Check if a value is an object

Light ECMAScript (JavaScript) Value Notation - human written, concise, typed, flexible

type-check allows you to check the types of JavaScript values at runtime with a Haskell like type syntax.

JS type check (TypeScript supported) functions like `isPlainObject() isArray()` etc. A simple & small integration.

A little library for asserting types and values, with zero dependencies.

Check which JavaScript environment your code is running in at runtime: browser, Node.js, Bun, etc

Check if a value is a plain object

Property based testing framework for JavaScript (like QuickCheck)

Returns true if a value is a plain object, array or function.

option parsing and help generation

Check if something is a generator function

Error comparison and information related utility for node and the browser

Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for data descriptors and accessor descriptors.

Returns true if a number or string value is a finite number. Useful for regex matches, parsing, user input, etc.

Given some data, jsesc returns the shortest possible stringified & ASCII-safe representation of that data.

Check if a path is a file, directory, or symlink

Work with IANA language tags.

Check if a string is a valid JavaScript identifier

Check if a value is a regular expression

Deterministic and safely JSON.stringify to quickly serialize JavaScript objects