fix: Allow unquoted slash in attributes

[panyang05]

This pull request introduces the ability to allow unquoted slashes in attributes within the Svelte compiler. The key changes include modifications to the parser to handle unquoted slashes, as well as updates to the test cases to ensure this new feature is properly validated.

Changes to the Svelte compiler:

• packages/svelte/src/compiler/phases/1-parse/state/element.js: Modified the read_attribute function to handle unquoted slashes in attribute values. When it's an unquoted slash, parser will handle it as a quoted slash.

Updates to test cases:

• packages/svelte/tests/parser-legacy/samples/attribute-unquoted/input.svelte: Added a new test case for an anchor tag with an unquoted slash in the href attribute.
• packages/svelte/tests/parser-legacy/samples/attribute-unquoted/output.json: Updated the expected output JSON to reflect the new test case and ensure the parser correctly handles the unquoted slash. [1] [2]

Documentation:

• .changeset/long-boxes-flow.md: Added a changeset entry to document the new feature allowing unquoted slashes in attributes.

Issues Related:
#7782

[changeset-bot]

🦋 Changeset detected

Latest commit: ea9d4cf

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

[Rich-Harris]

preview: https://svelte-dev-git-preview-svelte-14615-svelte.vercel.app/

this is an automated message

[github-actions]

Playground

pnpm add https://pkg.pr.new/svelte@14615

[Rich-Harris]

Thank you — this fails with <a href=/foo>, any chance you can look into that and augment the test to cover both cases?

[panyang05]

Thank you — this fails with <a href=/foo>, any chance you can look into that and augment the test to cover both cases?

Hi, please let me know if this fixes the issue. Thanks!

[Rich-Harris]

perfect, thank you!