feat: ERC20RoyaltyEnforcer

[gitaalekhyapaul]

What?

• Added ERC20RoyaltyEnforcer contract to enforce royalty payments when redeeming ERC20 token delegations
• Added comprehensive test suite for the enforcer

Why?

• Enable token delegations with royalty distribution requirements
• Ensure secure and reliable royalty payments to specified recipients
• Prevent unauthorized transfers and protect delegator/recipient funds

How?

The flow works as follows:

sequenceDiagram
participant Delegator
participant DelegationManager
participant ERC20RoyaltyEnforcer
participant ERC20Token
participant RoyaltyRecipients
participant Redeemer
Delegator->>DelegationManager: Delegate tokens with royalty terms
DelegationManager->>ERC20RoyaltyEnforcer: beforeHook()
Note over ERC20RoyaltyEnforcer: Validate transfer details<br/>Lock execution<br/>Cache balances
alt Invalid conditions
ERC20RoyaltyEnforcer-->>DelegationManager: Revert with error
end
Delegator->>ERC20Token: Transfer tokens to enforcer
DelegationManager->>ERC20RoyaltyEnforcer: afterHook()
alt Insufficient balance
ERC20RoyaltyEnforcer-->>DelegationManager: Revert with ERC20InsufficientBalance
end
ERC20RoyaltyEnforcer->>RoyaltyRecipients: Distribute royalties
Note over ERC20RoyaltyEnforcer: Calculate remaining balance
alt Remaining balance > 0
ERC20RoyaltyEnforcer->>Redeemer: Transfer remaining tokens
end
Note over ERC20RoyaltyEnforcer: Unlock execution

Loading

• Implemented core royalty enforcement logic in src/enforcers/ERC20RoyaltyEnforcer.sol

• Added state management for:

  • Execution locking to prevent reentrancy
  • Balance caching for validation
  • Royalty distribution tracking

• Added validation checks for:

  • Transfer recipient must be enforcer
  • Transfer amount >= total royalties
  • Valid redeemer address
  • Single execution mode only
  • Zero ETH value
  • Valid calldata format

• Added comprehensive test coverage in test/enforcers/ERC20RoyaltyEnforcerTest.t.sol

• Key test scenarios:

  • Valid royalty execution
  • Balance caching
  • Enforcer locking
  • Error cases (invalid recipient, insufficient amount, etc)