fix: Improve authentication handling in fetchWithAuth.

[anuragchvn-blip]

🚀 What This PR Does

• Improves fetchWithAuth by adding better error handling for getAccessToken().
• Logs meaningful errors when retrieving an access token fails.
• Ensures API calls in Supabase SDK always have proper authentication headers.

🔧 Why This Is Important

• Prevents silent failures in authentication.
• Improves debugging experience for developers using Supabase SDK.

✅ How to Test

1. Run Supabase SDK in a Node.js and browser environment.
2. Intentionally break getAccessToken() to verify error logging.

Would love feedback from maintainers! 🚀

[m1nsuppp]

It's great to see the error handling here! Just a thought: the catch block will only execute if getAccessToken() throws an error. If getAccessToken() returns null (and doesn't throw an error), the catch block won't be reached. We might want to add a check to ensure accessToken has a valid value after the try block, or clarify the expected behavior of getAccessToken() to ensure it always either returns a token or throws an error.

[anuragchvn-blip]

Thanks for the feedback, @m1nsuppp! You're absolutely right—if getAccessToken() returns null without throwing an error, the catch block won't be triggered. I’ll update the implementation to explicitly check whether accessToken is valid after the try block. We could either throw an error manually if it's null or ensure getAccessToken() always throws when it fails.

Would love your thoughts on the best approach here!