jsx-eslint/eslint-plugin-react

no-array-index-key not triggered when spreading props

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#1,625 opened on Dec 24, 2017

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enhancementhelp wanted

Description

There's no warning or error when doing something like this:

people.map(({ name, email }, key) => {
  const props = {
    key,
    name,
    email,
  };

  return <Person {...props} />;
});

I realize this is a bit of an edge case, but maybe we can find a way to catch these uses as well.

Contributor guide

Tech stack
javascriptreact
Domain
toolingdeveloper 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.
stale
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Familiarity with ESLint plugin structureUnderstanding of AST traversal
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
20
Research direction
The issue is about the `no array index key` rule not triggering when the key is spread via props. To fix this, examine the rule implementation in `lib/rules/no array index key.js`. The rule currently checks for `key` prop directly on JSX elements but does not detect `{...props}` spreading. Investigate how other rules handle prop spreading, and consider adding a helper to look for `key` in object expressions used in JSX spread attributes. Also check the rule's test file (`tests/lib/rules/no array index key.js`) for existing test cases and add new ones covering spread scenarios.