feat(format/yaml): flow collection blank lines and spacing by dyc3 · Pull Request #11064 · biomejs/biome

dyc3 · 2026-07-23T21:14:51Z

Summary

fixes a bunch of spacing/blank-line quirks in flow context

implemented by fable 5

Test Plan

updated snapshots

Docs

changeset-bot · 2026-07-23T21:14:55Z

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Latest commit: ddef529

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github-actions · 2026-07-23T21:15:01Z

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_{This is an automated analysis by AgentScan}

Blank lines between flow entries now survive only when the collection breaks: they print as literal line breaks behind if_group_breaks, so they no longer force `{ a,\n\nb }` to expand. A comment right after the opening bracket on a mapping key's line ends that line, as Prettier treats it. Also matches Prettier's spacing quirks: `[ : ]` becomes `[: ]`, a tag with empty content keeps its separating space (`{ foo: !!str , ... }`), and an empty sequence entry with an inline comment gets a double space (`- # comment`). Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01472YxeN6U2t4LWfaqkieAv

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01472YxeN6U2t4LWfaqkieAv

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017JxH5Z1zv28qj1CcHABVee

coderabbitai · 2026-07-28T20:23:23Z

Walkthrough

Updates YAML comment placement for flow collections beginning on mapping key lines. Adds spacing for empty block and flow entries, preserves separators and blank lines in flow collections, and updates YAML fixtures covering empty entries and collapsed or retained empty lines.

Possibly related PRs

biomejs/biome#10989: Updates the same YAML comment-placement dispatch chain.
biomejs/biome#10814: Modifies flow-sequence entry separator formatting.
biomejs/biome#11011: Overlaps with flow-mapping implicit-entry and value-less formatting.

Suggested reviewers: ematipico, siketyan

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly reflects the main YAML formatter change around flow collection blank lines and spacing.
Description check	✅ Passed	The description matches the PR and mentions fixing spacing and blank-line quirks in flow context.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

✨ Finishing Touches

🧪 Generate unit tests (beta)

Create PR with unit tests
Commit unit tests in branch dyc3/yaml-fmt-flow-spacing

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coderabbitai

Actionable comments posted: 2

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@crates/biome_yaml_formatter/src/comments.rs`:
- Around line 159-162: Update the on_key_line calculation in the
comment-handling logic to require enclosing to be the immediate mapping value,
replacing the ancestor-wide match that also accepts nested flow collections.
Preserve the existing line-token condition, and add a regression test covering a
comment after an inner opening bracket to ensure it is not moved to the outer
mapping key.

In `@crates/biome_yaml_formatter/src/yaml/auxiliary/block_sequence_entry.rs`:
- Around line 14-24: Add snapshot coverage for the formatter branches in
crates/biome_yaml_formatter/src/yaml/auxiliary/block_sequence_entry.rs:14-24 by
adding a block-sequence “- # comment” fixture, and in
crates/biome_yaml_formatter/src/yaml/lists/flow_map_entry_list.rs:22-36 by
adding both collapsed and expanded blank-line flow-mapping cases. Ensure the
snapshots cover the relevant valid and invalid formatter inputs.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

Push a commit to this branch (recommended)
Create a new PR with the fixes

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: 2bd0cdd8-0c2e-499e-a03a-e062c53bc645

📥 Commits

Reviewing files that changed from the base of the PR and between 61e35a3 and ddef529.

⛔ Files ignored due to path filters (8)

crates/biome_yaml_formatter/tests/specs/prettier/yaml/flow-mapping/empty-line-collapse.yml.snap is excluded by !**/*.snap and included by **
crates/biome_yaml_formatter/tests/specs/prettier/yaml/flow-sequence/empty-item-colon.yml.snap is excluded by !**/*.snap and included by **
crates/biome_yaml_formatter/tests/specs/prettier/yaml/flow-sequence/empty-line-collapse.yml.snap is excluded by !**/*.snap and included by **
crates/biome_yaml_formatter/tests/specs/prettier/yaml/spec/spec-example-6-1-indentation-spaces.yml.snap is excluded by !**/*.snap and included by **
crates/biome_yaml_formatter/tests/specs/prettier/yaml/spec/spec-example-7-2-empty-content.yml.snap is excluded by !**/*.snap and included by **
crates/biome_yaml_formatter/tests/specs/prettier/yaml/spec/spec-example-8-15-block-sequence-entry-types.yml.snap is excluded by !**/*.snap and included by **
crates/biome_yaml_formatter/tests/specs/yaml/flow/empty_entries.yaml.snap is excluded by !**/*.snap and included by **
crates/biome_yaml_formatter/tests/specs/yaml/flow/flow_sequence_formatting.yaml.snap is excluded by !**/*.snap and included by **

📒 Files selected for processing (9)

crates/biome_yaml_formatter/src/comments.rs
crates/biome_yaml_formatter/src/utils.rs
crates/biome_yaml_formatter/src/yaml/auxiliary/block_sequence_entry.rs
crates/biome_yaml_formatter/src/yaml/auxiliary/flow_map_implicit_entry.rs
crates/biome_yaml_formatter/src/yaml/auxiliary/flow_yaml_node.rs
crates/biome_yaml_formatter/src/yaml/lists/flow_map_entry_list.rs
crates/biome_yaml_formatter/src/yaml/lists/flow_sequence_entry_list.rs
crates/biome_yaml_formatter/tests/specs/yaml/flow/empty_entries.yaml
crates/biome_yaml_formatter/tests/specs/yaml/flow/flow_sequence_formatting.yaml

coderabbitai · 2026-07-28T20:23:26Z

+    let on_key_line = enclosing
+        .ancestors()
+        .any(|ancestor| ancestor == *value.syntax())
+        && lines_before_through_end_tokens(value.syntax()) == 0;


