Returns true if a value has the characteristics of a valid JavaScript data descriptor.
Last updated 2 years ago by jonschlinkert .
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Returns true if a value has the characteristics of a valid JavaScript data descriptor.

Please consider following this project's author, Jon Schlinkert, and consider starring the project to show your :heart: and support.


Install with npm:

$ npm install --save is-data-descriptor


var isDataDesc = require('is-data-descriptor');


true when the descriptor has valid properties with valid values.

// `value` can be anything
isDataDesc({value: 'foo'})
isDataDesc({value: function() {}})
isDataDesc({value: true})
//=> true

false when not an object

//=> false
//=> false
//=> false

false when the object has invalid properties

isDataDesc({value: 'foo', bar: 'baz'})
//=> false
isDataDesc({value: 'foo', bar: 'baz'})
//=> false
isDataDesc({value: 'foo', get: function(){}})
//=> false
isDataDesc({get: function(){}, value: 'foo'})
//=> false

false when a value is not the correct type

isDataDesc({value: 'foo', enumerable: 'foo'})
//=> false
isDataDesc({value: 'foo', configurable: 'foo'})
//=> false
isDataDesc({value: 'foo', writable: 'foo'})
//=> false

Valid properties

The only valid data descriptor properties are the following:

  • configurable (required)
  • enumerable (required)
  • value (optional)
  • writable (optional)

To be a valid data descriptor, either value or writable must be defined.

Invalid properties

A descriptor may have additional invalid properties (an error will not be thrown).

var foo = {};

Object.defineProperty(foo, 'bar', {
  enumerable: true,
  whatever: 'blah', // invalid, but doesn't cause an error
  get: function() {
    return 'baz';

//=> 'baz'


<summary> Contributing</summary>

Pull requests and stars are always welcome. For bugs and feature requests, please create an issue.

<summary> Running Tests</summary>

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:

$ npm install && npm test
<summary> Building docs</summary>

(This project's is generated by verb, please don't edit the readme directly. Any changes to the readme must be made in the readme template.)

To generate the readme, run the following command:

$ npm install -g verbose/verb#dev verb-generate-readme && verb

Related projects

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Jon Schlinkert


Copyright © 2017, Jon Schlinkert. Released under the MIT License.

This file was generated by verb-generate-readme, v0.6.0, on November 01, 2017.

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