JSPM

Check whether a value is "empty".

Check if a directory is empty.

Check if an Iterable is empty

Returns true if a value exists, false if empty. Works with deeply nested values using object paths.

Check if an object is empty or not.

Test if a value is an empty array.

Check empty for: array, string, object, function, number, date

Test if a value is an empty collection.

Check if array is absolutely empty.

A tiny CLI tool to detect empty folders inside your project (defaults to src/). Perfect for Next.js / React / Node projects to keep your structure clean.

Tiny utility to check if a value is empty

Check that given string, function or arrow function have empty body, using `parse-function`.

Simple JS library that checks if value is an empty object, collection, string

Check if entity is falsy or empty.

Check if entity is truthy or non-empty.

CLI checks if given file exists and is not empty

two utils to check the given value is empty or not

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

check file if empty

Check if argv has a specific flag

Simple set of functions to check variables. Includes check of undefined / defined / defined and not null / defined and not empty / is number / is function is object

Get the native type of a value.

Check if something is a Node.js stream

Check if the character represented by a given Unicode code point is fullwidth

Fast cleaner is an npm module designed to clean javascript objects from unwanted values like `undefined`, `NaN`, `{}`(empty objects) .. etc.

Fast cleaner is an npm module designed to clean javascript objects from unwanted values like `undefined`, `NaN`, `{}`(empty objects) .. etc.

Returns true if a number or string value is a finite number. Useful for regex matches, parsing, user input, etc.

Check if a path is a file, directory, or symlink

Tests a value’s type against a string like 'positive integer' or 'non-empty map'.

Returns `true` if the given string looks like a glob pattern or an extglob pattern. This makes it easy to create code that only uses external modules like node-glob when necessary, resulting in much faster code execution and initialization time, and a bet

Check if the process is running inside Windows Subsystem for Linux (Bash on Windows)

Returns true if the value is an object and not an array or null.

Returns true if a string has an extglob.

Check if a value is a plain object

Check if a file path is a binary file

type-check allows you to check the types of JavaScript values at runtime with a Haskell like type syntax.

Returns true if an object was created by the `Object` constructor, or Object.create(null).

Check if an object is empty

Detect whether the terminal supports Unicode

Detect the file type of a file, stream, or data

Returns true if a value is a plain object, array or function.

Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for data descriptors and accessor descriptors.

Check if something is a generator function

Returns true if the platform is windows. UMD module, works with node.js, commonjs, browser, AMD, electron, etc.

Returns true if a value has the characteristics of a valid JavaScript data descriptor.

Returns true if a value has the characteristics of a valid JavaScript accessor descriptor.

Check if a value is an object

Detect whether a terminal supports hyperlinks

Type check values

unist utility to recursively walk over nodes, with ancestral information

unist utility to check if a node passes a test

Check if object is empty the modern way ⚡

Check which JavaScript environment your code is running in at runtime: browser, Node.js, Bun, etc

Check if your package was installed globally

Runtime library to validate data against TypeScript interfaces

Lint files staged by git

Check if a path is the current working directory

Check if a value is a regular expression

micromark extension to support GFM task list items

Check if your code is running as an npm script

Check whether a request can be retried based on the `error.code`

Test if a value is an empty object.

Isomorphic, functional type-checking for Javascript

mdast extension to parse and serialize GFM task list items

Run elm-review from Node.js

Check if something is a promise

Check if a string matches the name of a Node.js builtin module

Returns `true` if the path appears to be relative.

Returns true if a file path is absolute. Does not rely on the path module and can be used as a polyfill for node.js native `path.isAbolute`.

Check if a file path is a text file

Check if a URL is absolute

Update notifications for your CLI app

Check if a path is in the current working directory

Check to see if an object is empty (has keys)

Check if a value is a Fetch network error

Returns `true` if the value is a primitive.

Displays a beginner-friendly message telling your user to upgrade their version of Node

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

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

A little library for asserting types and values, with zero dependencies.

JavaScript Standard Style - ESLint Shareable Config

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

Check if a value is a natural number

Check if a module ID is resolvable with require()

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

Typescript-compatible minimalistic shallow equality check for arrays/objects

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

URI validation functions

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.

Cross-platform CLI tool for multi-format localization management with auto-translation support.

Check if a Buffer/Uint8Array is a GZIP file

A utility to check for null, undefined, empty string, empty array, and empty object.

A straightforward implementation of base58-check encoding

Check if a number is a redirect HTTP status code

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.

