A pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module.

Perform async work synchronously in Node.js using `worker_threads` with first-class TypeScript support.

This plugin adds `TypeScript` support to `eslint-plugin-import`

Is this JS value callable? Works with Functions and GeneratorFunctions, despite ES6 @@toStringTag.

Robustly `.call.bind()` a function

ES2017 spec-compliant Object.values shim.

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

ES2019 spec-compliant String.prototype.trimStart shim.

An ES2019 spec-compliant `Array.prototype.flat` shim/polyfill/replacement that works as far down as ES3.

An ES2015 mostly-spec-compliant `Reflect.getPrototypeOf` sham/polyfill/replacement that works in as many engines as possible

An ES7/ES2016 spec-compliant `Array.prototype.includes` shim/polyfill/replacement that works as far down as ES3.

Runtime-agnostic core of ESLint

ES2017 spec-compliant Object.entries shim.

ES spec-like internal slots

TypeScript Execute (tsx): Node.js enhanced with esbuild to run TypeScript & ESM files

Is this specifier a node.js core module?

Which kind of Collection (Map, Set, WeakMap, WeakSet) is this JavaScript value? Works cross-realm, without `instanceof`, and despite Symbol.toStringTag.

Implementation of Function.prototype.bind

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

BDD/TDD assertion library for node.js and the browser. Test framework agnostic.