🐊Putout plugin adds ability to declare undefined variables

get value at property, don't throw if parent is undefined

Optionals for JS - wrapper for possibly undefined values, inspired by Java Optional API

Test if a value is undefined.

Simple function that return the first non null or undefined argument

Replace null with undefined on any value

This method returns undefined.

A simple module that works exactly as Object.assign, but skips assigning undefined values.

Ignore keys which have undefined values to compare from a deep equal operation with chai expect

import.meta.vitest -> undefined

is-undefined function part of http://amp.ampersandjs.com.

Checks if `value` is `null` or `undefined`.

Convert `null` values to `undefined` in a way that TypeScript understands

Fela plugin to remove invalid undefined values

Invariant and non-null/undefined assertion check with type guards

ESLint plugin to detect undefined CSS classes in HTML/JSX

Fail fast when accessing undefined properties on objects.

Vue3 SVG icon components integrated from [`Carbon`](undefined)

Same as JSON but with added support for `Date`, `undefined`, `Map`, `Set`, and more.

Basic sort algorithm that has similar behavior to Array.prototype.sort for null and undefined, but also allows sorting by an object property.