fix(parse/css): slightly better recovery for @apply
#8725
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🦋 Changeset detectedLatest commit: 35ee91c The changes in this PR will be included in the next version bump. This PR includes changesets to release 13 packages
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WalkthroughThe changes introduce improved CSS parser recovery for Tailwind's Suggested labels
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🧹 Nitpick comments (2)
crates/biome_css_parser/src/lexer/mod.rs (1)
1364-1371: Consider also terminating utilities on{for robustness. Right now a{encountered mid scan would be consumed intoident; addingBEOto the break set would make recovery more predictable on malformed inputs.Proposed tweak
- match dispatched { - WHS | SEM | BEC => break, - _ => {} - } + match dispatched { + WHS | SEM | BEO | BEC => break, + _ => {} + }crates/biome_css_parser/src/syntax/at_rule/tailwind.rs (1)
165-178: Good centralisation of@applylist boundaries viaTW_APPLY_CLASS_LIST_END. Also, this can likely be aconst(no need forstatic).Proposed tweak
-static TW_APPLY_CLASS_LIST_END: TokenSet<CssSyntaxKind> = token_set![T![;], T!['}']]; +const TW_APPLY_CLASS_LIST_END: TokenSet<CssSyntaxKind> = token_set![T![;], T!['}']];
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crates/biome_css_parser/tests/css_test_suite/error/tailwind/when-enabled/apply-missing-semicolon.css.snapis excluded by!**/*.snapand included by**
📒 Files selected for processing (4)
.changeset/easy-ears-guess.mdcrates/biome_css_parser/src/lexer/mod.rscrates/biome_css_parser/src/syntax/at_rule/tailwind.rscrates/biome_css_parser/tests/css_test_suite/error/tailwind/when-enabled/apply-missing-semicolon.css
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📓 Path-based instructions (1)
**/*.rs
📄 CodeRabbit inference engine (CONTRIBUTING.md)
**/*.rs: Use inline rustdoc documentation for rules, assists, and their options
Use thedbg!()macro for debugging output in Rust tests and code
Use doc tests (doctest) format with code blocks in rustdoc comments; ensure assertions pass in tests
Files:
crates/biome_css_parser/src/syntax/at_rule/tailwind.rscrates/biome_css_parser/src/lexer/mod.rs
🧠 Learnings (18)
📓 Common learnings
Learnt from: ematipico
Repo: biomejs/biome PR: 7852
File: crates/biome_css_parser/src/syntax/property/mod.rs:161-168
Timestamp: 2025-10-25T07:22:18.540Z
Learning: In the Biome CSS parser, lexer token emission should not be gated behind parser options like `is_tailwind_directives_enabled()`. The lexer must emit correct tokens regardless of parser options to enable accurate diagnostics and error messages when the syntax is used incorrectly.
📚 Learning: 2025-11-24T18:06:03.545Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Implement error recovery in list parsing using `or_recover()` to wrap unparseable tokens in a `BOGUS_*` node and consume tokens until a recovery token is found
Applied to files:
crates/biome_css_parser/src/syntax/at_rule/tailwind.rscrates/biome_css_parser/src/lexer/mod.rs
📚 Learning: 2025-11-24T18:06:03.545Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Use `ParseSeparatedList` and `ParseNodeList` for parsing lists with error recovery to avoid infinite loops
Applied to files:
crates/biome_css_parser/src/syntax/at_rule/tailwind.rscrates/biome_css_parser/src/lexer/mod.rs
📚 Learning: 2025-11-24T18:06:03.545Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Use `p.eat(token)` for optional tokens, `p.expect(token)` for required tokens, `parse_rule(p).ok(p)` for optional nodes, and `parse_rule(p).or_add_diagnostic(p, error)` for required nodes
Applied to files:
crates/biome_css_parser/src/syntax/at_rule/tailwind.rscrates/biome_css_parser/src/lexer/mod.rs
📚 Learning: 2025-11-24T18:06:03.545Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Implement a token source struct that wraps the lexer and implements `TokenSourceWithBufferedLexer` and `LexerWithCheckpoint` for lookahead and re-lexing capabilities
Applied to files:
crates/biome_css_parser/src/syntax/at_rule/tailwind.rscrates/biome_css_parser/src/lexer/mod.rs
📚 Learning: 2025-11-24T18:05:27.810Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:27.810Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : When formatting AST nodes, use mandatory tokens from the AST instead of hardcoding token strings (e.g., use `node.l_paren_token().format()` instead of `token("(")`)
Applied to files:
crates/biome_css_parser/src/syntax/at_rule/tailwind.rscrates/biome_css_parser/src/lexer/mod.rs
📚 Learning: 2025-10-25T07:22:18.540Z
Learnt from: ematipico
Repo: biomejs/biome PR: 7852
File: crates/biome_css_parser/src/syntax/property/mod.rs:161-168
Timestamp: 2025-10-25T07:22:18.540Z
Learning: In the Biome CSS parser, lexer token emission should not be gated behind parser options like `is_tailwind_directives_enabled()`. The lexer must emit correct tokens regardless of parser options to enable accurate diagnostics and error messages when the syntax is used incorrectly.
