Worked on enhancing the stripe/stripe-js repository by introducing a new property, unitAmountDecimal, to the StripeCheckoutLineItem type, enabling more accurate handling of decimal unit amounts in payment transactions. This update required careful API development and integration with TypeScript to ensure type safety and maintainability. The work also included bumping Stripe.js to version 9.0.2 to support the new decimal capability and maintain compatibility with upstream changes. Unit testing was employed to validate the new functionality and ensure reliability. The changes addressed precise decimal handling requirements, improving transaction accuracy for developers integrating with Stripe’s JavaScript-based payment solutions.