Fix Axios adapter binding for Cloudflare Workers environment

[tharropoulos]

Change Summary

What is this?

This PR addresses a critical issue where Typesense library users encounter "Illegal invocation" errors when using custom Axios adapters in Cloudflare Workers environment. The error occurs because the fetch adapter loses its this context when used in Workers. This implementation ensures proper binding of the adapter to the correct context, making the library usable on edge computing environments.

Changes

Added Features:

1. New Method in ApiCall.ts:
   • getAdapter(): A private method that intelligently handles Axios adapter configuration:
     • Safely returns undefined when no adapter is configured
     • Preserves function adapters as-is when directly provided
     • Automatically detects Cloudflare Workers environment
     • Binds the adapter to globalThis specifically in Workers environment

Code Changes:

1. In ApiCall.ts:
   • Import AxiosAdapter type for better type safety
   • Replace direct adapter usage with the new getAdapter() method in performRequest
   • Add environment detection logic for Cloudflare Workers
   • Implement proper this binding for the adapter in Workers context

Context

On issue #254 @isaacrowntree encountered that behavior on an edge runtime on Cloudflare Workers.

PR Checklist

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