Socket
Socket
Sign inDemoInstall

is-js

Package Overview
Dependencies
0
Maintainers
1
Versions
4
Alerts
File Explorer

Advanced tools

Install Socket

Detect and block malicious and high-risk dependencies

Install

is-js


Version published
Weekly downloads
126
decreased by-33.68%
Maintainers
1
Created
Weekly downloads
 

Readme

Source

is.js

A collection of user-defined type guards to handle some of Javascript's less-than-ideal behavior.

Installing

$ npm install is-js
$ yarn add is-js

Usage

  • array
  • bigint
  • bool
  • date
  • error
  • func
  • nil
  • number
  • object
  • promise
  • promiseLike
  • regex
  • string
  • symbol
  • undef

array

array(arg): arg is any[]

Determines if the argument is an array.

remarks Defaults to the native Array.isArray method, if present.

Parameters
NameType
argany
Returns

arg is any[]

true if the given argument is an array


bigint

bigint(value): boolean

Determines if the argument is a BigInt

remarks This method does not support polyfilled BigInt implementations; please defer to the library in use to determine the type of an unknown argument.

Parameters
NameTypeDescription
valueunknownValue in question
Returns

boolean

true if the given argument is a native BigInt


bool

bool(value): value is boolean

Determines if the argument is a boolean

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is boolean

true if the given argument is a boolean


date

date(value): value is Date

Determines if the argument is a date.

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is Date

true if the given argument is a date


error

error(value): value is Error

Determines if the argument is an error.

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is Error

true if the given argument is an error


func

func(value): value is Function

Determines if the argument is a function.

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is Function

true if the given argument is a function


nil

nil(value): value is null

Determines if the argument is null

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is null

true if the given argument is null


number

number(value): value is number

Determines if the argument is a number

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is number

true if the given argument is a number


object

object(value): value is Object

Determines if the argument is an object.

remarks Nearly everything in Javascript is an object; this method discerns between native primitives (e.g. true, 3, some text) and their object-wrapped variants (Boolean, Number, String)

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is Object

true if the given argument is an object


promise

promise(value): value is Promise<unknown>

Determines if the argument is a native promise.

remarks Some libraries and frameworks still include their own polyfilled Promises, in which case this method is unreliable. If you are using such a library, please defer to the provided Promise implementation or use promiseLike

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is Promise<unknown>

true if the given argument is a string


promiseLike

promiseLike(value): value is Object

Determines if the argument conforms to the minimal interface of a Promise; that is, it has a method named then.

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is Object

true if the given argument conforms to the Promise interface


regex

regex(value): value is RegExp

Determines if the argument is a regular expression.

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is RegExp

true if the given argument is a regular expression


string

string(value): value is string

Determines if the argument is a string.

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is string

true if the given argument is a string


symbol

symbol(value): value is Symbol

Determines if the argument is a symbol

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is Symbol

true if the given argument is a symbol


undef

undef(value): value is undefined

Determines if the argument is undefined

Parameters
NameTypeDescription
valueunknownValue in question
Returns

value is undefined

true if the given argument is undefined

Keywords

FAQs

Last updated on 13 Mar 2022

Did you know?

Socket

Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.

Install

Related posts

SocketSocket SOC 2 Logo

Product

  • Package Alerts
  • Integrations
  • Docs
  • Pricing
  • FAQ
  • Roadmap

Packages

Stay in touch

Get open source security insights delivered straight into your inbox.


  • Terms
  • Privacy
  • Security

Made with ⚡️ by Socket Inc