is-shared-array-buffer

node's assert.deepEqual algorithm

`Object.defineProperty`, but not IE 8's broken one.

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

Robust call-bound JavaScript intrinsics, using `call-bind` and `get-intrinsic`.

A simple cache for a few of the JS Error constructors.

An AST-based pattern checker for JavaScript.

An Esprima-compatible JavaScript parser built on Acorn

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

A query library for ECMAScript AST using a CSS selector like query language.

A robust, ES3 compatible, "has own property" predicate.

A JavaScript parser

prelude.ls is a functionally oriented utility library. It is powerful and flexible. Almost all of its functions are curried. It is written in, and is the recommended base library for, LiveScript.

Which kind of boxed JS primitive is this?

The semantic version parser used by npm.

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

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

Get an iterator for any JS language value. Works robustly across all environments, all versions.

Which kind of boxed JS primitive is this?

Get the byte length of an ArrayBuffer, even in engines without a `.byteLength` method.

Robustly `.call.bind()` a function

Array#isArray for older browsers

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

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

An AST-based pattern checker for JavaScript.

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