https://github.com/stringparser/utils-type
robust type checking for js
https://github.com/stringparser/utils-type
Last synced: 2 months ago
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robust type checking for js
- Host: GitHub
- URL: https://github.com/stringparser/utils-type
- Owner: stringparser
- Created: 2014-09-08T17:42:03.000Z (over 11 years ago)
- Default Branch: master
- Last Pushed: 2017-02-12T11:25:22.000Z (almost 9 years ago)
- Last Synced: 2025-02-09T06:48:44.773Z (12 months ago)
- Language: JavaScript
- Homepage:
- Size: 97.7 KB
- Stars: 2
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: readme.md
Awesome Lists containing this project
README
# utils-type [![NPM version][badge-version]][x-npm]
[documentation](#documentation) -
[install](#install) -
[notes](#notes) -
[todo](#todo)
[![build][badge-build]][x-travis]
#### simple
```js
var type = require('utils-type');
type(42); // -> { number: 42 }
type(NaN); // -> { nan: true }
type(null); // -> { null: true }
type(true); // -> { boolean: true }
type(false); // -> { boolean: true }
type(Infinity); // -> { infinity: Infinity }
type(undefined); // -> { undefined: true }
type('a string'); // -> { string: 'a string' }
type(/a regex/); // -> { object: /a regex/, regexp: /a regex/ } }
type(function(){ }); // -> { object: [Function], function: [Function] }
type({ type : 'toy' }); // -> { object: { type: 'toy' } }
type(new Date()); // -> { object: Mon Sep 08 2014 19:10:32, date: Mon Sep 08 2014 19:10:32 GMT+0200 (CEST) }
type(new Error()); // -> { object: [Error], error: [Error] }
type(new Stream());
// -> {
// object: { domain: null, _events: {}, _maxListeners: 10 },
// stream: { domain: null, _events: {}, _maxListeners: 10 },
// eventemitter: { domain: null, _events: {}, _maxListeners: 10 }
// }
```
#### composition
The function returns an object. The type matched by `that` type returns itself.
```js
type(1).number // -> 1 (that is truthy)
type([1,2,3]).array // -> [1,2,3] (truthy)
type(type([1,2,3]).array[1]).number // -> 1 (truthy)
```
#### comprehensive
```js
type(-1).number // -> -1
type(-1).integer // -> -1
type(NaN).nan // -> true
type(0.4).float // -> 0.4
type(Infinity).infinity // -> Infinity
type(new EventEmitter())
// -> {
// object: { domain: null, _events: {}, _maxListeners: 10 },
// eventemitter: { domain: null, _events: {}, _maxListeners: 10 }
// }
```
#### `falsy` values maintain the value if it makes sense
```js
type(0).number // -> true
type(0).integer // -> 0
type('').string // -> ' '
type(null).null // -> true
type(NaN).number // -> undefined
type(false).boolean // -> true
type(undefined).undefined // -> true
```
Why:
- `NaN` is not a number
- `false` is a boolean, returning it will be misleading
- `0` is a number, but for `integer` its value its maintained
- `the empty string` is changed to an space so is truthy and operations can be made on it
- `null` and `undefined` are self explanatory
---
### Documentation
The `module.exports` a function
```js
var type = require('utils-type');
```
that takes one argument.
### type
```js
function type(value)
```
_arguments_
- `value` type any, from where types will be obtained
_returns_
- object with as many properties as types the argument has
```js
var type = require('utils-type');
var items = type([1,2,3]);
Object.keys(items); // =>
// ['object', 'array']
```
### install
With [npm][x-npm]
$ npm install utils-type
### test
$ npm test
### notes
The module uses `Objec.create` in order to not produce false positives when checking properties on the returned object. So it basically needs support for object create. Polyfill it, for more info:
[http://kangax.github.io/compat-table/es5/](http://kangax.github.io/compat-table/es5/)
### todo
- [ ] Include browser tests
### license
The MIT License (MIT)
Copyright (c) 2014-present Javier Carrillo
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
[x-npm]: https://npmjs.org/package/utils-type
[x-travis]: https://travis-ci.org/stringparser/utils-type/builds
[badge-build]: https://travis-ci.org/stringparser/utils-type.svg?branch=master
[badge-version]: http://img.shields.io/npm/v/utils-type.svg?style=flat-square