fix: remove 'implements' from class declaration

[ciscorn]

related: #14743 #14744 @Rich-Harris

This PR fixes a compilation issue that occurs when esrap 1.3.0 or later is used.

When compiling the following component...

<script lang="ts">
  interface MyInterface {}
  class MyClass implements MyInterface {}
</script>

<p>hello</p>

...the following error occurs:

error during build:
src/routes/Component.svelte (4:26): Expected '{', got 'implements' (Note that you need plugins to import files that are not JavaScript)
file: /***/***/***/src/routes/Component.svelte:4:26

2:   interface MyInterface {}
3: 
4:   class MyClass implements MyInterface {}

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• 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
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• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.
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Tests and linting

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

[changeset-bot]

🦋 Changeset detected

Latest commit: 54ba0bb

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

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svelte	Patch

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[github-actions]

Playground

pnpm add https://pkg.pr.new/svelte@14749

[paoloricciuti]

I think it make sense...can you add a test for this?

[ciscorn]

@paoloricciuti Thanks

Of course, I’d like to add a test, but I can’t figure out the appropriate place for it.
Looks like the preceding hotfix (#14744) didn’t include tests either.

[paoloricciuti]

@paoloricciuti Thanks

Of course, I’d like to add a test, but I can’t figure out the appropriate place for it. Looks like the preceding hotfix (#14744) didn’t include tests either.

I would just add a "smoke test" in /packages/svelte/tests/runtime-browser/samples/. You can create a new folder, give it a descriptive name and create a

main.svelte

<script lang="ts">
	interface MyInterface {}
	class MyClass implements MyInterface {}
</script>

and
_config.js

import { test } from '../../assert';

export default test({});

this is failing on main and should not in you branch.

[ciscorn]

@paoloricciuti

Many thanks for your kind guidance! I’ve added the test as suggested.

I’ve also confirmed it fails on the main branch.

[paoloricciuti]

@paoloricciuti

Many thanks for your kind guidance! I’ve added the test as suggested.

I’ve also confirmed it fails on the main branch.

Great...let's wait on greens! Thanks a lot!