Applied to files:
crates/biome_css_parser/src/syntax/at_rule/tailwind.rscrates/biome_css_parser/src/lexer/mod.rs.changeset/easy-ears-guess.mdcrates/biome_css_parser/tests/css_test_suite/error/tailwind/when-enabled/apply-missing-semicolon.css
📚 Learning: 2025-11-24T18:06:03.545Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : Parse rules must return `ParsedSyntax::Absent` if the rule can't predict by the next token(s) if they form the expected node, and must not progress the parser in this case
Applied to files:
crates/biome_css_parser/src/syntax/at_rule/tailwind.rs
📚 Learning: 2025-11-24T18:06:03.545Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/src/**/*.rs : A parser struct must implement the `Parser` trait and save the token source, parser context, and optional parser options
Applied to files:
crates/biome_css_parser/src/syntax/at_rule/tailwind.rs
📚 Learning: 2025-11-24T18:06:03.545Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_parser/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:06:03.545Z
Learning: Applies to crates/biome_parser/**/lexer/mod.rs : Implement a `Lexer` trait from `biome_parser` crate for the lexer struct that consumes characters from source code and emits tokens
Applied to files:
crates/biome_css_parser/src/lexer/mod.rs
📚 Learning: 2025-11-24T18:05:27.810Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:27.810Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : For tokens that are not mandatory, use helper functions instead of hardcoding
Applied to files:
crates/biome_css_parser/src/lexer/mod.rs
📚 Learning: 2025-11-09T12:47:46.298Z
Learnt from: ematipico
Repo: biomejs/biome PR: 8031
File: crates/biome_html_parser/src/syntax/svelte.rs:140-147
Timestamp: 2025-11-09T12:47:46.298Z
Learning: In the Biome HTML parser, `expect` and `expect_with_context` consume the current token and then lex the next token. The context parameter in `expect_with_context` controls how the next token (after the consumed one) is lexed, not the current token being consumed. For example, in Svelte parsing, after `bump_with_context(T!["{:"], HtmlLexContext::Svelte)`, the next token is already lexed in the Svelte context, so `expect(T![else])` is sufficient unless the token after `else` also needs to be lexed in a specific context.
Applied to files:
crates/biome_css_parser/src/lexer/mod.rs
📚 Learning: 2025-11-24T18:05:27.810Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_js_formatter/CONTRIBUTING.md:0-0
Timestamp: 2025-11-24T18:05:27.810Z
Learning: Applies to crates/biome_js_formatter/**/*.rs : Do not attempt to 'fix' the code; if a token/node is known to be mandatory but is missing, return `None` instead
Applied to files:
crates/biome_css_parser/src/lexer/mod.rs
📚 Learning: 2025-12-21T21:15:03.796Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: CONTRIBUTING.md:0-0
Timestamp: 2025-12-21T21:15:03.796Z
Learning: Changesets should be concise (1-3 sentences) and provide quick overview of changes without overwhelming details
Applied to files:
.changeset/easy-ears-guess.md
📚 Learning: 2025-12-21T21:15:03.796Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: CONTRIBUTING.md:0-0
Timestamp: 2025-12-21T21:15:03.796Z
Learning: Changesets should describe user-facing changes only; internal refactoring without behavior changes does not require a changeset
Applied to files:
.changeset/easy-ears-guess.md
📚 Learning: 2025-08-05T14:43:29.581Z
Learnt from: dyc3
Repo: biomejs/biome PR: 7081
File: packages/@biomejs/biome/configuration_schema.json:7765-7781
Timestamp: 2025-08-05T14:43:29.581Z
Learning: The file `packages/biomejs/biome/configuration_schema.json` is auto-generated and should not be manually edited or reviewed for schema issues; any changes should be made at the code generation source.
Applied to files:
.changeset/easy-ears-guess.md
📚 Learning: 2025-12-04T13:29:49.287Z
Learnt from: dyc3
Repo: biomejs/biome PR: 8291
File: crates/biome_html_formatter/tests/specs/prettier/vue/html-vue/elastic-header.html:10-10
Timestamp: 2025-12-04T13:29:49.287Z
Learning: Files under `crates/biome_html_formatter/tests/specs/prettier` are test fixtures synced from Prettier and should not receive detailed code quality reviews (e.g., HTTP vs HTTPS, formatting suggestions, etc.). These files are test data meant to validate formatter behavior and should be preserved as-is.
Applied to files:
crates/biome_css_parser/tests/css_test_suite/error/tailwind/when-enabled/apply-missing-semicolon.css
📚 Learning: 2026-01-02T14:58:16.536Z
Learnt from: CR
Repo: biomejs/biome PR: 0
File: crates/biome_analyze/CONTRIBUTING.md:0-0
Timestamp: 2026-01-02T14:58:16.536Z
Learning: Applies to crates/biome_analyze/**/tests/specs/**/* : Create test files with `invalid` and `valid` prefixes to represent code that should and should not trigger the rule
Applied to files:
crates/biome_css_parser/tests/css_test_suite/error/tailwind/when-enabled/apply-missing-semicolon.css
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🔇 Additional comments (4)
.changeset/easy-ears-guess.md (1)
1-5: Nice, concise changeset that explains the user-visible fix.crates/biome_css_parser/src/lexer/mod.rs (1)
1353-1357: Good: treat{/}as real tokens inTailwindUtilitycontext. This should stop the lexer from “eating” the block close into the@applytoken.crates/biome_css_parser/tests/css_test_suite/error/tailwind/when-enabled/apply-missing-semicolon.css (1)
1-3: Perfect minimal repro fixture for the missing-semicolon recovery.crates/biome_css_parser/src/syntax/at_rule/tailwind.rs (1)
180-191: Recovery using the same end-token set (+ line-break recovery) is a solid upgrade. Please just sanity-check that the missing;path leaves}untouched so the surrounding block closes normally (i.e. no token “smearing”).
ematipico
approved these changes
Jan 10, 2026
Merging this PR will not alter performance
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Summary
Test Plan
fixes #8715
Docs