From 28278f7fe133acfab2f3851e0d20e636e7eff6b4 Mon Sep 17 00:00:00 2001
From: Arsenii Kulikov <klkvrr@gmail.com>
Date: Fri, 1 Nov 2024 02:09:47 +0400
Subject: [PATCH] chore: fmt + README updates (#18)

---
 chapter1/README.md                  |  3 ++-
 chapter1/contracts/src/ERC20Fee.sol | 16 ++++++++++++----
 chapter1/erc20-fee/README.md        |  6 +++---
 3 files changed, 17 insertions(+), 8 deletions(-)

diff --git a/chapter1/README.md b/chapter1/README.md
index 78f11db..0125645 100644
--- a/chapter1/README.md
+++ b/chapter1/README.md
@@ -6,4 +6,5 @@
 - [bls-multisig](./bls-multisig): Multisig based on BLS signatures verified through precompiles from EIP-2537
 - [eof](./eof): Introduction to EOF
 - [simple-7702](./simple-7702): Demo of full EIP-7702 flow with cast and forge
-- [delegate-p256](./delegate-p256): Account controlled by a P256 key through EIP-7702 and EIP-7212
\ No newline at end of file
+- [delegate-p256](./delegate-p256): Account controlled by a P256 key through EIP-7702 and EIP-7212
+- [erc20-fee](./erc20-fee): Demo of EIP-7702 delegation contract allowing to pay gas fee in ERC20
\ No newline at end of file
diff --git a/chapter1/contracts/src/ERC20Fee.sol b/chapter1/contracts/src/ERC20Fee.sol
index 4f3903b..c116312 100644
--- a/chapter1/contracts/src/ERC20Fee.sol
+++ b/chapter1/contracts/src/ERC20Fee.sol
@@ -6,7 +6,7 @@ interface IERC20 {
 }
 
 contract TestERC20 {
-    mapping (address => uint256) public balance;
+    mapping(address => uint256) public balance;
 
     function transfer(address _to, uint256 _value) public returns (bool success) {
         balance[msg.sender] -= _value;
@@ -21,12 +21,20 @@ contract TestERC20 {
 
 /// @notice Contract designed for being delegated to by EOAs to authorize an ERC20 transfer with ERC20 as fee.
 contract ERC20Fee {
-
     /// @notice Internal nonce used for replay protection, must be tracked and included into prehashed message.
     uint256 public nonce;
 
     /// @notice Main entrypoint to send tx.
-    function execute(address to, bytes memory data, uint256 value, IERC20 feeToken, uint256 fee, uint8 v, bytes32 r, bytes32 s) public {
+    function execute(
+        address to,
+        bytes memory data,
+        uint256 value,
+        IERC20 feeToken,
+        uint256 fee,
+        uint8 v,
+        bytes32 r,
+        bytes32 s
+    ) public {
         bytes32 digest = keccak256(abi.encode(nonce++, to, data, value, feeToken, fee));
         address addr = ecrecover(digest, v, r, s);
 
@@ -36,4 +44,4 @@ contract ERC20Fee {
         require(success, "call failed");
         require(feeToken.transfer(msg.sender, fee));
     }
-}
\ No newline at end of file
+}
diff --git a/chapter1/erc20-fee/README.md b/chapter1/erc20-fee/README.md
index 546ef2f..dc2472d 100644
--- a/chapter1/erc20-fee/README.md
+++ b/chapter1/erc20-fee/README.md
@@ -26,7 +26,7 @@ export CHARLES_ADDRESS="0x90F79bf6EB2c4f870365E785982E1f101E93b906"
 forge create TestERC20 --private-key $BOB_PK
 export ERC20=<ERC20 addr>
 cast send $ERC20 'mint(address,uint256)' $ALICE_ADDRESS 10000000000000000000 --private-key $BOB_PK # 10E9 tokens
-cast call $ERC20 'balance(address)' $ALICE_ADDRESS
+cast call $ERC20 'balance(address)(uint256)' $ALICE_ADDRESS
 ```
 
 - We need to deploy a contract which verifies the user signature and execute ERC20 transfers.:
@@ -71,7 +71,7 @@ cast send $ALICE_ADDRESS "execute(address,bytes,uint256,address,uint256,uint8,by
 
 - Bob will receive the ERC20 token as the fee, and Charles will receive the ERC20 token
 ```bash
-cast call $ERC20 "balance(address)" $BOB_ADDRESS
-cast call $ERC20 "balance(address)" $CHARLES_ADDRESS
+cast call $ERC20 "balance(address)(uint256)" $BOB_ADDRESS
+cast call $ERC20 "balance(address)(uint256)" $CHARLES_ADDRESS
 ```