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  • License MIT

constructor-based type checking

Package Exports

  • utils-type

This package does not declare an exports field, so the exports above have been automatically detected and optimized by JSPM instead. If any package subpath is missing, it is recommended to post an issue to the original package (utils-type) to support the "exports" field. If that is not possible, create a JSPM override to customize the exports field for this package.

Readme

utils-typeNPM version

A posteriory, constructor-based, simple type checking for JS.

Heavily inspired by api design of ianstorm's is.

Implementation state : missing browser tests.

install

$ npm install utils-type

usage

var is = require('utils-type');

is( 0 );
// -> { number: '0' }
is( 42 );
// -> { number: 42 }
is( NaN );
// -> { number: 'NaN', nan: true }
is( null );
// -> { null: true }
is( true );
// -> { boolean: true, true: true }
is( false );
 // -> { boolean: 'false', false: true }
is( Infinity );
// -> { number: Infinity, infinity: true }
is( undefined );
// -> { undefined: true }
is( 'a string');
// -> { string: 'a string' }
is( /a regex/ );
// -> { object: true, regexp: /a regex/ }
is( [ Math.E ] );
// -> { object: true,  array: [ 2.718281828459045 ] }
is( { type : 'toy' });
// -> { object: { type: 'toy' } }
is( new Date());
// -> { object: true,  date: Mon Sep 08 2014 19:10:32 GMT+0200 (CEST) }
is( new Error() );
// -> { object: true, error: [Error] }
is( new Stream() );
// -> { object: true, eventemitter: true, stream: { domain: null, _events: {}, _maxListeners: 10 } }
is( new EventEmitter() );
// -> { object: true, eventemitter: { domain: null, _events: {}, _maxListeners: 10 } }
is( function(){ } );
// -> { object: true, function: [Function] }

Composing

var arr = [1,/heythere/,3];

is(is(arr).array[0]).number
// -> 1           (truthy)
is(is(arr).array[1]).regexp
// -> /heythere/  (truthy)
is(is(arr).array[2]).object
// -> undefined   (number is not an object, just because the prop is not defined on the returned object)
var check = is(arr);

var grab = check.array[4] || check.array[3] || type[2] > 1

a posteriory what? => Why

is[ConstructorName](var) -> priori. You know what you have to check and you do so. is(var) -> posteriory. You dismiss edge cases (null and undefined) and write what you can find out of the type.

Give var and get WTF is that thing.

todo

  • Make browser tests
  • Make more server tests
  • Provide a map to rename type/instances names as properties since it seems to be an issue for some environments.

license

LICENSE