Dolan Murvihill developed comprehensive TypeScript type definitions and accompanying tests for the expect-cookies library within the grafana/k6-DefinitelyTyped repository. Focusing on type safety and developer experience, Dolan implemented and verified typings that cover a range of cookie manipulation scenarios, ensuring robust support for cookie assertions in automated tests. The work involved leveraging TypeScript’s advanced typing features and thorough testing practices to align with DefinitelyTyped standards. By delivering versioned typings and collaborating through pull requests, Dolan enhanced the reliability and usability of expect-cookies for TypeScript users, demonstrating depth in type definitions, testing methodologies, and collaborative open-source development workflows.