is-data-descriptor

Returns true if a value has the characteristics of a valid JavaScript data descriptor.

Install

Install with npm:

$ npm i is-data-descriptor --save

Usage

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

Examples

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

isDataDesc('a')
//=> false
isDataDesc(null)
//=> false
isDataDesc([])
//=> 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';
  }
});

console.log(foo.bar);
//=> 'baz'

Related projects

• is-accessor-descriptor: Returns true if a value has the characteristics of a valid JavaScript accessor descriptor. | homepage
• is-descriptor: Returns true if a value has the characteristics of a valid JavaScript descriptor. Works for… more | homepage
• isobject: Returns true if the value is an object and not an array or null. | homepage

Running tests

Install dev dependencies:

$ npm i -d && npm test

Contributing

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

Author

Jon Schlinkert

• github/jonschlinkert
• twitter/jonschlinkert

License

Copyright © 2015 Jon Schlinkert Released under the MIT license.

This file was generated by verb on December 28, 2015.