Worked on web-infra-dev/rslib to improve web infrastructure by addressing a bug related to tree-shaking and module optimization. Focused on ensuring that import.meta.url was properly removed during the build process, which reduced dead code in bundles and improved startup times. Updated the test suite to validate that require is generated through a function returning import.meta.url, increasing confidence in future refactors and regression protection. Collaborated closely with another contributor to co-author the fix, emphasizing clear attribution and traceability. Utilized JavaScript, Node.js, and TypeScript, with a strong emphasis on testing and build optimization to enhance module system reliability.