What version of Oxlint are you using?

1.59.0

What command did you run?

oxlint -c oxlint.json test.tsx

What does your .oxlintrc.json (or oxlint.config.ts) config file look like?

{
  "plugins": ["react"],
  "rules": {
    "react/no-array-index-key": "error"
  }
}

What happened?

react/no-array-index-key flags array index usage inside template literal expressions like key={`${item.type + index}`}. ESLint only flags direct usage like key={index} or simple expressions like key={1 + index}.

Minimal reproduction

test.tsx:

function List({items}: {items: {type: string; text: string}[]}) {
  return (
    <ul>
      {items.map((item, index) => (
        <li key={`${item.type + index}`}>{item.text}</li>
      ))}
    </ul>
  )
}

Expected: No error. The key combines item.type with index via string concatenation inside a template literal, producing a composite key.

Actual:

x eslint-plugin-react(no-array-index-key): Usage of Array index in keys is not allowed
  ,-[test.tsx:5:9]
4 |             {items.map((item, index) => (
5 |                 <li key={`${item.type + index}`}>{item.text}</li>
  :                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^