You don't need this anymore. Now, Supabase user can bind custom fetch implementation. See https://supabase.com/docs/reference/javascript/initializing#custom-fetch-implementation
Cloudflare Workers is an amazing serverless platform to be used as your app backend. Supabase is a Firebase-alike database service using PostgreSQL. I though they are a good match that complement each other.
However, Cloudflare Workers does not support XMLHttpRequest object and only support native fetch. This makes Supabase JS Clients does not work on Cloudflare Workers. Supabase JS Client internally uses cross-fetch package to polyfill fetch which inside of it, uses XMLHttpRequest.
To resolve this, I use patch-package to patch cross-fetch package as minimal as possible. A bit hacky, but it works!
This repo contains minimal Cloudflare Workers project with the patch automatically applied.