fix(linter/unicorn/prefer-at): skip object numeric-key access#23909
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camc314 merged 2 commits intoJun 30, 2026
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With `checkAllIndexAccess: true`, `unicorn/prefer-at` reported and
auto-fixed numeric-key access on plain objects (e.g. `tokens[60]` where
`const tokens = { 60: ... }`), rewriting it to `tokens.at(60)`. Plain
objects have no `.at()` method, so the autofix produced broken code.
Skip receivers that are obviously not array-like: object literals,
non-string literals, function/class expressions, and identifiers bound
to a `const` initialized to one of those. Strings keep `.at()`, so
string receivers are still reported and fixed. Ports the receiver
discrimination from eslint-plugin-unicorn
(sindresorhus/eslint-plugin-unicorn#2999).
Fixes oxc-project#23870
Merging this PR will not alter performance
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gaurav0107
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June 28, 2026 21:39
camc314
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## Summary Fixes #23870. With `checkAllIndexAccess: true`, `unicorn/prefer-at` reported and auto-fixed numeric-key access on plain objects, rewriting e.g. `tokens[60]` (where `const tokens = { 60: '#666666' }`) to `tokens.at(60)`. Plain objects have no `.at()` method, so the autofix produced code that fails to type-check (`TS2339`) / throws at runtime. This skips receivers that are obviously not array-like before reporting under `checkAllIndexAccess`: - object literals — `({ 1: 1 })[1]` - non-string literals, function expressions, and class expressions - identifiers bound to a `const` whose initializer is one of the above — `const o = { 1: 1 }; o[1]` — including through TypeScript `as` / `satisfies` / `!` wrappers Strings keep `.at()`, so string receivers are still reported and fixed (`"abc"[1]` -> `"abc".at(1)`). The guard runs only under the opt-in `checkAllIndexAccess` option and short-circuits on a cheap `matches!` before any symbol-table lookup, so the default-config hot path is unchanged. Ports the receiver discrimination from eslint-plugin-unicorn ([sindresorhus/eslint-plugin-unicorn#2999](sindresorhus/eslint-plugin-unicorn#2999), issue #2229). ## Test plan - Added `pass` cases covering the exact repro plus object-literal, `const`-bound, TS `as const` / `as` / non-null receivers, function/class/non-string-literal receivers, and the addition-index branch. - Added a `fail` + `fix` case proving string-literal receivers are still reported and fixed. - `cargo test -p oxc_linter` — 1162 passed, 0 failed. Co-authored-by: Cameron <cameron.clark@hey.com>
Boshen
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Jul 6, 2026
# Oxlint ### 🚀 Features - 7db7a29 allocator: Add `ReplaceWith` trait (#24012) (overlookmotel) - a2c97f3 linter/unicorn: Implement `explicit-timer-delay` rule (#23612) (Mikhail Baev) - 85735cb linter/unicorn: Implement `no-confusing-array-with` rule (#23638) (Shekhu☺️ ) - cb4fbb9 linter/eslint: Implement no-unreachable-loop rule (#23975) (Todor Andonov) - dc32112 linter/eslint/no-constant-binary-expression: Check relational comparisons (#24088) (camc314) - 439c344 linter/jsdoc: Added missing options to `jsdoc/require-param` rule (#23364) (kapobajza) - 62af717 linter/unicorn/filename-case: Add `lowercase` and `screamingSnakeCase` (#24045) (Boshen) - d963967 linter/unicorn/no-array-sort: Add `allowAfterSpread` option (#24043) (Boshen) - 0a75682 linter: Add per-rule timings for type-aware linting (#22488) (camchenry) - 743e222 