fix(linter): respect flags overrides for `RegExp(/regex/i, "u")` by Sysix · Pull Request #22678 · oxc-project/oxc

Sysix · 2026-05-22T15:06:54Z

Pull request overview

This PR fixes linter handling of RegExp/new RegExp when the first argument is a regex literal and the second argument overrides flags (e.g. RegExp(/ab/u, "i")), aligning analysis with runtime behavior and addressing #13436.

closes #13436

Sysix · 2026-05-22T15:07:08Z

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codspeed-hq · 2026-05-22T15:12:53Z

Merging this PR will not alter performance

✅ 5 untouched benchmarks
⏩ 55 skipped benchmarks¹

_{Comparing 05-22-fix_linter_respect_flags_overrides_for_regexp__regex_i_u_ (0e91242) with main (b84941e)}

55 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. ↩

Copilot

Pull request overview

This PR fixes linter handling of RegExp/new RegExp when the first argument is a regex literal and the second argument overrides flags (e.g. RegExp(/ab/u, "i")), aligning analysis with runtime behavior and addressing #13436.

Changes:

Update ConstructorParser to support regex-literal text for the constructor pattern argument and always parse the flags argument as a string/template literal.
Update linter regex utilities to (a) avoid processing RegExpLiteral nodes that are part of RegExp(...)/new RegExp(...), and (b) reparse patterns only when Unicode-related flags (u/v) differ.
Extend no_misleading_character_class tests and snapshots to cover overridden-flag scenarios.

Reviewed changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
crates/oxc_regular_expression/src/parser/parser_impl.rs	Improves constructor parsing to accept regex-literal patterns and correctly parse constructor flags.
crates/oxc_linter/src/utils/regex.rs	Adjusts regex-node dispatch to respect constructor flag overrides and avoid double-processing literals.
crates/oxc_linter/src/snapshots/eslint_no_misleading_character_class.snap	Updates diagnostics snapshots for newly covered overridden-flag cases.
crates/oxc_linter/src/rules/eslint/no_misleading_character_class.rs	Adds/adjusts test cases covering overridden flags for `RegExp`/`new RegExp`.

camc314 · 2026-05-24T11:40:28Z

Merge activity

May 24, 11:40 AM UTC: The merge label '0-merge' was detected. This PR will be added to the Graphite merge queue once it meets the requirements.
May 24, 1:17 PM UTC: camc314 added this pull request to the Graphite merge queue.
May 24, 1:21 PM UTC: Merged by the Graphite merge queue.

) > ## Pull request overview > > This PR fixes linter handling of `RegExp`/`new RegExp` when the first argument is a regex literal and the second argument overrides flags (e.g. `RegExp(/ab/u, "i")`), aligning analysis with runtime behavior and addressing #13436. closes #13436

# Oxlint ### 🚀 Features - 10da26b linter: `no-misleading-character-class` add suggestions for regex literal (#22681) (Sysix) - b84941e linter/vue: Implement no-expose-after-await rule (#22675) (bab) - 98b98c1 linter/vue: Implement no-computed-properties-in-data rule (#22674) (bab) - 868e2e8 linter: Add suggestion for `no-misleading-character-class` (#22631) (Sysix) - 2d4c919 oxlint: Support `vite-plus/resolveConfig` for vite.config.ts (#22456) (leaysgur) - 2a60012 linter/vue: Implement require-render-return rule (#22613) (bab) - 9f227fd linter/vue: Implement no-deprecated-props-default-this rule (#21892) (bab) - 9cd28b3 linter: Add debug option to print files to be linted (#22546) (camchenry) - 87f065e linter/vue: Implement return-in-emits-validator rule (#21935) (bab) - ea0380c linter/unicorn: Implement `import-style` rule (#22173) (Hao Chen) - dde40fe linter/vue: Implement no-watch-after-await rule (#22006) (bab) - a735eb0 linter/vue: Implement valid-next-tick rule (#22531) (bab) - 6dc615d linter/vue: Implement no-shared-component-data rule (#21842) (bab) - a656418 linter/vue: Implement valid-define-options rule (#22107) (bab) - bb6f1b2 linter/vue: Implement require-slots-as-functions rule (#22244) (bab) - 5fa4774 linter/n: Implement `callback-return` rule (#22470) (Mikhail Baev) ### 🐛 Bug Fixes - 52bd016 linter: Respect allow unused disable directives in LSP (#22715) (camc314) - fa7c463 semantic: Correct TS enum member symbol spans (#22689) (camc314) - ed445ba linter: Respect flags overrides for `RegExp(/regex/i, "u")` (#22678) (Sysix) - 26b9396 semantic: Resolve parameter decorators outside parameter scope (#22623) (camc314) - 203952d linter: `no-misleading-character-class` fix `is_unicode_code_point_escape` check (#22655) (Sysix) - 2f64d3d linter: `no-misleading-character-class` own diagnostic for surrogate pairs without u flag (#22654) (Sysix) - 0c6ebc2 linter/eslint/no-lone-blocks: Do not flag empty loops (#22649) (Mikhail Baev) - 2a7562e linter/no-focused-tests: Mark fixer as a suggestion (#22645) (camc314) - dbe644f linter: Respect args none for unused rest parameters (#22627) (camc314) - d0211b0 linter: Allow undefined in DummyRuleMap index (#22626) (camc314) - 36fc0ec oxlint/lsp: "ignore this" actions merge with existing directive (#22604) (Sysix) - f7f370e linter/vitest/prefer-expect-type-of: Recommend `toBeTypeOf` instead of `expectTypeOf` (#22612) (Mikhail Baev) - 77063e5 linter/consistent-indexed-object-style: Preserve interface modifiers in fixes (#22579) (camc314) - 4f33aa7 linter: Treat `TSGlobalDeclaration` as ambient in `has_ambient_typescript_ancestor` (#22577) (camc314) ### ⚡ Performance - c22938d linter/no-async-endpoint-handlers: Populate node types (#22601) (camc314) - 607486e linter/no-negated-condition: Populate node types (#22602) (camc314) - 4dcaa59 linter/consistent-type-imports: Populate node types (#22600) (camc314) - 5bd3b25 linter/no-unused-vars: Avoid cloned ancestor iterator (#22598) (camc314) - 97fe9ba linter/no-extra-non-null-assertion: Reduce node matches (#22588) (camc314) - ae98296 linter/consistent-indexed-object-style: Populate node types (#22578) (camc314) # Oxfmt ### 🚀 Features - 16b8058 oxfmt: Support `vite-plus/resolveConfig` for vite.config.ts (#22454) (leaysgur) ### 🐛 Bug Fixes - 5a26479 formatter: Preserve import phases (#22692) (Cameron) ### ⚡ Performance - 78cf83f formatter: Pre-size output buffer using source text length (#22594) (Dunqing) Co-authored-by: Dunqing <[email protected]>

