Submission Details
Severity:
Reverting with custom errors is more gas-efficient
Summary
Reverting with a custom error is more efficient in terms of gas than a 'require' structure.
Vulnerability Details
KittyConnect has some modifiers which make a check using 'require' instead of custom errors, which requires a higher amount of gas. These modifiers are onlyKittyConnectOwner(), onlyShopPartner() and onlyKittyBridge().
Impact
Low impact, gas optimization.
Tools Used
Manual review
Remix IDE
Recommendations
Declare custom errors in KittyConnect and make the modifiers revert with these errors:
contract KittyConnect is ERC721 {
+error KittyConnect__NotKittyConnectOwner();
+error KittyConnect__NotAPartner();
+error KittyConnect__NotKittyBridge();
.
.
.
modifier onlyKittyConnectOwner() {
- require(msg.sender == i_kittyConnectOwner, "KittyConnect__NotKittyConnectOwner");
+ if(msg.sender != i_kittyConnectOwner) revert KittyConnect__NotKittyConnectOwner();
_;
}
modifier onlyShopPartner() {
- require(s_isKittyShop[msg.sender], "KittyConnect__NotAPartner");
+ if(!s_isKittyShop[msg.sender]) revert KittyConnect__NotAPartner();
_;
}
modifier onlyKittyBridge() {
- require(msg.sender == address(i_kittyBridge), "KittyConnect__NotKittyBridge");
+ if(msg.sender != address(i_kittyBridge) revert KittyConnect__NotKittyBridge();
_;
}
Rewards breakdown
nSLOC
235This contest has a flat reward structure with the following payouts:
100 EXP
20 EXP
2 EXP
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