linter/react: Add `disallowedValues` option for `forbid-dom-props` rule (#23970) (Mikhail Baev) ### 🐛 Bug Fixes - 7b80010 linter: Use direct binding symbol ids (#24216) (camc314) - 8f94b49 linter/import/no-duplicates: Don't flag a type-only import beside a side-effect import (#24030) (Boshen) - d8c3fee linter/react/rules-of-hooks: Flag `useEffectEvent` escapes (#23764) (Rayan Salhab) - 0a7312b linter/no-deprecated-functions: Map `require.requireActual` to `jest.requireActual` (#23627) (Jerry Zhao) - d9e3ab3 linter/eslint/no-useless-return: Handle switch case continuation (#23984) (camc314) - 0b25582 ast: Type binding node `typeAnnotation` as `TSTypeAnnotation | null` (#23113) (Boshen) - 122d112 linter/eslint/no-restricted-imports: Flag dynamic import() expressions (#24029) (Boshen) - 59b6b83 linter: Avoid `OnceLock` re-entry on cyclic `export *` re-exports (#23632) (Jerry Zhao) - dd09af0 linter/import/namespace: Avoid panic on destructuring of an unresolvable namespace re-export (#23626) (Jerry Zhao) - bdb51c7 linter/jest/prefer-ending-with-an-expect: Validate config patterns (#24122) (camc314) - e383843 linter/unicorn/prefer-modern-dom-apis: Skip fixer for non identifier arguments (#23630) (Jerry Zhao) - 0ac4c83 linter: Detect circular config extends (#24115) (camc314) - bae1edf linter/import/namespace: Check namespace imports after named imports (#24094) (camc314) - cd8fdfe linter/eslint/no-eval: Recognize Array.from family thisArg (#24091) (camc314) - 851ee43 linter/eslint/no-eval: Resolve this binding for functions returned from an IIFE (#23643) (Jerry Zhao) - 002ab35 linter/unicorn: Avoid prefer-array-find rest destructuring false positive (#23654) (ColemanDunn) - 01c8775 linter/unicorn/filename-case: Keep digits attached in screamingSnakeCase (#24056) (Boshen) - f256941 linter: Recognize `@effect/vitest` as a vitest import source (#24025) (Boshen) - 73eeb1d linter/import/extensions: Honor per-extension `never` for explicit extensions (#24031) (Boshen) - d4ebe1f linter: Reject non-object oxlint config files (#24026) (Boshen) - 45d607d linter/react/forbid-component-props: Make allow/disallow lists optional in schema (#24024) (Boshen) - 54076ad linter/unicorn/no-array-for-each: Suggest entries loop for index callbacks (#24004) (camc314) - d057736 linter/jsdoc: Avoid param root underflow (#23945) (camc314) - 29c76bf linter/unicorn/prefer-at: Skip object numeric-key access (#23909) (Gaurav Dubey) ### ⚡ Performance - 657a8fc linter/oxc/bad-array-method-on-arguments: Only run on member expressions instead of all identifiers (#24164) (camchenry) - 073d9e7 linter/eslint/prefer-rest-params: Run on functions instead of all identifiers (#24163) (camchenry) - e5a4162 linter/jest/no-confusing-set-timeout: Early exit fast path (#24092) (camc314) - bca7ce5 linter: Only run react-perf rules on JSX attribute nodes (#24083) (camchenry) - 6881bf6 linter: Compute `apply_overrides` rule set lazily (#23648) (Jerry Zhao) - 911c106 linter/eslint/no-obj-calls: Use resolved reference instead of scope walk (#23895) (Marius Schulz) - dc8fd9a linter/unicorn/prefer-dom-node-text-content: Change dispatch to run only on less common node types (#23897) (Connor Shea) - fdbd34d linter/eslint/no-useless-call: Fast-path static callees (#24077) (camc314) - b1be114 linter/import/extensions: Skip empty config and borrow extensions (#24075) (camc314) - 4781b2d linter/eslint/no-obj-calls: Use direct global matches (#24076) (camc314) - e6cee89 linter: Avoid node-chain allocation for non-Jest calls (#23907) (Yagiz Nizipli) - 30dc517 linter/typescript/no-restricted-types: O(1) banned-type