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)