JSPM

Returns true if a file path does not contain any invalid characters.

Detect the archive type of a Buffer/Uint8Array

Determine if a filename and/or buffer is text or binary. Smarter detection than the other solutions.

`util.inspect` with additional type information

Check if a binary is working

Validates if a value is an array.

Check if the process is running in a Continuous Integration (CI) environment

Check if a string is an IP address

Validates if a value is a number.

JavaScript Standard Style JSX support - ESLint Shareable Config

A tiny javascript type testing tool

Function argument validation for humans

Match BCP 47 language tags with language ranges per RFC 4647

Check dependencies in your node module

Checks if the given value is a window object.

Binary wrapper that makes your programs seamlessly available as local dependencies

Returns true if the value passed is all whitespace.

Validates if a value is an integer.

Check if a Buffer/Uint8Array is a PNG image

Check if a string only contains alphanumeric characters

find undeclared identifiers and property accesses in a javascript file.

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

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

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

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

Binary wrapper that makes your programs seamlessly available as local dependencies

Binary wrapper for Flow - A static type checker for JavaScript

Ensure a path doesn't contain null bytes

Check whether a value is "empty".

Check if a Buffer/Uint8Array is a JPEG image

JavaScript Standard Style

Check if mobile browser.

Test if an object has a specified property.

Validate domain name

Check whether a RegExp flag is supported

Check if a Buffer/Uint8Array is a GIF image

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.

Test if a value is object-like.

Check if an environment is big endian.

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

ESLint shareable config for the Google style

Test if a value is a regular expression string.

Test if a value is a string.

Check if a string is HTML

Check if a URL is relative

Test if a value is a boolean.

Test if a value is a function.

Test if a value is a Float64Array.

maximally minimal type-testing library

ESLint shareable config for XO

Test if a value is a Uint32Array.

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

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

Check for outdated, incorrect, and unused dependencies.

Test if a value is an object.

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

Test if a value is a Float32Array.

Test if a value is a number.

check if an AST node is a function of some sort

JavaScript/TypeScript linter (ESLint wrapper) with great defaults

Test if a value is a Buffer object.

Check TypeScript type definitions

Test if a value is a regular expression.

Test whether a path exists on the filesystem.

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

Test if a value is a plain object.

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

Determine the specification defined classification of an object.

Check if a Buffer/Uint8Array is a TAR file

Determine a value's type.

Is this a bluebird promise I see before me?

Test if a value is a Uint8Array.

Test if a value is a Uint16Array.

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

Check if an environment is little endian.

Check if a value is a `Blob`

Check if browser is Firefox

Check if browser is Internet Explorer

Check if a process is running

Promisified version of node-which

Check whether a binary exists in the PATH environment variable

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

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

Detect the audio type of a Buffer/Uint8Array

Check if Electron is running in development

Verify if something is a Promise

Is given string a language code (as per IANA)

check if the current node version has async_hooks.

Checks if the given value is null or undefined

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

Checks if a given object is iterable

Checks TypeScript types match expected values

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

Check whether a package or organization name is available on npm

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

Checks if the given value is a native function.

Check if a string is a valid JavaScript identifier

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

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

Check if a string is an IP address

A gulp plugin for processing files with ESLint

Keep watch of your bundle size

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.

JavaScript Standard Style React/JSX support - ESLint Shareable Config

Check if a Buffer/Uint8Array is a ZIP file

A JSON fixer

Check if a directory is empty.

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

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

A TypeScript ESLint config that loves you

Detect the image type of an ArrayBuffer/Uint8Array

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

JavaScript Semistandard Style - ESLint Shareable Config

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

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

Check if a value is a function

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

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

Check if a Buffer/Uint8Array is a BZIP2 file

ESLint shareable config for XO with 2-space indent

Validates password according to flexible and intuitive specifications

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

Test if a finite numeric value is an odd number.

is-iojs determines if runtime is io.js.

Keep your library size in check

Check if a string is a valid filename

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

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

Check the validity of the format of an EU VAT number

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

Context menu for your Electron app

A collection of functions for working with different casings.

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

Aids humans and automation in managing npm audit results

Check if the machine is running Windows or not.

Check whether a binary version satisfies a semver range

Check if an object is an array or a typed array

Validate hostname based on RFC-1123

Test if a value is NaN.

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

TypeScript Standard Style based on StandardJS

Markdown TaskList components

Hunspell compatible spell checker

Check if the package is being installed by another package

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

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

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

Check if the process is running as administrator on Windows

Check if a value is undefined or not.

Test if a value is an Int32Array.

Test if a value is a Uint8ClampedArray.

Test if a value is an Int16Array.

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

Detect the appearance of an element in the browser DOM

Test if a finite numeric value is an even number.

Checks that given package is installed globally or locally.

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

Test if an object's own property is enumerable.

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

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

Assert a given object is a valid glob option

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

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

Test if a value is a collection.

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

Test if a value is an Int8Array.

Test if a value is an arguments object.

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

code > prettier > stylelint > formatted code

A pure css library to beautify checkbox and radio buttons.

Check if the process is running with elevated privileges

Validate glob options

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

ESlint plugin to define custom module dependency rules.

Check if a file path is an image

Fully customizable animated bouncy checkbox for React Native

Checks if an input string is a capitalized or not.

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

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

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

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

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

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

Test if a value is an Error object.

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

Standard assertion utilities.

Compile TypeScript interfaces into a description that allows runtime validation

Get or check the current macOS version

Run your TypeScript type tests using Jest

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

Test if a value is an ArrayBuffer.

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

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

Minimal JavaScript type checking library

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

Base58Check encoding

Easily expose your http server's health.

Test if a value is array-like.

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

Test if a value is an array-like object.

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

Assertions and Validations for TypeScript

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

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

Check if something is a positive number

Shallow equal check object.

Check that all files match prettier code style.

Run elm-review from Node.js

Test if a value is a Complex64Array.

Check types

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

Check if a String/Buffer is TTF

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

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

Lint CSS for email support against caniemail database.

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

Test if a value is a typed array.

Test if a value is a complex typed array.

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

Check if a file path is a video file

Test if a value is a Complex128Array.

Noir ESLint shareable config

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

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

Utilities for formatting and linting a Dockerfile.

Type checking for .eslintrc.json

Check whether a file can be executed

Check if a file is a directory

Check if an Array is sorted

Check if a number is in a given range

ESLint sharable config for strict linting

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

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?)

Check if a String/Buffer/ArrayBuffer is OTF

Check if a JavaScript environment has a DOM

Check if NPM package names conflict

Test if a value is typed-array-like.

Validates if a value is a JavaScript object.

Library to check variable type and properties in object.

Build a navigation structure programatically

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

Check if something is a negative number

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

Convert Ethereum address to a checksummed address

Utility to check if internet is connected or not

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

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

Test whether a module is available as a dependency