1 # is-data-descriptor [![NPM version](https://img.shields.io/npm/v/is-data-descriptor.svg?style=flat)](https://www.npmjs.com/package/is-data-descriptor) [![NPM monthly downloads](https://img.shields.io/npm/dm/is-data-descriptor.svg?style=flat)](https://npmjs.org/package/is-data-descriptor) [![NPM total downloads](https://img.shields.io/npm/dt/is-data-descriptor.svg?style=flat)](https://npmjs.org/package/is-data-descriptor) [![Linux Build Status](https://img.shields.io/travis/jonschlinkert/is-data-descriptor.svg?style=flat&label=Travis)](https://travis-ci.org/jonschlinkert/is-data-descriptor)
3 > Returns true if a value has the characteristics of a valid JavaScript data descriptor.
5 Please consider following this project's author, [Jon Schlinkert](https://github.com/jonschlinkert), and consider starring the project to show your :heart: and support.
9 Install with [npm](https://www.npmjs.com/):
12 $ npm install --save is-data-descriptor
18 var isDataDesc = require('is-data-descriptor');
23 `true` when the descriptor has valid properties with valid values.
26 // `value` can be anything
27 isDataDesc({value: 'foo'})
28 isDataDesc({value: function() {}})
29 isDataDesc({value: true})
33 `false` when not an object
44 `false` when the object has invalid properties
47 isDataDesc({value: 'foo', bar: 'baz'})
49 isDataDesc({value: 'foo', bar: 'baz'})
51 isDataDesc({value: 'foo', get: function(){}})
53 isDataDesc({get: function(){}, value: 'foo'})
57 `false` when a value is not the correct type
60 isDataDesc({value: 'foo', enumerable: 'foo'})
62 isDataDesc({value: 'foo', configurable: 'foo'})
64 isDataDesc({value: 'foo', writable: 'foo'})
70 The only valid data descriptor properties are the following:
72 * `configurable` (required)
73 * `enumerable` (required)
75 * `writable` (optional)
77 To be a valid data descriptor, either `value` or `writable` must be defined.
79 **Invalid properties**
81 A descriptor may have additional _invalid_ properties (an error will **not** be thrown).
86 Object.defineProperty(foo, 'bar', {
88 whatever: 'blah', // invalid, but doesn't cause an error
101 <summary><strong>Contributing</strong></summary>
103 Pull requests and stars are always welcome. For bugs and feature requests, [please create an issue](../../issues/new).
108 <summary><strong>Running Tests</strong></summary>
110 Running and reviewing unit tests is a great way to get familiarized with a library and its API. You can install dependencies and run tests with the following command:
113 $ npm install && npm test
119 <summary><strong>Building docs</strong></summary>
121 _(This project's readme.md is generated by [verb](https://github.com/verbose/verb-generate-readme), please don't edit the readme directly. Any changes to the readme must be made in the [.verb.md](.verb.md) readme template.)_
123 To generate the readme, run the following command:
126 $ npm install -g verbose/verb#dev verb-generate-readme && verb
133 You might also be interested in these projects:
135 * [is-accessor-descriptor](https://www.npmjs.com/package/is-accessor-descriptor): Returns true if a value has the characteristics of a valid JavaScript accessor descriptor. | [homepage](https://github.com/jonschlinkert/is-accessor-descriptor "Returns true if a value has the characteristics of a valid JavaScript accessor descriptor.")
136 * [is-data-descriptor](https://www.npmjs.com/package/is-data-descriptor): Returns true if a value has the characteristics of a valid JavaScript data descriptor. | [homepage](https://github.com/jonschlinkert/is-data-descriptor "Returns true if a value has the characteristics of a valid JavaScript data descriptor.")
137 * [is-descriptor](https://www.npmjs.com/package/is-descriptor): Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for… [more](https://github.com/jonschlinkert/is-descriptor) | [homepage](https://github.com/jonschlinkert/is-descriptor "Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for data descriptors and accessor descriptors.")
138 * [isobject](https://www.npmjs.com/package/isobject): Returns true if the value is an object and not an array or null. | [homepage](https://github.com/jonschlinkert/isobject "Returns true if the value is an object and not an array or null.")
142 | **Commits** | **Contributor** |
144 | 21 | [jonschlinkert](https://github.com/jonschlinkert) |
145 | 2 | [realityking](https://github.com/realityking) |
151 * [github/jonschlinkert](https://github.com/jonschlinkert)
152 * [twitter/jonschlinkert](https://twitter.com/jonschlinkert)
156 Copyright © 2017, [Jon Schlinkert](https://github.com/jonschlinkert).
157 Released under the [MIT License](LICENSE).
161 _This file was generated by [verb-generate-readme](https://github.com/verbose/verb-generate-readme), v0.6.0, on November 01, 2017._