Typechecker in Vanilla JS
npm install @fdaciuk/is> Typechecker in Vanilla JS
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Because type checking in JS is hard. See some examples:
``js`
console.log(typeof 1) // 'number'
console.log(typeof 'javascript') // 'string'
console.log(typeof {}) // 'object'
console.log(typeof []) // 'object' wat?
console.log(typeof null) // 'object' wat? wat?
console.log(typeof new String('js')) // 'object' :|
That's why @fdaciuk/is is useful. See some examples using this library in ES2015:
`js
import is from '@fdaciuk/is'
console.log(is('number', 10)) // true
console.log(is('object', {})) // true
console.log(is('array', [])) // true
console.log(is('object', [])) // false
console.log(is('string', new String('js'))) // true (yes, 'string', not 'object')
`
Yarn
`console`
yarn add @fdaciuk/is
NPM
`console`
npm i --save @fdaciuk/is
AMD
`js`
define(['is'], function (is) {
console.log(is('arguments', arguments)) // true
})
CommonJS
`js`
var is = require('@fdaciuk/is').default
console.log(is('array', [])) // true
ES6 / ES2015 Module
`js
import is from '@fdaciuk/is'
const isString = is('string')
console.log(isString('daciuk')) // true
`
Method of window object
`js`
console.log(window.is('number', 10)) // true
`js`
is(typeToTest, value)
// or
is(typeToTest)(value)
is
A function that checks if a value is of a type:
`js
import is from '@fdaciuk/is'
// or using commonjs:
// var is = require('@fdaciuk/is').default
const value = []
if (is('array', value)) {
// do something
}
`
typeOf
A function that returns a real type of a value:
`js
import { typeOf } from '@fdaciuk/is'
// or using commonjs:
// var typeOf = require('@fdaciuk/is').typeOf
console.log(typeOf([])) // 'array'
console.log(typeOf(123)) // 'number'
console.log(typeOf(new String('hey'))) // 'string', not 'object'
``
Check CONTRIBUTING.md
MIT © Fernando Daciuk
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[travis-url]: https://travis-ci.org/fdaciuk/is
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[codeclimate-image]: https://img.shields.io/codeclimate/github/fdaciuk/is.svg?style=flat-square
[codeclimate-url]: https://codeclimate.com/github/fdaciuk/is
[license-image]: https://img.shields.io/badge/license-MIT-blue.svg?style=flat-square
[license-url]: https://github.com/fdaciuk/licenses/blob/master/MIT-LICENSE.md
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[contributing-url]: CONTRIBUTING.md