Worked on expanding testing coverage for the ONFT721 contract within the LayerZero-Labs/devtools repository, focusing on cross-chain NFT functionality. Developed comprehensive unit tests for MyONFT721.sol, validating constructor logic, cross-chain token transfers, and message composition to ensure contract robustness. Leveraged Solidity and TypeScript alongside testing frameworks such as Foundry and Hardhat to enhance the reliability of the test suite. This approach enabled safer future refactoring and accelerated development cycles by catching potential issues early. The work emphasized thorough validation of smart contract behavior, contributing to more maintainable and secure cross-chain NFT features within the project’s codebase.