jsx-eslint/eslint-plugin-react

no-unstable-nested-components does not detect components starting with underscore

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#4002 opened on Apr 28, 2026

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bughelp wanted

Description

A pattern we use commonly in our codebase (pre-dates me, and we're too far along the road now to change) is to prefix some components with an underscore e.g. when forwarding refs, or to signal a component shouldn't be exported etc.

Components with this naming convention do not get detected as parent components, and thus the unstable nested components are not flagged

function _Parent() {
  function NotFlagged() {
    return <b>oh no</b>
  }

  return <NotFlagged />
}

Given there have been other issues raised relating, and carve outs added for, this naming convention:

I think this constitutes a bug/oversight in this rule. Happy to make a PR, if there is agreement

Contributor guide

Tech stack
javascriptreact
Domain
frontenddeveloper experience
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
basic JavaScriptReact component naming conventions
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
Locate the rule implementation in the plugin's source code, likely in `lib/rules/no unstable nested components.js`. Review the logic that detects parent components; it likely uses a naming pattern like `/^[A Z]/` or similar. Update the regex or check to also include components starting with underscore (e.g., `/^[ A Z]/`). Ensure the fix aligns with existing carve outs for underscore in other rules, referenced in issues #3560 and #2603. Test with the provided example to confirm the rule flags the nested component.