How to support both Node and Cloudflare?

[pvcnt]

I run an open source project, Mergeable (an inbox for pull requests) on Cloudflare Workers, essentially because they are free for my use case. However, users that want to self-host this project need a Docker image. Already using React Router, I am currently trying to move to SSR, while still support those two very different runtimes.

I have a prototype that mostly works, except for the need to have a very different entry.server.ts. I put a switch in it, depending on the runtime, but the issue is that renderToReadableStream is not available at all when using Node, and just importing generates a build error. I can think of workarounds such as dynamically import renderToReadableStream / renderToPipeableStream inside handleRequest, but that does not look very elegant. Is there a way of handling several entry.server.ts?

[sergiodxa]

You can't because ReactDOM doesn't export renderToReadableStream in Node even if it could be used. This is not an issue with RR but ReactDOM package itself.

[pvcnt]

I understand that, but was hoping that React Router would provide me a way to easily support different runtimes with different entry.server.ts file, especially because different runtimes may require vastly different logic in this file (e.g., Cloudflare vs. Node). I actually found this discussion asking a similar question. Is that something that could actually be implemented in RR? Or else, what would be your recommendation?

[sergiodxa]

Maybe you could do something like this (note I never tried)

import * as ReactDOMServer from "react-dom/server";

if ("renderToReadableStream" in ReactDOMServer) {
  // use renderToReadableStream
} else {
  // use renderToPipeableStream
}

[pvcnt]

It does yes. :) I was afraid it would increase bundle size, but it does not seem to.

[sergiodxa]

That's only server-side, it doesn't affect the client-side bundle size

[pvcnt]

There are also limits to the server-side bundle that can be uploaded to Cloudflare Workers, but I'm still far from reaching it even on the free plan.