JSPM

Check if a string only contains alphanumeric characters

Returns `true` if an array has a glob pattern.

Check if a Buffer/Uint8Array is a JPEG image

Validate an email address according to RFCs 5321, 5322, and others

Binary wrapper that makes your programs seamlessly available as local dependencies

Update notifications for your CLI app, maintained in CommonJS (CJS)

Check whether a value is "empty".

Check if mobile browser.

Binary wrapper for Flow - A static type checker for JavaScript

JavaScript Standard Style

Ensure a path doesn't contain null bytes

Wrap your standards in a tortilla and cover it in special sauce.

Test if an object has a specified property.

ESLint shareable config for the Google style

Test if a value is an array.

Return a function which tests if every element in an array passes a test condition.

Determine the name of a value's constructor.

Check if a Buffer/Uint8Array is a GIF image

Validate domain name

Test if a value is object-like.

Check whether a RegExp flag is supported

ESLint shareable config for XO

Check if an environment is big endian.

Test if a double-precision floating-point numeric value is infinite.

Check if a URL is relative

Check if a string is HTML

maximally minimal type-testing library

Test if a double-precision floating-point numeric value is NaN.

Test if a value is a regular expression string.

Test if a value is a regular expression.

Try to downgrade the permissions of a process with root privileges and block access if it fails

Test if a value is an object.

Test if a value is a string.

JavaScript/TypeScript linter (ESLint wrapper) with great defaults

Test if a value is a Float32Array.

Test if a value is a number.

Determine a value's type.

Determine the specification defined classification of an object.

Test if a value is a boolean.

Test if a value is a function.

A simple and composable way to validate data in JavaScript (and TypeScript).

Test if a value is a Float64Array.

Test whether a path exists on the filesystem.

Test if a value is a Uint32Array.

Test if a value is a Buffer object.

check if an AST node is a function of some sort

Test if a value is a Uint8Array.

Test if a value is a plain object.

Test if a value is a Uint16Array.

Check for outdated, incorrect, and unused dependencies.

Get a property from an object using dot (object path) notation.

Tiny wrapper around ansi-colors to add colored symbols and a timestamp.

Check if an environment is little endian.

Check if a Buffer/Uint8Array is a TAR file

Is this a bluebird promise I see before me?

Check if a process is running

Check TypeScript type definitions

Check if browser is Internet Explorer

Detect potential issues with users system that could prevent Yeoman from working correctly

Check if a value is a `Blob`

Utilities to get and check variable types (isString, isPlainObject, isRegExp, etc)

Check if browser is Firefox

Is given string a language code (as per IANA)

Check whether a binary exists in the PATH environment variable

check if the current node version has async_hooks.

Promisified version of node-which

ESLint shareable config for TypeScript to be used with eslint-config-xo

Determine if an array or object is equivalent with another, *not* recursively

Verify if something is a Promise

Checks TypeScript types match expected values

Detect the audio type of a Buffer/Uint8Array

Check if Electron is running in development

Checks if a given object is iterable

Checks if the given value is null or undefined

Returns true if the given is falsey (according to JavaScript) or matches a 'falsey' keyword.

check if an AST node is a MemberExpression, in general or a specific one

Check if a string is an IP address

Checks if the given value is a native function.

Reshape into a better npm audit for the community and encourage more people to include security audit into their process.

Check if a string is a valid JavaScript identifier

Check if a Buffer/Uint8Array is a ZIP file

A JSON fixer

A gulp plugin for processing files with ESLint

Looks up the first non-whitespace character to the left/right of a given index

Check whether a package or organization name is available on npm

3x as fast as `is-whitespace` and `whitespace-regex` thanks to `is-string-blank`. This package is a simple function that accepts an argument and returns `true` if it is a string AND it is not blank. Supports Node and Browser environments.

Utils to deal with TCP ports and hostnames. Safe for everyday use.

Keep watch of your bundle size

JavaScript Standard Style React/JSX support - ESLint Shareable Config

A TypeScript ESLint config that loves you

Check if a value is a function

Check if a directory is empty.

Parse dotenv files for Boolean, Array, and Number variable types, built for CrocodileJS

Ember CLI addon for detecting missing npm and bower dependencies before executing ember commands

A proxy to `path`, replacing `\` with `/` for all results

checks whether a hyperlink is alive (200 OK) or dead

Check if a Node.js Buffer or Uint8Array is UTF-8

checks the all of the hyperlinks in a markdown text to determine if they are alive or dead

Detect the image type of an ArrayBuffer/Uint8Array

JavaScript Semistandard Style - ESLint Shareable Config

ESLint shareable config for React to be used with eslint-config-xo

ESLint shareable config for XO with 2-space indent

Validates password according to flexible and intuitive specifications

Check if a Buffer/Uint8Array is a BZIP2 file

Check if a string is a valid filename

Test if a finite numeric value is an odd number.

Aids humans and automation in managing npm audit results

Checks for URLs during typing and pasting and automatically converts them to links.

Keep your library size in check

allows easy type enforcement for all JS types objects and classes. it is also extensible and provides simple to use type checks for your own custom classes and types

is-iojs determines if runtime is io.js.

Returns true if an object has an own, nested property using dot notation paths ('a.b.c').

Context menu for your Electron app

Check the validity of the format of an EU VAT number

Check if an object is an array or a typed array

A collection of functions for working with different casings.

Test if a finite double-precision floating-point number is an integer.

Validate hostname based on RFC-1123

Check if the machine is running Windows or not.

Check whether a binary version satisfies a semver range

Test if a double-precision floating-point numeric value is positive zero.

Test if a value is NaN.

Returns `true` if a value exists in the given string, array or object.