lookups (#23827) (Yagiz Nizipli) ### 📚 Documentation - 6ca9125 linter/typescript: Clarify consistent-type-imports behavior (#23972) (camc314) # Oxfmt ### 🚀 Features - 4f4313e formatter_css: Update oxc-css-parser 0.0.5 (#24120) (leaysgur) - 0ccd8a1 formatter_graphql: Update oxc-graphql-parser 0.0.5 (#24106) (leaysgur) - 89ec3d9 formatter_core: Add literal line and root indention primitives (#24051) (leaysgur) - 213a96b formatter_core: Add no-expand-parent for multiline text (#24050) (leaysgur) - 0e5bcc9 formatter_graphql: Update oxc-graphql-parser 0.0.4 (#24039) (leaysgur) - e0b35a1 formatter_css: Update `oxc-css-parser@0.0.3` (#23974) (leaysgur) ### 🐛 Bug Fixes - 1fe6546 formatter: Omit unneeded `;` for type members with `no-semi` (#24212) (leaysgur) - 0ad7316 formatter: Print space for `ForStatement`.`update` only if exists (#24211) (leaysgur) - 3abbed5 formatter: Print `;` before jsdoc type-cast parens with no-semi (#24208) (leaysgur) - 9af3833 formatter_css: Make scss formatter consistent (#24207) (leaysgur) - 46d7194 formatter_css: Use fill IR for `@forward` members (#24206) (leaysgur) - e31038f formatter_css: Keep comment inside sass config list (#24205) (leaysgur) - d3b9591 formatter: Add parens around `await/yield` with `<T>` (#24202) (leaysgur) - 2121a55 oxfmt: Reuse tinypool process during the same LSP process (#24197) (leaysgur) - 9bf4b4a formatter_css: Align CSS output to Prettier 3.9.1 (#24100) (leaysgur) - cd2452e formatter_css: Align SCSS output to Prettier 3.9.1 (#24097) (leaysgur) - 4ee8745 formatter_css: Keep selector value contain line-break without breaking line (#24055) (leaysgur) - e1ece97 formatter_graphql: Break `implements` list by print-width (#23997) (leaysgur) - 0a6b16c formatter_json: Preserve key and literal value for json-stringify (#23996) (leaysgur) - 903ab6e formatter_css: Preserve newlines in css-in-js selector list (#23992) (leaysgur) - ea5d095 oxfmt: Update `--migrate prettier` (#23963) (leaysgur) ### ⚡ Performance - 468e1e3 formatter_core: Make printer queues cursor-based (#24098) (Boshen) - c59f2fe rust: Return impl ExactSizeIterator from slice-backed accessors (#24144) (Boshen) - c292fb2 formatter: Inline fits element dispatcher (#23982) (camc314) Co-authored-by: Boshen <1430279+Boshen@users.noreply.github.com>
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Summary
Fixes #23870.
With
checkAllIndexAccess: true,unicorn/prefer-atreported and auto-fixed numeric-key access on plain objects, rewriting e.g.tokens[60](whereconst tokens = { 60: '#666666' }) totokens.at(60). Plain objects have no.at()method, so the autofix produced code that fails to type-check (TS2339) / throws at runtime.This skips receivers that are obviously not array-like before reporting under
checkAllIndexAccess:({ 1: 1 })[1]constwhose initializer is one of the above —const o = { 1: 1 }; o[1]— including through TypeScriptas/satisfies/!wrappersStrings keep
.at(), so string receivers are still reported and fixed ("abc"[1]->"abc".at(1)). The guard runs only under the opt-incheckAllIndexAccessoption and short-circuits on a cheapmatches!before any symbol-table lookup, so the default-config hot path is unchanged.Ports the receiver discrimination from eslint-plugin-unicorn (sindresorhus/eslint-plugin-unicorn#2999, issue #2229).
Test plan
passcases covering the exact repro plus object-literal,const-bound, TSas const/as/ non-null receivers, function/class/non-string-literal receivers, and the addition-index branch.fail+fixcase proving string-literal receivers are still reported and fixed.cargo test -p oxc_linter— 1162 passed, 0 failed.