JSPM

Check if a value is a natural number

Check if an input value is a ssh url or not.

Returns `true` if the value is a primitive.

Coalesce for JavaScript. Returns the first value that is not undefined or null.

Check if a Buffer/Uint8Array is a GZIP file

Detect which package manager you're using (yarn or npm)

URI validation functions

Check if a module ID is resolvable with require()

A straightforward implementation of base58-check encoding

A simple Node.js module to check if a TCP port is already bound.

Check if a number is a redirect HTTP status code

Returns true if a windows file path has invalid characters.

Drop-in replacement for `fs.existsSync` with zero dependencies. Other libs I found either have crucial differences from fs.existsSync, or unnecessary dependencies. See README.md for more info.

Check if a string is a URL

Return true if a value is a valid glob pattern or patterns.

Get the operating system CPU architecture

Detect the archive type of a Buffer/Uint8Array

Check whether operating system CPU architecture is 64-bit or 32-bit (Supports browsers)

A type checking library where each exported function returns either true or false and does not throw. Also added tests.

Check if a value is an Observable

Check if a binary is working

Check if a local or remote port is reachable

Check if a string is SVG

Binary wrapper that makes your programs seamlessly available as local dependencies

Type assertions aka less-broken `typeof`

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

Hook and modify stdout and stderr

hast utility to check if a node has a property

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

Validates if a value is a number.

Match BCP 47 language tags with language ranges per RFC 4647

Check if a string is an IP address

Check dependencies in your node module

Function argument validation for humans

A tiny javascript type testing tool

Checks if the given value is a window object.

Returns true if the value passed is all whitespace.

Binary wrapper that makes your programs seamlessly available as local dependencies

JavaScript Standard Style JSX support - ESLint Shareable Config

Check if a Buffer/Uint8Array is a PNG image

Validates if a value is an integer.

A HOC enabling you to easily implement extended property equality checks for your React Components

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)

Binary wrapper that makes your programs seamlessly available as local dependencies

Check whether a value is "empty".

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

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

Check if a Buffer/Uint8Array is a JPEG image

Binary wrapper for Flow - A static type checker for JavaScript

Check if mobile browser.

Ensure a path doesn't contain null bytes

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.

Validate domain name

Check if a Buffer/Uint8Array is a GIF image

Test if an object has a specified property.

Check whether a RegExp flag is supported

Test if a value is object-like.

JavaScript Standard Style

Check if an environment is big endian.

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

Test if a value is a regular expression string.

Test if a value is a string.

ESLint shareable config for the Google style

Test if a value is a boolean.

Test if a value is a function.

Check if a string is HTML

Test if a value is a Float64Array.

Check if a URL is relative

ESLint shareable config for XO

Test if a value is a Uint32Array.

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

Test if a value is an object.

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

Test if a value is a Float32Array.

Test if a value is a number.

Check for outdated, incorrect, and unused dependencies.

maximally minimal type-testing library

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

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 plain object.

Test whether a path exists on the filesystem.

Check TypeScript type definitions

Test if a value is a regular expression.

JavaScript/TypeScript linter (ESLint wrapper) with great defaults

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

Determine the specification defined classification of an object.

Determine a value's type.

Check if a Buffer/Uint8Array is a TAR file

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

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.

Is this a bluebird promise I see before me?

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

Check if two values are shallowly equal to each other.

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

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

Verify if something is a Promise

Check if Electron is running in development

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

Detect the audio type of a Buffer/Uint8Array

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

Checks if the given value is a native function.

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

Check if a string is a valid JavaScript identifier

Check whether a package or organization name is available on npm

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.

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

A gulp plugin for processing files with ESLint

Check if a string is an IP address

Check if a Buffer/Uint8Array is a ZIP file

JavaScript Standard Style React/JSX support - ESLint Shareable Config

A TypeScript ESLint config that loves you

A JSON fixer

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

Check if a directory is empty.

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

Detect the image type of an ArrayBuffer/Uint8Array

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

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

JavaScript Semistandard Style - ESLint Shareable Config

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

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

Check if a value is a function

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

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

Test if a finite numeric value is an odd number.

[![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 a string is a valid filename

is-iojs determines if runtime is io.js.

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.

Keep your library size in check

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

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

Aids humans and automation in managing npm audit results

A collection of functions for working with different casings.

Check if an object is an array or a typed array

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.

TypeScript Standard Style based on StandardJS

Check if the package is being installed by another package

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

Hunspell compatible spell checker

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

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

Check if the process is running as administrator on Windows

Markdown TaskList components

Check if a value is undefined or not.

Detect the appearance of an element in the browser DOM

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

Test if an object's own property is enumerable.

Test if a finite numeric value is an even number.

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

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

Test if a value is a Uint8ClampedArray.

Test if a value is an Int16Array.

Checks that given package is installed globally or locally.

Test if a value is an Int32Array.

Assert a given object is a valid glob option

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

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

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

Test if a value is an Int8Array.

Test if a value is a collection.

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

Test if a value is an arguments object.

A pure css library to beautify checkbox and radio buttons.

Check if the process is running with elevated privileges

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

code > prettier > stylelint > formatted code

Validate glob options

ESlint plugin to define custom module dependency rules.

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

Fully customizable animated bouncy checkbox for React Native

Check if a file path is an image

Checks if an input string is a capitalized or not.

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

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

Standard assertion utilities.

React components for [Stripe.js and Elements](https://stripe.com/docs/stripe-js).

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 an Error object.

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

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

Compile TypeScript interfaces into a description that allows runtime validation

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

Get or check the current macOS version

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

*A mostly reasonable approach to JavaScript*

Run your TypeScript type tests using Jest

[](https://github.com/crabas0npm/numquam-corporis-veniam/actions/workflows/ci.yml?query=branch%3Amain) [Chat on slack](https://@crabas0npm

Base58Check encoding

Test if a value is an ArrayBuffer.

Minimal JavaScript type checking library

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

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

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

Easily expose your http server's health.

Test if a value is an array-like object.

Test if a value is array-like.

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

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

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

Check if something is a positive number

Assertions and Validations for TypeScript

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

Run elm-review from Node.js

Lint CSS for email support against caniemail database.

Test if a value is a Complex64Array.

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

Check if a String/Buffer is TTF

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

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

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

Check if a number is in a given range

Check that all files match prettier code style.

Test if a value is a typed array.