Support prefetch in core

[bluwy]

Changes

close #8926

Add new prefetch option. Supersedes @astrojs/prefetch. Check the docs and RFC for more information on how it works.

• RFC: Support prefetch in core roadmap#755
• NOTE: The @astrojs/prefetch integration will be deprecated after this is merged and released.

Tip for reviewing

• The core logic changes are in src/core. src/core/prefetch/index.ts contains the client-side script.

• The documentation is in the changeset and src/@types/astro/ts. They take a lot of lines, and the docs for prefetch.prefetchAll and prefetch.defaultStrategy are duplicated. I think it's needed for docs to detect it.

Testing

Added e2e tests to make sure a request is sent

Docs

Main docs: withastro/docs#5271

This PR also has changesets and JSDoc for review.

[changeset-bot]

🦋 Changeset detected

Latest commit: d89b60e

The changes in this PR will be included in the next version bump.

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[martrapp]

LVGTM: I am very happy that the different prefetch approaches are unified here and the special handling in ViewTransition.astro is replaced by core functions!

[github-actions]

This PR is blocked because it contains a minor changeset. A reviewer will merge this at the next release if approved.

[sarah11918]

Love this, @bluwy and I'm also getting into the docs PR for this too!

I left some suggestions, mostly about getting explicit options shown etc. as this is a reference page and people might be coming here to look something up or check on it quickly. Duplication of content here and in the guide isn't always a bad thing, since the guide will walk through more and this can be for people who already pretty much know what the feature is about, they just don't know for example all the possible hover, tap etc.

Also, I do not know what's up with documenting the options twice. We're going to need to call in someone else to confirm that.

[sarah11918]

Docs look great!

it's merge day