Worked on the mozilla/gecko-dev repository to enhance text measurement reliability on HTML Canvas by developing a targeted Web Platform Test. Focused on ensuring that a null character contributes zero width when measuring text, the solution addressed inconsistencies across different canvas contexts, such as 2D and offscreen canvases. The approach involved integrating the test into the Web Platform Tests workflow using JavaScript and HTML, with a test-only directive to prevent production impact. Emphasized test-driven quality by aligning with CI and review standards, leveraging skills in Canvas API and web platform testing to strengthen rendering consistency and reduce potential regressions.