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eslint-community/regexpp

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@eslint-community/regexpp is a regular expression parser and validator for ECMAScript, providing APIs to parse regex literals into an AST and to validate literals, patterns, and flags. It also includes an AST visitor utility for walking parsed regular expression nodes, useful for tools and linters that need to analyze regex structure safely.

Project status

  • Active maintenance: The source appears actively maintained, with the most recent upstream push on 2025-10-23 and corresponding updates in v4.12.2 on 2025-10-22. There have been no updates yet in 2026 as of 2026-06-09, but the gap is under a year.
  • Update cadence: Updates were relatively frequent in 2024 (multiple updates across June and October), then slowed to a single update in 2025 (v4.12.x in Oct), and currently no new updates in 2026.

AI summary generated

AI-generated from public sources. May be inaccurate. Report

Recent updates

  • v4.12.2

    v4.12.2 contains what the release notes describe as Unicode data updates (“updates unicode resource with latest”). The code changes confirm this, and additionally introduce new Unicode property data for ES2026.

  • v4.12.1

    v4.12.1 is a small bug fix release. It adjusts the regex flag validation logic so that the `d` (d flag) is treated as invalid for ES2021. The update is backed by new/updated test fixtures.

  • v4.12.0

    v4.12.0 adds support for inline regular expression group modifiers. It introduces new AST node types for modifier blocks and integrates them into the parser, validator, and visitor traversal.

    BreakingFeatures

  • v4.11.2

    This release (v4.11.2) is described as a single bug fix related to generating npm provenance statements during the publish process. The provided diff, however, also includes GitHub Actions workflow permission changes and adds multiple new Test262 parser fixture files.

  • v4.11.1

    v4.11.1 primarily regenerates Unicode data used by the library, refreshing identifier and Unicode property tables. The release notes only mention the Unicode resource update, but the diff also shows additional data/property expansion and a tooling dependency change.

  • v4.11.0

    v4.11.0 adds parsing and validation support for ES2025 duplicate named capturing groups. The implementation also refactors how duplicate group names and backreference resolution are represented in the internal AST, and updates the library’s notion of the latest ECMAScript version to 2025.

    Features

  • v4.10.1

    v4.10.1 is a small release focused on updating the bundled Unicode resource data. The release notes only mention a Unicode data update, but the code diff shows additional internal structural and tooling changes.

  • v4.10.0

    v4.10.0 adds a new public export for `RegExpSyntaxError`. The implementation also refactors how syntax errors are constructed internally, including changing the `RegExpSyntaxError` constructor signature and introducing a helper used by `RegExpValidator`.

    Features

  • v4.9.1

    v4.9.1 is a small patch release that fixes a character class AST typing issue (“wrong character class parent type”). It also includes Unicode property validation changes that reorganize where some logic lives in the codebase, plus a few development dependency bumps.

  • v4.9.0

    Release v4.9.0 updates regexpp's Unicode identifier data to align with Unicode v15.1. The change is implemented as regenerated Unicode ID range data used by the library when classifying code points for identifier rules.

    Features