Determine type of a variable

All the functions from core-util-is plus a few extras, in both CJS and ESM formats for use in Node.js or browser.

Usage

Import

const { isString } = require('is-it-type');

or:

import { isString } from 'is-it-type';

Use a method

isString('abc'); // true

All methods return true or false.

Methods

Same as core-util-is:

• isArray
• isBoolean
• isNull
• isNullOrUndefined
• isNumber
• isString
• isSymbol
• isUndefined
• isRegExp
• isDate
• isError
• isFunction
• isPrimitive

NB core-util-is's isBuffer is not included. isObject method differs from core-util-is's method of same name (see below).

Additional functions

Strings

• isEmptyString - true if === ''
• isFullString - true if a string which !== ''

Numbers

• isInteger - true if is an integer number (positive, negative or zero)
• isPositiveInteger - true if is an integer number > 0
• isPositiveIntegerOrZero - true if is an integer number >= 0
• isNegativeInteger - true if is an integer number < 0
• isNegativeIntegerOrZero - true if is an integer number <= 0

Objects

• isObject - true if passed object (not including arrays, regexps and other built-ins)
• isEmptyObject - true if passed object with no properties

Other

• isType( type, input ) - true if typeof input === type

Versioning

This module follows semver. Breaking changes will only be made in major version updates.

All active NodeJS release lines are supported (v12+ at time of writing). After a release line of NodeJS reaches end of life according to Node's LTS schedule, support for that version of Node may be dropped at any time, and this will not be considered a breaking change. Dropping support for a Node version will be made in a minor version update (e.g. 1.2.0 to 1.3.0). If you are using a Node version which is approaching end of life, pin your dependency of this module to patch updates only using tilde (~) e.g. ~1.2.3 to avoid breakages.

Tests

Use npm test to run the tests. Use npm run cover to check coverage.

Changelog

See changelog.md

Issues

If you discover a bug, please raise an issue on Github. https://github.com/overlookmotel/is-it-type/issues

Contribution

Pull requests are very welcome. Please:

• ensure all tests pass before submitting PR
• add tests for new features
• document new functionality/API additions in README
• do not add an entry to Changelog (Changelog is created when cutting releases)

Changelog

5.1.2

Bug fixes:

• Publish package.json file in ESM dirs to NPM

5.1.1

Docs:

• Fix changelog

5.1.0

Semver minor:

• Drop support for Node v10

Performance:

• Speed up isObject
• Export Array.isArray directly

Dependencies:

• Update dependencies

Dev:

• Use NPM v7 for development
• Use Github Actions for CI
• Clean up after cover NPM script even if fails
• Update dev dependencies

Docs:

• Remove Greenkeeper badge
• Update license year
• Remove license indentation

5.0.0

Breaking changes:

• Remove isArguments method
• isObject return false for all built-ins

Bug fixes:

• Avoid relying on Object.prototype.toString to identify types

4.1.1

Build:

• Fix Rollup config [fix]

Deps:

• Update @babel/runtime dependency

Dev:

• Update dev dependencies

4.1.0

Features:

• isArguments method
• Drop support for Node v13

Dependencies:

• Update @babel/runtime dependency

Tests:

• Correct test [fix]

Dev:

• Update dev dependencies
• Simplify lint scripts

4.0.0

Breaking changes:

• isObject returns false for arrays and other built-ins

Dependencies:

• Update @babel/runtime dependency

No code:

• Remove duplicate code comment

Tests:

• Run coverage in dev mode
• Move ESLint config into config file [nocode]

Dev:

• Run tests on CI on Node v14
• Update dev dependencies
• .editorconfig config
• Replace .npmignore with files list in package.json

3.1.1

Bug fixes:

• ESM export fully tree-shakable

3.1.0

Features:

• ESM import without es path

Refactor:

• Remove extraneous code

Dev:

• Improve config for running tests on ESM build

3.0.2

Refactor:

• Shorten isEmptyObject function

3.0.1

Docs:

• README update

3.0.0

Breaking changes:

• Remove isBuffer function
• Re-implement core-util-is functions

Features:

• ESM exports

Refactor:

• Imports specify file extension

Dev:

• Update dev dependencies
• ESLint not ignore dot files
• Remove npm-debug.log from .gitignore

No code:

• Config files header comments
• Line spacing

Docs:

• README update

2.0.0

Breaking changes:

• Drop support for Node v8

Dev:

• Update dev dependencies
• Remove sudo from Travis CI config
• ESLint ignore coverage dir

Docs:

• Versioning policy
• Update license year

1.2.0

Features:

• Number methods

Tests:

• Split into multiple files

Dev:

• Update dev dependencies

1.1.2

Docs:

• Add isEmptyObject to README

1.1.1

Dev:

• CI run tests on Node 13

1.1.0

Features:

• isEmptyObject method

Dev:

• Update dev dependencies

1.0.0

Initial release