Worked on the pedroslopez/whatsapp-web.js repository to address a compatibility issue with the WhatsApp Web API’s fetchMessages method. Focused on adapting the message retrieval logic to align with the updated loadEarlierMsgs signature, the developer refactored the method to use an options object rather than positional arguments. This JavaScript and TypeScript update prevented runtime crashes related to undefined properties and maintained existing behavior while ensuring future compatibility. The work involved careful API integration and regression safety measures, resulting in improved reliability for end users and reduced support incidents. No new features were added, but a critical bug fix was delivered efficiently.