#eqeqeq

#Configuration

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

export default defineConfig([
  js.configs.recommended,
  {
    rules: {
      'eqeqeq': 'error',
    },
  },
]);

#Rule Details

Requires the use of === and !== instead of == and !=. Using strict equality operators helps avoid unexpected type coercion in comparisons.

#Options

This rule supports three modes:

• "always" (default): Always require === and !==. Supports a null sub-option:
  • "always" (default): Enforce strict equality for null comparisons too
  • "ignore": Skip enforcement for null comparisons
  • "never": Enforce ==/!= for null comparisons and ===/!== for everything else
• "smart": Allow == for typeof comparisons, same-type literal comparisons, and null checks
• "allow-null": Shorthand for ["always", {"null": "ignore"}]

Examples of incorrect code for this rule:

a == b;
a != b;
typeof a == 'number'; // in "always" mode

Examples of correct code for this rule:

a === b;
a !== b;
typeof a === 'number';

// With "smart" option:
typeof a == 'number';
null == a;
'hello' == 'world';

// With "allow-null" option:
a == null;
null != a;

#Original Documentation

• ESLint eqeqeq