Prevent static assets from being caught by catch-all routes

[matthewp]

Changes

• ssrAssetsPerEnvironment is a recently added property that's used to know what to copy over to the client folder
• This iterates over them and adds them to the manifest so the Node adapter knows to serve them.

Testing

• Added a new fixture packages/integrations/node/test/fixtures/ssr-assets-middleware/ with an index.astro that imports a CSS file and a [...path].astro catch-all page — the minimal setup required to reproduce the bug.
• Added a regression test in node-middleware.test.js (middleware with fastify and catch-all route: SSR assets in manifest) that builds with assetsInlineLimit: 0, starts a Fastify server, and asserts that requesting the CSS asset URL returns text/css rather than text/html from the catch-all. The test fails on unfixed code and passes with the fix.

Docs

No docs update needed — this is a bug fix restoring documented behavior with no API changes.

Fixes #16039

[changeset-bot]

🦋 Changeset detected

Latest commit: cc3efea

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[codspeed-hq]

Merging this PR will not alter performance

✅ 18 untouched benchmarks

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_{Comparing node-middleware-missing-assets (cc3efea) with main (47694d0)}

[delucis]

Noting that our docs say

Note that middleware mode does not do file serving. You’ll need to configure your HTTP framework to do that for you. By default the client assets are written to ./dist/client/.

I guess these assets are unrelated to that?

[matthewp]

@delucis The description wasn't great so I updated it.

Middleware mode doesn't serve static assets. The bug was that static assets were being caught by catch-all routes [...path].astro because we didn't have them in manifest.assets. Here is where we return undefined if a request is for static assets:

astro/packages/astro/src/core/app/base.ts

Line 244 in 1768ad5

if (this.manifest.assets.has(url.pathname)) return undefined;

So this was preventing the request from hitting the next middleware (see the test, it's the fastify static middleware)

[delucis]

Thanks for the clarification! Maybe we can tweak the changeset to describe that and not suggest that those assets will definitely load (if a user doesn’t add their own static file middleware)?

Suggested change

	Fixes CSS, fonts, and other assets failing to load when using `@astrojs/node` in middleware mode with a catch-all route. Previously these assets were incorrectly matched by the catch-all instead of being served as static files.
	Fixes catch-all routes incorrectly intercepting requests for static assets when using the `@astrojs/node` adapter in middleware mode.

Otherwise all looks good to me!