fix(html/astro): keep a blank after the frontmatter

[PFiS1737]

Summary

No AI

Biome now keeps a blank line after the frontmatter section in Astro files.

Fix #8038

Test Plan

I added some blank lines to the full_support test case to ensure that multiple blank lines are formatted into a single one.

Note that some snapshot files were removed — I guess this means some leftover differences with Prettier have been eliminated. 🎉

Docs

[changeset-bot]

🦋 Changeset detected

Latest commit: e660ad8

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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[coderabbitai]

Walkthrough

Added a changelog file and updated tests and formatter so Astro frontmatter is followed by a blank line. The Astro test fixture was extended with extra blank lines and an HTML snippet. In the HTML root formatter, frontmatter.format() is now followed by empty_line() instead of hard_line_break() when frontmatter is present. No public API or exported symbols changed.

Suggested reviewers

• ematipico
• dyc3

Pre-merge checks and finishing touches

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately and concisely describes the main change: keeping a blank line after frontmatter in Astro files, matching the core objective.
Description check	✅ Passed	The description clearly explains the fix, references the issue, outlines the test plan, and notes snapshot changes—all directly related to the changeset.
Linked Issues check	✅ Passed	The PR fully addresses issue #8038 by implementing blank line preservation after frontmatter in Astro files through formatter changes and test updates.
Out of Scope Changes check	✅ Passed	All changes are scoped to the frontmatter blank-line fix: changelog entry, test fixture updates, and formatter logic—no unrelated modifications detected.

✨ Finishing touches

• 📝 Generate docstrings

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Post copyable unit tests in a comment

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📜 Recent review details

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Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 48f26ca and e660ad8.

📒 Files selected for processing (1)

• crates/biome_html_formatter/src/html/auxiliary/root.rs (1 hunks)

🧰 Additional context used

🧠 Learnings (11)

📚 Learning: 2025-10-15T09:22:15.851Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:15.851Z
Learning: Applies to crates/biome_formatter/src/**/*.rs : After generation, remove usages of `format_verbatim_node` and implement real formatting with biome_formatter utilities

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-10-15T09:22:15.851Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:15.851Z
Learning: Applies to crates/biome_formatter/src/context.rs : Create HtmlFormatContext in context.rs with comments and source_map fields and implement FormatContext and CstFormatContext

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-10-15T09:22:15.851Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:15.851Z
Learning: Applies to crates/biome_formatter/src/cst.rs : Create FormatHtmlSyntaxNode in cst.rs implementing FormatRule<HtmlSyntaxNode> and AsFormat/IntoFormat for HtmlSyntaxNode using the provided plumbing

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-10-15T09:22:46.002Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:46.002Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : Import and use the `FormatNode` trait for AST nodes

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-10-15T09:22:15.851Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:15.851Z
Learning: Applies to crates/biome_formatter/src/lib.rs : Implement FormatLanguage for HtmlFormatLanguage with associated types: SyntaxLanguage=HtmlLanguage, Context=HtmlFormatContext, FormatRule=FormatHtmlSyntaxNode

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-10-15T09:22:15.851Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:15.851Z
Learning: Applies to crates/biome_formatter/src/lib.rs : Expose a documented public function `format_node(options: HtmlFormatOptions, root: &HtmlSyntaxNode) -> FormatResult<Formatted<HtmlFormatContext>>` delegating to `biome_formatter::format_node`

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-10-15T09:22:15.851Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:15.851Z
Learning: Applies to crates/biome_formatter/tests/language.rs : Create tests/language.rs defining `HtmlTestFormatLanguage` and implement the TestFormatLanguage trait

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-10-15T09:22:46.002Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:46.002Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : Do not attempt to fix code; if a mandatory token/node is missing, return `None` instead

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-10-15T09:22:15.851Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:15.851Z
Learning: Applies to crates/biome_formatter/src/lib.rs : Add the provided AsFormat, IntoFormat, and iterator plumbing code to lib.rs

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-10-15T09:22:15.851Z

Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-10-15T09:22:15.851Z
Learning: Applies to crates/biome_formatter/src/comments.rs : Define HtmlCommentStyle implementing CommentStyle in comments.rs

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

📚 Learning: 2025-09-13T16:16:06.459Z

Learnt from: ematipico
Repo: biomejs/biome PR: 7467
File: crates/biome_service/src/file_handlers/html.rs:456-466
Timestamp: 2025-09-13T16:16:06.459Z
Learning: In biome_formatter, consecutive LineMode::Hard elements are automatically collapsed to a single newline by the printer. The printer has a test "it_prints_consecutive_hard_lines_as_one" that demonstrates this behavior - multiple consecutive hard line breaks result in only one newline in the output, not extra blank lines.

Applied to files:

• crates/biome_html_formatter/src/html/auxiliary/root.rs

🧬 Code graph analysis (1)

crates/biome_html_formatter/src/html/auxiliary/root.rs (2)

crates/biome_html_syntax/src/generated/nodes.rs (1)

• frontmatter (618-620)

crates/biome_html_formatter/src/generated.rs (16)

• format (28-33)
• format (66-71)
• format (104-109)
• format (142-144)
• format (174-179)
• format (212-217)
• format (250-255)
• format (288-293)
• format (326-331)
• format (364-370)
• format (404-409)
• format (442-447)
• format (480-485)
• format (512-517)
• format (550-555)
• format (588-594)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (9)

• GitHub Check: Test (depot-ubuntu-24.04-arm-16)
• GitHub Check: Test (depot-windows-2022-16)
• GitHub Check: Documentation
• GitHub Check: End-to-end tests
• GitHub Check: Check Dependencies
• GitHub Check: Lint project (depot-windows-2022)
• GitHub Check: Lint project (depot-ubuntu-24.04-arm-16)
• GitHub Check: Test Node.js API
• GitHub Check: autofix

🔇 Additional comments (1)

crates/biome_html_formatter/src/html/auxiliary/root.rs (1)

20-22: Correct implementation of blank line after frontmatter.

The change from hard_line_break() to empty_line() properly inserts a blank line after the frontmatter section, as suggested in the previous review.

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[dyc3]

thank you!