[astro 5] not detecting "hybrid" (server) build when having only static pages but some server-islands

[PaulSenon]

Astro Info

Astro                    v5.0.5
Node                     v20.18.1
System                   Linux (arm64)
Package Manager          pnpm
Output                   static
Adapter                  @astrojs/netlify
Integrations             none

If this issue only occurs in one browser, which browser is a problem?

No response

Describe the Bug

When you are in output: static and have NO page (src/pages/**/*.astro) opting out for prerender (with export const prerender = false;), BUT you have some SSR component imported with server:defer (a.k.a. server-island) then the astro hook astro:config:done it returning buildOutput: static instead of server and it makes the adapters not building the ssr entrypoint for the server-islands.

this must be a little edge case from Astro v5 when they merged the static and hybrid mode. Now it doesn't assume we are hybrid when we don't have any ssr page (even if they contains server-islands)

Tip

As a workaround simply add a unused page with export const prerender = false; and it will trick Astro to think we are hybrid

What's the expected result?

When I have have output: static, and only static pages, but at least one server-island, then astro should detect the output as "hybrid" (server to be precise).

Read the README from reproduction URL

Link to Minimal Reproducible Example

https://github.com/PaulSenon/issue-reproduction-astro-netlify-adapter/tree/astro-static-issue?tab=readme-ov-file

Participation

• I am willing to submit a pull request for this issue.

[ematipico]

@PaulSenon I checked out your reproduction, and running pnpm build shows the expected output.

[jee-r]

Hello, I’m experiencing the same issue both locally and on Vercel. I’ve created a repository with two branches:

• The main branch reproduces the issue.
  https://github.com/jee-r/issue-astro-island-server/tree/main
• The workaround branch demonstrates the workaround by adding an SSR page.
  https://github.com/jee-r/issue-astro-island-server/tree/workaround

Let me know if further clarification is needed!