Server islands doesn't work with `Astro.self`

[vixalien]

Astro Info

Astro                    v5.14.5
Vite                     v6.4.0
Node                     v25.0.0
System                   Linux (x64)
Package Manager          pnpm
Output                   server
Adapter                  @deno/astro-adapter (v0.3.2)
Integrations             none

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

No response

Describe the Bug

I have code like this, which should load the batch component itself recursively when loading

---
interface Props {
  site_id: number;
  next_cursor?: string;
  count?: number;
}

import { getProfileMedia } from "../api";
import MediaLink from "./media-link.astro";

const { site_id, next_cursor: cursor, count = 1 } = Astro.props;

const { media, next_cursor } = await getProfileMedia(site_id, {
  cursor,
});
---

<>
  {media.map((item) => <MediaLink image={item.image} />)}
  {
    next_cursor && (
      <Astro.self
        site_id={site_id}
        next_cursor={next_cursor}
        count={count + 1}
        server:defer
      />
    )
  }
</>

Instead I get this error

Error: Could not find server component path
    at ServerIslandComponent.getComponentPath (/home/alien/sites/memories/node_modules/.pnpm/astro@5.14.5_@types+node@24.8.1_jiti@2.6.1_lightningcss@1.30.1_rollup@4.52.4_typescript@5.9.3/node_modules/astro/dist/runtime/server/render/server-islands.js:82:13)
    at ServerIslandComponent.getIslandContent (/home/alien/sites/memories/node_modules/.pnpm/astro@5.14.5_@types+node@24.8.1_jiti@2.6.1_lightningcss@1.30.1_rollup@4.52.4_typescript@5.9.3/node_modules/astro/dist/runtime/server/render/server-islands.js:108:32)
    at ServerIslandComponent.init (/home/alien/sites/memories/node_modules/.pnpm/astro@5.14.5_@types+node@24.8.1_jiti@2.6.1_lightningcss@1.30.1_rollup@4.52.4_typescript@5.9.3/node_modules/astro/dist/runtime/server/render/server-islands.js:52:32)
    at bufferHeadContent (file:///home/alien/sites/memories/node_modules/.pnpm/astro@5.14.5_@types+node@24.8.1_jiti@2.6.1_lightningcss@1.30.1_rollup@4.52.4_typescript@5.9.3/node_modules/astro/dist/runtime/server/render/astro/render.js:126:37)
    at process.processTicksAndRejections (node:internal/process/task_queues:103:5)
    at async renderToAsyncIterable (file:///home/alien/sites/memories/node_modules/.pnpm/astro@5.14.5_@types+node@24.8.1_jiti@2.6.1_lightningcss@1.30.1_rollup@4.52.4_typescript@5.9.3/node_modules/astro/dist/runtime/server/render/astro/render.js:143:5)
    at async renderPage (file:///home/alien/sites/memories/node_modules/.pnpm/astro@5.14.5_@types+node@24.8.1_jiti@2.6.1_lightningcss@1.30.1_rollup@4.52.4_typescript@5.9.3/node_modules/astro/dist/runtime/server/render/page.js:36:24)
    at async lastNext (file:///home/alien/sites/memories/node_modules/.pnpm/astro@5.14.5_@types+node@24.8.1_jiti@2.6.1_lightningcss@1.30.1_rollup@4.52.4_typescript@5.9.3/node_modules/astro/dist/core/render-context.js:201:25)
    at async callMiddleware (file:///home/alien/sites/memories/node_modules/.pnpm/astro@5.14.5_@types+node@24.8.1_jiti@2.6.1_lightningcss@1.30.1_rollup@4.52.4_typescript@5.9.3/node_modules/astro/dist/core/middleware/callMiddleware.js:11:10)
    at async RenderContext.render (file:///home/alien/sites/memories/node_modules/.pnpm/astro@5.14.5_@types+node@24.8.1_jiti@2.6.1_lightningcss@1.30.1_rollup@4.52.4_typescript@5.9.3/node_modules/astro/dist/core/render-context.js:235:22)

Removing the server:defer works without issue

What's the expected result?

I would expect it to work

Link to Minimal Reproducible Example

https://stackblitz.com/edit/github-wl4aagvi?file=src%2Fcomponents%2Fbatch.astro

Participation

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

[matthewp]

I think this is probably happening in teh compiler which finds teh component name. My instinct is that this is probably pretty hard to fix but maybe not.

[Fryuni]

The compiler only tracks direct import names. Using server:defer with any identifier that it hasn't tracked is silently ignored.

Live compiler result here

This code:

---
import Foo from './Foo.astro'
import Bar from './Bar.astro'

const Other = Bar;
---
<Foo server:defer />
<Other server:defer />

Result in the this metadata and no warnings nor errors:

{
  "containsHead": false,
  "diagnostics": [],
  "map": "",
  "propagation": true,
  "scope": "7pkktdcb",
  "serverComponents": [
    {
      "exportName": "default",
      "localName": "Foo",
      "specifier": "./Foo.astro",
      "resolvedPath": "./Foo.astro"
    }
  ]
}

[vixalien]

wow, seems like this is much higher priority then

[Fryuni]

I don't think we should have as a goal to support any arbitrary value since that is not statically knowable and would require making this decidable at runtime.

We can add support for Astro.self and some warning if it is some other identifier that we don't know about, or maybe even error if a server:defer is used where we can't create a Server Island.

[matthewp]

I think we can special case Astro.self assuming it's a static value.