why?

The library was written as a simple coding exercise, but then appeared useful to share :wink:

how?

npm install --save wots

and then

// use as ES6 module
import wots from 'wots';

// use in NodeJs
var wots = require('wots');

// use as global variable via UnPKG
<script src="https://unpkg.com/wots"></script>

// ... then ...

if (wots(myNotAlwaysNumericVariable) === 'NaN') {
  // do some stuff
  // e.g. console.log('I cannot count on it')
} else if (wots(myNotAlwaysNumericVariable) === 'Infinity') {
  // do some other stuff
  // e.g. console.log('Please do not force me to use this value in a loop!')
}

what?

wots() function returns reasonable type names for tested values:

| description | input | result | | :------------------ | :---------------------------------- |:------------- | | null | null | 'null' | | undefined | undefined | 'undefined' | | strings | 'foo' | 'string' | | | '' | 'string' | | | ['Hello', 'world!'].join(' ') | 'string' | | | new String() | 'string' | | numbers | 5 | 'number' | | | parseInt(42) | 'number' | | | new Number('3') | 'number' | | | NaN | 'NaN' | | | Infinity | 'Infinity' | | | 1 / -0 | 'Infinity' | | boolean values | false | 'boolean' | | | !!nonEmptyVariable | 'boolean' | | |new Boolean('0') | 'boolean' | | regular expressions | /^test$/g | 'regexp' | | | new RegExp('needle', 'i') | 'regexp' | | arrays | ['foo', 'bar', 'baz'] | 'array' | | | new Array(10) | 'array' | | objects | { foo: 'bar'} | 'object' | | | {} | 'object' | | | new Object() | 'object' | | | Object.create(null) | 'object | | functions | function () {} | 'function' | | | new Function('return null') | 'function' | | date objects | new Date() | 'date' | | errors | new Error('error!') | 'error' | | | new TypeError('type error!') | 'error' | | arguments objects | (function(){return arguments;})() | 'arguments' | | class constructors | new MyClass() | 'myclass' | | | new Buffer() | 'buffer' | | | new XMLHttpRequest() | 'xmlhttprequest' | | promises | new Promise(function() {}) | 'promise' | | | Promise.resolve('data') | 'promise' | | | Promise.reject(new Error('Oop!')) | 'promise' |

Note: for more examples see test file

Since version 0.2.0 the library also exposes static methods listed below:

wots.isNull()
wots.isUndefined()
wots.isString()
wots.isNumber()
wots.isNaN()
wots.isInfinity()
wots.isBoolean()
wots.isRegExp()
wots.isArray()
wots.isObject()
wots.isFunction()
wots.isDate()
wots.isError()
wots.isArguments()
wots.isPromise()

the name

wots basically stands for what is but is shorter :wink: