Reason

My eyes feel pain when i see:

if ( x+'' === x ) { ... } // if that string
if ( x*1 === x ) { ... } // if that number
... // and many others

s-is

Let me introduce a simple way to ensure the correctness of the target data. As I see it.

installation for Node.js

npm i s-is --save

installation for Browser

bower i s-is --save

In javascript definition of data types associated with some difficulties. Due to the fact that the original methods do not always work as expected. We are forced to turn to non-standard decisions. Not always, these decisions are correct, and even rarer - code still readable. If we are interested in conditional of 10 data types.And we want them correctly and to determine.

NaN, null, undefined, infinity, number, string, boolean, function, array, object

Example

var is = require('s-is');

is.array([]);      // => true
is.array({});      // => false
is('Array', []);   // => true

is.nan('Hello !');       // => false
is('NaN','Hello !');     // => false
is('NaN','Hello !' - 2); // => true
is.nan(NaN);             // => true 

Note - This approach is implemented for all the previously identified 10 of types data.

ES6

It gives us a lot of benefits and expands our capabilities. And also adds surprises.

// try it
typeof Symbol() == 'symbol'; // => true
// but
typeof ( new Promise(new Function) ) == 'object'; // => true
// or
typeof (class test {}) == 'function'; // => true

typeof

In connection with such innovations was established method of determining the 10 data types, plus all the innovations.

var is = require('s-is');

is.typeof( {} );               // => "object" 
is.typeof( [] );               // => "array" 
is.typeof( NaN );              // => "nan"
is.typeof( Infinity );         // => "infinity"
is.typeof( null );             // => "null" 
is.typeof( 5 );                // => "number"
is.typeof( '5' );              // => "string"
is.typeof( true );             // => "boolean"
is.typeof( undefined );        // => "undefined"
is.typeof( function () {} );   // => "function"

// just more example
is.typeof( Symbol() );         // => "symbol"
is.typeof( process );          // => "object"
is.typeof( new function Test () {} ); // => "object" 
is.typeof( new class test {} );// => "object"
is.typeof( class test {} );    // => "function"

Helpers

And in the end, we frequently need to define some specific objects. This applies mainly to proven technologies.

var is = require('s-is');

// date
is.date( new Date() );    // => true
is('date', new Date() );  // => true
is('date', (new Date()).getDate() );  // => false

// promise
var p = new Promise(new Function);
is.promise( p );                       // => true
is('promise', p );                     // => true
is.promise( {} );                      // => false
is('promise', {then: new Function} );  // => true
// isn't native
is._object( {} );                      // => true
is._object( new function Test () {} ); // => true
is._object( new class test {} );       // => true
is('_object',  window );               // => false
is('_object', process );               // => false
is('_object', new Promise(new Function) );// => false

// arguments
(function ( x ) {
    console.log(
        '\n is.argument', is.argument(arguments),
        '\n is.empty', is.empty(arguments),
        '\n arguments', arguments
    );
})(1);
(function ( x ) {
    console.log(
        '\n is.argument', is.argument(arguments),
        '\n is.empty', is.empty(arguments),
        '\n arguments', arguments
    );
})();

API documentation

Table of results that generates a test script module.termainal