fix(formatter): preserve parens around intrinsic in type alias annotation#21410
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…tation (#21410) ## Summary Fixes #20205 — `type t = (intrinsic);` was losing its parentheses during formatting, changing the AST on re-parse or producing unparseable TypeScript. ## Why this happens The parser treats a leading `intrinsic` identifier in a type alias annotation as `TSIntrinsicKeyword`: - `type t = intrinsic;` → `TSIntrinsicKeyword` - `type t = (intrinsic);` → `TSParenthesizedType(TSTypeReference(IdentifierReference))` `oxc_formatter` runs the parser with `preserve_parens: false`, which drops the `TSParenthesizedType` wrapper. Without re-emitting the parens: | Input | Naive output | Re-parses as | |-------|-------------|--------------| | `type t = (intrinsic);` | `type t = intrinsic;` | `TSIntrinsicKeyword` (different AST) | | `type t = (intrinsic) \| string;` | `type t = intrinsic \| string;` | **Syntax error** — oxc and TypeScript both reject it | | `type t = (intrinsic) & string;` | `type t = intrinsic & string;` | **Syntax error** | Prettier has the same bug and emits the broken outputs; we intentionally diverge to produce correct, round-trippable TypeScript. ## Fix In `FormatWrite<TSTypeReference>::write`, detect when the reference is a bare `intrinsic` identifier AND is the leftmost descendant of a `TSTypeAliasDeclaration` (directly, or through leftmost members of union/intersection types). When so, wrap the output in parens. Any other `intrinsic` position (right arm of union, array element, object property, type arguments, etc.) is unambiguous and is left alone. Fast-pathed on the name check so non-`intrinsic` references pay only a hash-prefixed string compare. ## Test plan - [x] New fixture `crates/oxc_formatter/tests/fixtures/ts/parenthesis/intrinsic.ts` covers direct, leftmost-union, leftmost-intersection, right-arm, tuple, object property, and type-argument positions - [x] Output round-trips through `oxc_parser` - [x] `cargo test -p oxc_formatter` — 269/269 passing - [x] `cargo run -p oxc_prettier_conformance` — js 746/753, ts 591/601 (no delta)
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# Oxlint ### 💥 BREAKING CHANGES - 24fb7eb allocator: [**BREAKING**] Rename `Box` and `Vec` methods (#21395) (overlookmotel) ### 🚀 Features - 38d8090 linter/jest: Implemented jest `version` settings in config file. (#21522) (Said Atrahouch) - 7dbbb99 linter/eslint: Implement suggestion for `no-case-declarations` rule (#21508) (Mikhail Baev) - 9b4d9f6 linter/prefer-template: Implement autofix (#21502) (François) - daa64ed linter/no-empty-pattern: Add `allowObjectPatternsAsParameters` option (#21474) (camc314) - cf2d281 linter/typescript: Implement explicit-member-accessibility (#21447) (Hunter Tunnicliff) - d48de6f linter/unicorn: Add help messages to 3 rule diagnostics (#21459) (Mukunda Rao Katta) - cffdc2e linter: Backfill rule version metadata (#21391) (Old Autumn) ### 🐛 Bug Fixes - 1e69b91 linter/no-useless-assignment: Improve diagnostic spans (#21581) (camc314) - f272594 linter/plugins: Align `RuleMeta.replacedBy` type with ESLint (#21544) (bab) - 4d57851 linter/eslint: Enhance `no-empty-function` rule to support async and generator functions in VariableDeclarator (#21542) (Mikhail Baev) - 00fc136 codegen: Preserve coverage comments before object properties (#21312) (bab) - a56b7b9 oxlint: Dont enable gitlab formatter by default (#21501) (camc314) - 9c9b6a2 linter/array-callback-return: Ignore non-exit CFG dead ends (#21497) (camc314) - 61088e0 linter/unicorn: Handle computed property access in `prefer-dom-node-remove` rule (#21470) (Mikhail Baev) - eab5934 linter: Report an error on unsupported `extends` values (#21406) (John Costa) - 3289ba0 linter/valid-expect-in-promise: Check a jest fn to be `test` instead of `describe` (#21422) (Said Atrahouch) - 4417fe3 linter/prefer-ending-with-an-expect: Ignore vi.mock factory callbacks (#21414) (Cédric Exbrayat) - a904883 linter/consistent-type-imports: Ignore vue/svelte/astro files (#21415) (bab) - 2498fe6 linter/no-unused-vars: Allow segments of dotted namespace declarations (#21416) (bab) - 44b5b35 linter: Preserve vitest-compatible jest rules when applying overrides (#21389) (Cameron) - 7bd8331 linter/prefer-ending-with-an-expect: Add missing `version` docs (#21390) (Said Atrahouch) - 43d8f0d linter/no-useless-assignment: Ignore writes read by closures (#21380) (camc314) ### 📚 Documentation - c1eeae3 linter: Add version to `rule.json` (#21547) (camchenry) - 0ec6ab2 linter: Improve the `vitest/no-importing-vitest-globals` rule documentation. (#21557) (connorshea) # Oxfmt ### 💥 BREAKING CHANGES - 24fb7eb allocator: [**BREAKING**] Rename `Box` and `Vec` methods (#21395) (overlookmotel) ### 🚀 Features - 5aa7fe1 oxfmt: Add `--disable-nested-config` CLI flag (#21514) (leaysgur) - b5cb8d1 oxfmt: Update prettier to 3.8.3 (#21451) (leaysgur) - 16713d5 oxfmt/cli: Support per-directory config (#21103) (leaysgur) - 952de06 oxfmt/lsp: Support per-directory config (#21081) (leaysgur) ### 🐛 Bug Fixes - a501a53 formatter: Handle comments after pipe in single-member union types (#21487) (John Costa) - 6f49fad oxfmt: Respect nested config.`ignorePatterns` (#21489) (leaysgur) - 7c98d52 oxfmt: Do not panic on finding invalid nested config (#21461) (leaysgur) - 41bb2d5 formatter: Preserve more `intrinsic` parens (#21449) (leaysgur) - f894750 formatter: Preserve parens around `intrinsic` in type alias annotation (#21410) (Dunqing) ### ⚡ Performance - df27b48 oxfmt: Skip ancestors check when no nested config found (#21517) (leaysgur) - 5e1522a oxfmt: Do not occupy the rayon thread solely for handover (#21408) (leaysgur) Co-authored-by: camc314 <18101008+camc314@users.noreply.github.com>
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Summary
Fixes #20205 —
type t = (intrinsic);was losing its parentheses during formatting, changing the AST on re-parse or producing unparseable TypeScript.Why this happens
The parser treats a leading
intrinsicidentifier in a type alias annotation asTSIntrinsicKeyword:type t = intrinsic;→TSIntrinsicKeywordtype t = (intrinsic);→TSParenthesizedType(TSTypeReference(IdentifierReference))oxc_formatterruns the parser withpreserve_parens: false, which drops theTSParenthesizedTypewrapper. Without re-emitting the parens:type t = (intrinsic);type t = intrinsic;TSIntrinsicKeyword(different AST)type t = (intrinsic) | string;type t = intrinsic | string;type t = (intrinsic) & string;type t = intrinsic & string;Prettier has the same bug and emits the broken outputs; we intentionally diverge to produce correct, round-trippable TypeScript.
Fix
In
FormatWrite<TSTypeReference>::write, detect when the reference is a bareintrinsicidentifier AND is the leftmost descendant of aTSTypeAliasDeclaration(directly, or through leftmost members of union/intersection types). When so, wrap the output in parens. Any otherintrinsicposition (right arm of union, array element, object property, type arguments, etc.) is unambiguous and is left alone.Fast-pathed on the name check so non-
intrinsicreferences pay only a hash-prefixed string compare.Test plan
crates/oxc_formatter/tests/fixtures/ts/parenthesis/intrinsic.tscovers direct, leftmost-union, leftmost-intersection, right-arm, tuple, object property, and type-argument positionsoxc_parsercargo test -p oxc_formatter— 269/269 passingcargo run -p oxc_prettier_conformance— js 746/753, ts 591/601 (no delta)