#no-self-compare

#Configuration

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

export default defineConfig([
  js.configs.recommended,
  {
    rules: {
      'no-self-compare': 'error',
    },
  },
]);

#Rule Details

Disallows comparing a value to itself using any of the equality or relational operators (===, ==, !==, !=, >, <, >=, <=). Such a comparison is typically a typo (the programmer likely meant a different operand) and is either always true, always false, or always NaN-sensitive, so the check is pointless.

Examples of incorrect code for this rule:

var x = 10;
if (x === x) {
}

if (x !== x) {
}

if (foo.bar().baz.qux >= foo.bar().baz.qux) {
}

Examples of correct code for this rule:

var x = 10;
var y = 10;
if (x === y) {
}

if (foo.bar.baz === foo.bar.qux) {
}

class C {
  #field;
  foo() {
    // Property access via private identifier and bracket string literal
    // are structurally distinct and allowed.
    return this.#field === this["#field"];
  }
}

#Original Documentation

• ESLint no-self-compare