isEmpty

isEmpty helps normalize emptiness checks across mixed data shapes.

It treats null, undefined, empty strings (including whitespace-only), empty arrays, empty maps/sets, and plain objects with no own keys as empty.

When to use

• Validating form payloads before submit.
• Guarding API parameters that can be optional or polymorphic.
• Creating reusable predicates for filtering or conditional rendering.

Behavior notes

• Whitespace-only strings are considered empty.
• Arrays, maps, and sets are evaluated by length/size.
• Only plain objects are considered for empty object checks.
• Numbers, booleans, dates, regex values, and class instances are not considered empty.

Examples

isEmpty('   ');
// true

isEmpty({ status: 'active' });
// false

Usage

import { isEmpty } from '@branditdev/utils';

const blankField = '   ';
const tags = ['docs'];
const payload = {};

export const isEmptyDemo = {
  blankFieldIsEmpty: isEmpty(blankField),
  tagsAreEmpty: isEmpty(tags),
  payloadIsEmpty: isEmpty(payload),
};

API

isEmpty(value): boolean

Defined in: validators/isEmpty/isEmpty.ts:21

Checks whether a value is empty.

Empty values include null, undefined, empty strings (after trimming), empty arrays, empty maps, empty sets, and plain objects with no own keys.

Parameters

Returns

boolean

true when the value is considered empty, otherwise false.

Source

export function isEmpty(value: unknown): boolean {
  if (value == null) return true;

  if (typeof value === 'string') {
    return value.trim().length === 0;
  }

  if (Array.isArray(value)) {
    return value.length === 0;
  }

  if (value instanceof Map || value instanceof Set) {
    return value.size === 0;
  }

  if (isPlainObject(value)) {
    return Object.keys(value).length === 0;
  }

  return false;
}

function isPlainObject(value: unknown): value is Record<string, unknown> {
  if (typeof value !== 'object' || value === null) {
    return false;
  }

  const prototype = Object.getPrototypeOf(value) as never;
  return prototype === Object.prototype || prototype === null;
}