fix(html): skip unsupported <script> types instead of treating as JS (fixes #9506, #9479)

[shivamtiwari3]

Summary

Fixes #9506
Fixes #9479.

The embed registry's script element detector was using fallback: Some(GuestLanguage::JsScript) in its EmbedTarget::Dynamic config. When resolve_script_language returned None for types like speculationrules or application/ld+json (which are ScriptType::Unsupported), EmbedTarget::resolve() applied the JsScript fallback via .or(*fallback), causing biome to parse non-JavaScript content as JavaScript.

---

Root Cause

In crates/biome_service/src/embed/registry.rs, HTML_DETECTORS had:

EmbedDetector::Element {
    tag: "script",
    target: EmbedTarget::Dynamic {
        resolver: resolve_script_language,
        fallback: Some(GuestLanguage::JsScript),  // ← problem
    },
},

resolve_script_language correctly returns None for ScriptType::Unsupported types (line if !script_type.is_javascript() { return None; }). However, EmbedTarget::resolve() applies the fallback when the resolver returns None:

Self::Dynamic { resolver, fallback } => resolver(candidate, file_source).or(*fallback),

So speculationrules and application/ld+json content was being passed to the JavaScript parser, producing false parse errors and incorrect lint diagnostics.

---

Solution

Remove the fallback (fallback: None). The resolve_script_language function already returns a correct GuestLanguage for every legitimate JavaScript script case — it only returns None for unsupported types or non-HTML file sources, both of which should mean "skip this element".

---

Testing

• Added no_diagnostics_for_unsupported_script_types in crates/biome_service/src/workspace/server.tests.rs that reproduces the exact scenario from both issues: an HTML file containing <script type="speculationrules"> and <script type="application/ld+json"> blocks. The test asserts zero diagnostics are returned.
• All existing biome_service tests (98) and biome_html_formatter tests (127) pass.

---

Checklist

• Fixes the root cause (not just the symptom)
• New test covers the exact failing scenario from the issues
• All existing tests pass
• No unrelated changes
• Code style matches project conventions
• Read CONTRIBUTING.md and followed its requirements

---

This PR was written primarily by Claude Code.

[changeset-bot]

🦋 Changeset detected

Latest commit: 6d3a70d

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

This PR includes changesets to release 13 packages

Name	Type
@biomejs/biome	Patch
@biomejs/cli-win32-x64	Patch
@biomejs/cli-win32-arm64	Patch
@biomejs/cli-darwin-x64	Patch
@biomejs/cli-darwin-arm64	Patch
@biomejs/cli-linux-x64	Patch
@biomejs/cli-linux-arm64	Patch
@biomejs/cli-linux-x64-musl	Patch
@biomejs/cli-linux-arm64-musl	Patch
@biomejs/wasm-web	Patch
@biomejs/wasm-bundler	Patch
@biomejs/wasm-nodejs	Patch
@biomejs/backend-jsonrpc	Patch

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[ematipico]

Thank you. I know the fix was simple :)

[coderabbitai]

Walkthrough

This pull request fixes false parse errors reported by Biome for unsupported HTML script types. Changes include modifying the script and style detector fallbacks from returning a default guest language to returning None, which signals to skip unsupported types entirely. Documentation has been expanded to clarify which script types are handled (speculationrules, application/ld+json, text/x-handlebars-\*) and how the resolver determines embedding behaviour. Regression tests validate that these script types no longer produce spurious diagnostics.

Suggested labels

A-Project, A-Parser, L-HTML

Suggested reviewers

• ematipico
• dyc3

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarises the main fix: removing the incorrect JsScript fallback for unsupported script types like speculationrules and application/ld+json.
Linked Issues check	✅ Passed	The PR successfully addresses both linked issues (#9506 and #9479) by removing the incorrect fallback that caused false parse errors for unsupported script types like speculationrules and application/ld+json.
Out of Scope Changes check	✅ Passed	All changes are directly scoped to fixing the embed registry's script detector fallback behaviour. The changeset entry, registry modifications, and regression test are all focused on the stated problem.
Description check	✅ Passed	The description comprehensively explains the root cause, solution, and testing approach for fixing false parse errors in unsupported script types.

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