Remove encryption of empty props to allow server island cacheability

[kaytwo]

Changes

This change removes the encryption of {} in the case of a server island with no props. Fixes #12949.

Testing

Added two tests: one test that ensures components with props keep getting them re-encrypted, and one where components without props don't have an empty encryption passed through to them.

Docs

Nominally a bugfix, brings the docs mention of caching in line with reality.

[changeset-bot]

🦋 Changeset detected

Latest commit: 077f174

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[codspeed-hq]

CodSpeed Performance Report

Merging #12956 will not alter performance

_{Comparing kaytwo:main (077f174) with main (cca3bc9)}

Summary

✅ 6 untouched benchmarks

[ascorbic]

@kaytwo your tests are failing, because fixture.fetch() doesn't work without a runnign server. Those tests will work in dev but not prod. Take a look at how the other dev and prod tests are implemented in that file. It would be good to have tests for both. You can run the tests locally by running node --test packages/astro/test/server-islands.test.js

[matthewp]

Great test, thank you!

[matthewp]

Can't really tell from the failures what the problem is with your tests. Looks like the fetches are failing, are you fetching in the same way as the other tests?

[matthewp]

Also this needs a changeset which you can add via pnpm changeset.

[ascorbic]

Can't really tell from the failures what the problem is with your tests. Looks like the fetches are failing, are you fetching in the same way as the other tests?

It's making dev server requests in the build tests, where the dev server isn't running

[matthewp]

Oh right, it should be doing it like this then (as the tests before it do):

const app = await fixture.loadTestAdapterApp();
const request = new Request('http://example.com/');

[kaytwo]

sorry about the confusing tests, I lost a fight with git and pushed the wrong commits at first. Should be good now on tests + fix.