github-actions Bot added the A-linter Area - Linter label May 22, 2026

Sysix force-pushed the 05-22-fix_linter_respect_flags_overrides_for_regexp__regex_i_u_ branch from 4aa60a7 to 0df085e Compare May 22, 2026 15:12

Sysix force-pushed the 05-22-fix_linter_respect_flags_overrides_for_regexp__regex_i_u_ branch from 0df085e to 20ce418 Compare May 22, 2026 15:43

Sysix requested a review from Copilot May 22, 2026 15:48

Copilot started reviewing on behalf of Sysix May 22, 2026 15:49 View session

Copilot AI reviewed May 22, 2026

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Comment thread crates/oxc_linter/src/utils/regex.rs

Comment thread crates/oxc_regular_expression/src/parser/parser_impl.rs Outdated

Comment thread crates/oxc_linter/src/rules/eslint/no_misleading_character_class.rs Outdated

Sysix force-pushed the 05-22-fix_linter_respect_flags_overrides_for_regexp__regex_i_u_ branch from 20ce418 to 65da5d0 Compare May 22, 2026 16:29

Sysix marked this pull request as ready for review May 22, 2026 16:33

Sysix requested review from camc314 and leaysgur as code owners May 22, 2026 16:33

Sysix assigned leaysgur and camc314 May 22, 2026

Sysix marked this pull request as draft May 22, 2026 17:18

Sysix force-pushed the 05-22-fix_linter_respect_flags_overrides_for_regexp__regex_i_u_ branch from 65da5d0 to 314bcb9 Compare May 22, 2026 18:07

Sysix mentioned this pull request May 22, 2026

feat(linter): no-misleading-character-class add suggestions for regex literal #22681

Merged

Sysix force-pushed the 05-22-fix_linter_respect_flags_overrides_for_regexp__regex_i_u_ branch 2 times, most recently from 8a766d6 to 0e91242 Compare May 22, 2026 19:14

Sysix marked this pull request as ready for review May 22, 2026 19:31

camc314 reviewed May 24, 2026

View reviewed changes

Comment thread crates/oxc_linter/src/utils/regex.rs

camc314 approved these changes May 24, 2026

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camc314 added the 0-merge Merge with Graphite Merge Queue label May 24, 2026

graphite-app Bot force-pushed the 05-22-fix_linter_respect_flags_overrides_for_regexp__regex_i_u_ branch from 0e91242 to ed445ba Compare May 24, 2026 13:18

graphite-app Bot merged commit ed445ba into main May 24, 2026
29 checks passed

graphite-app Bot removed the 0-merge Merge with Graphite Merge Queue label May 24, 2026

graphite-app Bot deleted the 05-22-fix_linter_respect_flags_overrides_for_regexp__regex_i_u_ branch May 24, 2026 13:21

oxc-guard Bot mentioned this pull request May 26, 2026

release(apps): oxlint v1.67.0 && oxfmt v0.52.0 #22735

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fix(linter): respect flags overrides for `RegExp(/regex/i, "u")`#22678

fix(linter): respect flags overrides for `RegExp(/regex/i, "u")`#22678
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Sysix commented May 22, 2026 •

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