feat(parse/tailwind): differentiate between number and non-number values

[dyc3]

Summary

This makes the tailwind parser parse values more precisely. Specifically, it lexes numbers as its own token and percentage values as their own syntax node. ratios were considered, but not included because there are still some edge cases that are too complicated for this PR.

Test Plan

snapshots

Docs

[changeset-bot]

⚠️ No Changeset found

Latest commit: 2467d2b

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[github-actions]

Parser conformance results on

js/262

Test result	main count	This PR count	Difference
Total	53208	53208	0
Passed	51990	51990	0
Failed	1176	1176	0
Panics	42	42	0
Coverage	97.71%	97.71%	0.00%

jsx/babel

Test result	main count	This PR count	Difference
Total	38	38	0
Passed	37	37	0
Failed	1	1	0
Panics	0	0	0
Coverage	97.37%	97.37%	0.00%

markdown/commonmark

Test result	main count	This PR count	Difference
Total	652	652	0
Passed	652	652	0
Failed	0	0	0
Panics	0	0	0
Coverage	100.00%	100.00%	0.00%

symbols/microsoft

Test result	main count	This PR count	Difference
Total	5467	5467	0
Passed	1915	1915	0
Failed	3552	3552	0
Panics	0	0	0
Coverage	35.03%	35.03%	0.00%

ts/babel

Test result	main count	This PR count	Difference
Total	658	658	0
Passed	574	574	0
Failed	84	84	0
Panics	0	0	0
Coverage	87.23%	87.23%	0.00%

ts/microsoft

Test result	main count	This PR count	Difference
Total	18876	18876	0
Passed	13010	13010	0
Failed	5865	5865	0
Panics	1	1	0
Coverage	68.92%	68.92%	0.00%

[codspeed-hq]

Merging this PR will not alter performance

✅ 10 untouched benchmarks
⏩ 246 skipped benchmarks¹

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_{Comparing dyc3/tw-parse-number-values (2467d2b) with main (ed26542)}

Footnotes

1. 246 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. ↩

[coderabbitai]

Walkthrough

This change extends the Tailwind parser to recognise and correctly parse numeric and percentage values. The lexer gains a TW_NUMBER token kind and now detects when consumed value or modifier spans contain only numeric characters, emitting TW_NUMBER instead of TW_VALUE and treating % as an explicit delimiter. The parser routes these numeric tokens to a new parse_numeric_value function that optionally consumes a trailing % to produce TW_NUMBER_VALUE or TW_PERCENTAGE_VALUE AST nodes. Grammar rules and type definitions are updated accordingly, with tests verifying both lexer tokenisation and end-to-end parsing of numeric and percentage Tailwind values.

Possibly related PRs

• biomejs/biome#10299: Directly overlapping changes to lexer and parser code for numeric and percentage Tailwind value recognition.

Suggested reviewers

• ematipico
• denbezrukov

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main feature: differentiating between number and non-number values in the Tailwind parser.
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.
Description check	✅ Passed	The PR description clearly explains the motivation (parse values more precisely by lexing numbers as distinct tokens and percentage values as syntax nodes) and directly relates to the changeset.

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✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch dyc3/tw-parse-number-values

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[coderabbitai]

🧹 Nitpick comments (1)

crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/ratio-value.txt (1)

1-1: 💤 Low value

Consider renaming this fixture.

The filename suggests a ratio value type, but w-3/4 is actually parsed as a number value (3) followed by a modifier (/4). Perhaps number-with-modifier.txt or fractional-modifier.txt would be clearer? Not a blocker, just a thought.

🤖 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_tailwind_parser/tests/tailwind_specs/ok/simple/ratio-value.txt`
at line 1, The fixture filename ratio-value.txt is misleading because the
content "w-3/4" parses as a numeric value with a fractional modifier; rename the
test file to something clearer (e.g., number-with-modifier.txt or
fractional-modifier.txt) and update any references to the fixture in tests or
test harness to use the new name so the filename matches the parsed token
structure.

🤖 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.

Nitpick comments:
In `@crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/ratio-value.txt`:
- Line 1: The fixture filename ratio-value.txt is misleading because the content
"w-3/4" parses as a numeric value with a fractional modifier; rename the test
file to something clearer (e.g., number-with-modifier.txt or
fractional-modifier.txt) and update any references to the fixture in tests or
test harness to use the new name so the filename matches the parsed token
structure.

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

Run ID: b28bb3ca-8d34-4aba-94b7-f621d2a74b01

📥 Commits

Reviewing files that changed from the base of the PR and between 9b1577f and 2467d2b.

⛔ Files ignored due to path filters (23)

• crates/biome_tailwind_factory/src/generated/node_factory.rs is excluded by !**/generated/**, !**/generated/** and included by **
• crates/biome_tailwind_factory/src/generated/syntax_factory.rs is excluded by !**/generated/**, !**/generated/** and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/error/arbitrary-candidate/missing-property.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/error/arbitrary-candidate/missing-value-in-arbitrary.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/brackets/css-values.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/brackets/gradient.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/candidates/arbitrary-candidate-0.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/candidates/arbitrary-candidate-1.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/candidates/arbitrary-candidate-2.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/gradients/precise-control.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/2-classes.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/modifier.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/negative.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/number-value.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/percentage-value.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/ratio-value.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/stress/stress-1.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/stress/stress-2.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/variants/consecutive-arbitrary-variants.txt.snap is excluded by !**/*.snap and included by **
• crates/biome_tailwind_syntax/src/generated/kind.rs is excluded by !**/generated/**, !**/generated/** and included by **
• crates/biome_tailwind_syntax/src/generated/macros.rs is excluded by !**/generated/**, !**/generated/** and included by **
• crates/biome_tailwind_syntax/src/generated/nodes.rs is excluded by !**/generated/**, !**/generated/** and included by **
• crates/biome_tailwind_syntax/src/generated/nodes_mut.rs is excluded by !**/generated/**, !**/generated/** and included by **

📒 Files selected for processing (8)

• crates/biome_tailwind_parser/src/lexer/mod.rs
• crates/biome_tailwind_parser/src/lexer/tests.rs
• crates/biome_tailwind_parser/src/syntax/value.rs
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/number-value.txt
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/percentage-value.txt
• crates/biome_tailwind_parser/tests/tailwind_specs/ok/simple/ratio-value.txt
• xtask/codegen/src/tailwind_kinds_src.rs
• xtask/codegen/tailwind.ungram