Markdown TaskList components

Hunspell compatible spell checker

TypeScript Standard Style based on StandardJS

Check if the process is running as administrator on Windows

Check if the package is being installed by another package

Test if a value is a number having an integer value.

TypeScript / JavaScript library for detect WebAssembly features in node.js & browser

Test if a value is an Int32Array.

Test if an object's own property is enumerable.

Test if a value is an Int16Array.

Test if a finite numeric value is an even number.

Assert a given object is a valid glob option

Check if a value is undefined or not.

Test if a value is a Uint8ClampedArray.

Test if a value is a number having a nonnegative integer value.

Checks that given package is installed globally or locally.

Detect the appearance of an element in the browser DOM

All the goodness of `feross/standard` with semicolons sprinkled on top.

$(document).ready() for the 21st century

A pure css library to beautify checkbox and radio buttons.

Async npm module for Node JS that reads the first line of a file

Check if the user is running the latest version of the app

code > prettier > stylelint > formatted code

A command line utility to read version from package.json and attach it into your module as a property

Test if a double-precision floating-point numeric value is negative zero.

Returns true if the current node version matches the given semver expression

Test if a value is a collection.

Check if the process is running with elevated privileges

Test if a value is an Int8Array.

Test if a value is an arguments object.

Validate glob options

ESlint plugin to define custom module dependency rules.

Check if a file path is an image

Create an error from the result of validate-glob-opts

allows easy type enforcement for all JS types objects and classes. it is also extensible and provides simple to use type checks for your own custom classes and types

Get or set a deep value using a keypath string. Supports bracket and dot notation

Test if a value is a number having a positive integer value.

Skema provides a handy & composable way to validate / transform / purify the input data.

Fully customizable animated bouncy checkbox for React Native

Test if a value is an Error object.

Standard assertion utilities.

A tool to enable the checking, inserting and removal of licenses

Checks if an input string is a capitalized or not.

Test whether a value has in its prototype chain a specified constructor as a prototype property.

Base58Check encoding

Checks if the given value is an array or array-like object.

check if an AST node is a call to require()

A gulp plugin to lint code with ESLint 8 and 9.

Run your TypeScript type tests using Jest

Minimal JavaScript type checking library

Test if a value is an ArrayBuffer.

Get or check the current macOS version

Compile TypeScript interfaces into a description that allows runtime validation

Test if a value is a complex number-like object.

Set of various predicates for type checking, assertions, filtering etc

Assertions and Validations for TypeScript

Run elm-review from Node.js

Test if a value is a number having a positive value.

check if an AST node is a call to require()

Determines whether a string ends with the characters of another string.

Easily expose your http server's health.

Test if a value is an array-like object.

Check if something is a positive number

Test if a value is array-like.

Shallow equal check object.

Lint CSS for email support against caniemail database.

Test if a value is a Complex64Array.

Type check values: `is.string('🦄') //=> true`

Check if a String/Buffer is TTF

Check whether a file can be executed

Check if a file path is a video file

Check if a file is a directory

Check if something is a Node.js stream. This is a fork of sindresorhus/is-stream, but with CommonJS support.

Upcast is a low-level JavaScript type checking and casting library

Check if a number is in a given range

[![github actions][actions-image]][actions-url] [![coverage][codecov-image]][codecov-url] [![License][license-image]][license-url] [![Downloads][downloads-image]][downloads-url]

Utilities for formatting and linting a Dockerfile.

Check types

Type checking for .eslintrc.json

Check that all files match prettier code style.

Test if a value is a typed array.

Test if a value is a complex typed array.

ESLint sharable config for strict linting

Noir ESLint shareable config

Return a function which tests if every element in an array-like object passes a test condition.

Test if a finite double-precision floating-point number is a nonnegative integer.

Check if an Array is sorted

Test if an array-like object supports the accessor (get/set) protocol.

Check if a JavaScript environment has a DOM

Validates if a value is a JavaScript object.

Test if a value is a Complex128Array.

Test if a value is an array-like object of numbers.

Test whether a module is available as a dependency

A light-weight jQuery "dirty forms" Plugin - it monitors HTML forms and alerts users to unsaved changes if they attempt to close the browser or navigate away from the page. (Are you sure?)

Convert Ethereum address to a checksummed address

Check if NPM package names conflict

Check if a String/Buffer/ArrayBuffer is OTF

Returns true if an array has duplicate elements or a string has duplicate characters.

Build templates for initial values

Test if a value is typed-array-like.

Checkbox component for react native, it works on iOS and Android.

Utility to check if internet is connected or not

Returns true if a value is the global or window object.

Check the validity of the format of an EU VAT number

Tiny, streaming, seedable CRC32 library, compatible with the crypto.Hash API

Determine if a variable or expression is a React element or component

Library to check variable type and properties in object.

If X, return Y, else throw Z.

Check if something is a negative number

Build a navigation structure programatically

Check that given value is valid hex color, using `hex-color-regex` - the best regex for matching hex color values

Validate the name of a custom element

Delete files and folders and any intermediate directories if they exist (sync and async).

Test if a finite double-precision floating-point number is a negative integer.

A simple function for interrupting program flow if a condition isn’t met.

Check if a string can be used as a JavaScript variable name

[![github actions][actions-image]][actions-url] [![coverage][codecov-image]][codecov-url] [![dependency status][deps-svg]][deps-url] [![dev dependency status][dev-deps-svg]][dev-deps-url] [![License][license-image]][license-url] [![Downloads][downloads-im

check if urls are dead or alive

Validates if a value is undefined.

Check if an email domain belongs to an educational instutition

Checks the integrity of an Endo bundle.

Tiny module for checking if Promise is globally available

Check to see if a token is expired using only the token itself without a secret key or validation

Check if an environment is little endian.

Test if an array-like value contains a search value.

Run commands if on specified node version.

Check if an object is empty or not.