🎯 Functional Correctness | 🟠 Major | ⚡ Quick win

Restrict this to the immediate mapping value.

ancestors().any(...) also matches nested flow collections, so a comment after an inner opening bracket can be moved to the outer mapping key. Require direct containment instead, and add a nested regression case.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the rest with a brief reason, keep changes minimal, and validate. In `@crates/biome_yaml_formatter/src/comments.rs` around lines 159 - 162, Update the on_key_line calculation in the comment-handling logic to require enclosing to be the immediate mapping value, replacing the ancestor-wide match that also accepts nested flow collections. Preserve the existing line-token condition, and add a regression test covering a comment after an inner opening bracket to ensure it is not moved to the outer mapping key.

coderabbitai · 2026-07-28T20:23:26Z

+        // An entry without a value but with a comment on its line still gets
+        // the space that would separate the value from the `-`, so the
+        // comment ends up two columns over: `-  # comment`
+        if value.is_none()
+            && f.comments()
+                .dangling_comments(node.syntax())
+                .first()
+                .is_some_and(|comment| comment.lines_before() == 0)
+        {
+            write!(f, [text(" ", None)])?;
+        }


📐 Maintainability & Code Quality | 🟠 Major | ⚡ Quick win

Add snapshots for these unexercised formatter branches.

crates/biome_yaml_formatter/src/yaml/auxiliary/block_sequence_entry.rs#L14-L24: add a block sequence - # comment fixture.

crates/biome_yaml_formatter/src/yaml/lists/flow_map_entry_list.rs#L22-L36: add collapsed and expanded blank-line cases for a flow mapping.

As per coding guidelines, “All code changes must include appropriate tests”; formatter changes also require snapshot coverage for valid and invalid cases.

📍 Affects 2 files

crates/biome_yaml_formatter/src/yaml/auxiliary/block_sequence_entry.rs#L14-L24 (this comment)

crates/biome_yaml_formatter/src/yaml/lists/flow_map_entry_list.rs#L22-L36

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the rest with a brief reason, keep changes minimal, and validate. In `@crates/biome_yaml_formatter/src/yaml/auxiliary/block_sequence_entry.rs` around lines 14 - 24, Add snapshot coverage for the formatter branches in crates/biome_yaml_formatter/src/yaml/auxiliary/block_sequence_entry.rs:14-24 by adding a block-sequence “- # comment” fixture, and in crates/biome_yaml_formatter/src/yaml/lists/flow_map_entry_list.rs:22-36 by adding both collapsed and expanded blank-line flow-mapping cases. Ensure the snapshots cover the relevant valid and invalid formatter inputs.

Source: Coding guidelines

@dyc3 is this relevant?

ematipico · 2026-07-29T08:01:19Z

+        // An entry without a value but with a comment on its line still gets
+        // the space that would separate the value from the `-`, so the
+        // comment ends up two columns over: `-  # comment`
+        if value.is_none()
+            && f.comments()
+                .dangling_comments(node.syntax())
+                .first()
+                .is_some_and(|comment| comment.lines_before() == 0)
+        {
+            write!(f, [text(" ", None)])?;
+        }


@dyc3 is this relevant?

github-actions Bot added A-Formatter Area: formatter L-Yaml Language: Yaml labels Jul 23, 2026

dyc3 force-pushed the dyc3/yaml-fmt-flow-spacing branch from 69ce2d4 to a90cbe7 Compare July 25, 2026 19:48

dyc3 marked this pull request as ready for review July 25, 2026 19:51

ematipico reviewed Jul 26, 2026

View reviewed changes

Comment thread crates/biome_yaml_formatter/src/utils.rs Outdated

Comment thread crates/biome_yaml_formatter/src/comments.rs Outdated

dyc3 force-pushed the dyc3/yaml-fmt-flow-spacing branch 2 times, most recently from 3c84655 to f869e74 Compare July 27, 2026 11:57

Base automatically changed from dyc3/yaml-fmt-middle-comments to main July 28, 2026 20:17

dyc3 and others added 4 commits July 28, 2026 16:18

refactor(format/yaml): apply review conventions to flow spacing

12b8289

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01472YxeN6U2t4LWfaqkieAv

docs(format/yaml): reword flow spacing comments

8630515

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017JxH5Z1zv28qj1CcHABVee

docs(format/yaml): clarify line break counting doc

ddef529

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_017JxH5Z1zv28qj1CcHABVee

dyc3 force-pushed the dyc3/yaml-fmt-flow-spacing branch from f869e74 to ddef529 Compare July 28, 2026 20:19

coderabbitai Bot reviewed Jul 28, 2026

View reviewed changes

dyc3 requested a review from ematipico July 29, 2026 01:13

ematipico approved these changes Jul 29, 2026

View reviewed changes

dyc3 merged commit cba196d into main Jul 29, 2026
27 checks passed

dyc3 deleted the dyc3/yaml-fmt-flow-spacing branch July 29, 2026 14:03

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feat(format/yaml): flow collection blank lines and spacing - #11064

feat(format/yaml): flow collection blank lines and spacing#11064
dyc3 merged 4 commits into
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dyc3/yaml-fmt-flow-spacing

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