Fix value property to return undefined for nodes without value concept by bartveneman · Pull Request #260 · projectwallace/css-parser

bartveneman · 2026-06-24T19:15:51Z

Summary

Fixed a regression where certain CSS node types were incorrectly returning null instead of undefined for their value property. This distinction is semantically important: null means "has a value, but it is absent", while undefined means "value is not a property of this node type".

Key Changes

Updated CSSNode.value getter in src/css-node.ts to explicitly return undefined for node types that don't have a value concept, rather than attempting to read from the arena value fields
Added comprehensive regression tests in src/api.test.ts covering 20+ node types that should return undefined for their value property, including:
- Structural nodes: StyleSheet, Rule, Block, SelectorList, Selector
- Selector types: TypeSelector, ClassSelector, IdSelector, PseudoClassSelector, PseudoElementSelector, UniversalSelector, Combinator, Nth
- Value nodes: Value, Identifier, Hash, String
- At-rule nodes: Atrule, MediaQuery
- Other nodes: Raw

Implementation Details

The fix adds an explicit type check that returns undefined early for all node types except the five that actually store values in the arena:

DECLARATION
FUNCTION
ATTRIBUTE_SELECTOR
SUPPORTS_QUERY
PRELUDE_SELECTORLIST

This ensures the correct semantic distinction between nodes that have no value concept (undefined) and nodes that have a value but it's empty (null).

https://claude.ai/code/session_01KETKttcckhFQtg8JzjxvuU

…lue concept Node types like SelectorList, TypeSelector, Selector, Block, etc. have no value property in their type definitions. The value getter was falling through to the arena lookup and returning null (length === 0) for these nodes when it should return undefined, since null signals "has a value field but it is absent" while undefined signals "value is not a property of this node type at all". Added a guard in the value getter so only DECLARATION, FUNCTION, ATTRIBUTE_SELECTOR, SUPPORTS_QUERY, and PRELUDE_SELECTORLIST reach the arena value_start/value_length lookup. All other types now correctly return undefined. Added 20 regression tests covering the reported node types and representatives from every category (structural, selector, value, at-rule). Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KETKttcckhFQtg8JzjxvuU

github-actions · 2026-06-24T19:16:28Z

⚠️ Duplicate Dependencies (found: 35, threshold: 1)

📦 Package	📋 Versions
tinybench	2 versions root@ @vitest/coverage-v8@4.1.9 vitest@4.1.9 tinybench@2.9.0 root@ tinybench@6.0.2
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@rolldown/binding-wasm32-wasi	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-wasm32-wasi@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-wasm32-wasi@1.1.2
obug	2 versions root@ @vitest/coverage-v8@4.1.9 obug@2.1.1 root@ tsdown@0.22.3 obug@2.1.3
picomatch	2 versions root@ tailwindcss@2.2.19 chokidar@3.6.0 anymatch@3.1.3 picomatch@2.3.2 root@ @vitest/coverage-v8@4.1.9 vitest@4.1.9 @vitest/mocker@4.1.9 vite@8.0.16 picomatch@4.0.4
postcss-value-parser	2 versions root@ tailwindcss@2.2.19 reduce-css-calc@2.1.8 postcss-value-parser@3.3.1 root@ tailwindcss@2.2.19 autoprefixer@10.4.23 postcss-value-parser@4.2.0
glob-parent	2 versions root@ tailwindcss@2.2.19 chokidar@3.6.0 glob-parent@5.1.2 root@ tailwindcss@2.2.19 glob-parent@6.0.2
yaml	2 versions root@ tailwindcss@2.2.19 cosmiconfig@7.1.0 yaml@1.10.3 root@ @vitest/coverage-v8@4.1.9 vitest@4.1.9 @vitest/mocker@4.1.9 vite@8.0.16 yaml@2.9.0
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rolldown	2 versions root@ @vitest/coverage-v8@4.1.9 vitest@4.1.9 @vitest/mocker@4.1.9 vite@8.0.16 rolldown@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2
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@rolldown/binding-darwin-arm64	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-darwin-arm64@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-darwin-arm64@1.1.2
@rolldown/binding-darwin-x64	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-darwin-x64@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-darwin-x64@1.1.2
@rolldown/binding-freebsd-x64	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-freebsd-x64@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-freebsd-x64@1.1.2
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@rolldown/binding-linux-s390x-gnu	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-linux-s390x-gnu@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-linux-s390x-gnu@1.1.2
@rolldown/binding-linux-x64-gnu	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-linux-x64-gnu@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-linux-x64-gnu@1.1.2
@rolldown/binding-linux-x64-musl	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-linux-x64-musl@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-linux-x64-musl@1.1.2
@rolldown/binding-openharmony-arm64	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-openharmony-arm64@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-openharmony-arm64@1.1.2
@rolldown/binding-win32-arm64-msvc	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-win32-arm64-msvc@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-win32-arm64-msvc@1.1.2
@rolldown/binding-win32-x64-msvc	2 versions root@ @vitest/coverage-v8@4.1.9 ... vite@8.0.16 rolldown@1.0.3 @rolldown/binding-win32-x64-msvc@1.0.3 root@ tsdown@0.22.3 rolldown@1.1.2 @rolldown/binding-win32-x64-msvc@1.1.2
tinyexec	2 versions root@ @vitest/coverage-v8@4.1.9 vitest@4.1.9 tinyexec@1.1.2 root@ tsdown@0.22.3 tinyexec@1.2.4

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⚠️ Package Size Increase

📦 Package	📏 Base Size	📏 Source Size	📈 Size Change
@projectwallace/css-parser	41 kB	41 kB	+12 B

TypeScript correctly rejects .value access on types that omit the property (StyleSheet, Rule, SelectorList, etc.) — that's the whole point. Tests that verify the runtime getter returns undefined must cast through the base CSSNode class, which has the generic value getter. Use a local get_value() helper to avoid repeating the cast on every assertion. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01KETKttcckhFQtg8JzjxvuU

bartveneman merged commit 355d077 into main Jun 24, 2026
8 checks passed

bartveneman deleted the claude/laughing-hawking-opc13h branch June 24, 2026 19:26

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Fix value property to return undefined for nodes without value concept#260

Fix value property to return undefined for nodes without value concept#260
bartveneman merged 2 commits into
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claude/laughing-hawking-opc13h

bartveneman commented Jun 24, 2026

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bartveneman commented Jun 24, 2026

Summary

Key Changes

Implementation Details

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github-actions Bot commented Jun 24, 2026

⚠️ Duplicate Dependencies (found: 35, threshold: 1)

⚠️ Package Size Increase

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