[denbezrukov]

AI assistance was used for implementation, tests, and this description.

Summary

Fix parsing of unary and identifier-led binary expressions inside SCSS bracketed lists:

$gap: 8px;
$offsets: [-$gap, +$gap];
$flags: [not false, true and not false, foo == foo];

Test Plan

• cargo test -p biome_css_parser
• cargo test -p biome_css_formatter

[agentscanapp]

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• the description follows our PR template
• any related issues are linked
• existing tests still pass

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Latest commit: b6d5f35

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ℹ️ Recent review info

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📥 Commits

Reviewing files that changed from the base of the PR and between 4db3f58 and b6d5f35.

⛔ Files ignored due to path filters (6)

• crates/biome_css_formatter/tests/specs/scss/expression/parity-core-list-operands-identifier-operators.scss.snap is excluded by !**/*.snap and included by **
• crates/biome_css_formatter/tests/specs/scss/expression/parity-core-list-operands.scss.snap is excluded by !**/*.snap and included by **
• crates/biome_css_parser/tests/css_test_suite/error/scss/expression/parity-core-list-operands-recovery.scss.snap is excluded by !**/*.snap and included by **
• crates/biome_css_parser/tests/css_test_suite/ok/scss/expression/parity-core-list-operands-identifier-operators.scss.snap is excluded by !**/*.snap and included by **
• crates/biome_css_parser/tests/css_test_suite/ok/scss/expression/parity-core-list-operands.scss.snap is excluded by !**/*.snap and included by **
• crates/biome_css_parser/tests/css_test_suite/ok/value/parity-core-list-operands.css.snap is excluded by !**/*.snap and included by **

📒 Files selected for processing (11)

• crates/biome_css_formatter/tests/specs/scss/expression/parity-core-list-operands-identifier-operators.scss
• crates/biome_css_formatter/tests/specs/scss/expression/parity-core-list-operands.scss
• crates/biome_css_parser/src/syntax/mod.rs
• crates/biome_css_parser/src/syntax/scss/expression/mod.rs
• crates/biome_css_parser/src/syntax/scss/expression/precedence.rs
• crates/biome_css_parser/src/syntax/scss/mod.rs
• crates/biome_css_parser/src/syntax/scss/value/mod.rs
• crates/biome_css_parser/tests/css_test_suite/error/scss/expression/parity-core-list-operands-recovery.scss
• crates/biome_css_parser/tests/css_test_suite/ok/scss/expression/parity-core-list-operands-identifier-operators.scss
• crates/biome_css_parser/tests/css_test_suite/ok/scss/expression/parity-core-list-operands.scss
• crates/biome_css_parser/tests/css_test_suite/ok/value/parity-core-list-operands.css

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Walkthrough

The parser now recognises unary and identifier-led SCSS expressions in bracketed values, while preserving CSS grid-line identifiers. New fixtures cover parsing, malformed-expression recovery, and formatting.

Priority: ⬇️ Low

Change: Bug fix

Merge Risk: ⚪ Minimal · up to b6d5f

No concrete merge-blocking behavior is established by the supplied change context; the added fixtures cover the stated parsing and formatting cases.

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly identifies the fix for unary and identifier-led SCSS list expressions.
Description check	✅ Passed	The description explains the SCSS parsing fix, gives examples and lists the test commands.
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.

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• Commit to this branch
• Create a new PR

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[codspeed]

Merging this PR will not alter performance

✅ 65 untouched benchmarks
⏩ 348 skipped benchmarks¹

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_{Comparing dbezrukov/scss-p04-list-operands (b6d5f35) with main (aaf4c81)}

Footnotes

1. 348 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