Worked on the eslint/eslint repository to enhance the accuracy of static analysis when global objects are shadowed by local identifiers in JavaScript code. Addressed a bug affecting the prefer-promise-reject-errors and no-extra-boolean-cast rules by refining detection logic to distinguish between global and locally shadowed Promise and Boolean references. This update reduced false positives and improved the reliability of linting results for large codebases. The solution included adding regression tests to ensure ongoing correctness and maintaining the original intent and performance of the rules. Utilized skills in ESLint, JavaScript, and testing to deliver targeted, maintainable improvements to core linting functionality.