is-data-descriptor

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

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Install

Install with npm:

$ npm install --save is-data-descriptor

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'

About

$ npm install && npm test

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

Related projects

You might also be interested in these projects:

• is-accessor-descriptor: Returns true if a value has the characteristics of a valid JavaScript accessor descriptor. | homepage
• is-data-descriptor: Returns true if a value has the characteristics of a valid JavaScript data 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

Contributors

Author

Jon Schlinkert

• github/jonschlinkert
• twitter/jonschlinkert

License

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

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