[v6 / Cloudflare] serverIslandMap?.get is not a function in pre-rendered page #15886
Description
Astro Info
Astro v6.0.4
Node v25.8.1
System macOS (arm64)
Package Manager pnpm
Output static
Adapter @astrojs/cloudflare
Integrations none
If this issue only occurs in one browser, which browser is a problem?
All
Describe the Bug
A server island component (server:defer) inside a pre-rendered page does not work correctly.
In preview environment (pnpm build then pnpm preview), the following error is thrown:
17:15:49 [ERROR] TypeError: serverIslandMap?.get is not a function
at page (file:///Users/jimmy/Documents/repro-cf-v6/dist/server/entry.mjs:9188:32)
at async callComponentAsTemplateResultOrResponse (file:///Users/jimmy/Documents/repro-cf-v6/dist/server/entry.mjs:7116:25)
at async renderToReadableStream (file:///Users/jimmy/Documents/repro-cf-v6/dist/server/entry.mjs:7064:26)
at async renderPage (file:///Users/jimmy/Documents/repro-cf-v6/dist/server/entry.mjs:8320:14)
at async lastNext (file:///Users/jimmy/Documents/repro-cf-v6/dist/server/entry.mjs:11522:25)
at async callMiddleware (file:///Users/jimmy/Documents/repro-cf-v6/dist/server/entry.mjs:8412:10)
at async RenderContext.render (file:///Users/jimmy/Documents/repro-cf-v6/dist/server/entry.mjs:11556:73)
at async App.render (file:///Users/jimmy/Documents/repro-cf-v6/dist/server/entry.mjs:12451:20)
at async Object.handle [as fetch] (file:///Users/jimmy/Documents/repro-cf-v6/dist/server/entry.mjs:12961:20)
I have added some console.log to see what is the value of serverIslandMap at that stage, and it has returned a string with value $$server-islands-map$$.
In dev server this is working correctly when prerenderEnvironment is set to workerd. When set to node, a 400 is returned with server island request.
Might be related with #15767
What's the expected result?
No error should be thrown.
Link to Minimal Reproducible Example
https://github.com/CaiJimmy/astro-v6-prerender
Participation
- I am willing to submit a pull request for this issue.