Developed automated test coverage for the Storefront Magento Payments Smart Buttons checkout process in the magento/magento2-page-builder repository, focusing on the edge case where a product’s total is zero. Leveraged MFTF and PHP to implement an end-to-end test that validates correct button behavior and checkout flow under this scenario, addressing a critical path in the release cycle. The work centered on expanding validation and improving release confidence by ensuring that this unique checkout case is reliably handled. Emphasized thorough testing and scenario coverage rather than bug fixes, contributing to safer releases and more robust payment functionality within the Magento ecosystem.