Is this value a JS Number object? This module works cross-realm/iframe, and despite ES6 @@toStringTag.
Define multiple non-enumerable properties at once. Uses `Object.defineProperty` when available; falls back to standard assignment in older engines.
Gets the description of a Symbol. Handles `Symbol()` vs `Symbol('')` properly when possible.
Determine if a function is a native generator function.
Which kind of Collection (Map, Set, WeakMap, WeakSet) is this JavaScript value? Works cross-realm, without `instanceof`, and despite Symbol.toStringTag.
Encode FormData content into the multipart/form-data format
Is this value a JS regex? Works cross-realm/iframe, and despite ES6 @@toStringTag
Is this JS value callable? Works with Functions and GeneratorFunctions, despite ES6 @@toStringTag.
The `postinstall` script helper for handling native bindings in legacy `npm` versions
Robustly `.call.bind()` a function
An ES2015 mostly-spec-compliant `Reflect.getPrototypeOf` sham/polyfill/replacement that works in as many engines as possible
An ESnext spec-compliant `Array.prototype.findLast` shim/polyfill/replacement that works as far down as ES3.
Improved typeof detection for node.js and the browser.
Simple and complete DOM testing utilities that encourage good testing practices.
An ES2019 spec-compliant `Array.prototype.flat` shim/polyfill/replacement that works as far down as ES3.
Helper functions for V8 coverage files.
Fast, disk space efficient package manager
Simple and complete React DOM testing utilities that encourage good testing practices.
Is this value negative zero? === will lie to you
ES Math-related intrinsics and helpers, robustly cached.
ES proposal-spec-compliant Object.fromEntries shim.
An ES7/ES2016 spec-compliant `Array.prototype.includes` shim/polyfill/replacement that works as far down as ES3.
ES2017 spec-compliant Object.values shim.
TypeScript-first schema declaration and validation library with static type inference