[LAU-01C] Event Usability Enhancement

[dkuppitz]

LAU-01C: Event Usability Enhancement

Type	Severity	Location
Code Style		LzAppUpgradeable.sol:L45-L47

Description:

The referenced events do not contain any indexed arguments declared.

Example:

event SetTrustedRemote(uint16 _remoteChainId, bytes _path);
event SetTrustedRemoteAddress(uint16 _remoteChainId, bytes _remoteAddress);
event SetMinDstGas(uint16 _dstChainId, uint16 _type, uint256 _minDstGas);

Recommendation:

We advise the indexed keyword to be introduced to the _remoteChainId and _dstChainId variables, optimizing off-chain filters of these events in relation to their chain ID.

[dkuppitz]

Thank you for the recommendations provided in audit item LAU-01C, regarding the use of indexed parameters in events for efficient off-chain filtering. I acknowledge the importance of adhering to best practices for event usability and recognize the value of implementing indexed arguments for chain ID parameters.

Your recommendation aligns with general best practices for Solidity event indexing, which are indeed beneficial for off-chain event filtering and analysis. However, there are reasons for maintaining the current design without the indexed parameters:

1. Consistency with LayerZero Standards: The event signatures in our implementation mirror those in the original LayerZero implementation. This decision is strategic, ensuring that developers who are accustomed to LayerZero's interface will find the same patterns in our upgradeable version.

2. Adherence to Original Design: The design and event structure set forth by LayerZero have been tested and verified. By staying true to their established event structure, we minimize the risk of introducing discrepancies and ensure that our contract’s behavior is predictable and in line with established standards.

3. Third-Party Integrations: Adjusting the event signatures could potentially affect third-party services and integrators that rely on the specific event structure provided by LayerZero. Even though our contract has not been deployed yet, aligning with the LayerZero event structure provides a seamless integration for any service that has integrated with LayerZero's contracts.

In light of these considerations we have chosen to keep the event signatures as they are to maintain uniformity with LayerZero's original contracts.

We appreciate your understanding and acknowledge that while this approach diverges from typical Solidity best practices, it is taken with careful consideration of the broader context in which this contract operates.

Your input is greatly valued, and should LayerZero update their event structures, or if a future iteration of this contract deems it feasible, we will certainly look to implement the use of indexed arguments in our events.