fix: catch error on @const tag in svelte:boundary in DEV mode

[adiguba]

• Close svelte:boundary doesn't catch errors inside a @const tag #15368

I'm not sure to understand the reason, but in DEV mode, the @const tag add a $.get() "to eagerly evaluate the expression in order to hit any 'Cannot access x before initialization' errors"

When used in a <svelte:boundary>, this code need to be inside the $.boundary().
So I added const_dev_statements property into SvelteBoundary which is populated by ConstTag when his parent is a Svelteboundary.

Not sure if this need a test, neither how to test in dev mode.

Before submitting the PR, please make sure you do the following

• It's really useful if your PR references an issue where it is discussed ahead of time. In many cases, features are absent for a reason. For large changes, please create an RFC: https://github.com/sveltejs/rfcs
• Prefix your PR title with feat:, fix:, chore:, or docs:.
• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.
• If this PR changes code within packages/svelte/src, add a changeset (npx changeset).

Tests and linting

• Run the tests with pnpm test and lint the project with pnpm lint

[changeset-bot]

🦋 Changeset detected

Latest commit: 0ab422b

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

This PR includes changesets to release 1 package

Name	Type
svelte	Patch

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

[svelte-docs-bot]

Preview: https://svelte-dev-git-preview-svelte-15369-svelte.vercel.app/

[paoloricciuti]

We definitely need a test for this

neither how to test in dev mode.

you can specify compileOption.dev = true in the config

[adiguba]

Test added.
But I'm not sure how to handle the conflict on index.d.ts...

[paoloricciuti]

But I'm not sure how to handle the conflict on index.d.ts...

Should be fixed now

[github-actions]

Playground

pnpm add https://pkg.pr.new/svelte@15369

[adiguba]

Please wait to merge.
I dislike the way I handle that.
I think I can do it more simply...

[adiguba]

I think it's way better like that, since it modifies fewer files...

[paoloricciuti]

I think it's way better like that, since it modifies fewer files...

I agree...much better now...let me just check a couple of things as soon as we get the actual playground

[paoloricciuti]

I was trying to understand if the dev flag was needed but while exploring this I think the whole accessing eagerly const tags is not really needed. Commenting the line make no test fail... @dummdidumm you added that line here ...any insight?