ECMAScript extensions and shims

Brand checking of React Elements.

A querystring parser that supports nesting and arrays, with a depth limit

babel's modular runtime helpers

Get and robustly cache all JS language-level intrinsics at first require time

Implementation of Function.prototype.bind

Robustly `.call.bind()` a function

string representations of objects in node and the browser

Determine if the JS environment has Symbol support. Supports spec, or shams.

Store information about any JS value in a side channel. Uses WeakMap if available.

ECMAScript spec abstract operations.

Define multiple non-enumerable properties at once. Uses `Object.defineProperty` when available; falls back to standard assignment in older engines.

An Object.keys replacement, in case Object.keys is not available. From https://github.com/es-shims/es5-shim

ES6 spec-compliant RegExp.prototype.flags shim.

Is this value a JS regex? Works cross-realm/iframe, and despite ES6 @@toStringTag

Is this value a JS Date object? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Object.prototype.hasOwnProperty.call shortcut

Runtime type checking for React props and similar objects.

Is this an arguments object? It's a harder question than you think.

node's assert.deepEqual algorithm

Modern JavaScript date utility library

ES2015-compliant shim for Object.is - differentiates between -0 and +0

A simple utility for conditionally joining classNames together

Accessible Accordion component for React