fix: Cloudflare templates break when prerendering is enabled

[ariofrio]

Issue Description

The Cloudflare templates fail when prerendering is enabled (#31) due to incompatibility between its custom entry point and React Router Vite plugin's prerendering assumptions.

Technical Details

1. During prerendering, the plugin expects the entry point to be virtual:react-router/server-build
2. Cloudflare templates use a different entry point, causing the plugin to fail
3. The plugin sets rollupOptions.entryFileNames to serverBuildFile from react-router.config.ts, which prevents multiple entry points in rollupOptions.input

Solution

Fix prerendering in the Cloudflare templates by:

1. Workaround for Vite plugin limitation: Forcing entryFileNames to be [name] to support multiple entry points
2. Specifying two entry points in input:
   • index.js: matches default serverBuildFile React Router configuration
   • worker.js: matched by updated main = "./build/server/worker.js" in wrangler.toml
3. Explicitly setting index.js as the serverBuildFile in react-router.config.ts for clarity and discoverability

Updated both cloudflare and cloudflare-d1 templates.

Proposed Long-term Fix

The React Router Vite plugin should be updated to support custom entry points for use cases like Cloudflare Workers.

Suggested Implementation

{
  input: viteUserConfig.build?.rollupOptions?.input ?? {
    [ctx.reactRouterConfig.serverBuildFile]: serverBuildId,
  },
  output: {
    entryFileNames:
      typeof viteUserConfig.build?.rollupOptions?.input === "string"
        ? ctx.reactRouterConfig.serverBuildFile
        : "[name]",
    format: ctx.reactRouterConfig.serverModuleFormat,
  },
};

I considered leaving entryFileNames as the Rollup default [name].js, but this made it harder for the developer to match the input entries in vite.config.ts to the file names in wrangler.toml and react-router.config.ts. On the other hand, this changes Rollup's defaults and should be documented. Happy to change it back to Rollup's default and change input to {index: ..., worker: ...} if the maintainers have an opinion on this.

We should probably document this feature in general anyway though.

Next Steps

• Open PR for official support for multiple entry points in React Router Vite plugin
• Remove the workaround of forcing entryFileNames to be [name] in the Cloudflare templates once the React Router Vite plugin is updated

[supachaidev]

The current entry.server.ts in the templates uses the renderToReadableStream function which causes the pre-rendering to output the html files with [object ReadableStream] as content.

Not sure how to make Cloudflare templates work with the react-dom/server renderToPipeableStream function instead.

So, with current Cloudflare templates, even with the fix from this PR, pre-rendering does not work.

[caprolactam]

hi @supachaidev.

I omit detailed explanations, but this is an issue caused by the conditional exports feature in Node.js and React.

The workaround is to provide workerd resolution conditions in Node.js.

NODE_OPTIONS='--conditions workerd' react-router build

If you are windows users, use cross-env.

{
"scripts": {
    "build": "cross-env NODE_OPTIONS=\"--conditions workerd\" react-router build",
  }
}

If you are using React@18, use worker instead of workerd.

NODE_OPTIONS='--conditions worker' react-router build

For code examples, refer to this repository and commit.

[supachaidev]

hi @supachaidev.

I omit detailed explanations, but this is an issue caused by the conditional exports feature in Node.js and React.

The workaround is to provide workerd resolution conditions in Node.js.

NODE_OPTIONS='--conditions workerd' react-router build

If you are windows users, use cross-env.

{
"scripts": {
    "build": "cross-env NODE_OPTIONS=\"--conditions workerd\" react-router build",
  }
}

If you are using React@18, use worker instead of workerd.

NODE_OPTIONS='--conditions worker' react-router build

For code examples, refer to this repository and commit.

Thank you.

[markdalgleish]

Thanks for the PR! Sorry for not getting to this earlier.

We're currently in the process of updating the Cloudflare templates to use @cloudflare/vite-plugin and the Vite Environment API. We've updated the cloudflare template — is this still an issue there?