prefer-includes

Configuration

rslint.config.ts

import { defineConfig, ts } from '@rslint/core';

export default defineConfig([
  ts.configs.recommended,
  {
    rules: {
      '@typescript-eslint/prefer-includes': 'error',
    },
  },
]);

Rule Details

Disallow indexOf(...) !== -1 / indexOf(...) === -1 style checks when includes(...) expresses intent more clearly.

Examples of incorrect code for this rule:

if (arr.indexOf(value) !== -1) {
  doSomething();
}

Examples of correct code for this rule:

if (arr.includes(value)) {
  doSomething();
}

Original Documentation

https://typescript-eslint.io/rules/prefer-includes