Don't polyfill globalThis for Cloudflare preset

[IgorMinar]

Environment

unenv @ main (c4be2cb505b159a21a42920da925aff6e077f831)

Reproduction

Simple worker like:

export default {
	async fetch(request, env, ctx) {
		return new Response('Hello World!');
	},
};

Is due to inject for global process in Nodeless preset which the Cloudflare preset depends on:

https://github.com/unjs/unenv/blob/c4be2cb505b159a21a42920da925aff6e077f831/src/presets/nodeless.ts#L52

This process polyfill then pulls in globalThis polyfiil: https://github.com/unjs/unenv/blob/c4be2cb505b159a21a42920da925aff6e077f831/src/runtime/polyfill/process.ts#L2

which then due to suboptimal code generation by ESBuild's inject, results in unnecessary globalThis polyfill in Cloudflare Workers apps:

// node_modules/.pnpm/[email protected]/node_modules/unenv/runtime/polyfill/global-this.mjs
function getGlobal() {
  if (typeof globalThis !== "undefined") {
    return globalThis;
  }
  if (typeof self !== "undefined") {
    return self;
  }
  if (typeof window !== "undefined") {
    return window;
  }
  if (typeof globalThis !== "undefined") {
    return globalThis;
  }
  return {};
}
var global_this_default = getGlobal();

// node_modules/.pnpm/[email protected]/node_modules/unenv/runtime/polyfill/process.mjs
var process_default = global_this_default.process;

// src/index.js
var src_default = {
  async fetch(request, env, ctx) {
    return new Response("Hello World!");
  }
};
export {
  src_default as default
};
//# sourceMappingURL=index.js.map

Describe the bug

Ideally, we'd use straight globalThis directly in the process polyfill, and in environments which don't reliably provide globalThis we inject the polyfill via the preset configuration.

Additional context

No response

Logs

No response

[IgorMinar]

@pi0 I've looked up the compat table just to realize that globalThis has been around for ages (since Node v12 for example) and also all browsers support it: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/globalThis#browser_compatibility

Could we simply drop the globalThis polyfill since it's extremely unlikely that it's having any effect and it only adds bloat? As far as I can tell this would be a non-breaking change, and could be done as a part of the 1.9.x release train. Thoughts?

[pi0]

I think mainly service worker and web workers lack globalThis instead of self that need support (not sure if it is changed in major of browsers but ~2-3 years ago that added polyfill it was a hard requirement -- unenv also make it possible to run on sw). This article also worth to read if interested.

---

Re cloudflare and modern runtime presets that we are sure have it, we might try to adopt an aliasing strategy. Make a generic "#unenv/global-this": "polyfill/global-this" and map it to "#unenv/global-this-native" for cloudflare preset wdyt?

[pi0]

@IgorMinar Can this be closed? (haven't went though $cloudflare variants)

[pi0]

My understanding is that cloudflare preset is not using polyfill and it is already resolved for the case, closing issue for maintenance please ping me to reopen if I missed something from our past discussions.