This package has been deprecated

Author message:

This package was deprecated, please use @jsweb/truetype

truetype

Simple JS module to check types more concisely

Check type of a variable in JavaScript is not so easy.

The builtin operators typeof, instanceof and other methods are not precise to report the exact type of a variable.

So, this module aims to check types of variables with more useful returns.

---

Installation

You can install truetype with NPM, Yarn, Snipacks, Unpkg CDN...

NPM

npm i -S truetype

Yarn

yarn add truetype

Snipacks

snipacks add unpkg truetype.js truetype

CDN

<script src="https://unpkg.com/truetype"></script>

Usage

ES6

import truetype from 'truetype'

CommonJS

var truetype = require('truetype')

AMD (RequireJS)

require(['truetype'], function(truetype) {
    //...
})

Instance

Just call it with your variable as argument:

const x = 'foo bar', type = truetype(x)

truetype is a function that returns a custom Class Object with the following props and methods:

truetype(x).value

The value of x itself.

truetype(x).instance()

Returns a string with the x constructor name like Object, Array, String, Number...

The returned value can be a builtin or custom constructor name.

truetype(1).instance() 		// returns Number
 
class Foo {
    constructor(x) {
        this.x = x
    }
}
 
const bar = new Foo(1)
 
truetype(bar).instance()	// returns Foo

truetype(x).is{Instance}()

Predefined methods that check if x type is {Instance} and returns a Boolean.

truetype({}).isObject()             // returns true
truetype([]).isArray() 			        // returns true
truetype('foo').isString() 		      // returns true
truetype(true).isBoolean() 		      // returns true
truetype(new Date).isDate() 	      // returns true
truetype(1).isNumber() 			        // returns true
truetype(/\w/).isRegExp() 		      // returns true
truetype(function(){}).isFunction() // returns true

There are 5 special methods to check values:

truetype(1).isInteger() 			// returns true
truetype(1.0).isFloat() 		// returns true
truetype(null).isNull()			// returns true
truetype(null).isNotNull()		// returns false
truetype(undefined).isDefined()	// returns false

truetype(x).is(type)

Check if x type is equal type argument and returns a Boolean.

It's possible to check predefined and custom constructor types.

truetype(1).is('String')	// returns false
truetype(1).is('Number')	// returns true
truetype(1).is('Integer')		// returns true
truetype(1).is('Float')		// returns false
 
//Custom types
class Foo {
    constructor(x) {
        this.x = x
    }
}
 
const bar = new Foo(1)
 
truetype(bar).is('Foo')		// returns true