Get the operating system CPU architecture

Check if a string is a URL

Returns true if a windows file path has invalid characters.

Check if a local or remote port is reachable

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

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 string is SVG

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

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

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

Detect the archive type of a Buffer/Uint8Array

Hook and modify stdout and stderr

hast utility to check if a node has a property

Binary wrapper that makes your programs seamlessly available as local dependencies

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

Detect the archive type of a Buffer/Uint8Array

`util.inspect` with additional type information

Match BCP 47 language tags with language ranges per RFC 4647

Type assertions aka less-broken `typeof`

Validates if a value is an array.

Check if a string is an IP address

Function argument validation for humans

Check if a binary is working

Check dependencies in your node module

Validates if a value is a number.

Check if a directory is empty

Validates if a value is an integer.

Check if a Buffer/Uint8Array is a PNG image

Returns true if the value passed is all whitespace.

A tiny javascript type testing tool

Check if a string only contains alphanumeric characters

Checks if the given value is a window object.

find undeclared identifiers and property accesses in a javascript file.

JavaScript Standard Style JSX support - ESLint Shareable Config

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

Binary wrapper that makes your programs seamlessly available as local dependencies

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

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

Check if mobile browser.

Ensure a path doesn't contain null bytes

Check if a Buffer/Uint8Array is a JPEG image

Binary wrapper that makes your programs seamlessly available as local dependencies

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

Binary wrapper for Flow - A static type checker for JavaScript

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 whether a RegExp flag is supported

JavaScript Standard Style

Test if an object has a specified property.

A utility library to check if a value is empty in JavaScript.

Check if a Buffer/Uint8Array is a GIF image

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

Test if a value is object-like.

maximally minimal type-testing library

Test if a value is a string.

Validate domain name

Check if a string is HTML

ESLint shareable config for the Google style

Test if a value is an empty array-like object.

Test if a value is a boolean.

Check if an environment is big endian.

Test if a value is a function.

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

Test if a value is a Float64Array.

Test if a value is an object.

Test if a value is a Uint32Array.

Check if a URL is relative

Test if a value is a Float32Array.

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

Test if a value is a number.

ESLint shareable config for XO

Determine the specification defined classification of an object.

Test if a value is a regular expression string.

Test if a value is a Buffer object.

Test if a value is a plain object.

Test if a value is a regular expression.

Determine a value's type.

Test whether a path exists on the filesystem.

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

Check if a Buffer/Uint8Array is a TAR file

Test if a value is a Uint8Array.

Test if a value is a Uint16Array.

Check TypeScript type definitions

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 for outdated, incorrect, and unused dependencies.

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

Check if the current Linux session is using Wayland

check if an AST node is a function of some sort

Check if browser is Firefox

Check if a value is a `Blob`

Check empty object, array, string,.. for nodejs

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

Check if browser is Internet Explorer

JavaScript/TypeScript linter (ESLint wrapper) with great defaults

Check if Electron is running in development

check if the current node version has async_hooks.

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

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

Is given string a language code (as per IANA)

Promisified version of node-which

Check if a process is running

Check if the process is running in an SSH session

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

Check whether a binary exists in the PATH environment variable

Checks TypeScript types match expected values

Check if a value is a function

Checks if the given value is null or undefined

Verify if something is a Promise

Check if a string is a valid JavaScript identifier

Test if a value is an empty string.

A utility to check if a React node is empty

A gulp plugin for processing files with ESLint

Check whether a package or organization name is available on npm

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

Checks if the given value is a native function.

Check if a string is an IP address

A JSON fixer

Check if a Buffer/Uint8Array is a ZIP file

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

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

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

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

Keep watch of your bundle size

JavaScript Standard Style React/JSX support - ESLint Shareable Config

Detect the audio type of a Buffer/Uint8Array

Context menu for your Electron app

Detect the image type of an ArrayBuffer/Uint8Array

Checks if a given object is iterable

Check if the machine is running Windows or not.

A TypeScript ESLint config that loves you

Test if a finite numeric value is an odd number.

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

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

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

Check if a Buffer/Uint8Array is a BZIP2 file

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

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

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

JavaScript Semistandard Style - ESLint Shareable Config

ESLint shareable config for XO with 2-space indent

Check if a value is undefined or not.

Keep your library size in check

Detect the appearance of an element in the browser DOM

Validates password according to flexible and intuitive specifications

Check empty object, array, string,.. for nodejs

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

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

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

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