fix: fallback to undiciFetch when globalThis.fetch is unavailable

[deep-innovator]

Problem

On Windows with older Node.js versions, globalThis.fetch is not available at module load time, causing the original nativeFetch definition to fail immediately.

Solution

• Keep nativeFetch as a direct request function, preserving the original signature (input, init) => Promise<Response>.
• Fall back to undiciFetch synchronously when globalThis.fetch is unavailable.
• This maintains the existing no-proxy path behavior while fixing the startup error on Windows.

Verification

• No breaking changes to the call site return nativeFetch(input, init).
• Works both with native fetch and the undiciFetch fallback.

[Astro-Han]

I reproduced the current failure by deleting globalThis.fetch before importing src/node-network.ts. On main, that throws at the eager bind, so this PR is fixing the right spot.

One thing still missing is a regression test for the no-fetch module-load path. The current tests cover proxy decisions after import, but not the startup case this change is meant to fix.

Also worth confirming the support target here. package.json still says node >=20, so this is either a best-effort compatibility fix for unsupported runtimes or a sign that the engine floor should be revisited.

[deep-innovator]

Thanks for the review! I'll wait for your further guidance on this

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---- Replied Message ---- | From | ***@***.***> | | Date | 04/07/2026 20:43 | | To | ***@***.***> | | Cc | ***@***.***>***@***.***> | | Subject | Re: [jackwener/opencli] fix: fallback to undiciFetch when globalThis.fetch is unavailable (PR #840) | Astro-Han left a comment (jackwener/OpenCLI#840) I reproduced the current failure by deleting globalThis.fetch before importing src/node-network.ts. On main, that throws at the eager bind, so this PR is fixing the right spot. One thing still missing is a regression test for the no-fetch module-load path. The current tests cover proxy decisions after import, but not the startup case this change is meant to fix. Also worth confirming the support target here. package.json still says node >=20, so this is either a best-effort compatibility fix for unsupported runtimes or a sign that the engine floor should be revisited. — Reply to this email directly, view it on GitHub, or unsubscribe. You are receiving this because you authored the thread.Message ID: ***@***.***>

[Astro-Han]

Would it be simpler to make nativeFetch a tiny wrapper instead of choosing once at module load? As written, if fetch is missing during import but gets installed later, the direct path is still pinned to undiciFetch for the rest of the process.