memory symbol,
+        uint8 decimals
+    ) external returns (address) {
+        ERC20 erc20 = new ERC20(name, symbol, decimals);
+
+        // register the ERC20 contract with the ERC20 registry
+        ERC20_REGISTRY_CONTRACT.register_erc20_from_factory(address(erc20));
+
+        // transfer ownership of the ERC20 contract to the sender
+        erc20.transferOwnership(msg.sender);
+
+        emit ERC20Created(address(erc20), msg.sender);
+        return address(erc20);
+    }
+}

x/evm/contracts/i_erc20_registry/IERC20Registry.sol

@@ -11,6 +11,7 @@ IERC20Registry constant ERC20_REGISTRY_CONTRACT = IERC20Registry(
 
 interface IERC20Registry {
     function register_erc20() external;
+    function register_erc20_from_factory(address erc20) external;
     function register_erc20_store(address account) external;
     function is_erc20_store_registered(
         address account

x/evm/keeper/common_test.go

@@ -152,13 +152,13 @@ type TestKeepers struct {
 
 // createDefaultTestInput common settings for createTestInput
 func createDefaultTestInput(t testing.TB) (sdk.Context, TestKeepers) {
-	return createTestInput(t, false)
+	return createTestInput(t, false, true)
 }
 
 // createTestInput encoders can be nil to accept the defaults, or set it to override some of the message handlers (like default)
-func createTestInput(t testing.TB, isCheckTx bool) (sdk.Context, TestKeepers) {
+func createTestInput(t testing.TB, isCheckTx, withInitialize bool) (sdk.Context, TestKeepers) {
 	// Load default move config
-	return _createTestInput(t, isCheckTx, dbm.NewMemDB())
+	return _createTestInput(t, isCheckTx, withInitialize, dbm.NewMemDB())
 }
 
 var keyCounter uint64
@@ -180,6 +180,7 @@ func keyPubAddr() (crypto.PrivKey, crypto.PubKey, sdk.AccAddress) {
 func _createTestInput(
 	t testing.TB,
 	isCheckTx bool,
+	withInitialize bool,
 	db dbm.DB,
 ) (sdk.Context, TestKeepers) {
 	keys := storetypes.NewKVStoreKeys(
@@ -269,8 +270,13 @@ func _createTestInput(
 			},
 		},
 	)
-	evmParams := evmtypes.DefaultParams()
-	require.NoError(t, evmKeeper.Params.Set(ctx, evmParams))
+
+	if withInitialize {
+		evmParams := evmtypes.DefaultParams()
+		evmParams.AllowCustomERC20 = false
+		require.NoError(t, evmKeeper.Params.Set(ctx, evmParams))
+		require.NoError(t, evmKeeper.Initialize(ctx))
+	}
 
 	// set erc20 keeper
 	*erc20Keeper = *evmKeeper.ERC20Keeper().(*evmkeeper.ERC20Keeper)