fix: don't access requestAnimationFrame eagerly

[benmccann]

closes #13961

allows testing some browser code without jsdom

performance-wise these are equivalent because rollup will replace BROWSER and evaluate the ternary at compilation time

[changeset-bot]

⚠️ No Changeset found

Latest commit: 3294923

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

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

[pkg-pr-new]

pnpm add https://pkg.pr.new/svelte@14026

commit: 3294923

[dummdidumm]

This should've had a comment explaining why we do that

[benmccann]

changeset too. sent a PR for those here: #14040

[PierBover]

Is there a way to disable this behavior?

5.1.5 completely broke our Svelte 5 app. It all works as expected with 5.1.4 and previous versions.

I've been looking at the changes of 5.1.5 and this is the only new thing that could have impacted us.

I would like to test if this is indeed the issue.

Edit:

The issue is related to snippets and 5.1.5. I'm creating a repro and will open an issue.