kind-of-modern

Tiny, zero-dependency utility that returns the lowercase type of any JavaScript value. Modern, cross‑realm safe, and Node + browser compatible.

Install

npm i kind-of-modern

Usage

import kindOf from 'kind-of-modern'

kindOf('hello') // 'string'
kindOf(123) // 'number'
kindOf(true) // 'boolean'
kindOf(Symbol('x')) // 'symbol'
kindOf(1n) // 'bigint'
kindOf(() => {}) // 'function'
kindOf([]) // 'array'
kindOf(new Date()) // 'date'
kindOf(/re/) // 'regexp'
kindOf(new Error('oops')) // 'error'
kindOf(new Map()) // 'map'
kindOf(new Set()) // 'set'
kindOf(new WeakMap()) // 'weakmap'
kindOf(new WeakSet()) // 'weakset'
kindOf(null) // 'null'
kindOf(undefined) // 'undefined'
kindOf(Promise.resolve()) // 'promise'
kindOf(new Uint8Array()) // 'typedarray'
kindOf(Buffer.from('x')) // 'buffer' (Node)
kindOf({}) // 'object'

Named export is also available:

import { kindOf } from 'kind-of-modern'

Why modern?

• Uses Object.prototype.toString (respects Symbol.toStringTag) for accurate, cross‑realm detection.
• Detects Node Buffer and groups all TypedArray variants under typedarray.
• Strict TypeScript types and ESM + CJS builds with auto .d.ts.

API

type Kind =
  | 'string'
  | 'number'
  | 'boolean'
  | 'symbol'
  | 'bigint'
  | 'function'
  | 'array'
  | 'date'
  | 'regexp'
  | 'error'
  | 'map'
  | 'set'
  | 'weakmap'
  | 'weakset'
  | 'null'
  | 'undefined'
  | 'promise'
  | 'typedarray'
  | 'buffer'
  | 'object'

Benchmarks

npm run bench

This will build the package and run a micro‑benchmark comparing against the legacy kind-of package.

Publishing

• ESM + CJS: exports, main, and module are set.
• Types: .d.ts is emitted automatically.
• Size: minified build stays under 2KB.