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prefer-no-lodash-is-equal

What it flags​

Usages of isEqual imported from Lodash (lodash-es). Deep structural equality can be costly; a hand-written comparison of the fields that matter is usually cheaper and clearer.

Options​

This rule has no options.

// eslint.config.js (flat config)
import rxAngular from '@rx-angular/eslint-plugin';

export default [
  {
    plugins: { '@rx-angular': rxAngular },
    rules: {
      '@rx-angular/prefer-no-lodash-is-equal': 'error',
    },
  },
];
// .eslintrc (legacy)
"rules": {
  "@rx-angular/prefer-no-lodash-is-equal": "error"
}

❌ Incorrect​

import { isEqual } from 'lodash-es';

if (isEqual(prevObj, currObj)) {
  // ...
}

✅ Correct​

if (prevObj.prop === currObj.prop && prevObj.arr.length === currObj.arr.length && prevObj.arr.every((prevItem, i) => prevItem.x === currObj.arr[i].x && prevItem.y === currObj.arr[i].y)) {
  // ...
}
if (isEqual(prevObj, currObj)) {
  // ...
}

function isEqual<T>(a: T, b: T): boolean {
  return JSON.stringify(a) === JSON.stringify(b);
}

Why​

The immutability rationale (comparing serializable state cheaply instead of deep-equality on arbitrary objects) belongs to the immutability & serializable state concept.